Create SQL script that create database and tables
Not sure why SSMS doesn’t take into account execution order but it just doesn’t. This is not an issue for small databases but what if your database has 200 objects? In that case order of execution does matter because it’s not really easy to go through all of these.
For unordered scripts generated by SSMS you can go following
a) Execute script (some objects will be inserted some wont, there will be some errors)
b) Remove all objects from the script that have been added to database
c) Go back to a) until everything is eventually executed
Alternative option is to use third party tool such as ApexSQL Script or any other tools already mentioned in this thread (SSMS toolpack, Red Gate and others).
All of these will take care of the dependencies for you and save you even more time.
Calculating the area under a curve given a set of coordinates, without knowing the function
If you have sklearn isntalled, a simple alternative is to use sklearn.metrics.auc
This computes the area under the curve using the trapezoidal rule given arbitrary x, and y array
import numpy as np
from sklearn.metrics import auc
dx = 5
xx = np.arange(1,100,dx)
yy = np.arange(1,100,dx)
print('computed AUC using sklearn.metrics.auc: {}'.format(auc(xx,yy)))
print('computed AUC using np.trapz: {}'.format(np.trapz(yy, dx = dx)))
both output the same area: 4607.5
the advantage of sklearn.metrics.auc is that it can accept arbitrarily-spaced 'x' array, just make sure it is ascending otherwise the results will be incorrect
Bootstrap Alert Auto Close
I found this to be a better solution
$(".alert-dismissible").fadeTo(2000, 500).slideUp(500, function(){
$(".alert-dismissible").alert('close');
});
Check a radio button with javascript
Today, in the year 2016, it is save to use document.querySelector
without knowing the ID (especially if you have more than 2 radio buttons):
document.querySelector("input[name=main-categories]:checked").value
How to check if a user likes my Facebook Page or URL using Facebook's API
Though this post has been here for quite a while, the solutions are not pure JS. Though Jason noted that requesting permissions is not ideal, I consider it a good thing since the user can reject it explicitly. I still post this code, though (almost) the same thing can also be seen in another post by ifaour. Consider this the JS only version without too much attention to detail.
The basic code is rather simple:
FB.api("me/likes/SOME_ID", function(response) {
if ( response.data.length === 1 ) { //there should only be a single value inside "data"
console.log('You like it');
} else {
console.log("You don't like it");
}
});
ALternatively, replace me
with the proper UserID of someone else (you might need to alter the permissions below to do this, like friends_likes
) As noted, you need more than the basic permission:
FB.login(function(response) {
//do whatever you need to do after a (un)successfull login
}, { scope: 'user_likes' });
Why does javascript map function return undefined?
You can implement like a below logic.
Suppose you want an array of values.
let test = [ {name:'test',lastname:'kumar',age:30},
{name:'test',lastname:'kumar',age:30},
{name:'test3',lastname:'kumar',age:47},
{name:'test',lastname:'kumar',age:28},
{name:'test4',lastname:'kumar',age:30},
{name:'test',lastname:'kumar',age:29}]
let result1 = test.map(element =>
{
if (element.age === 30)
{
return element.lastname;
}
}).filter(notUndefined => notUndefined !== undefined);
output : ['kumar','kumar','kumar']
How to print table using Javascript?
One cheeky solution :
function printDiv(divID) {
//Get the HTML of div
var divElements = document.getElementById(divID).innerHTML;
//Get the HTML of whole page
var oldPage = document.body.innerHTML;
//Reset the page's HTML with div's HTML only
document.body.innerHTML =
"<html><head><title></title></head><body>" +
divElements + "</body>";
//Print Page
window.print();
//Restore orignal HTML
document.body.innerHTML = oldPage;
}
HTML :
<form id="form1" runat="server">
<div id="printablediv" style="width: 100%; background-color: Blue; height: 200px">
Print me I am in 1st Div
</div>
<div id="donotprintdiv" style="width: 100%; background-color: Gray; height: 200px">
I am not going to print
</div>
<input type="button" value="Print 1st Div" onclick="javascript:printDiv('printablediv')" />
</form>
Can you 'exit' a loop in PHP?
You are looking for the break statement.
$arr = array('one', 'two', 'three', 'four', 'stop', 'five');
while (list(, $val) = each($arr)) {
if ($val == 'stop') {
break; /* You could also write 'break 1;' here. */
}
echo "$val<br />\n";
}
onclick event pass <li> id or value
Try this:
<li onclick="getPaging(this.id)" id="1">1</li>
<li onclick="getPaging(this.id)" id="2">2</li>
function getPaging(str)
{
$("#loading-content").load("dataSearch.php?"+str, hideLoader);
}
Using .Select and .Where in a single LINQ statement
Did you add the Select()
after the Where()
or before?
You should add it after, because of the concurrency logic:
1 Take the entire table
2 Filter it accordingly
3 Select only the ID's
4 Make them distinct.
If you do a Select first, the Where clause can only contain the ID attribute because all other attributes have already been edited out.
Update: For clarity, this order of operators should work:
db.Items.Where(x=> x.userid == user_ID).Select(x=>x.Id).Distinct();
Probably want to add a .toList()
at the end but that's optional :)
ping: google.com: Temporary failure in name resolution
I've faced the exactly same problem but I've fixed it with another approache.
Using Ubuntu 18.04, first disable systemd-resolved
service.
sudo systemctl disable systemd-resolved.service
Stop the service
sudo systemctl stop systemd-resolved.service
Then, remove the link to /run/systemd/resolve/stub-resolv.conf
in /etc/resolv.conf
sudo rm /etc/resolv.conf
Add a manually created resolv.conf
in /etc/
sudo vim /etc/resolv.conf
Add your prefered DNS server there
nameserver 208.67.222.222
I've tested this with success.
Wildcards in jQuery selectors
When you have a more complex id string the double quotes are mandatory.
For example if you have an id like this: id="2.2"
, the correct way to access it is: $('input[id="2.2"]')
As much as possible use the double quotes, for safety reasons.
Does it matter what extension is used for SQLite database files?
Pretty much down to personal choice. It may make sense to use an extension based on the database scheme you are storing; treat your database schema as a file format, with SQLite simply being an encoding used for that file format. So, you might use .bookmarks
if it's storing bookmarks, or .index
if it's being used as an index.
If you want to use a generic extension, I'd use .sqlite3
since that is most descriptive of what version of SQLite is needed to work with the database.
C# 4.0 optional out/ref arguments
Use an overloaded method without the out parameter to call the one with the out parameter for C# 6.0 and lower. I'm not sure why a C# 7.0 for .NET Core is even the correct answer for this thread when it was specifically asked if C# 4.0 can have an optional out parameter. The answer is NO!
Setting Oracle 11g Session Timeout
That's generally controlled by the profile associated with the user Tomcat is connecting as.
SQL> SELECT PROFILE, LIMIT FROM DBA_PROFILES WHERE RESOURCE_NAME = 'IDLE_TIME';
PROFILE LIMIT
------------------------------ ----------------------------------------
DEFAULT UNLIMITED
SQL> SELECT PROFILE FROM DBA_USERS WHERE USERNAME = USER;
PROFILE
------------------------------
DEFAULT
So the user I'm connected to has unlimited idle time - no time out.
jQuery Loop through each div
$('div.target').each(function() {
/* Measure the width of each image. */
var test = $(this).find('.scrolling img').width();
/* Find out how many images there are. */
var testimg = $(this).find('.scrolling img').length;
/* Do the maths. */
var final = (test* testimg)*1.2;
/* Apply the maths to the CSS. */
$(this).find('scrolling').width(final);
});
Here you loop through all your div's with class target and you do the calculations. Within this loop you can simply use $(this)
to indicate the currently selected <div>
tag.
Returning http status code from Web Api controller
Another option:
return new NotModified();
public class NotModified : IHttpActionResult
{
public Task<HttpResponseMessage> ExecuteAsync(CancellationToken cancellationToken)
{
var response = new HttpResponseMessage(HttpStatusCode.NotModified);
return Task.FromResult(response);
}
}
How do you add input from user into list in Python
shopList = []
maxLengthList = 6
while len(shopList) < maxLengthList:
item = input("Enter your Item to the List: ")
shopList.append(item)
print shopList
print "That's your Shopping List"
print shopList
wamp server does not start: Windows 7, 64Bit
You just need Visual C++ runtime 2015 installed, if you change your php version to the newest version you will get the error for it. this is why apache has php dependency error.
How do I make calls to a REST API using C#?
Here are a few different ways of calling an external API in C# (updated 2019).
.NET's built-in ways:
- WebRequest& WebClient - verbose APIs & Microsoft's documentation is not very easy to follow
- HttpClient - .NET's newest kid on the block & much simpler to use than above.
Free, open-source NuGet Packages, which frankly have a much better developer experience than .NET's built in clients:
- ServiceStack.Text (1,000 GitHub stars, 7 million NuGet downloads) (*) - fast, light and resilient.
- RestSharp (6,000 GitHub stars, 23 million NuGet downloads) (*) - simple REST and HTTP API Client
- Flurl (1,700 GitHub stars, 3 million NuGet downloads) (*)- a fluent, portable, testable HTTP client library
All the above packages provide a great developer experience (i.e., concise, easy API) and are well maintained.
(*) as at August 2019
Example: Getting a Todo item from a Fake Rest API using ServiceStack.Text.
The other libraries have very similar syntax.
class Program
{
static void Main(string[] args)
{
// Fake rest API
string url = "https://jsonplaceholder.typicode.com/todos/1";
// GET data from API & map to POCO
var todo = url.GetJsonFromUrl().FromJson<Todo>();
// Print the result to screen
todo.PrintDump();
}
public class Todo
{
public int UserId { get; set; }
public int Id { get; set; }
public string Title { get; set; }
public bool Completed { get; set; }
}
}
Running the above example in a .NET Core Console app, produces the following output.
Install these packages using NuGet
Install-Package ServiceStack.Text, or
Install-Package RestSharp, or
Install-Package Flurl.Http
What's the best way to check if a String represents an integer in Java?
Since there's possibility that people still visit here and will be biased against Regex after the benchmarks... So i'm gonna give an updated version of the benchmark, with a compiled version of the Regex. Which opposed to the previous benchmarks, this one shows Regex solution actually has consistently good performance.
Copied from Bill the Lizard and updated with compiled version:
private final Pattern pattern = Pattern.compile("^-?\\d+$");
public void runTests() {
String big_int = "1234567890";
String non_int = "1234XY7890";
long startTime = System.currentTimeMillis();
for(int i = 0; i < 100000; i++)
IsInt_ByException(big_int);
long endTime = System.currentTimeMillis();
System.out.print("ByException - integer data: ");
System.out.println(endTime - startTime);
startTime = System.currentTimeMillis();
for(int i = 0; i < 100000; i++)
IsInt_ByException(non_int);
endTime = System.currentTimeMillis();
System.out.print("ByException - non-integer data: ");
System.out.println(endTime - startTime);
startTime = System.currentTimeMillis();
for(int i = 0; i < 100000; i++)
IsInt_ByRegex(big_int);
endTime = System.currentTimeMillis();
System.out.print("\nByRegex - integer data: ");
System.out.println(endTime - startTime);
startTime = System.currentTimeMillis();
for(int i = 0; i < 100000; i++)
IsInt_ByRegex(non_int);
endTime = System.currentTimeMillis();
System.out.print("ByRegex - non-integer data: ");
System.out.println(endTime - startTime);
startTime = System.currentTimeMillis();
for (int i = 0; i < 100000; i++)
IsInt_ByCompiledRegex(big_int);
endTime = System.currentTimeMillis();
System.out.print("\nByCompiledRegex - integer data: ");
System.out.println(endTime - startTime);
startTime = System.currentTimeMillis();
for (int i = 0; i < 100000; i++)
IsInt_ByCompiledRegex(non_int);
endTime = System.currentTimeMillis();
System.out.print("ByCompiledRegex - non-integer data: ");
System.out.println(endTime - startTime);
startTime = System.currentTimeMillis();
for(int i = 0; i < 100000; i++)
IsInt_ByJonas(big_int);
endTime = System.currentTimeMillis();
System.out.print("\nByJonas - integer data: ");
System.out.println(endTime - startTime);
startTime = System.currentTimeMillis();
for(int i = 0; i < 100000; i++)
IsInt_ByJonas(non_int);
endTime = System.currentTimeMillis();
System.out.print("ByJonas - non-integer data: ");
System.out.println(endTime - startTime);
}
private boolean IsInt_ByException(String str)
{
try
{
Integer.parseInt(str);
return true;
}
catch(NumberFormatException nfe)
{
return false;
}
}
private boolean IsInt_ByRegex(String str)
{
return str.matches("^-?\\d+$");
}
private boolean IsInt_ByCompiledRegex(String str) {
return pattern.matcher(str).find();
}
public boolean IsInt_ByJonas(String str)
{
if (str == null) {
return false;
}
int length = str.length();
if (length == 0) {
return false;
}
int i = 0;
if (str.charAt(0) == '-') {
if (length == 1) {
return false;
}
i = 1;
}
for (; i < length; i++) {
char c = str.charAt(i);
if (c <= '/' || c >= ':') {
return false;
}
}
return true;
}
Results:
ByException - integer data: 45
ByException - non-integer data: 465
ByRegex - integer data: 272
ByRegex - non-integer data: 131
ByCompiledRegex - integer data: 45
ByCompiledRegex - non-integer data: 26
ByJonas - integer data: 8
ByJonas - non-integer data: 2
HTML 5 Video "autoplay" not automatically starting in CHROME
Extremeandy has mentioned as of Chrome 66 autoplay video has been disabled.
After looking into this I found that muted videos are still able to be autoplayed. In my case the video didn't have any audio, but adding muted to the video tag has fixed it:
Hopefully this will help others also.
How to pass variable from jade template file to a script file?
See this question: JADE + EXPRESS: Iterating over object in inline JS code (client-side)?
I'm having the same problem. Jade does not pass local variables in (or do any templating at all) to javascript scripts, it simply passes the entire block in as literal text. If you use the local variables 'address' and 'port' in your Jade file above the script tag they should show up.
Possible solutions are listed in the question I linked to above, but you can either:
- pass every line in as unescaped text (!= at the beginning of every line), and simply put "-" before every line of javascript that uses a local variable, or:
- Pass variables in through a dom element and access through JQuery (ugly)
Is there no better way? It seems the creators of Jade do not want multiline javascript support, as shown by this thread in GitHub: https://github.com/visionmedia/jade/pull/405
EOFError: EOF when reading a line
width, height = map(int, input().split())
def rectanglePerimeter(width, height):
return ((width + height)*2)
print(rectanglePerimeter(width, height))
Running it like this produces:
% echo "1 2" | test.py
6
I suspect IDLE is simply passing a single string to your script. The first input()
is slurping the entire string. Notice what happens if you put some print statements in after the calls to input()
:
width = input()
print(width)
height = input()
print(height)
Running echo "1 2" | test.py
produces
1 2
Traceback (most recent call last):
File "/home/unutbu/pybin/test.py", line 5, in <module>
height = input()
EOFError: EOF when reading a line
Notice the first print statement prints the entire string '1 2'
. The second call to input()
raises the EOFError
(end-of-file error).
So a simple pipe such as the one I used only allows you to pass one string. Thus you can only call input()
once. You must then process this string, split it on whitespace, and convert the string fragments to ints yourself. That is what
width, height = map(int, input().split())
does.
Note, there are other ways to pass input to your program. If you had run test.py
in a terminal, then you could have typed 1
and 2
separately with no problem. Or, you could have written a program with pexpect to simulate a terminal, passing 1
and 2
programmatically. Or, you could use argparse to pass arguments on the command line, allowing you to call your program with
test.py 1 2
ASP.NET MVC Razor render without encoding
In case of ActionLink, it generally uses HttpUtility.Encode on the link text.
In that case
you can use
HttpUtility.HtmlDecode(myString)
it worked for me when using HtmlActionLink to decode the string that I wanted to pass. eg:
@Html.ActionLink(HttpUtility.HtmlDecode("myString","ActionName",..)
Can you split/explode a field in a MySQL query?
Here's what I've got so far (found it on the page Ben Alpert mentioned):
SELECT REPLACE(
SUBSTRING(
SUBSTRING_INDEX(c.`courseNames`, ',', e.`courseId` + 1)
, LENGTH(SUBSTRING_INDEX(c.`courseNames`, ',', e.`courseId`)
) + 1)
, ','
, ''
)
FROM `clients` c INNER JOIN `clientenrols` e USING (`clientId`)
Why does using from __future__ import print_function breaks Python2-style print?
First of all, from __future__ import print_function
needs to be the first line of code in your script (aside from some exceptions mentioned below). Second of all, as other answers have said, you have to use print
as a function now. That's the whole point of from __future__ import print_function
; to bring the print
function from Python 3 into Python 2.6+.
from __future__ import print_function
import sys, os, time
for x in range(0,10):
print(x, sep=' ', end='') # No need for sep here, but okay :)
time.sleep(1)
__future__
statements need to be near the top of the file because they change fundamental things about the language, and so the compiler needs to know about them from the beginning. From the documentation:
A future statement is recognized and treated specially at compile
time: Changes to the semantics of core constructs are often
implemented by generating different code. It may even be the case that
a new feature introduces new incompatible syntax (such as a new
reserved word), in which case the compiler may need to parse the
module differently. Such decisions cannot be pushed off until runtime.
The documentation also mentions that the only things that can precede a __future__
statement are the module docstring, comments, blank lines, and other future statements.
PHP Email sending BCC
You have $headers .= '...';
followed by $headers = '...';
; the second line is overwriting the first.
Just put the $headers .= "Bcc: $emailList\r\n";
say after the Content-type
line and it should be fine.
On a side note, the To
is generally required; mail servers might mark your message as spam otherwise.
$headers = "From: [email protected]\r\n" .
"X-Mailer: php\r\n";
$headers .= "MIME-Version: 1.0\r\n";
$headers .= "Content-Type: text/html; charset=ISO-8859-1\r\n";
$headers .= "Bcc: $emailList\r\n";
Angular is automatically adding 'ng-invalid' class on 'required' fields
Since the inputs are empty and therefore invalid when instantiated, Angular correctly adds the ng-invalid
class.
A CSS rule you might try:
input.ng-dirty.ng-invalid {
color: red
}
Which basically states when the field has had something entered into it at some point since the page loaded and wasn't reset to pristine by $scope.formName.setPristine(true)
and something wasn't yet entered and it's invalid then the text turns red
.
Other useful classes for Angular forms (see input for future reference )
ng-valid-maxlength
- when ng-maxlength
passes
ng-valid-minlength
- when ng-minlength
passes
ng-valid-pattern
- when ng-pattern
passes
ng-dirty
- when the form has had something entered since the form loaded
ng-pristine
- when the form input has had nothing inserted since loaded (or it was reset via setPristine(true)
on the form)
ng-invalid
- when any validation fails (required
, minlength
, custom ones, etc)
Likewise there is also ng-invalid-<name>
for all these patterns and any custom ones created.
How do I find a list of Homebrew's installable packages?
brew help
will show you the list of commands that are available.
brew list
will show you the list of installed packages. You can also append formulae, for example brew list postgres
will tell you of files installed by postgres (providing it is indeed installed).
brew search <search term>
will list the possible packages that you can install. brew search post
will return multiple packages that are available to install that have post in their name.
brew info <package name>
will display some basic information about the package in question.
You can also search http://searchbrew.com or https://brewformulas.org (both sites do basically the same thing)
org.apache.poi.POIXMLException: org.apache.poi.openxml4j.exceptions.InvalidFormatException:
Try this:
package my_default;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.util.Iterator;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.xssf.usermodel.XSSFCell;
import org.apache.poi.xssf.usermodel.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
public class Test {
public static void main(String[] args) {
try {
// Create Workbook instance holding reference to .xlsx file
XSSFWorkbook workbook = new XSSFWorkbook();
// Get first/desired sheet from the workbook
XSSFSheet sheet = createSheet(workbook, "Sheet 1", false);
// XSSFSheet sheet = workbook.getSheetAt(1);//Don't use this line
// because you get Sheet index (1) is out of range (no sheets)
//Write some information in the cells or do what you want
XSSFRow row1 = sheet.createRow(0);
XSSFCell r1c2 = row1.createCell(0);
r1c2.setCellValue("NAME");
XSSFCell r1c3 = row1.createCell(1);
r1c3.setCellValue("AGE");
//Save excel to HDD Drive
File pathToFile = new File("D:\\test.xlsx");
if (!pathToFile.exists()) {
pathToFile.createNewFile();
}
FileOutputStream fos = new FileOutputStream(pathToFile);
workbook.write(fos);
fos.close();
System.out.println("Done");
} catch (Exception e) {
e.printStackTrace();
}
}
private static XSSFSheet createSheet(XSSFWorkbook wb, String prefix, boolean isHidden) {
XSSFSheet sheet = null;
int count = 0;
for (int i = 0; i < wb.getNumberOfSheets(); i++) {
String sName = wb.getSheetName(i);
if (sName.startsWith(prefix))
count++;
}
if (count > 0) {
sheet = wb.createSheet(prefix + count);
} else
sheet = wb.createSheet(prefix);
if (isHidden)
wb.setSheetHidden(wb.getNumberOfSheets() - 1, XSSFWorkbook.SHEET_STATE_VERY_HIDDEN);
return sheet;
}
}
Recursive Lock (Mutex) vs Non-Recursive Lock (Mutex)
What are non-recursive mutexes good for?
They are absolutely good when you have to make sure the mutex is unlocked before doing something. This is because pthread_mutex_unlock
can guarantee that the mutex is unlocked only if it is non-recursive.
pthread_mutex_t g_mutex;
void foo()
{
pthread_mutex_lock(&g_mutex);
// Do something.
pthread_mutex_unlock(&g_mutex);
bar();
}
If g_mutex
is non-recursive, the code above is guaranteed to call bar()
with the mutex unlocked.
Thus eliminating the possibility of a deadlock in case bar()
happens to be an unknown external function which may well do something that may result in another thread trying to acquire the same mutex. Such scenarios are not uncommon in applications built on thread pools, and in distributed applications, where an interprocess call may spawn a new thread without the client programmer even realising that. In all such scenarios it's best to invoke the said external functions only after the lock is released.
If g_mutex
was recursive, there would be simply no way to make sure it is unlocked before making a call.
How to code a very simple login system with java
One way you could do it is have a file with the username and pass directly under it. Then uses the Scanner class and when you create it, make the file the parameter for the Scanner. Then use the methods hasNext(); and nextLine to verify the username and password;
String user;
String pass;
Scanner scan = new Scanner(new File("File.txt"));
while(scan.hasNext){ //While the file still has more lines remaining
if(scan.nextLine() == user){
if(scan.nextLine == pass){
lblDisplay.setText("Credentials Accepted.");
}
else{
lblDisplay.setText("Please try again.");
}
}
}
How to convert a private key to an RSA private key?
This may be of some help (do not literally write out the backslashes '\' in the commands, they are meant to indicate that "everything has to be on one line"):
It seems that all the commands (in grey) take any type of key file (in green) as "in" argument. Which is nice.
Here are the commands again for easier copy-pasting:
openssl rsa -in $FF -out $TF
openssl rsa -aes256 -in $FF -out $TF
openssl pkcs8 -topk8 -nocrypt -in $FF -out $TF
openssl pkcs8 -topk8 -v2 aes-256-cbc -v2prf hmacWithSHA256 -in $FF -out $TF
and
openssl rsa -check -in $FF
openssl rsa -text -in $FF
How to clear a notification in Android
If you are generating Notification from a Service that is started in the foreground using
startForeground(NOTIFICATION_ID, notificationBuilder.build());
Then issuing
notificationManager.cancel(NOTIFICATION_ID);
does not end up canceling the Notification, and the notification still appears in the status bar. In this particular case, you will need to issue
stopForeground( true );
from within the service to put it back into background mode and to simultaneously cancel the notifications. Alternately, you can push it into the background without having it cancel the notification and then cancel the notification.
stopForeground( false );
notificationManager.cancel(NOTIFICATION_ID);
What is function overloading and overriding in php?
Overloading is defining functions that have similar signatures, yet have different parameters. Overriding is only pertinent to derived classes, where the parent class has defined a method and the derived class wishes to override that method.
In PHP, you can only overload methods using the magic method __call
.
An example of overriding:
<?php
class Foo {
function myFoo() {
return "Foo";
}
}
class Bar extends Foo {
function myFoo() {
return "Bar";
}
}
$foo = new Foo;
$bar = new Bar;
echo($foo->myFoo()); //"Foo"
echo($bar->myFoo()); //"Bar"
?>
onclick go full screen
//set height of html
$("html").css("height", screen.height);
//set width of html
$("html").css("width", screen.width);
//go to full screen mode
document.documentElement.webkitRequestFullscreen();
Trigger an event on `click` and `enter`
You call both event listeners using .on()
then use a if
inside the function:
$(function(){
$('#searchButton').on('keypress click', function(e){
var search = $('#usersSearch').val();
if (e.which === 13 || e.type === 'click') {
$.post('../searchusers.php', {search: search}, function (response) {
$('#userSearchResultsTable').html(response);
});
}
});
});
How do you specifically order ggplot2 x axis instead of alphabetical order?
It is a little difficult to answer your specific question without a full, reproducible example. However something like this should work:
#Turn your 'treatment' column into a character vector
data$Treatment <- as.character(data$Treatment)
#Then turn it back into a factor with the levels in the correct order
data$Treatment <- factor(data$Treatment, levels=unique(data$Treatment))
In this example, the order of the factor will be the same as in the data.csv
file.
If you prefer a different order, you can order them by hand:
data$Treatment <- factor(data$Treatment, levels=c("Y", "X", "Z"))
However this is dangerous if you have a lot of levels: if you get any of them wrong, that will cause problems.
Call parent method from child class c#
One way to do this would be to pass the instance of ParentClass
to the ChildClass
on construction
public ChildClass
{
private ParentClass parent;
public ChildClass(ParentClass parent)
{
this.parent = parent;
}
public void LoadData(DateTable dt)
{
// do something
parent.CurrentRow++; // or whatever.
parent.UpdateProgressBar(); // Call the method
}
}
Make sure to pass the reference to this
when constructing ChildClass
inside parent:
if(loadData){
ChildClass childClass = new ChildClass(this); // here
childClass.LoadData(this.Datatable);
}
Caveat: This is probably not the best way to organise your classes, but it directly answers your question.
EDIT: In the comments you mention that more than 1 parent class wants to use ChildClass
. This is possible with the introduction of an interface, eg:
public interface IParentClass
{
void UpdateProgressBar();
int CurrentRow{get; set;}
}
Now, make sure to implement that interface on both (all?) Parent Classes and change child class to this:
public ChildClass
{
private IParentClass parent;
public ChildClass(IParentClass parent)
{
this.parent = parent;
}
public void LoadData(DateTable dt)
{
// do something
parent.CurrentRow++; // or whatever.
parent.UpdateProgressBar(); // Call the method
}
}
Now anything that implements IParentClass
can construct an instance of ChildClass
and pass this
to its constructor.
Bootstrap 4: responsive sidebar menu to top navbar
If this isn't a good solution for any reason, please let me know. It worked fine for me.
What I did is to hide the Sidebar and then make appear the navbar with breakpoints
@media screen and (max-width: 771px) {
#fixed-sidebar {
display: none;
}
#navbar-superior {
display: block !important;
}
}
String.replaceAll single backslashes with double backslashes
To avoid this sort of trouble, you can use replace
(which takes a plain string) instead of replaceAll
(which takes a regular expression). You will still need to escape backslashes, but not in the wild ways required with regular expressions.
Restart android machine
I think the only way to do this is to run another machine in parallel and use that machine to issue commands to your android box similar to how you would with a phone. If you have issues with the IP changing you can reserve an ip on your router and have the machine grab that one instead of asking the routers DHCP for one. This way you can ping the machine and figure out if it's done rebooting to continue the script.
Parameterize an SQL IN clause
In SQL Server 2016+ another possibility is to use the OPENJSON
function.
This approach is blogged about in OPENJSON - one of best ways to select rows by list of ids.
A full worked example below
CREATE TABLE dbo.Tags
(
Name VARCHAR(50),
Count INT
)
INSERT INTO dbo.Tags
VALUES ('VB',982), ('ruby',1306), ('rails',1478), ('scruffy',1), ('C#',1784)
GO
CREATE PROC dbo.SomeProc
@Tags VARCHAR(MAX)
AS
SELECT T.*
FROM dbo.Tags T
WHERE T.Name IN (SELECT J.Value COLLATE Latin1_General_CI_AS
FROM OPENJSON(CONCAT('[', @Tags, ']')) J)
ORDER BY T.Count DESC
GO
EXEC dbo.SomeProc @Tags = '"ruby","rails","scruffy","rubyonrails"'
DROP TABLE dbo.Tags
C++: constructor initializer for arrays
In the specific case when the array is a data member of the class you can't initialize it in the current version of the language. There's no syntax for that. Either provide a default constructor for array elements or use std::vector
.
A standalone array can be initialized with aggregate initializer
Foo foo[3] = { 4, 5, 6 };
but unfortunately there's no corresponding syntax for the constructor initializer list.
CentOS 7 and Puppet unable to install nc
Nc is a link to nmap-ncat.
It would be nice to use nmap-ncat in your puppet, because NC is a virtual name of nmap-ncat.
Puppet cannot understand the links/virtualnames
your puppet should be:
package {
'nmap-ncat':
ensure => installed;
}
Writing files in Node.js
There are a lot of details in the File System API. The most common way is:
const fs = require('fs');
fs.writeFile("/tmp/test", "Hey there!", function(err) {
if(err) {
return console.log(err);
}
console.log("The file was saved!");
});
// Or
fs.writeFileSync('/tmp/test-sync', 'Hey there!');
Paste Excel range in Outlook
Often this question is asked in the context of Ron de Bruin's RangeToHTML
function, which creates an HTML PublishObject
from an Excel.Range
, extracts that via FSO, and inserts the resulting stream HTML in to the email's HTMLBody
. In doing so, this removes the default signature (the RangeToHTML
function has a helper function GetBoiler
which attempts to insert the default signature).
Unfortunately, the poorly-documented Application.CommandBars
method is not available via Outlook:
wdDoc.Application.CommandBars.ExecuteMso "PasteExcelTableSourceFormatting"
It will raise a runtime 6158:
But we can still leverage the Word.Document
which is accessible via the MailItem.GetInspector
method, we can do something like this to copy & paste the selection from Excel to the Outlook email body, preserving your default signature (if there is one).
Dim rng as Range
Set rng = Range("A1:F10") 'Modify as needed
With OutMail
.To = "[email protected]"
.BCC = ""
.Subject = "Subject"
.Display
Dim wdDoc As Object '## Word.Document
Dim wdRange As Object '## Word.Range
Set wdDoc = OutMail.GetInspector.WordEditor
Set wdRange = wdDoc.Range(0, 0)
wdRange.InsertAfter vbCrLf & vbCrLf
'Copy the range in-place
rng.Copy
wdRange.Paste
End With
Note that in some cases this may not perfectly preserve the column widths or in some instances the row heights, and while it will also copy shapes and other objects in the Excel range, this may also cause some funky alignment issues, but for simple tables and Excel ranges, it is very good:
How to hide a div after some time period?
Here's a complete working example based on your testing. Compare it to what you have currently to figure out where you are going wrong.
<html>
<head>
<title>Untitled Document</title>
<script type="text/javascript" src="http://code.jquery.com/jquery-latest.js"></script>
<script type="text/javascript">
$(document).ready( function() {
$('#deletesuccess').delay(1000).fadeOut();
});
</script>
</head>
<body>
<div id=deletesuccess > hiiiiiiiiiii </div>
</body>
</html>
get current date and time in groovy?
Date
has the time part, so we only need to extract it from Date
I personally prefer the default format
parameter of the Date
when date and time needs to be separated instead of using the extra SimpleDateFormat
Date date = new Date()
String datePart = date.format("dd/MM/yyyy")
String timePart = date.format("HH:mm:ss")
println "datePart : " + datePart + "\ttimePart : " + timePart
How to set the component size with GridLayout? Is there a better way?
Don't use GridLayout for something it wasn't meant to do. It sounds to me like GridBagLayout would be a better fit for you, either that or MigLayout (though you'll have to download that first since it's not part of standard Java). Either that or combine layout managers such as BoxLayout for the lines and GridLayout to hold all the rows.
For example, using GridBagLayout:
import java.awt.*;
import javax.swing.*;
public class LayoutEg1 extends JPanel{
private static final int ROWS = 10;
public LayoutEg1() {
setLayout(new GridBagLayout());
for (int i = 0; i < ROWS; i++) {
GridBagConstraints gbc = makeGbc(0, i);
JLabel label = new JLabel("Row Label " + (i + 1));
add(label, gbc);
JPanel panel = new JPanel();
panel.add(new JCheckBox("check box"));
panel.add(new JTextField(10));
panel.add(new JButton("Button"));
panel.setBorder(BorderFactory.createEtchedBorder());
gbc = makeGbc(1, i);
add(panel, gbc);
}
}
private GridBagConstraints makeGbc(int x, int y) {
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridwidth = 1;
gbc.gridheight = 1;
gbc.gridx = x;
gbc.gridy = y;
gbc.weightx = x;
gbc.weighty = 1.0;
gbc.insets = new Insets(5, 5, 5, 5);
gbc.anchor = (x == 0) ? GridBagConstraints.LINE_START : GridBagConstraints.LINE_END;
gbc.fill = GridBagConstraints.HORIZONTAL;
return gbc;
}
private static void createAndShowUI() {
JFrame frame = new JFrame("Layout Eg1");
frame.getContentPane().add(new LayoutEg1());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
createAndShowUI();
}
});
}
}
What is The difference between ListBox and ListView
A ListView
is basically like a ListBox
(and inherits from it), but it also has a View
property. This property allows you to specify a predefined way of displaying the items. The only predefined view in the BCL (Base Class Library) is GridView
, but you can easily create your own.
Another difference is the default selection mode: it's Single
for a ListBox
, but Extended
for a ListView
Multipart forms from C# client
Thanks for the answers, everybody! I recently had to get this to work, and used your suggestions heavily. However, there were a couple of tricky parts that did not work as expected, mostly having to do with actually including the file (which was an important part of the question). There are a lot of answers here already, but I think this may be useful to someone in the future (I could not find many clear examples of this online). I wrote a blog post that explains it a little more.
Basically, I first tried to pass in the file data as a UTF8 encoded string, but I was having problems with encoding files (it worked fine for a plain text file, but when uploading a Word Document, for example, if I tried to save the file that was passed through to the posted form using Request.Files[0].SaveAs(), opening the file in Word did not work properly. I found that if you write the file data directly using a Stream (rather than a StringBuilder), it worked as expected. Also, I made a couple of modifications that made it easier for me to understand.
By the way, the Multipart Forms Request for Comments and the W3C Recommendation for mulitpart/form-data are a couple of useful resources in case anyone needs a reference for the specification.
I changed the WebHelpers class to be a bit smaller and have simpler interfaces, it is now called FormUpload
. If you pass a FormUpload.FileParameter
you can pass the byte[] contents along with a file name and content type, and if you pass a string, it will treat it as a standard name/value combination.
Here is the FormUpload class:
// Implements multipart/form-data POST in C# http://www.ietf.org/rfc/rfc2388.txt
// http://www.briangrinstead.com/blog/multipart-form-post-in-c
public static class FormUpload
{
private static readonly Encoding encoding = Encoding.UTF8;
public static HttpWebResponse MultipartFormDataPost(string postUrl, string userAgent, Dictionary<string, object> postParameters)
{
string formDataBoundary = String.Format("----------{0:N}", Guid.NewGuid());
string contentType = "multipart/form-data; boundary=" + formDataBoundary;
byte[] formData = GetMultipartFormData(postParameters, formDataBoundary);
return PostForm(postUrl, userAgent, contentType, formData);
}
private static HttpWebResponse PostForm(string postUrl, string userAgent, string contentType, byte[] formData)
{
HttpWebRequest request = WebRequest.Create(postUrl) as HttpWebRequest;
if (request == null)
{
throw new NullReferenceException("request is not a http request");
}
// Set up the request properties.
request.Method = "POST";
request.ContentType = contentType;
request.UserAgent = userAgent;
request.CookieContainer = new CookieContainer();
request.ContentLength = formData.Length;
// You could add authentication here as well if needed:
// request.PreAuthenticate = true;
// request.AuthenticationLevel = System.Net.Security.AuthenticationLevel.MutualAuthRequested;
// request.Headers.Add("Authorization", "Basic " + Convert.ToBase64String(System.Text.Encoding.Default.GetBytes("username" + ":" + "password")));
// Send the form data to the request.
using (Stream requestStream = request.GetRequestStream())
{
requestStream.Write(formData, 0, formData.Length);
requestStream.Close();
}
return request.GetResponse() as HttpWebResponse;
}
private static byte[] GetMultipartFormData(Dictionary<string, object> postParameters, string boundary)
{
Stream formDataStream = new System.IO.MemoryStream();
bool needsCLRF = false;
foreach (var param in postParameters)
{
// Thanks to feedback from commenters, add a CRLF to allow multiple parameters to be added.
// Skip it on the first parameter, add it to subsequent parameters.
if (needsCLRF)
formDataStream.Write(encoding.GetBytes("\r\n"), 0, encoding.GetByteCount("\r\n"));
needsCLRF = true;
if (param.Value is FileParameter)
{
FileParameter fileToUpload = (FileParameter)param.Value;
// Add just the first part of this param, since we will write the file data directly to the Stream
string header = string.Format("--{0}\r\nContent-Disposition: form-data; name=\"{1}\"; filename=\"{2}\";\r\nContent-Type: {3}\r\n\r\n",
boundary,
param.Key,
fileToUpload.FileName ?? param.Key,
fileToUpload.ContentType ?? "application/octet-stream");
formDataStream.Write(encoding.GetBytes(header), 0, encoding.GetByteCount(header));
// Write the file data directly to the Stream, rather than serializing it to a string.
formDataStream.Write(fileToUpload.File, 0, fileToUpload.File.Length);
}
else
{
string postData = string.Format("--{0}\r\nContent-Disposition: form-data; name=\"{1}\"\r\n\r\n{2}",
boundary,
param.Key,
param.Value);
formDataStream.Write(encoding.GetBytes(postData), 0, encoding.GetByteCount(postData));
}
}
// Add the end of the request. Start with a newline
string footer = "\r\n--" + boundary + "--\r\n";
formDataStream.Write(encoding.GetBytes(footer), 0, encoding.GetByteCount(footer));
// Dump the Stream into a byte[]
formDataStream.Position = 0;
byte[] formData = new byte[formDataStream.Length];
formDataStream.Read(formData, 0, formData.Length);
formDataStream.Close();
return formData;
}
public class FileParameter
{
public byte[] File { get; set; }
public string FileName { get; set; }
public string ContentType { get; set; }
public FileParameter(byte[] file) : this(file, null) { }
public FileParameter(byte[] file, string filename) : this(file, filename, null) { }
public FileParameter(byte[] file, string filename, string contenttype)
{
File = file;
FileName = filename;
ContentType = contenttype;
}
}
}
Here is the calling code, which uploads a file and a few normal post parameters:
// Read file data
FileStream fs = new FileStream("c:\\people.doc", FileMode.Open, FileAccess.Read);
byte[] data = new byte[fs.Length];
fs.Read(data, 0, data.Length);
fs.Close();
// Generate post objects
Dictionary<string, object> postParameters = new Dictionary<string, object>();
postParameters.Add("filename", "People.doc");
postParameters.Add("fileformat", "doc");
postParameters.Add("file", new FormUpload.FileParameter(data, "People.doc", "application/msword"));
// Create request and receive response
string postURL = "http://localhost";
string userAgent = "Someone";
HttpWebResponse webResponse = FormUpload.MultipartFormDataPost(postURL, userAgent, postParameters);
// Process response
StreamReader responseReader = new StreamReader(webResponse.GetResponseStream());
string fullResponse = responseReader.ReadToEnd();
webResponse.Close();
Response.Write(fullResponse);
Creating a list/array in excel using VBA to get a list of unique names in a column
You can try my suggestion for a work around in Doug's approach.
But if you want to stick with your logic though, you can try this:
Option Explicit
Sub GetUnique()
Dim rng As Range
Dim myarray, myunique
Dim i As Integer
ReDim myunique(1)
With ThisWorkbook.Sheets("Sheet1")
Set rng = .Range(.Range("A1"), .Range("A" & .Rows.Count).End(xlUp))
myarray = Application.Transpose(rng)
For i = LBound(myarray) To UBound(myarray)
If IsError(Application.Match(myarray(i), myunique, 0)) Then
myunique(UBound(myunique)) = myarray(i)
ReDim Preserve myunique(UBound(myunique) + 1)
End If
Next
End With
For i = LBound(myunique) To UBound(myunique)
Debug.Print myunique(i)
Next
End Sub
This uses array instead of range.
It also uses Match
function instead of a nested For Loop
.
I didn't have the time to check the time difference though.
So I leave the testing to you.
How to insert new cell into UITableView in Swift
Here is your code for add data into both tableView:
import UIKit
class ViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
@IBOutlet weak var table1Text: UITextField!
@IBOutlet weak var table2Text: UITextField!
@IBOutlet weak var table1: UITableView!
@IBOutlet weak var table2: UITableView!
var table1Data = ["a"]
var table2Data = ["1"]
override func viewDidLoad() {
super.viewDidLoad()
}
@IBAction func addData(sender: AnyObject) {
//add your data into tables array from textField
table1Data.append(table1Text.text)
table2Data.append(table2Text.text)
dispatch_async(dispatch_get_main_queue(), { () -> Void in
//reload your tableView
self.table1.reloadData()
self.table2.reloadData()
})
table1Text.resignFirstResponder()
table2Text.resignFirstResponder()
}
//delegate methods
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
if tableView == table1 {
return table1Data.count
}else if tableView == table2 {
return table2Data.count
}
return Int()
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
if tableView == table1 {
let cell = table1.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as! UITableViewCell
let row = indexPath.row
cell.textLabel?.text = table1Data[row]
return cell
}else if tableView == table2 {
let cell = table2.dequeueReusableCellWithIdentifier("Cell1", forIndexPath: indexPath) as! UITableViewCell
let row = indexPath.row
cell.textLabel?.text = table2Data[row]
return cell
}
return UITableViewCell()
}
}
And your result will be:
matplotlib.pyplot will not forget previous plots - how can I flush/refresh?
I would rather use plt.clf()
after every plt.show()
to just clear the current figure instead of closing and reopening it, keeping the window size and giving you a better performance and much better memory usage.
Similarly, you could do plt.cla()
to just clear the current axes.
To clear a specific axes, useful when you have multiple axes within one figure, you could do for example:
fig, axes = plt.subplots(nrows=2, ncols=2)
axes[0, 1].clear()
How to cancel a Task in await?
Or, in order to avoid modifying slowFunc
(say you don't have access to the source code for instance):
var source = new CancellationTokenSource(); //original code
source.Token.Register(CancelNotification); //original code
source.CancelAfter(TimeSpan.FromSeconds(1)); //original code
var completionSource = new TaskCompletionSource<object>(); //New code
source.Token.Register(() => completionSource.TrySetCanceled()); //New code
var task = Task<int>.Factory.StartNew(() => slowFunc(1, 2), source.Token); //original code
//original code: await task;
await Task.WhenAny(task, completionSource.Task); //New code
You can also use nice extension methods from https://github.com/StephenCleary/AsyncEx and have it looks as simple as:
await Task.WhenAny(task, source.Token.AsTask());
html select only one checkbox in a group
If someone need a solution without an external javascript libraries you could use this example. A group of checkboxes allowing 0..1 values. You may click on the checkbox component or associated label text.
<input id="mygroup1" name="mygroup" type="checkbox" value="1" onclick="toggleRadioCheckbox(this)" /> <label for="mygroup1">Yes</label>
<input id="mygroup0" name="mygroup" type="checkbox" value="0" onclick="toggleRadioCheckbox(this)" /> <label for="mygroup0">No</label>
- - - - - - - -
function toggleRadioCheckbox(sender) {
// RadioCheckbox: 0..1 enabled in a group
if (!sender.checked) return;
var fields = document.getElementsByName(sender.name);
for(var idx=0; idx<fields.length; idx++) {
var field = fields[idx];
if (field.checked && field!=sender)
field.checked=false;
}
}
How do I pass an object to HttpClient.PostAsync and serialize as a JSON body?
The straight up answer to your question is: No. The signature for the PostAsync
method is as follows:
public Task PostAsync(Uri requestUri, HttpContent content)
So, while you can pass an object
to PostAsync
it must be of type HttpContent
and your anonymous type does not meet that criteria.
However, there are ways to accomplish what you want to accomplish. First, you will need to serialize your anonymous type to JSON, the most common tool for this is Json.NET. And the code for this is pretty trivial:
var myContent = JsonConvert.SerializeObject(data);
Next, you will need to construct a content object to send this data, I will use a ByteArrayContent
object, but you could use or create a different type if you wanted.
var buffer = System.Text.Encoding.UTF8.GetBytes(myContent);
var byteContent = new ByteArrayContent(buffer);
Next, you want to set the content type to let the API know this is JSON.
byteContent.Headers.ContentType = new MediaTypeHeaderValue("application/json");
Then you can send your request very similar to your previous example with the form content:
var result = client.PostAsync("", byteContent).Result
On a side note, calling the .Result
property like you're doing here can have some bad side effects such as dead locking, so you want to be careful with this.
How to get the ActionBar height?
The action bar height differs according to the applied theme.
If you're using AppCompatActivity the height will be different in most of cases from the normal Activity.
If you're using AppCompatActivity you should use R.attr.actionBarSize instead of android.R.attr.actionBarSize
public static int getActionBarHeight(Activity activity) {
TypedValue typedValue = new TypedValue();
int attributeResourceId = android.R.attr.actionBarSize;
if (activity instanceof AppCompatActivity) {
attributeResourceId = R.attr.actionBarSize;
}
if (activity.getTheme().resolveAttribute(attributeResourceId, typedValue, true)) {
return TypedValue.complexToDimensionPixelSize(typedValue.data, activity.getResources().getDisplayMetrics());
}
return (int) Math.floor(activity.getResources()
.getDimension(R.dimen.my_default_value));
}
How do I use variables in Oracle SQL Developer?
There are two types of variable in SQL-plus: substitution and bind.
This is substitution (substitution variables can replace SQL*Plus command options or other hard-coded text):
define a = 1;
select &a from dual;
undefine a;
This is bind (bind variables store data values for SQL and PL/SQL statements executed in the RDBMS; they can hold single values or complete result sets):
var x number;
exec :x := 10;
select :x from dual;
exec select count(*) into :x from dual;
exec print x;
SQL Developer supports substitution variables, but when you execute a query with bind :var
syntax you are prompted for the binding (in a dialog box).
Reference:
UPDATE substitution variables are a bit tricky to use, look:
define phone = '+38097666666';
select &phone from dual; -- plus is stripped as it is a number
select '&phone' from dual; -- plus is preserved as it is a string
What is the right way to debug in iPython notebook?
You can use ipdb
inside jupyter with:
from IPython.core.debugger import Tracer; Tracer()()
Edit: the functions above are deprecated since IPython 5.1. This is the new approach:
from IPython.core.debugger import set_trace
Add set_trace()
where you need a breakpoint. Type help
for ipdb
commands when the input field appears.
Creating a List of Lists in C#
I have been toying with this idea too, but I was trying to achieve a slightly different behavior. My idea was to make a list which inherits itself, thus creating a data structure that by nature allows you to embed lists within lists within lists within lists...infinitely!
Implementation
//InfiniteList<T> is a list of itself...
public class InfiniteList<T> : List<InfiniteList<T>>
{
//This is necessary to allow your lists to store values (of type T).
public T Value { set; get; }
}
T is a generic type parameter. It is there to ensure type safety in your class. When you create an instance of InfiniteList, you replace T with the type you want your list to be populated with, or in this instance, the type of the Value property.
Example
//The InfiniteList.Value property will be of type string
InfiniteList<string> list = new InfiniteList<string>();
A "working" example of this, where T is in itself, a List of type string!
//Create an instance of InfiniteList where T is List<string>
InfiniteList<List<string>> list = new InfiniteList<List<string>>();
//Add a new instance of InfiniteList<List<string>> to "list" instance.
list.Add(new InfiniteList<List<string>>());
//access the first element of "list". Access the Value property, and add a new string to it.
list[0].Value.Add("Hello World");
Can you do a partial checkout with Subversion?
Sort of. As Bobby says:
svn co file:///.../trunk/foo file:///.../trunk/bar file:///.../trunk/hum
will get the folders, but you will get separate folders from a subversion perspective. You will have to go separate commits and updates on each subfolder.
I don't believe you can checkout a partial tree and then work with the partial tree as a single entity.
Check if a list contains an item in Ansible
Ansible has a version_compare
filter since 1.6.
You can do something like below in when
conditional:
when: ansible_distribution_version | version_compare('12.04', '>=')
This will give you support for major & minor versions comparisons and you can compare versions using operators like:
<, lt, <=, le, >, gt, >=, ge, ==, =, eq, !=, <>, ne
You can find more information about this here: Ansible - Version comparison filters
Otherwise if you have really simple case you can use what @ProfHase85 suggested
HTML Drag And Drop On Mobile Devices
There is a new polyfill for translating touch events to drag-and-drop, such that HTML5 Drag And Drop is utilizable on mobile.
The polyfill was introduced by Bernardo Castilho on this post.
Here's a demo from that post.
The post also presents several considerations of the folyfill design.
How to programmatically clear application data
You can use the package-manager tool to clear data for installed apps (similar to pressing the 'clear data' button in the app settings on your device).
So using adb you could do:
adb shell pm clear my.wonderful.app.package
Why do you need to put #!/bin/bash at the beginning of a script file?
It can be useful to someone that uses a different system that does not have that library readily available. If that is not declared and you have some functions in your script that are not supported by that system, you should declare #/bin/bash. I've ran into this problem before at work and now I just include it as a practice.
Do I really need to encode '&' as '&'?
Could you show us what your title
actually is? When I submit
<!DOCTYPE html>
<html>
<title>Dolce & Gabbana</title>
<body>
<p>am i allowed loose & mpersands?</p>
</body>
</html>
to http://validator.w3.org/ - explicitly asking it to use the experimental HTML 5 mode - it has no complaints about the &
s...
React proptype array with shape
If I am to define the same proptypes for a particular shape multiple times, I like abstract it out to a proptypes file so that if the shape of the object changes, I only have to change the code in one place. It helps dry up the codebase a bit.
Example:
// Inside my proptypes.js file
import PT from 'prop-types';
export const product = {
id: PT.number.isRequired,
title: PT.string.isRequired,
sku: PT.string.isRequired,
description: PT.string.isRequired,
};
// Inside my component file
import PT from 'prop-types';
import { product } from './proptypes;
List.propTypes = {
productList: PT.arrayOf(product)
}
What is a "callback" in C and how are they implemented?
A simple call back program. Hope it answers your question.
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include "../../common_typedef.h"
typedef void (*call_back) (S32, S32);
void test_call_back(S32 a, S32 b)
{
printf("In call back function, a:%d \t b:%d \n", a, b);
}
void call_callback_func(call_back back)
{
S32 a = 5;
S32 b = 7;
back(a, b);
}
S32 main(S32 argc, S8 *argv[])
{
S32 ret = SUCCESS;
call_back back;
back = test_call_back;
call_callback_func(back);
return ret;
}
VBA: How to display an error message just like the standard error message which has a "Debug" button?
For Me I just wanted to see the error in my VBA application so in the function I created the below code..
Function Database_FileRpt
'-------------------------
On Error GoTo CleanFail
'-------------------------
'
' Create_DailyReport_Action and code
CleanFail:
'*************************************
MsgBox "********************" _
& vbCrLf & "Err.Number: " & Err.Number _
& vbCrLf & "Err.Description: " & Err.Description _
& vbCrLf & "Err.Source: " & Err.Source _
& vbCrLf & "********************" _
& vbCrLf & "...Exiting VBA Function: Database_FileRpt" _
& vbCrLf & "...Excel VBA Program Reset." _
, , "VBA Error Exception Raised!"
*************************************
' Note that the next line will reset the error object to 0, the variables
above are used to remember the values
' so that the same error can be re-raised
Err.Clear
' *************************************
Resume CleanExit
CleanExit:
'cleanup code , if any, goes here. runs regardless of error state.
Exit Function ' SUB or Function
End Function ' end of Database_FileRpt
' ------------------
exit application when click button - iOS
You can use exit method to quit an ios app :
exit(0);
You should say same alert message and ask him to quit
Another way is by using [[NSThread mainThread] exit]
However you should not do this way
According to Apple, your app should not terminate on its own. Since the user did not hit the Home button, any return to the Home screen gives the user the impression that your app crashed. This is confusing, non-standard behavior and should be avoided.
Get viewport/window height in ReactJS
class AppComponent extends React.Component {
constructor(props) {
super(props);
this.state = {height: props.height};
}
componentWillMount(){
this.setState({height: window.innerHeight + 'px'});
}
render() {
// render your component...
}
}
Set the props
AppComponent.propTypes = {
height:React.PropTypes.string
};
AppComponent.defaultProps = {
height:'500px'
};
viewport height is now available as {this.state.height} in rendering template
Clearing a text field on button click
A simple JavaScript function will do the job.
function ClearFields() {
document.getElementById("textfield1").value = "";
document.getElementById("textfield2").value = "";
}
And just have your button call it:
<button type="button" onclick="ClearFields();">Clear</button>
ValueError: all the input arrays must have same number of dimensions
You can also cast (n,) to (n,1) by enclosing within brackets [ ].
e.g. Instead of np.append(b,a,axis=0)
use np.append(b,[a],axis=0)
a=[1,2]
b=[[5,6],[7,8]]
np.append(b,[a],axis=0)
returns
array([[5, 6],
[7, 8],
[1, 2]])
Python: How to remove empty lists from a list?
list1 = [[], [], [], [], [], 'text', 'text2', [], 'moreText']
list2 = []
for item in list1:
if item!=[]:
list2.append(item)
print(list2)
output:
['text', 'text2', 'moreText']
WPF checkbox binding
You must make your binding bidirectional :
<checkbox IsChecked="{Binding Path=MyProperty, Mode=TwoWay}"/>
Node.js Error: Cannot find module express
D:\learn\Node.js\node app.js
module.js:549
throw err;
^
Error: Cannot find module 'body-parser'
at Function.Module._resolveFilename (module.js:547:15)
at Function.Module._load (module.js:474:25)
at Module.require (module.js:596:17)
at require (internal/module.js:11:18)
Sometimes version not match with package.json
Fixed the problem by checking the package.json then use the following commands:
npm install [email protected]
it resolved for me.
how to display none through code behind
Since this is a login div, shouldn't the default be to NOT display it. I am going to go ahead and assume then you want to display it then via javascript.
<div id="login" style="display:none;">Content</div>
Then using jQuery:
<script type="javascript">$('#login').show();</script>
Another method you might consider is something like this:
<div id="login" style="display:<%=SetDisplay() %>">Content</div>
And the SetDisplay() method output "none" or "block"
SQL Server : export query as a .txt file
The BCP Utility can also be used in the form of a .bat file, but be cautious of escape sequences (ie quotes "" must be used in conjunction with ) and the appropriate tags.
.bat Example:
C:
bcp "\"YOUR_SERVER\".dbo.Proc" queryout C:\FilePath.txt -T -c -q
-- Add PAUSE here if you'd like to see the completed batch
-q MUST be used in the presence of quotations within the query itself.
BCP can also run Stored Procedures if necessary. Again, be cautious: Temporary Tables must be created prior to execution or else you should consider using Table Variables.
Android eclipse DDMS - Can't access data/data/ on phone to pull files
When I say file system I meant the whole file system. But you can only browse part of the file system on a retail phone, perhaps even most of file system but not ./data. Sorry for any confusion this may have caused.
This is alarming to me because I have a rooted my retail Nexus One and a developer/unlocked Nexus One. Since I rooted my retail Nexus One I can't figure out why I can't browse the whole file system like I can on my developer Nexus One.
How do a send an HTTPS request through a proxy in Java?
HTTPS proxy doesn't make sense because you can't terminate your HTTP connection at the proxy for security reasons. With your trust policy, it might work if the proxy server has a HTTPS port. Your error is caused by connecting to HTTP proxy port with HTTPS.
You can connect through a proxy using SSL tunneling (many people call that proxy) using proxy CONNECT command. However, Java doesn't support newer version of proxy tunneling. In that case, you need to handle the tunneling yourself. You can find sample code here,
http://www.javaworld.com/javaworld/javatips/jw-javatip111.html
EDIT: If you want defeat all the security measures in JSSE, you still need your own TrustManager. Something like this,
public SSLTunnelSocketFactory(String proxyhost, String proxyport){
tunnelHost = proxyhost;
tunnelPort = Integer.parseInt(proxyport);
dfactory = (SSLSocketFactory)sslContext.getSocketFactory();
}
...
connection.setSSLSocketFactory( new SSLTunnelSocketFactory( proxyHost, proxyPort ) );
connection.setDefaultHostnameVerifier( new HostnameVerifier()
{
public boolean verify( String arg0, SSLSession arg1 )
{
return true;
}
} );
EDIT 2: I just tried my program I wrote a few years ago using SSLTunnelSocketFactory and it doesn't work either. Apparently, Sun introduced a new bug sometime in Java 5. See this bug report,
http://bugs.sun.com/view_bug.do?bug_id=6614957
The good news is that the SSL tunneling bug is fixed so you can just use the default factory. I just tried with a proxy and everything works as expected. See my code,
public class SSLContextTest {
public static void main(String[] args) {
System.setProperty("https.proxyHost", "proxy.xxx.com");
System.setProperty("https.proxyPort", "8888");
try {
SSLContext sslContext = SSLContext.getInstance("SSL");
// set up a TrustManager that trusts everything
sslContext.init(null, new TrustManager[] { new X509TrustManager() {
public X509Certificate[] getAcceptedIssuers() {
System.out.println("getAcceptedIssuers =============");
return null;
}
public void checkClientTrusted(X509Certificate[] certs,
String authType) {
System.out.println("checkClientTrusted =============");
}
public void checkServerTrusted(X509Certificate[] certs,
String authType) {
System.out.println("checkServerTrusted =============");
}
} }, new SecureRandom());
HttpsURLConnection.setDefaultSSLSocketFactory(
sslContext.getSocketFactory());
HttpsURLConnection
.setDefaultHostnameVerifier(new HostnameVerifier() {
public boolean verify(String arg0, SSLSession arg1) {
System.out.println("hostnameVerifier =============");
return true;
}
});
URL url = new URL("https://www.verisign.net");
URLConnection conn = url.openConnection();
BufferedReader reader =
new BufferedReader(new InputStreamReader(conn.getInputStream()));
String line;
while ((line = reader.readLine()) != null) {
System.out.println(line);
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
This is what I get when I run the program,
checkServerTrusted =============
hostnameVerifier =============
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
......
As you can see, both SSLContext and hostnameVerifier are getting called. HostnameVerifier is only involved when the hostname doesn't match the cert. I used "www.verisign.net" to trigger this.
What's the maximum value for an int in PHP?
32-bit builds of PHP:
- Integers can be from -2,147,483,648 to 2,147,483,647 (~ ± 2 billion)
64-bit builds of PHP:
- Integers can be from -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807 (~ ± 9 quintillion)
Numbers are inclusive.
Note: some 64-bit builds once used 32-bit integers, particularly older Windows builds of PHP
Values outside of these ranges are represented by floating point values, as are non-integer values within these ranges. The interpreter will automatically determine when this switch to floating point needs to happen based on whether the result value of a calculation can't be represented as an integer.
PHP has no support for "unsigned" integers as such, limiting the maximum value of all integers to the range of a "signed" integer.
Starting a shell in the Docker Alpine container
Usually, an Alpine Linux image doesn't contain bash
, Instead you can use /bin/ash
, /bin/sh
, ash
or only sh
.
/bin/ash
docker run -it --rm alpine /bin/ash
/bin/sh
docker run -it --rm alpine /bin/sh
ash
docker run -it --rm alpine ash
sh
docker run -it --rm alpine sh
I hope this information helps you.
Iterating through a range of dates in Python
For those who are interested in Pythonic functional way:
from datetime import date, timedelta
from itertools import count, takewhile
for d in takewhile(lambda x: x<=date(2009,6,9), map(lambda x:date(2009,5,30)+timedelta(days=x), count())):
print(d)
SQL update query using joins
You can use the following query:
UPDATE im
SET mf_item_number = (some value)
FROM item_master im
JOIN group_master gm
ON im.sku = gm.sku
JOIN Manufacturer_Master mm
ON gm.ManufacturerID = mm.ManufacturerID
WHERE im.mf_item_number like 'STA%' AND
gm.manufacturerID = 34 `sql`
Pandas dataframe get first row of each group
maybe this is what you want
import pandas as pd
idx = pd.MultiIndex.from_product([['state1','state2'], ['county1','county2','county3','county4']])
df = pd.DataFrame({'pop': [12,15,65,42,78,67,55,31]}, index=idx)
pop
state1 county1 12
county2 15
county3 65
county4 42
state2 county1 78
county2 67
county3 55
county4 31
df.groupby(level=0, group_keys=False).apply(lambda x: x.sort_values('pop', ascending=False)).groupby(level=0).head(3)
> Out[29]:
pop
state1 county3 65
county4 42
county2 15
state2 county1 78
county2 67
county3 55
Replacing last character in a String with java
Already @Abubakkar Rangara answered easy way to handle your problem
Alternative is :
String[] result = null;
if(fieldName.endsWith(",")) {
String[] result = fieldName.split(",");
for(int i = 1; i < result.length - 1; i++) {
result[0] = result[0].concat(result[i]);
}
}
Hunk #1 FAILED at 1. What's that mean?
In some cases, there is no difference in file versions, but only in indentation, spacing, line ending or line numbers.
To patch despite those differences, it's possible to use the following two arguments :
--ignore-whitespace : It ignores whitespace differences (indentation, etc).
--fuzz 3 : the "--fuzz X" option sets the maximum fuzz factor to lines. This option only applies to context and unified diffs; it ignores up to X lines while looking for the place to install a hunk. Note that a larger fuzz factor increases the odds of making a faulty patch. The default fuzz factor is 2; there is no point to setting it to more than the number of lines of context in the diff, ordinarily 3.
Don't forget to user "--dry-run" : It'll try the patch without applying it.
Example :
patch --verbose --dry-run --ignore-whitespace --fuzz 3 < /path/to/patch.patch
More informations about Fuzz :
https://www.gnu.org/software/diffutils/manual/html_node/Inexact.html
Where is the Global.asax.cs file?
That's because you created a Web Site instead of a Web Application. The cs/vb
files can only be seen in a Web Application, but in a website you can't have a separate cs/vb
file.
Edit: In the website you can add a cs file behavior like..
<%@ Application CodeFile="Global.asax.cs" Inherits="ApplicationName.MyApplication" Language="C#" %>
~/Global.asax.cs:
namespace ApplicationName
{
public partial class MyApplication : System.Web.HttpApplication
{
protected void Application_Start()
{
}
}
}
converting Java bitmap to byte array
Try something like this:
Bitmap bmp = intent.getExtras().get("data");
ByteArrayOutputStream stream = new ByteArrayOutputStream();
bmp.compress(Bitmap.CompressFormat.PNG, 100, stream);
byte[] byteArray = stream.toByteArray();
bmp.recycle();
How to pass command line argument to gnuplot?
You can pass arguments to a gnuplot script since version 5.0, with the flag -c
. These arguments are accessed through the variables ARG0
to ARG9
, ARG0
being the script, and ARG1
to ARG9
string variables. The number of arguments is given by ARGC
.
For example, the following script ("script.gp")
#!/usr/local/bin/gnuplot --persist
THIRD=ARG3
print "script name : ", ARG0
print "first argument : ", ARG1
print "third argument : ", THIRD
print "number of arguments: ", ARGC
can be called as:
$ gnuplot -c script.gp one two three four five
script name : script.gp
first argument : one
third argument : three
number of arguments: 5
or within gnuplot as
gnuplot> call 'script.gp' one two three four five
script name : script.gp
first argument : one
third argument : three
number of arguments: 5
In gnuplot 4.6.6 and earlier, there exists a call
mechanism with a different (now deprecated) syntax. The arguments are accessed through $#
, $0
,...,$9
. For example, the same script above looks like:
#!/usr/bin/gnuplot --persist
THIRD="$2"
print "first argument : ", "$0"
print "second argument : ", "$1"
print "third argument : ", THIRD
print "number of arguments: ", "$#"
and it is called within gnuplot as (remember, version <4.6.6)
gnuplot> call 'script4.gp' one two three four five
first argument : one
second argument : two
third argument : three
number of arguments: 5
Notice there is no variable for the script name, so $0
is the first argument, and the variables are called within quotes. There is no way to use this directly from the command line, only through tricks as the one suggested by @con-fu-se.
Relative instead of Absolute paths in Excel VBA
I think the problem is that opening the file without a path will only work if your "current directory" is set correctly.
Try typing "Debug.Print CurDir" in the Immediate Window - that should show the location for your default files as set in Tools...Options.
I'm not sure I'm completely happy with it, perhaps because it's somewhat of a legacy VB command, but you could do this:
ChDir ThisWorkbook.Path
I think I'd prefer to use ThisWorkbook.Path to construct a path to the HTML file. I'm a big fan of the FileSystemObject in the Scripting Runtime (which always seems to be installed), so I'd be happier to do something like this (after setting a reference to Microsoft Scripting Runtime):
Const HTML_FILE_NAME As String = "my_input.html"
With New FileSystemObject
With .OpenTextFile(.BuildPath(ThisWorkbook.Path, HTML_FILE_NAME), ForReading)
' Now we have a TextStream object that we can use to read the file
End With
End With
How to get a list of images on docker registry v2
Get catalogs
Default, registry api return 100 entries of catalog, there is the code:
When you curl the registry api:
curl --cacert domain.crt https://your.registry:5000/v2/_catalog
it equivalents with:
curl --cacert domain.crt https://your.registry:5000/v2/_catalog?n=100
This is a pagination methond.
When the sum of entries beyond 100, you can do in two ways:
First: give a bigger number
curl --cacert domain.crt https://your.registry:5000/v2/_catalog?n=2000
Sencond: parse the next linker url
curl --cacert domain.crt https://your.registry:5000/v2/_catalog
A link element contained in response header:
curl --cacert domain.crt https://your.registry:5000/v2/_catalog
response header:
Link: </v2/_catalog?last=pro-octopus-ws&n=100>; rel="next"
The link element have the last entry of this request, then you can request the next 'page':
curl --cacert domain.crt https://your.registry:5000/v2/_catalog?last=pro-octopus-ws
If the response header contains link element, you can do it in a loop.
Get Images
When you get the result of catalog, it like follows:
{
"repositories": [
"busybox",
"ceph/mds"
]
}
you can get the images in every catalog:
curl --cacert domain.crt https://your.registry:5000/v2/busybox/tags/list
returns:
{"name":"busybox","tags":["latest"]}
Difference between "Complete binary tree", "strict binary tree","full binary Tree"?
Complete Binary Tree:
All levels are completely filled except the lowest level and one main thing all the leaf elements must have left child.
Strict Binary Tree:
In this tree every non-leaf node has no child i.e. neither left nor right.
Full Binary Tree:
Every Node has either zero child or Two children (never having single child).
How to execute a file within the python interpreter?
For Python 3:
>>> exec(open("helloworld.py").read())
Make sure that you're in the correct directory before running the command.
To run a file from a different directory, you can use the below command:
with open ("C:\\Users\\UserName\\SomeFolder\\helloworld.py", "r") as file:
exec(file.read())
In PHP with PDO, how to check the final SQL parametrized query?
I initially avoided turning on logging to monitor PDO because I thought that it would be a hassle but it is not hard at all. You don't need to reboot MySQL (after 5.1.9):
Execute this SQL in phpMyAdmin or any other environment where you may have high db privileges:
SET GLOBAL general_log = 'ON';
In a terminal, tail your log file. Mine was here:
>sudo tail -f /usr/local/mysql/data/myMacComputerName.log
You can search for your mysql files with this terminal command:
>ps auxww|grep [m]ysqld
I found that PDO escapes everything, so you can't write
$dynamicField = 'userName';
$sql = "SELECT * FROM `example` WHERE `:field` = :value";
$this->statement = $this->db->prepare($sql);
$this->statement->bindValue(':field', $dynamicField);
$this->statement->bindValue(':value', 'mick');
$this->statement->execute();
Because it creates:
SELECT * FROM `example` WHERE `'userName'` = 'mick' ;
Which did not create an error, just an empty result. Instead I needed to use
$sql = "SELECT * FROM `example` WHERE `$dynamicField` = :value";
to get
SELECT * FROM `example` WHERE `userName` = 'mick' ;
When you are done execute:
SET GLOBAL general_log = 'OFF';
or else your logs will get huge.
disabling spring security in spring boot app
You could just comment the maven dependency for a while:
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-mongodb</artifactId>
</dependency>
<!-- <dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-security</artifactId>
</dependency>-->
</dependencies>
It worked fine for me
Disabling it from application.properties
is deprecated for Spring Boot
2.0
How to connect android wifi to adhoc wifi?
You are correct that this is currently not natively supported in Android, although Google has been saying it will be coming ever since Android was officially launched.
While not natively supported, the hardware on every android device released to date do support it. It is just disabled in software, and you would need to enable it in order to use these features.
It is however, fairly easy to do this, but you need to be root, and the specifics may be slightly different between different devices. Your best source for more informationa about this, would be XDA developers: http://forum.xda-developers.com/forumdisplay.php?f=564.
Most of the existing solutions are based on replacing wpa_supplicant, and is the method I would recommend if possible on your device. For more details, see http://szym.net/2010/12/adhoc-wifi-in-android/.
Update: Its been a few years now, and whenever I need an ad hoc network connection on my phone I use CyanogenMod. It gives you both programmatic and scripted access to these functions, and the ability to create ad hoc (ibss) networks in the WiFi settings menu.
Not unique table/alias
Your query contains columns which could be present with the same name in more than one table you are referencing, hence the not unique error. It's best if you make the references explicit and/or use table aliases when joining.
Try
SELECT pa.ProjectID, p.Project_Title, a.Account_ID, a.Username, a.Access_Type, c.First_Name, c.Last_Name
FROM Project_Assigned pa
INNER JOIN Account a
ON pa.AccountID = a.Account_ID
INNER JOIN Project p
ON pa.ProjectID = p.Project_ID
INNER JOIN Clients c
ON a.Account_ID = c.Account_ID
WHERE a.Access_Type = 'Client';
SELECT * FROM multiple tables. MySQL
What you do here is called a JOIN
(although you do it implicitly because you select from multiple tables). This means, if you didn't put any conditions in your WHERE clause, you had all combinations of those tables. Only with your condition you restrict your join to those rows where the drink id matches.
But there are still X multiple rows in the result for every drink, if there are X photos with this particular drinks_id. Your statement doesn't restrict which photo(s) you want to have!
If you only want one row per drink, you have to tell SQL what you want to do if there are multiple rows with a particular drinks_id. For this you need grouping and an aggregate function. You tell SQL which entries you want to group together (for example all equal drinks_ids) and in the SELECT, you have to tell which of the distinct entries for each grouped result row should be taken. For numbers, this can be average, minimum, maximum (to name some).
In your case, I can't see the sense to query the photos for drinks if you only want one row. You probably thought you could have an array of photos in your result for each drink, but SQL can't do this. If you only want any photo and you don't care which you'll get, just group by the drinks_id (in order to get only one row per drink):
SELECT name, price, photo
FROM drinks, drinks_photos
WHERE drinks.id = drinks_id
GROUP BY drinks_id
name price photo
fanta 5 ./images/fanta-1.jpg
dew 4 ./images/dew-1.jpg
In MySQL, we also have GROUP_CONCAT, if you want the file names to be concatenated to one single string:
SELECT name, price, GROUP_CONCAT(photo, ',')
FROM drinks, drinks_photos
WHERE drinks.id = drinks_id
GROUP BY drinks_id
name price photo
fanta 5 ./images/fanta-1.jpg,./images/fanta-2.jpg,./images/fanta-3.jpg
dew 4 ./images/dew-1.jpg,./images/dew-2.jpg
However, this can get dangerous if you have ,
within the field values, since most likely you want to split this again on the client side. It is also not a standard SQL aggregate function.
In a javascript array, how do I get the last 5 elements, excluding the first element?
Here is one I haven't seen that's even shorter
arr.slice(1).slice(-5)
Run the code snippet below for proof of it doing what you want
_x000D_
_x000D_
var arr1 = [0, 1, 2, 3, 4, 5, 6, 7],_x000D_
arr2 = [0, 1, 2, 3];_x000D_
_x000D_
document.body.innerHTML = 'ARRAY 1: ' + arr1.slice(1).slice(-5) + '<br/>ARRAY 2: ' + arr2.slice(1).slice(-5);
_x000D_
_x000D_
_x000D_
Another way to do it would be using lodash https://lodash.com/docs#rest - that is of course if you don't mind having to load a huge javascript minified file if your trying to do it from your browser.
_.slice(_.rest(arr), -5)
How to add a spinner icon to button when it's in the Loading state?
A lazy way to do this is with the UTF-8 entity code for a half circle \25E0
(aka ◠
), which looks like ? and then keyframe animate it. It's a simple as:
_x000D_
_x000D_
.busy
{
animation: spin 1s infinite linear;
display:inline-block;
font-weight: bold;
font-family: sans-serif;
font-size: 35px;
font-style:normal;
color:#555;
}
.busy::before
{
content:"\25E0";
}
@keyframes spin
{
0% {transform: rotate(0deg);}
100% {transform: rotate(359deg);}
}
_x000D_
<i class="busy"></i>
_x000D_
_x000D_
_x000D_
How do I limit the number of rows returned by an Oracle query after ordering?
(untested) something like this may do the job
WITH
base AS
(
select * -- get the table
from sometable
order by name -- in the desired order
),
twenty AS
(
select * -- get the first 30 rows
from base
where rownum < 30
order by name -- in the desired order
)
select * -- then get rows 21 .. 30
from twenty
where rownum > 20
order by name -- in the desired order
There is also the analytic function rank, that you can use to order by.
How to add a Hint in spinner in XML
I've managed to add a 'hint' that is omitted from the drop down list. If my code looks a bit weird it's because I'm using Xamarin.Android so it's in C# but for all intents (heh) and purposes the Java equivalent should have the same effect.
The gist is that I've created a custom ArrayAdapter that will detect if it is the hint in the GetDropDownView method. If so then it will inflate an empty XML to hide the hint from the drop down.
My spinnerItem.xml is ...
<?xml version="1.0" encoding="utf-8"?>
<TextView
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/spinnerText"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingLeft="@dimen/text_left_padding"
android:textAppearance="?android:attr/textAppearanceLarge"/>
My 'empty' hintSpinnerDropdownItem.xml which will hide the hint.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
I pass in an array of CustomObj without the hint. That's why I have the additional AddPrompt method to insert the hint at the beginning before it's passed to the parent constructor.
public class CustomArrayAdapter: ArrayAdapter<CustomObj>
{
private const int HintPosition = 0;
private const CustomObj HintValue = null;
private const string Hint = "Hint";
public CustomArrayAdapter(Context context, int textViewResourceId, CustomObj[] customObjs) : base(context, textViewResourceId, AddPrompt(customObjs))
{
private static CustomObj[] AddPrompt(CustomObj[] customObjs)
{
CustomObj[] customObjsWithHint = new CustomObj[customObjs.Length + 1];
CustomObj[] hintPlaceholder = { HintValue };
Array.Copy(hintPlaceholder , customObjsWithHint , 1);
Array.Copy(customObjs, 0, customObjsWithHint , 1, customObjs.Length);
return customObjsWithHint ;
}
public override Android.Views.View GetView(int position, Android.Views.View convertView, ViewGroup parent)
{
CustomObj customObj = GetItem(position);
bool isHint = customObj == HintValue;
if (convertView == null)
{
convertView = LayoutInflater.From(base.Context).Inflate(Resource.Layout.spinnerItem, parent, false);
}
TextView textView = convertView.FindViewById<TextView>(Resource.Id.spinnerText);
textView.Text = isHint ? Hint : customObj.Value;
textView.SetTextColor(isHint ? Color.Gray : Color.Black);
return convertView;
public override Android.Views.View GetDropDownView(int position, Android.Views.View convertView, ViewGroup parent)
{
CustomObj customObj = GetItem(position);
if (position == HintPosition)
{
convertView = LayoutInflater.From(base.Context).Inflate(Resource.Layout.hintSpinnerDropdownItem, parent, false);
}
else
{
convertView = LayoutInflater.From(base.Context).Inflate(Resource.Layout.spinnerItem, parent, false);
TextView textView = convertView.FindViewById<TextView>(Resource.Id.spinnerText);
textView.Text = customObj.Value;
}
return convertView;
}
}
scale fit mobile web content using viewport meta tag
I had same problem as yours, but my concern was list view. When i try to scroll list view fixed header also scroll little bit. Problem was list view height smaller than viewport (browser) height. You just need to reduce your viewport height lower than content tag (list view within content tag) height.
Here is my meta tag;
<meta name="viewport" content="width=device-width,height=90%, user-scalable = no">
Hope this will help.Thnks.
Setting focus to a textbox control
create a textbox:
<TextBox Name="tb">
..hello..
</TextBox>
focus() ---> it is used to set input focus to the textbox control
tb.focus()
jQuery date formatting
If you are using jquery ui then you may use it like below, you can specify your own date format
$.datepicker.formatDate( "D dd-M-yy", new Date()) // Output "Fri 08-Sep-2017"
running multiple bash commands with subprocess
import subprocess
cmd = "vsish -e ls /vmkModules/lsom/disks/ | cut -d '/' -f 1 | while read diskID ; do echo $diskID; vsish -e cat /vmkModules/lsom/disks/$diskID/virstoStats | grep -iE 'Delete pending |trims currently queued' ; echo '====================' ;done ;"
def subprocess_cmd(command):
process = subprocess.Popen(command,stdout=subprocess.PIPE, shell=True)
proc_stdout = process.communicate()[0].strip()
for line in proc_stdout.decode().split('\n'):
print (line)
subprocess_cmd(cmd)
"Uncaught TypeError: Illegal invocation" in Chrome
In your code you are assigning a native method to a property of custom object.
When you call support.animationFrame(function () {})
, it is executed in the context of current object (ie support). For the native requestAnimationFrame function to work properly, it must be executed in the context of window
.
So the correct usage here is support.animationFrame.call(window, function() {});
.
The same happens with alert too:
var myObj = {
myAlert : alert //copying native alert to an object
};
myObj.myAlert('this is an alert'); //is illegal
myObj.myAlert.call(window, 'this is an alert'); // executing in context of window
Another option is to use Function.prototype.bind() which is part of ES5 standard and available in all modern browsers.
var _raf = window.requestAnimationFrame ||
window.mozRequestAnimationFrame ||
window.webkitRequestAnimationFrame ||
window.msRequestAnimationFrame ||
window.oRequestAnimationFrame;
var support = {
animationFrame: _raf ? _raf.bind(window) : null
};
Difference between null and empty ("") Java String
A string can be empty or have a null
value. If a string is null
, it isn't referring to anything in memory. Try s.length()>0
. This is because if a string is empty, it still returns a length of 0. So if you enter nothing for the same, then it will still continue looping since it doesn't register the string as null
. Whereas if you check for length, then it will exit out of it's loop.
What are best practices that you use when writing Objective-C and Cocoa?
Don't use unknown strings as format strings
When methods or functions take a format string argument, you should make sure that you have control over the content of the format string.
For example, when logging strings, it is tempting to pass the string variable as the sole argument to NSLog
:
NSString *aString = // get a string from somewhere;
NSLog(aString);
The problem with this is that the string may contain characters that are interpreted as format strings. This can lead to erroneous output, crashes, and security problems. Instead, you should substitute the string variable into a format string:
NSLog(@"%@", aString);
How to see remote tags?
You can list the tags on remote repository with ls-remote
, and then check if it's there. Supposing the remote reference name is origin
in the following.
git ls-remote --tags origin
And you can list tags local with tag
.
git tag
You can compare the results manually or in script.
window.location.reload with clear cache
I wrote this javascript script and included it in the header (before anything loads). It seems to work. If the page was loaded more than one hour ago or the situation is undefined it will reload everything from server.
The time of one hour = 3600000 milliseconds can be changed in the following line:
if(alter > 3600000)
With regards,
Birke
<script type="text/javascript">
//<![CDATA[
function zeit()
{
if(document.cookie)
{
a = document.cookie;
cookiewert = "";
while(a.length > 0)
{
cookiename = a.substring(0,a.indexOf('='));
if(cookiename == "zeitstempel")
{
cookiewert = a.substring(a.indexOf('=')+1,a.indexOf(';'));
break;
}
a = a.substring(a.indexOf(cookiewert)+cookiewert.length+1,a.length);
}
if(cookiewert.length > 0)
{
alter = new Date().getTime() - cookiewert;
if(alter > 3600000)
{
document.cookie = "zeitstempel=" + new Date().getTime() + ";";
location.reload(true);
}
else
{
return;
}
}
else
{
document.cookie = "zeitstempel=" + new Date().getTime() + ";";
location.reload(true);
}
}
else
{
document.cookie = "zeitstempel=" + new Date().getTime() + ";";
location.reload(true);
}
}
zeit();
//]]>
</script>
What are the differences between git branch, fork, fetch, merge, rebase and clone?
Fork Vs. Clone - two words that both mean copy
Please see this diagram. (Originally from http://www.dataschool.io/content/images/2014/Mar/github1.png).
.-------------------------. 1. Fork .-------------------------.
| Your GitHub repo | <-------------- | Joe's GitHub repo |
| github.com/you/coolgame | | github.com/joe/coolgame |
| ----------------------- | 7. Pull Request | ----------------------- |
| master -> c224ff7 | --------------> | master -> c224ff7 (c) |
| anidea -> 884faa1 (a) | | anidea -> 884faa1 (b) |
'-------------------------' '-------------------------'
| ^
| 2. Clone |
| |
| |
| |
| |
| | 6. Push (anidea => origin/anidea)
v |
.-------------------------.
| Your computer | 3. Create branch 'anidea'
| $HOME/coolgame |
| ----------------------- | 4. Update a file
| master -> c224ff7 |
| anidea -> 884faa1 | 5. Commit (to 'anidea')
'-------------------------'
(a) - after you have pushed it
(b) - after Joe has accepted it
(c) - eventually Joe might merge 'anidea' (make 'master -> 884faa1')
Fork
- A copy to your remote repo (cloud) that links it to Joe's
- A copy you can then clone to your local repo and F*%$-up
- When you are done you can push back to your remote
- You can then ask Joe if he wants to use it in his project by clicking pull-request
Clone
- a copy to your local repo (harddrive)
ReactJS: setTimeout() not working?
setTimeout(() => {
this.setState({ position: 1 });
}, 3000);
The above would also work because the ES6 arrow function does not change the context of this
.
ReactJS - Get Height of an element
An alternative solution, in case you want to retrieve the size of a React element synchronously without having to visibly render the element, you can use ReactDOMServer and DOMParser.
I use this function to get the height of a my list item renderer when using react-window (react-virtualized) instead of having to hardcode the required itemSize
prop for a FixedSizeList.
utilities.js:
/**
* @description Common and reusable functions
*
* @requires react-dom/server
*
* @public
* @module
*
*/
import ReactDOMServer from "react-dom/server";
/**
* @description Retrieve the width and/or heigh of a React element without rendering and committing the element to the DOM.
*
* @param {object} elementJSX - The target React element written in JSX.
* @return {object}
* @public
* @function
*
* @example
*
* const { width, height } = getReactElementSize( <div style={{ width: "20px", height: "40px" }} ...props /> );
* console.log(`W: ${width}, H: ${height}); // W: 20, H: 40
*
*/
const getReactElementSize = (elementJSX) => {
const elementString = ReactDOMServer.renderToStaticMarkup(elementJSX);
const elementDocument = new DOMParser().parseFromString(elementString, "text/html");
const elementNode = elementDocument.getRootNode().body.firstChild;
const container = document.createElement("div");
const containerStyle = {
display: "block",
position: "absolute",
boxSizing: "border-box",
margin: "0",
padding: "0",
visibility: "hidden"
};
Object.assign(container.style, containerStyle);
container.appendChild(elementNode);
document.body.appendChild(container);
const width = container.clientWidth;
const height = container.clientHeight;
container.removeChild(elementNode);
document.body.removeChild(container);
return {
width,
height
};
};
/**
* Export module
*
*/
export {
getReactElementSize
};
Create a folder and sub folder in Excel VBA
I know this has been answered and there were many good answers already, but for people who come here and look for a solution I could post what I have settled with eventually.
The following code handles both paths to a drive (like "C:\Users...") and to a server address (style: "\Server\Path.."), it takes a path as an argument and automatically strips any file names from it (use "\" at the end if it's already a directory path) and it returns false if for whatever reason the folder could not be created. Oh yes, it also creates sub-sub-sub-directories, if this was requested.
Public Function CreatePathTo(path As String) As Boolean
Dim sect() As String ' path sections
Dim reserve As Integer ' number of path sections that should be left untouched
Dim cPath As String ' temp path
Dim pos As Integer ' position in path
Dim lastDir As Integer ' the last valid path length
Dim i As Integer ' loop var
' unless it all works fine, assume it didn't work:
CreatePathTo = False
' trim any file name and the trailing path separator at the end:
path = Left(path, InStrRev(path, Application.PathSeparator) - 1)
' split the path into directory names
sect = Split(path, "\")
' what kind of path is it?
If (UBound(sect) < 2) Then ' illegal path
Exit Function
ElseIf (InStr(sect(0), ":") = 2) Then
reserve = 0 ' only drive name is reserved
ElseIf (sect(0) = vbNullString) And (sect(1) = vbNullString) Then
reserve = 2 ' server-path - reserve "\\Server\"
Else ' unknown type
Exit Function
End If
' check backwards from where the path is missing:
lastDir = -1
For pos = UBound(sect) To reserve Step -1
' build the path:
cPath = vbNullString
For i = 0 To pos
cPath = cPath & sect(i) & Application.PathSeparator
Next ' i
' check if this path exists:
If (Dir(cPath, vbDirectory) <> vbNullString) Then
lastDir = pos
Exit For
End If
Next ' pos
' create subdirectories from that point onwards:
On Error GoTo Error01
For pos = lastDir + 1 To UBound(sect)
' build the path:
cPath = vbNullString
For i = 0 To pos
cPath = cPath & sect(i) & Application.PathSeparator
Next ' i
' create the directory:
MkDir cPath
Next ' pos
CreatePathTo = True
Exit Function
Error01:
End Function
I hope someone may find this useful. Enjoy! :-)
How to get Latitude and Longitude of the mobile device in android?
Use the LocationManager
.
LocationManager lm = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
Location location = lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);
double longitude = location.getLongitude();
double latitude = location.getLatitude();
The call to getLastKnownLocation()
doesn't block - which means it will return null
if no position is currently available - so you probably want to have a look at passing a LocationListener
to the requestLocationUpdates()
method instead, which will give you asynchronous updates of your location.
private final LocationListener locationListener = new LocationListener() {
public void onLocationChanged(Location location) {
longitude = location.getLongitude();
latitude = location.getLatitude();
}
}
lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 2000, 10, locationListener);
You'll need to give your application the ACCESS_FINE_LOCATION
permission if you want to use GPS.
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
You may also want to add the ACCESS_COARSE_LOCATION
permission for when GPS isn't available and select your location provider with the getBestProvider()
method.
Generate random numbers following a normal distribution in C/C++
Monte Carlo method
The most intuitive way to do this would be to use a monte carlo method. Take a suitable range -X, +X. Larger values of X will result in a more accurate normal distribution, but takes longer to converge.
a. Choose a random number z between -X to X.
b. Keep with a probability of N(z, mean, variance)
where N is the gaussian distribution. Drop otherwise and go back to step (a).
Objective-C and Swift URL encoding
//use NSString instance method like this:
+ (NSString *)encodeURIComponent:(NSString *)string
{
NSString *s = [string stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
return s;
}
+ (NSString *)decodeURIComponent:(NSString *)string
{
NSString *s = [string stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
return s;
}
remember,you should only do encode or decode for your parameter value, not all the url you request.
BackgroundWorker vs background Thread
Some of my thoughts...
- Use BackgroundWorker if you have a single task that runs in the background and needs to interact with the UI. The task of marshalling data and method calls to the UI thread are handled automatically through its event-based model. Avoid BackgroundWorker if...
- your assembly does not have or does not interact directly with the UI,
- you need the thread to be a foreground thread, or
- you need to manipulate the thread priority.
- Use a ThreadPool thread when efficiency is desired. The ThreadPool helps avoid the overhead associated with creating, starting, and stopping threads. Avoid using the ThreadPool if...
- the task runs for the lifetime of your application,
- you need the thread to be a foreground thread,
- you need to manipulate the thread priority, or
- you need the thread to have a fixed identity (aborting, suspending, discovering).
- Use the Thread class for long-running tasks and when you require features offered by a formal threading model, e.g., choosing between foreground and background threads, tweaking the thread priority, fine-grained control over thread execution, etc.
Install numpy on python3.3 - Install pip for python3
On fedora/rhel/centos you need to
sudo yum install -y python3-devel
before
mkvirtualenv -p /usr/bin/python3.3 test-3.3
pip install numpy
otherwise you'll get
SystemError: Cannot compile 'Python.h'. Perhaps you need to install python-dev|python-devel.
Apply pandas function to column to create multiple new columns?
For me this worked:
Input df
df = pd.DataFrame({'col x': [1,2,3]})
col x
0 1
1 2
2 3
Function
def f(x):
return pd.Series([x*x, x*x*x])
Create 2 new columns:
df[['square x', 'cube x']] = df['col x'].apply(f)
Output:
col x square x cube x
0 1 1 1
1 2 4 8
2 3 9 27
Input and output numpy arrays to h5py
h5py provides a model of datasets and groups. The former is basically arrays and the latter you can think of as directories. Each is named. You should look at the documentation for the API and examples:
http://docs.h5py.org/en/latest/quick.html
A simple example where you are creating all of the data upfront and just want to save it to an hdf5 file would look something like:
In [1]: import numpy as np
In [2]: import h5py
In [3]: a = np.random.random(size=(100,20))
In [4]: h5f = h5py.File('data.h5', 'w')
In [5]: h5f.create_dataset('dataset_1', data=a)
Out[5]: <HDF5 dataset "dataset_1": shape (100, 20), type "<f8">
In [6]: h5f.close()
You can then load that data back in using:
'
In [10]: h5f = h5py.File('data.h5','r')
In [11]: b = h5f['dataset_1'][:]
In [12]: h5f.close()
In [13]: np.allclose(a,b)
Out[13]: True
Definitely check out the docs:
http://docs.h5py.org
Writing to hdf5 file depends either on h5py or pytables (each has a different python API that sits on top of the hdf5 file specification). You should also take a look at other simple binary formats provided by numpy natively such as np.save
, np.savez
etc:
http://docs.scipy.org/doc/numpy/reference/routines.io.html
The term "Add-Migration" is not recognized
You have to know what is your Entity-Framework
version.
Also after that you have to check project.json
and control these sections:
In Dependencies
check:
Microsoft.EntityFrameworkCore.Tools": {
"version": "1.0.0-preview2-final",
"type": "build"
},
This section:
"version": "1.0.0-preview2-final",
is related with version of your Entity-Framework
and you have to change this with that.
After that the second section of the proj.json
is here, In the Tools
section of JSON
you have:
"Microsoft.EntityFrameworkCore.Tools": "1.0.0-preview2-final",
Also this part of code is related with your Entity-Framework
and last part of code in Dependencies section.
Note: After do this issues you should to close CMD
and restart visual studio.
Disabling SSL Certificate Validation in Spring RestTemplate
This problem is about SSL connection. When you try to connect to some resource https protocol requires to create secured connection. That means only your browser and website server know what data is being sent in requests bodies. This security is achieved by ssl certificates that stored on website and are being downloaded by your browser (or any other client, Spring RestTemplate with Apache Http Client behind in our case) with first connection to host. There are RSA256 encryption and many other cool things around. But in the end of a day: In case certificate is not registered or is invalid you will see certificate error (HTTPS connection is not secure). To fix certificate error website provider need to buy it for particular website or fix somehow e.g. https://www.register.com/ssl-certificates
Right way how problem can be solved
Not a right way how problem can be solved
- download broken SSL certificate from website
import SSL certificate to Java cacerts (certificate storage)
keytool -importcert -trustcacerts -noprompt -storepass changeit -alias citrix -keystore "C:\Program Files\Java\jdk-11.0.2\lib\security\cacerts" -file citrix.cer
Dirty (Insecure) way how problem can be solved
make RestTemplate to ignore SSL verification
@Bean
public RestTemplateBuilder restTemplateBuilder(@Autowired SSLContext sslContext) {
return new RestTemplateBuilder() {
@Override
public ClientHttpRequestFactory buildRequestFactory() {
return new HttpComponentsClientHttpRequestFactory(
HttpClients.custom().setSSLSocketFactory(
new SSLConnectionSocketFactory(sslContext
, NoopHostnameVerifier.INSTANCE)).build());
}
};
}
@Bean
public SSLContext insecureSslContext() throws KeyStoreException, NoSuchAlgorithmException, KeyManagementException {
return SSLContexts.custom()
.loadTrustMaterial(null, (x509Certificates, s) -> true)
.build();
}
Submit two forms with one button
You should be able to do this with JavaScript:
<input type="button" value="Click Me!" onclick="submitForms()" />
If your forms have IDs:
submitForms = function(){
document.getElementById("form1").submit();
document.getElementById("form2").submit();
}
If your forms don't have IDs but have names:
submitForms = function(){
document.forms["form1"].submit();
document.forms["form2"].submit();
}
Why can't I declare static methods in an interface?
I'll answer your question with an example. Suppose we had a Math class with a static method add. You would call this method like so:
Math.add(2, 3);
If Math were an interface instead of a class, it could not have any defined functions. As such, saying something like Math.add(2, 3) makes no sense.
Change event on select with knockout binding, how can I know if it is a real change?
Here is a solution that may help with this strange behaviour. I couldn't find a better solution than place a button to manually trigger the change event.
EDIT: Maybe a custom binding like this could help:
ko.bindingHandlers.changeSelectValue = {
init: function(element,valueAccessor){
$(element).change(function(){
var value = $(element).val();
if($(element).is(":focus")){
//Do whatever you want with the new value
}
});
}
};
And in your select data-bind attribute add:
changeSelectValue: yourSelectValue
Android Studio: Unable to start the daemon process
Try this... I have tried and work fine for me
This issue is related to low memory...
Close your browsers, visual Studio and other services..
after that run following command
ionic build android
it will run successfully..
//Solutions is
create "gradle.properties" file in android folder and add following line into file
org.gradle.jvmargs=-Xmx512m -XX:MaxPermSize=512m
<your project>\platforms\android\gradle.properties
You can open browser and others..
ionic build android
Now it will work fine.
How to make shadow on border-bottom?
Try:
_x000D_
_x000D_
div{_x000D_
-webkit-box-shadow:0px 1px 1px #de1dde;_x000D_
-moz-box-shadow:0px 1px 1px #de1dde;_x000D_
box-shadow:0px 1px 1px #de1dde;_x000D_
}
_x000D_
<div>wefwefwef</div>
_x000D_
_x000D_
_x000D_
It generally adds a 1px blurred shadow 1px from the bottom of the box
box-shadow: [horizontal offset] [vertical offset] [blur radius] [color];
CardView not showing Shadow in Android L
My recyclerview was slow in loading so by reading the stackoverflow.com I changed hardwareAccelerated to "false" then the elevation is not showing in the device. The I changed back to true. It works for me.
How to convert BigDecimal to Double in Java?
You can convert BigDecimal
to double
using .doubleValue()
. But believe me, don't use it if you have currency manipulations. It should always be performed on BigDecimal
objects directly. Precision loss in these calculations are big time problems in currency related calculations.
Why can't decimal numbers be represented exactly in binary?
In the equation
2^x = y ;
x = log(y) / log(2)
Hence, I was just wondering if we could have a logarithmic base system for binary like,
2^1, 2^0, 2^(log(1/2) / log(2)), 2^(log(1/4) / log(2)), 2^(log(1/8) / log(2)),2^(log(1/16) / log(2)) ........
That might be able to solve the problem, so if you wanted to write something like 32.41 in binary, that would be
2^5 + 2^(log(0.4) / log(2)) + 2^(log(0.01) / log(2))
Or
2^5 + 2^(log(0.41) / log(2))
How can I insert binary file data into a binary SQL field using a simple insert statement?
If you mean using a literal, you simply have to create a binary string:
insert into Files (FileId, FileData) values (1, 0x010203040506)
And you will have a record with a six byte value for the FileData field.
You indicate in the comments that you want to just specify the file name, which you can't do with SQL Server 2000 (or any other version that I am aware of).
You would need a CLR stored procedure to do this in SQL Server 2005/2008 or an extended stored procedure (but I'd avoid that at all costs unless you have to) which takes the filename and then inserts the data (or returns the byte string, but that can possibly be quite long).
In regards to the question of only being able to get data from a SP/query, I would say the answer is yes, because if you give SQL Server the ability to read files from the file system, what do you do when you aren't connected through Windows Authentication, what user is used to determine the rights? If you are running the service as an admin (God forbid) then you can have an elevation of rights which shouldn't be allowed.
Unable to create migrations after upgrading to ASP.NET Core 2.0
In my case, the cause of the problem was multiple startup projects. I have three projects in my solution: Mvc, Api, and Dal. DbContext and Migrations in the Dal project.
I had configured multiple startup projects. Both Mvc and Api projects were running when I clicked Start. But in this case I was getting this error.
"Unable to create an object of type 'MyContext'. Add an implementation
of 'IDesignTimeDbContextFactory' to the project, or see
https://go.microsoft.com/fwlink/?linkid=851728 for additional patterns
supported at design time."
I could successfully add migration after setting Mvc as the only startup project and selecting Dal in the Package Manager Console.
Could not install Gradle distribution from 'https://services.gradle.org/distributions/gradle-2.1-all.zip'
It also disturb me a lot but now it is fine
The solution is very simple (written blow) [window (android studio)]
- go to C:\Users\your user name.gradle
- open wrapper/dists and delete the folder that is distrubing you in my case --gradle-6.5--
- then go back to .gradle folder and this time open daemon folder and delete the folder with same number that is disturbing you in my case --6.5--
- Then again go back to .gradle folder and this time open caches folder and delete the folder with same number that is disturbing you in my case --6.5--
- now if your android studio is open then close it and again start it but this time with administrator mode by right clicking on the icon of android studio icon it is important
- you should have internet connection and now your android studio will setup every thing by its own (please don't distrub it while it is doing its operation)
How to resolve the error on 'react-native start'
All mentioned comments above are great, sharing the path that worked with me for this Blacklist file that need to be edited:
"Your project name\node_modules\metro-bundler\src" File name "blacklist.js"
How do you create a Swift Date object?
According to Apple's Data Formatting Guide
Creating a date formatter is not a cheap operation. If you are likely
to use a formatter frequently, it is typically more efficient to cache
a single instance than to create and dispose of multiple instances.
One approach is to use a static variable
And while I agree with @Leon that this should be failable initializer, when you enter seed data, we could have one that isn't failable (just like there is UIImage(imageLiteralResourceName:)
).
So here's my approach:
extension DateFormatter {
static let yyyyMMdd: DateFormatter = {
let formatter = DateFormatter()
formatter.dateFormat = "yyyy-MM-dd"
formatter.calendar = Calendar(identifier: .iso8601)
formatter.timeZone = TimeZone(secondsFromGMT: 0)
formatter.locale = Locale(identifier: "en_US_POSIX")
return formatter
}()
}
extension Date {
init?(yyyyMMdd: String) {
guard let date = DateFormatter.yyyyMMdd.date(from: yyyyMMdd) else { return nil }
self.init(timeInterval: 0, since: date)
}
init(dateLiteralString yyyyMMdd: String) {
let date = DateFormatter.yyyyMMdd.date(from: yyyyMMdd)!
self.init(timeInterval: 0, since: date)
}
}
And now enjoy simply calling:
// For seed data
Date(dateLiteralString: "2020-03-30")
// When parsing data
guard let date = Date(yyyyMMdd: "2020-03-30") else { return nil }
adb uninstall failed
You have the name of the apk and not the package name:
You should first know the package name. Fot this tape:
adb shel pm list packages
Once you have the package name (be carefull, package name is like com.intel.... and not package:com.intel...), tape:
adb shell pm uninstall -k "package_name"
and Bingo!
Setting the default ssh key location
If you are only looking to point to a different location for you identity file, the you can modify your ~/.ssh/config file with the following entry:
IdentityFile ~/.foo/identity
man ssh_config
to find other config options.
Importing class/java files in Eclipse
I had the same problem. But What I did is I imported the .java files and then I went to Search->File-> and then changed the package name to whatever package it should belong in this way I fixed a lot of java files which otherwise would require to go to every file and change them manually.
HTML5 iFrame Seamless Attribute
iO8 has removed support for the iframe seamless attribute.
- Tested in Safari, HomeScreen, new WKWebView and UIWebView.
Full Details and performance review of other iOS 8 changes:
HintPath vs ReferencePath in Visual Studio
My own experience has been that it's best to stick to one of two kinds of assembly references:
- A 'local' assembly in the current build directory
- An assembly in the GAC
I've found (much like you've described) other methods to either be too easily broken or have annoying maintenance requirements.
Any assembly I don't want to GAC, has to live in the execution directory. Any assembly that isn't or can't be in the execution directory I GAC (managed by automatic build events).
This hasn't given me any problems so far. While I'm sure there's a situation where it won't work, the usual answer to any problem has been "oh, just GAC it!". 8 D
Hope that helps!
Difference between _self, _top, and _parent in the anchor tag target attribute
Below is an image showing nested frames and the effect of different target values, followed by an explanation of the image.
Imagine a webpage containing 3 nested <iframe>
aka "frame"/"frameset". So:
- the outermost webpage/browser is the starting context
- the outermost webpage is the parent of frame 3
- frame 3 is the parent of frame 2
- frame 2 is the parent of frame 1
- frame 1 is the innermost frame
Then target attributes have these effects:
- If frame 1 has a link with
target="_self"
, the link targets frame 1 (i.e. the link targets the frame containing the link (i.e. targets itself))
- If frame 1 has a link with
target="_parent"
, the link targets frame 2 (i.e. the link targets the parent frame)
- If frame 1 has a link with
target="_top"
, the link targets the initial webpage (i.e. the link targets the topmost/outermost frame; (in this case; the link skips past the grandparent frame 3))
- If frame 2 has a link with
target="_top"
, the link also targets the initial webpage (i.e. again, the link targets the topmost/outermost frame)
- If any of these frames has a link with
target="_blank"
, the link targets an auxiliary browsing context, aka a "new window"/"new tab"
How to read input with multiple lines in Java
A lot of student exercises use Scanner
because it has a variety of methods to parse numbers. I usually just start with an idiomatic line-oriented filter:
import java.io.*;
public class FilterLine {
public static void main(String[] args) throws IOException {
BufferedReader in = new BufferedReader(
new InputStreamReader(System.in));
String s;
while ((s = in.readLine()) != null) {
System.out.println(s);
}
}
}
AngularJS - $http.post send data as json
i think the most proper way is to use the same piece of code angular use when doing a "get" request using you $httpParamSerializer
will have to inject it to your controller so you can simply do the following without having to use Jquery at all , $http.post(url,$httpParamSerializer({param:val}))
app.controller('ctrl',function($scope,$http,$httpParamSerializer){
$http.post(url,$httpParamSerializer({param:val,secondParam:secondVal}));
}
Why does DEBUG=False setting make my django Static Files Access fail?
Although it's not safest, but you can change in the source code. navigate to Python/2.7/site-packages/django/conf/urls/static.py
Then edit like following:
if settings.DEBUG or (prefix and '://' in prefix):
So then if settings.debug==False
it won't effect on the code, also after running try python manage.py runserver --runserver
to run static files.
NOTE: Information should only be used for testing only
How do I store and retrieve a blob from sqlite?
This worked fine for me (C#):
byte[] iconBytes = null;
using (var dbConnection = new SQLiteConnection(DataSource))
{
dbConnection.Open();
using (var transaction = dbConnection.BeginTransaction())
{
using (var command = new SQLiteCommand(dbConnection))
{
command.CommandText = "SELECT icon FROM my_table";
using (var reader = command.ExecuteReader())
{
while (reader.Read())
{
if (reader["icon"] != null && !Convert.IsDBNull(reader["icon"]))
{
iconBytes = (byte[]) reader["icon"];
}
}
}
}
transaction.Commit();
}
}
No need for chunking. Just cast to a byte array.