Getting assembly name
You can use the AssemblyName class to get the assembly name, provided you have the full name for the assembly:
AssemblyName.GetAssemblyName(Assembly.GetExecutingAssembly().FullName).Name
or
AssemblyName.GetAssemblyName(e.Source).Name
Can I automatically increment the file build version when using Visual Studio?
Each time I do a build it auto-increments the least-significant digit.
I don't have any idea how to update the others, but you should at least be seeing that already...
Equivalent to AssemblyInfo in dotnet core/csproj
Adding to NightOwl888's answer, you can go one step further and add an AssemblyInfo class rather than just a plain class:
How to download Visual Studio Community Edition 2015 (not 2017)
You can use these links to download Visual Studio 2015
Community Edition:
And for anyone in the future who might be looking for the other editions here are the links for them as well:
Professional Edition:
Enterprise Edition:
Adding an img element to a div with javascript
It should be:
document.getElementById("placehere").appendChild(elem);
And place your div before your javascript, because if you don't, the javascript executes before the div exists. Or wait for it to load. So your code looks like this:
<html>
<body>
<script type="text/javascript">
window.onload=function(){
var elem = document.createElement("img");
elem.setAttribute("src", "http://img.zohostatic.com/discussions/v1/images/defaultPhoto.png");
elem.setAttribute("height", "768");
elem.setAttribute("width", "1024");
elem.setAttribute("alt", "Flower");
document.getElementById("placehere").appendChild(elem);
}
</script>
<div id="placehere">
</div>
</body>
</html>
To prove my point, see this with the onload and this without the onload. Fire up the console and you'll find an error stating that the div doesn't exist or cannot find appendChild method of null.
Is there a sleep function in JavaScript?
function sleep(delay) {
var start = new Date().getTime();
while (new Date().getTime() < start + delay);
}
This code blocks for the specified duration. This is CPU hogging code. This is different from a thread blocking itself and releasing CPU cycles to be utilized by another thread. No such thing is going on here. Do not use this code, it's a very bad idea.
Calculating frames per second in a game
This is what I have used in many games.
#define MAXSAMPLES 100
int tickindex=0;
int ticksum=0;
int ticklist[MAXSAMPLES];
/* need to zero out the ticklist array before starting */
/* average will ramp up until the buffer is full */
/* returns average ticks per frame over the MAXSAMPLES last frames */
double CalcAverageTick(int newtick)
{
ticksum-=ticklist[tickindex]; /* subtract value falling off */
ticksum+=newtick; /* add new value */
ticklist[tickindex]=newtick; /* save new value so it can be subtracted later */
if(++tickindex==MAXSAMPLES) /* inc buffer index */
tickindex=0;
/* return average */
return((double)ticksum/MAXSAMPLES);
}
How to write DataFrame to postgres table?
Faster option:
The following code will copy your Pandas DF to postgres DB much faster than df.to_sql method and you won't need any intermediate csv file to store the df.
Create an engine based on your DB specifications.
Create a table in your postgres DB that has equal number of columns as the Dataframe (df).
Data in DF will get inserted in your postgres table.
from sqlalchemy import create_engine
import psycopg2
import io
if you want to replace the table, we can replace it with normal to_sql method using headers from our df and then load the entire big time consuming df into DB.
engine = create_engine('postgresql+psycopg2://username:password@host:port/database')
df.head(0).to_sql('table_name', engine, if_exists='replace',index=False) #drops old table and creates new empty table
conn = engine.raw_connection()
cur = conn.cursor()
output = io.StringIO()
df.to_csv(output, sep='\t', header=False, index=False)
output.seek(0)
contents = output.getvalue()
cur.copy_from(output, 'table_name', null="") # null values become ''
conn.commit()
re.sub erroring with "Expected string or bytes-like object"
I suppose better would be to use re.match() function. here is an example which may help you.
import re
import nltk
from nltk.tokenize import word_tokenize
nltk.download('punkt')
sentences = word_tokenize("I love to learn NLP \n 'a :(")
#for i in range(len(sentences)):
sentences = [word.lower() for word in sentences if re.match('^[a-zA-Z]+', word)]
sentences
Wait for Angular 2 to load/resolve model before rendering view/template
Try {{model?.person.name}} this should wait for model to not be undefined and then render.
Angular 2 refers to this ?. syntax as the Elvis operator. Reference to it in the documentation is hard to find so here is a copy of it in case they change/move it:
The Elvis Operator ( ?. ) and null property paths
The Angular “Elvis” operator ( ?. ) is a fluent and convenient way to guard against null and undefined values in property paths. Here it is, protecting against a view render failure if the currentHero is null.
The current hero's name is {{currentHero?.firstName}}Let’s elaborate on the problem and this particular solution.
What happens when the following data bound title property is null?
The title is {{ title }}The view still renders but the displayed value is blank; we see only "The title is" with nothing after it. That is reasonable behavior. At least the app doesn't crash.
Suppose the template expression involves a property path as in this next example where we’re displaying the firstName of a null hero.
The null hero's name is {{nullHero.firstName}}JavaScript throws a null reference error and so does Angular:
TypeError: Cannot read property 'firstName' of null in [null]Worse, the entire view disappears.
We could claim that this is reasonable behavior if we believed that the hero property must never be null. If it must never be null and yet it is null, we've made a programming error that should be caught and fixed. Throwing an exception is the right thing to do.
On the other hand, null values in the property path may be OK from time to time, especially when we know the data will arrive eventually.
While we wait for data, the view should render without complaint and the null property path should display as blank just as the title property does.
Unfortunately, our app crashes when the currentHero is null.
We could code around that problem with NgIf
<!--No hero, div not displayed, no error --><div *ngIf="nullHero">The null hero's name is {{nullHero.firstName}}</div>Or we could try to chain parts of the property path with &&, knowing that the expression bails out when it encounters the first null.
The null hero's name is {{nullHero && nullHero.firstName}}These approaches have merit but they can be cumbersome, especially if the property path is long. Imagine guarding against a null somewhere in a long property path such as a.b.c.d.
The Angular “Elvis” operator ( ?. ) is a more fluent and convenient way to guard against nulls in property paths. The expression bails out when it hits the first null value. The display is blank but the app keeps rolling and there are no errors.
<!-- No hero, no problem! -->The null hero's name is {{nullHero?.firstName}}It works perfectly with long property paths too:
a?.b?.c?.d
You cannot call a method on a null-valued expression
The simple answer for this one is that you have an undeclared (null) variable. In this case it is $md5. From the comment you put this needed to be declared elsewhere in your code
$md5 = new-object -TypeName System.Security.Cryptography.MD5CryptoServiceProvider
The error was because you are trying to execute a method that does not exist.
PS C:\Users\Matt> $md5 | gm
TypeName: System.Security.Cryptography.MD5CryptoServiceProvider
Name MemberType Definition
---- ---------- ----------
Clear Method void Clear()
ComputeHash Method byte[] ComputeHash(System.IO.Stream inputStream), byte[] ComputeHash(byte[] buffer), byte[] ComputeHash(byte[] buffer, int offset, ...
The .ComputeHash() of $md5.ComputeHash() was the null valued expression. Typing in gibberish would create the same effect.
PS C:\Users\Matt> $bagel.MakeMeABagel()
You cannot call a method on a null-valued expression.
At line:1 char:1
+ $bagel.MakeMeABagel()
+ ~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidOperation: (:) [], RuntimeException
+ FullyQualifiedErrorId : InvokeMethodOnNull
PowerShell by default allows this to happen as defined its StrictMode
When Set-StrictMode is off, uninitialized variables (Version 1) are assumed to have a value of 0 (zero) or $Null, depending on type. References to non-existent properties return $Null, and the results of function syntax that is not valid vary with the error. Unnamed variables are not permitted.
The type arguments for method cannot be inferred from the usage
Now my aim was to have one pair with an base type and a type definition (Requirement A). For the type definition I want to use inheritance (Requirement B). The use should be possible, without explicite knowledge over the base type (Requirement C).
After I know now that the gernic constraints are not used for solving the generic return type, I experimented a little bit:
Ok let's introducte Get2:
class ServiceGate
{
public IAccess<C, T> Get1<C, T>(C control) where C : ISignatur<T>
{
throw new NotImplementedException();
}
public IAccess<ISignatur<T>, T> Get2<T>(ISignatur<T> control)
{
throw new NotImplementedException();
}
}
class Test
{
static void Main()
{
ServiceGate service = new ServiceGate();
//var bla1 = service.Get1(new Signatur()); // CS0411
var bla = service.Get2(new Signatur()); // Works
}
}
Fine, but this solution reaches not requriement B.
Next try:
class ServiceGate
{
public IAccess<C, T> Get3<C, T>(C control, ISignatur<T> iControl) where C : ISignatur<T>
{
throw new NotImplementedException();
}
}
class Test
{
static void Main()
{
ServiceGate service = new ServiceGate();
//var bla1 = service.Get1(new Signatur()); // CS0411
var bla = service.Get2(new Signatur()); // Works
var c = new Signatur();
var bla3 = service.Get3(c, c); // Works!!
}
}
Nice! Now the compiler can infer the generic return types. But i don't like it. Other try:
class IC<A, B>
{
public IC(A a, B b)
{
Value1 = a;
Value2 = b;
}
public A Value1 { get; set; }
public B Value2 { get; set; }
}
class Signatur : ISignatur<bool>
{
public string Test { get; set; }
public IC<Signatur, ISignatur<bool>> Get()
{
return new IC<Signatur, ISignatur<bool>>(this, this);
}
}
class ServiceGate
{
public IAccess<C, T> Get4<C, T>(IC<C, ISignatur<T>> control) where C : ISignatur<T>
{
throw new NotImplementedException();
}
}
class Test
{
static void Main()
{
ServiceGate service = new ServiceGate();
//var bla1 = service.Get1(new Signatur()); // CS0411
var bla = service.Get2(new Signatur()); // Works
var c = new Signatur();
var bla3 = service.Get3(c, c); // Works!!
var bla4 = service.Get4((new Signatur()).Get()); // Better...
}
}
My final solution is to have something like ISignature<B, C>, where B ist the base type and C the definition...
Find the index of a char in string?
Contanis occur if using the method of the present letter, and store the corresponding number using the IndexOf method, see example below.
Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
Dim myString As String = "abcdef"
Dim numberString As String = String.Empty
If myString.Contains("d") Then
numberString = myString.IndexOf("d")
End If
End Sub
Another sample with TextBox
Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
Dim myString As String = "abcdef"
Dim numberString As String = String.Empty
If myString.Contains(me.TextBox1.Text) Then
numberString = myString.IndexOf(Me.TextBox1.Text)
End If
End Sub
Regards
Getting time span between two times in C#?
string startTime = "7:00 AM";
string endTime = "2:00 PM";
TimeSpan duration = DateTime.Parse(endTime).Subtract(DateTime.Parse(startTime));
Console.WriteLine(duration);
Console.ReadKey();
Will output: 07:00:00.
It also works if the user input military time:
string startTime = "7:00";
string endTime = "14:00";
TimeSpan duration = DateTime.Parse(endTime).Subtract(DateTime.Parse(startTime));
Console.WriteLine(duration);
Console.ReadKey();
Outputs: 07:00:00.
To change the format: duration.ToString(@"hh\:mm")
More info at: http://msdn.microsoft.com/en-us/library/ee372287.aspx
Addendum:
Over the years it has somewhat bothered me that this is the most popular answer I have ever given; the original answer never actually explained why the OP's code didn't work despite the fact that it is perfectly valid. The only reason it gets so many votes is because the post comes up on Google when people search for a combination of the terms "C#", "timespan", and "between".
How can I use the MS JDBC driver with MS SQL Server 2008 Express?
You can try the following. Works fine in my case:
- Download the current jTDS JDBC Driver
- Put jtds-x.x.x.jar in your classpath.
- Copy ntlmauth.dll to windows/system32. Choose the dll based on your hardware x86,x64...
- The connection url is: 'jdbc:jtds:sqlserver://localhost:1433/YourDB' , you don't have to provide username and password.
Hope that helps.
Any reason to prefer getClass() over instanceof when generating .equals()?
Correct me if I am wrong, but getClass() will be useful when you want to make sure your instance is NOT a subclass of the class you are comparing with. If you use instanceof in that situation you can NOT know that because:
class A { }
class B extends A { }
Object oA = new A();
Object oB = new B();
oA instanceof A => true
oA instanceof B => false
oB instanceof A => true // <================ HERE
oB instanceof B => true
oA.getClass().equals(A.class) => true
oA.getClass().equals(B.class) => false
oB.getClass().equals(A.class) => false // <===============HERE
oB.getClass().equals(B.class) => true
Formatting floats in a numpy array
In order to make numpy display float arrays in an arbitrary format, you can define a custom function that takes a float value as its input and returns a formatted string:
In [1]: float_formatter = "{:.2f}".format
The f here means fixed-point format (not 'scientific'), and the .2 means two decimal places (you can read more about string formatting here).
Let's test it out with a float value:
In [2]: float_formatter(1.234567E3)
Out[2]: '1234.57'
To make numpy print all float arrays this way, you can pass the formatter= argument to np.set_printoptions:
In [3]: np.set_printoptions(formatter={'float_kind':float_formatter})
Now numpy will print all float arrays this way:
In [4]: np.random.randn(5) * 10
Out[4]: array([5.25, 3.91, 0.04, -1.53, 6.68]
Note that this only affects numpy arrays, not scalars:
In [5]: np.pi
Out[5]: 3.141592653589793
It also won't affect non-floats, complex floats etc - you will need to define separate formatters for other scalar types.
You should also be aware that this only affects how numpy displays float values - the actual values that will be used in computations will retain their original precision.
For example:
In [6]: a = np.array([1E-9])
In [7]: a
Out[7]: array([0.00])
In [8]: a == 0
Out[8]: array([False], dtype=bool)
numpy prints a as if it were equal to 0, but it is not - it still equals 1E-9.
If you actually want to round the values in your array in a way that affects how they will be used in calculations, you should use np.round, as others have already pointed out.
Pass an array of integers to ASP.NET Web API?
I have created a custom model binder which converts any comma separated values (only primitive, decimal, float, string) to their corresponding arrays.
public class CommaSeparatedToArrayBinder<T> : IModelBinder
{
public bool BindModel(HttpActionContext actionContext, ModelBindingContext bindingContext)
{
Type type = typeof(T);
if (type.IsPrimitive || type == typeof(Decimal) || type == typeof(String) || type == typeof(float))
{
ValueProviderResult val = bindingContext.ValueProvider.GetValue(bindingContext.ModelName);
if (val == null) return false;
string key = val.RawValue as string;
if (key == null) { bindingContext.ModelState.AddModelError(bindingContext.ModelName, "Wrong value type"); return false; }
string[] values = key.Split(',');
IEnumerable<T> result = this.ConvertToDesiredList(values).ToArray();
bindingContext.Model = result;
return true;
}
bindingContext.ModelState.AddModelError(bindingContext.ModelName, "Only primitive, decimal, string and float data types are allowed...");
return false;
}
private IEnumerable<T> ConvertToDesiredArray(string[] values)
{
foreach (string value in values)
{
var val = (T)Convert.ChangeType(value, typeof(T));
yield return val;
}
}
}
And how to use in Controller:
public IHttpActionResult Get([ModelBinder(BinderType = typeof(CommaSeparatedToArrayBinder<int>))] int[] ids)
{
return Ok(ids);
}
Can (domain name) subdomains have an underscore "_" in it?
Recently the CAB-forum (*) decided that
All certificates containing an underscore character in any dNSName entry and having a validity period of more than 30 days MUST be revoked prior to January 15, 2019. https://cabforum.org/2018/11/12/ballot-sc-12-sunset-of-underscores-in-dnsnames/
This means that you are no longer allowed to use underscores in domains that will have a ssl/tls certificate.
(*) The Certification Authority Browser Forum (CA/Browser Forum) is a voluntary gathering of leading Certificate Issuers (as defined in Section 2.1(a)(1) and (2) below) and vendors of Internet browser software and other applications that use certificates (Certificate Consumers, as defined in Section 2.1(a)(3) below).
sum two columns in R
It could be that one or two of your columns may have a factor in them, or what is more likely is that your columns may be formatted as factors. Please would you give str(col1) and str(col2) a try? That should tell you what format those columns are in.
I am unsure if you're trying to add the rows of a column to produce a new column or simply all of the numbers in both columns to get a single number.
ValueError: setting an array element with a sequence
In my case, the problem was another. I was trying convert lists of lists of int to array. The problem was that there was one list with a different length than others. If you want to prove it, you must do:
print([i for i,x in enumerate(list) if len(x) != 560])
In my case, the length reference was 560.
Add bottom line to view in SwiftUI / Swift / Objective-C / Xamarin
import UIkit
extension UITextField
{
func underlinedLogin()
{
let border = CALayer()
let width = CGFloat(1.0)
border.borderColor = UIColor.black.cgColor
border.frame = CGRect(x: 0, y: self.frame.size.height - width, width: self.frame.size.width, height: self.frame.size.height)
border.borderWidth = width
self.layer.addSublayer(border)
self.layer.masksToBounds = true
}
}
call method on viewdidload
mobileNumberTextField.underlinedLogin()
passwordTextField.underlinedLogin()
//select like text field on mainstoryboard
How to get diff between all files inside 2 folders that are on the web?
You urls are not in the same repository, so you can't do it with the svn diff command.
svn: 'http://svn.boost.org/svn/boost/sandbox/boost/extension' isn't in the same repository as 'http://cloudobserver.googlecode.com/svn'
Another way you could do it, is export each repos using svn export, and then use the diff command to compare the 2 directories you exported.
// Export repositories
svn export http://svn.boost.org/svn/boost/sandbox/boost/extension/ repos1
svn export http://cloudobserver.googlecode.com/svn/branches/v0.4/Boost.Extension.Tutorial/libs/boost/extension/ repos2
// Compare exported directories
diff repos1 repos2 > file.diff
Reading a text file and splitting it into single words in python
Here is my totally functional approach which avoids having to read and split lines. It makes use of the itertools module:
Note for python 3, replace itertools.imap with map
import itertools
def readwords(mfile):
byte_stream = itertools.groupby(
itertools.takewhile(lambda c: bool(c),
itertools.imap(mfile.read,
itertools.repeat(1))), str.isspace)
return ("".join(group) for pred, group in byte_stream if not pred)
Sample usage:
>>> import sys
>>> for w in readwords(sys.stdin):
... print (w)
...
I really love this new method of reading words in python
I
really
love
this
new
method
of
reading
words
in
python
It's soo very Functional!
It's
soo
very
Functional!
>>>
I guess in your case, this would be the way to use the function:
with open('words.txt', 'r') as f:
for word in readwords(f):
print(word)
Grant execute permission for a user on all stored procedures in database?
USE [DATABASE]
DECLARE @USERNAME VARCHAR(500)
DECLARE @STRSQL NVARCHAR(MAX)
SET @USERNAME='[USERNAME] '
SET @STRSQL=''
select @STRSQL+=CHAR(13)+'GRANT EXECUTE ON ['+ s.name+'].['+obj.name+'] TO'+@USERNAME+';'
from
sys.all_objects as obj
inner join
sys.schemas s ON obj.schema_id = s.schema_id
where obj.type in ('P','V','FK')
AND s.NAME NOT IN ('SYS','INFORMATION_SCHEMA')
EXEC SP_EXECUTESQL @STRSQL
How to implement private method in ES6 class with Traceur
I came up with what I feel is a much better solution allowing:
no need for 'this._', that/self, weakmaps, symbols etc. Clear and straightforward 'class' code
private variables and methods are really private and have the correct 'this' binding
No use of 'this' at all which means clear code that is much less error prone
public interface is clear and separated from the implementation as a proxy to private methods
allows easy composition
with this you can do:
function Counter() {_x000D_
// public interface_x000D_
const proxy = {_x000D_
advance, // advance counter and get new value_x000D_
reset, // reset value_x000D_
value // get value_x000D_
}_x000D_
_x000D_
// private variables and methods_x000D_
let count=0;_x000D_
_x000D_
function advance() {_x000D_
return ++count;_x000D_
}_x000D_
_x000D_
function reset(newCount) {_x000D_
count=(newCount || 0);_x000D_
}_x000D_
_x000D_
function value() {_x000D_
return count;_x000D_
}_x000D_
_x000D_
return proxy;_x000D_
}_x000D_
_x000D_
let counter=Counter.New();_x000D_
console.log(counter instanceof Counter); // true_x000D_
counter.reset(100);_x000D_
console.log('Counter next = '+counter.advance()); // 101_x000D_
console.log(Object.getOwnPropertyNames(counter)); // ["advance", "reset", "value"]<script src="https://cdn.rawgit.com/kofifus/New/7987670c/new.js"></script>see New for the code and more elaborate examples including constructor and composition
Find duplicate values in R
A terser way, either with rev :
x[!(!duplicated(x) & rev(!duplicated(rev(x))))]
... rather than fromLast:
x[!(!duplicated(x) & !duplicated(x, fromLast = TRUE))]
... and as a helper function to provide either logical vector or elements from original vector :
duplicates <- function(x, as.bool = FALSE) {
is.dup <- !(!duplicated(x) & rev(!duplicated(rev(x))))
if (as.bool) { is.dup } else { x[is.dup] }
}
Treating vectors as data frames to pass to table is handy but can get difficult to read, and the data.table solution is fine but I'd prefer base R solutions for dealing with simple vectors like IDs.
What does "@" mean in Windows batch scripts
In batch file:
1 @echo off(solo)=>output nothing
2 echo off(solo)=> the “echo off” shows in the command line
3 echo off(then echo something) =>
4 @echo off(then echo something)=>
See, echo off(solo), means no output in the command line, but itself shows; @echo off(solo), means no output in the command line, neither itself;
What is the most efficient way to concatenate N arrays?
where 'n' is some number of arrays, maybe an array of arrays . . .
var answer = _.reduce(n, function(a, b){ return a.concat(b)})
VBA (Excel) Initialize Entire Array without Looping
I want to initialize every single element of the array to some initial value. So if I have an array Dim myArray(300) As Integer of 300 integers, for example, all 300 elements would hold the same initial value (say, the number 13).
Can anyone explain how to do this, without looping? I'd like to do it in one statement if possible.
What do I win?
Sub SuperTest()
Dim myArray
myArray = Application.Transpose([index(Row(1:300),)-index(Row(1:300),)+13])
End Sub
What are the differences between stateless and stateful systems, and how do they impact parallelism?
A stateful server keeps state between connections. A stateless server does not.
So, when you send a request to a stateful server, it may create some kind of connection object that tracks what information you request. When you send another request, that request operates on the state from the previous request. So you can send a request to "open" something. And then you can send a request to "close" it later. In-between the two requests, that thing is "open" on the server.
When you send a request to a stateless server, it does not create any objects that track information regarding your requests. If you "open" something on the server, the server retains no information at all that you have something open. A "close" operation would make no sense, since there would be nothing to close.
HTTP and NFS are stateless protocols. Each request stands on its own.
Sometimes cookies are used to add some state to a stateless protocol. In HTTP (web pages), the server sends you a cookie and then the browser holds the state, only to send it back to the server on a subsequent request.
SMB is a stateful protocol. A client can open a file on the server, and the server may deny other clients access to that file until the client closes it.
Change visibility of ASP.NET label with JavaScript
This is the easiest way I found:
BtnUpload.Style.Add("display", "none");
FileUploader.Style.Add("display", "none");
BtnAccept.Style.Add("display", "inherit");
BtnClear.Style.Add("display", "inherit");
I have the opposite in the Else, so it handles displaying them as well. This can go in the Page's Load or in a method to refresh the controls on the page.
Vendor code 17002 to connect to SQLDeveloper
I encountered same problem with ORACLE 11G express on Windows. After a long time waiting I got the same error message.
My solution is to make sure the hostname in tnsnames.ora (usually it's not "localhost") and the default hostname in sql developer(usually it's "localhost") same. You can either do this by changing it in the tnsnames.ora, or filling up the same in the sql developer.
Oh, of course you need to reboot all the oracle services (just to be safe).
Hope it helps.
I came across the similar problem again on another machine, but this time above solution doesn't work. After some trying, I found restarting all the oracle related services can fix the problem. Originally when the installation is done, connection can be made. Somehow after several reboot of computer, there is problem. I change all the oracle services with start time as auto. And once I could not connect, I restart them all over again (the core service should be restarted at last order), and works fine.
Some article says it might be due to the MTS problem. Microsoft's problem. Maybe!
How do you overcome the HTML form nesting limitation?
I went around the issue by including a checkbox depending on what form the person wanted to do. Then used 1 button to submit the whole form.
AJAX cross domain call
after doing some research, the only "solution" to this problem is to call:
if($.browser.mozilla)
netscape.security.PrivilegeManager.enablePrivilege('UniversalBrowserRead');
this will ask an user if he allows a website to continue. After he confirmed that, all ajax calls regardless of it's datatype will get executed.
This works for mozilla browsers, in IE < 8, an user has to allow a cross domain call in a similar way, some version need to get configured within browser options.
chrome/safari: I didn't find a config flag for those browsers so far.
using JSONP as datatype would be nice, but in my case I don't know if a domain I need to access supports data in that format.
Another shot is to use HTML5 postMessage which works cross-domain aswell, but I can't afford to doom my users to HTML5 browsers.
Delete all lines starting with # or ; in Notepad++
Find:
^[#;].*
Replace with nothing. The ^ indicates the start of a line, the [#;] is a character class to match either # or ;, and .* matches anything else in the line.
In versions of Notepad++ before 6.0, you won't be able to actually remove the lines due to a limitation in its regex engine; the replacement results in blank lines for each line matched. In other words, this:
# foo ; bar statement;
Will turn into:
statement;
However, the replacement will work in Notepad++ 6.0 if you add \r, \n or \r\n to the end of the pattern, depending on which line ending your file is using, resulting in:
statement;
C# find biggest number
Use Math.Max:
int x = 3, y = 4, z = 5;
Console.WriteLine(Math.Max(Math.Max(x, y), z));
Python sockets error TypeError: a bytes-like object is required, not 'str' with send function
An alternative solution is to introduce a method to the file instance that would do the explicit conversion.
import types
def _write_str(self, ascii_str):
self.write(ascii_str.encode('ascii'))
source_file = open("myfile.bin", "wb")
source_file.write_str = types.MethodType(_write_str, source_file)
And then you can use it as source_file.write_str("Hello World").
getFilesDir() vs Environment.getDataDirectory()
Try this
getExternalFilesDir(Environment.getDataDirectory().getAbsolutePath()).getAbsolutePath()
Python pandas: fill a dataframe row by row
df['y'] will set a column
since you want to set a row, use .loc
Note that .ix is equivalent here, yours failed because you tried to assign a dictionary
to each element of the row y probably not what you want; converting to a Series tells pandas
that you want to align the input (for example you then don't have to to specify all of the elements)
In [7]: df = pandas.DataFrame(columns=['a','b','c','d'], index=['x','y','z'])
In [8]: df.loc['y'] = pandas.Series({'a':1, 'b':5, 'c':2, 'd':3})
In [9]: df
Out[9]:
a b c d
x NaN NaN NaN NaN
y 1 5 2 3
z NaN NaN NaN NaN
How can I make a DateTimePicker display an empty string?
In case anybody has an issue with setting datetimepicker control to blank during the form load event, and then show the current date as needed, here is an example:
MAKE SURE THAT CustomFormat = " " has same number of spaces (at least one space) in both methods
Private Sub setDateTimePickerBlank(ByVal dateTimePicker As DateTimePicker)
dateTimePicker.Visible = True
dateTimePicker.Format = DateTimePickerFormat.Custom
dateTimePicker.CustomFormat = " "
End Sub
Private Sub dateTimePicker_MouseHover(ByVal sender As Object, ByVal e As
System.EventArgs) Handles dateTimePicker.MouseHover
Dim dateTimePicker As DateTimePicker = CType(sender, DateTimePicker)
If dateTimePicker.Text = " " Then
dateTimePicker.Text = Format(DateTime.Now, "MM/dd/yyyy")
End If
End Sub
How can I pass a reference to a function, with parameters?
The following is equivalent to your second code block:
var f = function () {
//Some logic here...
};
var fr = f;
fr(pars);
If you want to actually pass a reference to a function to some other function, you can do something like this:
function fiz(x, y, z) {
return x + y + z;
}
// elsewhere...
function foo(fn, p, q, r) {
return function () {
return fn(p, q, r);
}
}
// finally...
f = foo(fiz, 1, 2, 3);
f(); // returns 6
You're almost certainly better off using a framework for this sort of thing, though.
Calling Java from Python
Pyjnius.
Docs: http://pyjnius.readthedocs.org/en/latest/
Github: https://github.com/kivy/pyjnius
From the github page:
A Python module to access Java classes as Python classes using JNI.
PyJNIus is a "Work In Progress".
Quick overview
>>> from jnius import autoclass >>> autoclass('java.lang.System').out.println('Hello world') Hello world >>> Stack = autoclass('java.util.Stack') >>> stack = Stack() >>> stack.push('hello') >>> stack.push('world') >>> print stack.pop() world >>> print stack.pop() hello
How do I add a border to an image in HTML?
border="1" ON IMAGE tag or using css border:1px solid #000;
Simple JavaScript Checkbox Validation
var confirm=document.getElementById("confirm").value;
if((confirm.checked==false)
{
alert("plz check the checkbox field");
document.getElementbyId("confirm").focus();
return false;
}
How to configure nginx to enable kinda 'file browser' mode?
You need create /home/yozloy/html/test folder. Or you can use alias like below show:
location /test {
alias /home/yozloy/html/;
autoindex on;
}
Differences in string compare methods in C#
Good explanation and practices about string comparison issues may be found in the article New Recommendations for Using Strings in Microsoft .NET 2.0 and also in Best Practices for Using Strings in the .NET Framework.
Each of mentioned method (and other) has particular purpose. The key difference between them is what sort of StringComparison Enumeration they are using by default. There are several options:
- CurrentCulture
- CurrentCultureIgnoreCase
- InvariantCulture
- InvariantCultureIgnoreCase
- Ordinal
- OrdinalIgnoreCase
Each of above comparison type targets different use case:
- Ordinal
- Case-sensitive internal identifiers
- Case-sensitive identifiers in standards like XML and HTTP
- Case-sensitive security-related settings
- OrdinalIgnoreCase
- Case-insensitive internal identifiers
- Case-insensitive identifiers in standards like XML and HTTP
- File paths (on Microsoft Windows)
- Registry keys/values
- Environment variables
- Resource identifiers (handle names, for example)
- Case insensitive security related settings
- InvariantCulture or InvariantCultureIgnoreCase
- Some persisted linguistically-relevant data
- Display of linguistic data requiring a fixed sort order
- CurrentCulture or CurrentCultureIgnoreCase
- Data displayed to the user
- Most user input
Note, that StringComparison Enumeration as well as overloads for string comparison methods, exists since .NET 2.0.
String.CompareTo Method (String)
Is in fact type safe implementation of IComparable.CompareTo Method. Default interpretation: CurrentCulture.
Usage:
The CompareTo method was designed primarily for use in sorting or alphabetizing operations
Thus
Implementing the IComparable interface will necessarily use this method
String.Compare Method
A static member of String Class which has many overloads. Default interpretation: CurrentCulture.
Whenever possible, you should call an overload of the Compare method that includes a StringComparison parameter.
String.Equals Method
Overriden from Object class and overloaded for type safety. Default interpretation: Ordinal. Notice that:
The String class's equality methods include the static Equals, the static operator ==, and the instance method Equals.
StringComparer class
There is also another way to deal with string comparisons especially aims to sorting:
You can use the StringComparer class to create a type-specific comparison to sort the elements in a generic collection. Classes such as Hashtable, Dictionary, SortedList, and SortedList use the StringComparer class for sorting purposes.
Relative instead of Absolute paths in Excel VBA
You could use one of these for the relative path root:
ActiveWorkbook.Path
ThisWorkbook.Path
App.Path
ORA-00972 identifier is too long alias column name
The object where Oracle stores the name of the identifiers (e.g. the table names of the user are stored in the table named as USER_TABLES and the column names of the user are stored in the table named as USER_TAB_COLUMNS), have the NAME columns (e.g. TABLE_NAME in USER_TABLES) of size Varchar2(30)...and it's uniform through all system tables of objects or identifiers --
DBA_ALL_TABLES ALL_ALL_TABLES USER_ALL_TABLES
DBA_PARTIAL_DROP_TABS ALL_PARTIAL_DROP_TABS USER_PARTIAL_DROP_TABS
DBA_PART_TABLES ALL_PART_TABLES USER_PART_TABLES
DBA_TABLES ALL_TABLES USER_TABLES
DBA_TABLESPACES USER_TABLESPACES TAB
DBA_TAB_COLUMNS ALL_TAB_COLUMNS USER_TAB_COLUMNS
DBA_TAB_COLS ALL_TAB_COLS USER_TAB_COLS
DBA_TAB_COMMENTS ALL_TAB_COMMENTS USER_TAB_COMMENTS
DBA_TAB_HISTOGRAMS ALL_TAB_HISTOGRAMS USER_TAB_HISTOGRAMS
DBA_TAB_MODIFICATIONS ALL_TAB_MODIFICATIONS USER_TAB_MODIFICATIONS
DBA_TAB_PARTITIONS ALL_TAB_PARTITIONS USER_TAB_PARTITIONS
Joining 2 SQL SELECT result sets into one
Use a FULL OUTER JOIN:
select
a.col_a,
a.col_b,
b.col_c
from
(select col_a,col_bfrom tab1) a
join
(select col_a,col_cfrom tab2) b
on a.col_a= b.col_a
How to fix homebrew permissions?
New command for users on macOS High Sierra as it is not possible to chown on /usr/local:
bash/zsh:
sudo chown -R $(whoami) $(brew --prefix)/*
fish:
sudo chown -R (whoami) (brew --prefix)/*
Reference: Can't chown /usr/local in High Sierra
Why can't I find SQL Server Management Studio after installation?
It appears that SQL Server 2008 R2 can be downloaded with or without the management tools. I honestly have NO IDEA why someone would not want the management tools. But either way, the options are here:
http://www.microsoft.com/sqlserver/en/us/editions/express.aspx
and the one for 64 bit WITH the management tools (management studio) is here:
http://www.microsoft.com/sqlserver/en/us/editions/express.aspx
From the first link I presented, the 3rd and 4th include the management studio for 32 and 64 bit respectively.
How to trace the path in a Breadth-First Search?
I liked qiao's first answer very much!
The only thing missing here is to mark the vertexes as visited.
Why we need to do it?
Lets imagine that there is another node number 13 connected from node 11. Now our goal is to find node 13.
After a little bit of a run the queue will look like this:
[[1, 2, 6], [1, 3, 10], [1, 4, 7], [1, 4, 8], [1, 2, 5, 9], [1, 2, 5, 10]]
Note that there are TWO paths with node number 10 at the end.
Which means that the paths from node number 10 will be checked twice. In this case it doesn't look so bad because node number 10 doesn't have any children.. But it could be really bad (even here we will check that node twice for no reason..)
Node number 13 isn't in those paths so the program won't return before reaching to the second path with node number 10 at the end..And we will recheck it..
All we are missing is a set to mark the visited nodes and not to check them again..
This is qiao's code after the modification:
graph = {
1: [2, 3, 4],
2: [5, 6],
3: [10],
4: [7, 8],
5: [9, 10],
7: [11, 12],
11: [13]
}
def bfs(graph_to_search, start, end):
queue = [[start]]
visited = set()
while queue:
# Gets the first path in the queue
path = queue.pop(0)
# Gets the last node in the path
vertex = path[-1]
# Checks if we got to the end
if vertex == end:
return path
# We check if the current node is already in the visited nodes set in order not to recheck it
elif vertex not in visited:
# enumerate all adjacent nodes, construct a new path and push it into the queue
for current_neighbour in graph_to_search.get(vertex, []):
new_path = list(path)
new_path.append(current_neighbour)
queue.append(new_path)
# Mark the vertex as visited
visited.add(vertex)
print bfs(graph, 1, 13)
The output of the program will be:
[1, 4, 7, 11, 13]
Without the unneccecery rechecks..
How to convert milliseconds to seconds with precision
Surely you just need:
double seconds = milliseconds / 1000.0;
There's no need to manually do the two parts separately - you just need floating point arithmetic, which the use of 1000.0 (as a double literal) forces. (I'm assuming your milliseconds value is an integer of some form.)
Note that as usual with double, you may not be able to represent the result exactly. Consider using BigDecimal if you want to represent 100ms as 0.1 seconds exactly. (Given that it's a physical quantity, and the 100ms wouldn't be exact in the first place, a double is probably appropriate, but...)
ssh script returns 255 error
As @wes-floyd and @zpon wrote, add these parameters to SSH to bypass "Are you sure you want to continue connecting (yes/no)?"
-o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no
substring of an entire column in pandas dataframe
case the column isn't string, use astype to convert:
df['col'] = df['col'].astype(str).str[:9]
How to open a web page from my application?
I've been using this line to launch the default browser:
System.Diagnostics.Process.Start("http://www.google.com");
Chrome Fullscreen API
In Google's closure library project , there is a module which has do the job , below is the API and source code.
How to get the public IP address of a user in C#
lblmessage.Text =Request.ServerVariables["REMOTE_HOST"].ToString();
How to get multiple selected values of select box in php?
// CHANGE name="select2" TO name="select2[]" THEN
<?php
$mySelection = $_GET['select2'];
$nSelection = count($MySelection);
for($i=0; $i < $nSelection; $i++)
{
$numberVal = $MySelection[$i];
if ($numberVal == "11"){
echo("Eleven");
}
else if ($numberVal == "12"){
echo("Twelve");
}
...
...
}
?>
Javascript date.getYear() returns 111 in 2011?
https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Date/getYear
getYearis no longer used and has been replaced by thegetFullYearmethod.The
getYearmethod returns the year minus 1900; thus:
- For years greater than or equal to 2000, the value returned by
getYearis 100 or greater. For example, if the year is 2026,getYearreturns 126.- For years between and including 1900 and 1999, the value returned by
getYearis between 0 and 99. For example, if the year is 1976,getYearreturns 76.- For years less than 1900, the value returned by
getYearis less than 0. For example, if the year is 1800,getYearreturns -100.- To take into account years before and after 2000, you should use
getFullYearinstead ofgetYearso that the year is specified in full.
String date to xmlgregoriancalendar conversion
tl;dr
- Use modern java.time classes as much as possible, rather than the terrible legacy classes.
- Always specify your desired/expected time zone or offset-from-UTC rather than rely implicitly on JVM’s current default.
Example code (without exception-handling):
XMLGregorianCalendar xgc =
DatatypeFactory // Data-type converter.
.newInstance() // Instantiate a converter object.
.newXMLGregorianCalendar( // Converter going from `GregorianCalendar` to `XMLGregorianCalendar`.
GregorianCalendar.from( // Convert from modern `ZonedDateTime` class to legacy `GregorianCalendar` class.
LocalDate // Modern class for representing a date-only, without time-of-day and without time zone.
.parse( "2014-01-07" ) // Parsing strings in standard ISO 8601 format is handled by default, with no need for custom formatting pattern.
.atStartOfDay( ZoneOffset.UTC ) // Determine the first moment of the day as seen in UTC. Returns a `ZonedDateTime` object.
) // Returns a `GregorianCalendar` object.
) // Returns a `XMLGregorianCalendar` object.
;
Parsing date-only input string into an object of XMLGregorianCalendar class
Avoid the terrible legacy date-time classes whenever possible, such as XMLGregorianCalendar, GregorianCalendar, Calendar, and Date. Use only modern java.time classes.
When presented with a string such as "2014-01-07", parse as a LocalDate.
LocalDate.parse( "2014-01-07" )
To get a date with time-of-day, assuming you want the first moment of the day, specify a time zone. Let java.time determine the first moment of the day, as it is not always 00:00:00.0 in some zones on some dates.
LocalDate.parse( "2014-01-07" )
.atStartOfDay( ZoneId.of( "America/Montreal" ) )
This returns a ZonedDateTime object.
ZonedDateTime zdt =
LocalDate
.parse( "2014-01-07" )
.atStartOfDay( ZoneId.of( "America/Montreal" ) )
;
zdt.toString() = 2014-01-07T00:00-05:00[America/Montreal]
But apparently, you want the start-of-day as seen in UTC (an offset of zero hours-minutes-seconds). So we specify ZoneOffset.UTC constant as our ZoneId argument.
ZonedDateTime zdt =
LocalDate
.parse( "2014-01-07" )
.atStartOfDay( ZoneOffset.UTC )
;
zdt.toString() = 2014-01-07T00:00Z
The Z on the end means UTC (an offset of zero), and is pronounced “Zulu”.
If you must work with legacy classes, convert to GregorianCalendar, a subclass of Calendar.
GregorianCalendar gc = GregorianCalendar.from( zdt ) ;
gc.toString() = java.util.GregorianCalendar[time=1389052800000,areFieldsSet=true,areAllFieldsSet=true,lenient=true,zone=sun.util.calendar.ZoneInfo[id="UTC",offset=0,dstSavings=0,useDaylight=false,transitions=0,lastRule=null],firstDayOfWeek=2,minimalDaysInFirstWeek=4,ERA=1,YEAR=2014,MONTH=0,WEEK_OF_YEAR=2,WEEK_OF_MONTH=2,DAY_OF_MONTH=7,DAY_OF_YEAR=7,DAY_OF_WEEK=3,DAY_OF_WEEK_IN_MONTH=1,AM_PM=0,HOUR=0,HOUR_OF_DAY=0,MINUTE=0,SECOND=0,MILLISECOND=0,ZONE_OFFSET=0,DST_OFFSET=0]
Apparently, you really need an object of the legacy class XMLGregorianCalendar. If the calling code cannot be updated to use java.time, convert.
XMLGregorianCalendar xgc =
DatatypeFactory
.newInstance()
.newXMLGregorianCalendar( gc )
;
Actually, that code requires a try-catch.
try
{
XMLGregorianCalendar xgc =
DatatypeFactory
.newInstance()
.newXMLGregorianCalendar( gc );
}
catch ( DatatypeConfigurationException e )
{
e.printStackTrace();
}
xgc = 2014-01-07T00:00:00.000Z
Putting that all together, with appropriate exception-handling.
// Given an input string such as "2014-01-07", return a `XMLGregorianCalendar` object
// representing first moment of the day on that date as seen in UTC.
static public XMLGregorianCalendar getXMLGregorianCalendar ( String input )
{
Objects.requireNonNull( input );
if( input.isBlank() ) { throw new IllegalArgumentException( "Received empty/blank input string for date argument. Message # 11818896-7412-49ba-8f8f-9b3053690c5d." ) ; }
XMLGregorianCalendar xgc = null;
ZonedDateTime zdt = null;
try
{
zdt =
LocalDate
.parse( input )
.atStartOfDay( ZoneOffset.UTC );
}
catch ( DateTimeParseException e )
{
throw new IllegalArgumentException( "Faulty input string for date does not comply with standard ISO 8601 format. Message # 568db0ef-d6bf-41c9-8228-cc3516558e68." );
}
GregorianCalendar gc = GregorianCalendar.from( zdt );
try
{
xgc =
DatatypeFactory
.newInstance()
.newXMLGregorianCalendar( gc );
}
catch ( DatatypeConfigurationException e )
{
e.printStackTrace();
}
Objects.requireNonNull( xgc );
return xgc ;
}
Usage.
String input = "2014-01-07";
XMLGregorianCalendar xgc = App.getXMLGregorianCalendar( input );
Dump to console.
System.out.println( "xgc = " + xgc );
xgc = 2014-01-07T00:00:00.000Z
Modern date-time classes versus legacy
Date-time != String
Do not conflate a date-time value with its textual representation. We parse strings to get a date-time object, and we ask the date-time object to generate a string to represent its value. The date-time object has no ‘format’, only strings have a format.
So shift your thinking into two separate modes: model and presentation. Determine the date-value you have in mind, applying appropriate time zone, as the model. When you need to display that value, generate a string in a particular format as expected by the user.
Avoid legacy date-time classes
The Question and other Answers all use old troublesome date-time classes now supplanted by the java.time classes.
ISO 8601
Your input string "2014-01-07" is in standard ISO 8601 format.
The T in the middle separates date portion from time portion.
The Z on the end is short for Zulu and means UTC.
Fortunately, the java.time classes use the ISO 8601 formats by default when parsing/generating strings. So no need to specify a formatting pattern.
LocalDate
The LocalDate class represents a date-only value without time-of-day and without time zone.
LocalDate ld = LocalDate.parse( "2014-01-07" ) ;
ld.toString(): 2014-01-07
Start of day ZonedDateTime
If you want to see the first moment of that day, specify a ZoneId time zone to get a moment on the timeline, a ZonedDateTime. The time zone is crucial because the date varies around the globe by zone. A few minutes after midnight in Paris France is a new day while still “yesterday” in Montréal Québec.
Never assume the day begins at 00:00:00. Anomalies such as Daylight Saving Time (DST) means the day may begin at another time-of-day such as 01:00:00. Let java.time determine the first moment.
ZoneId z = ZoneId.of( "America/Montreal" ) ;
ZonedDateTime zdt = ld.atStartOfDay( z ) ;
zdt.toString(): 2014-01-07T00:00:00Z
For your desired format, generate a string using the predefined formatter DateTimeFormatter.ISO_LOCAL_DATE_TIME and then replace the T in the middle with a SPACE.
String output = zdt.format( DateTimeFormatter.ISO_LOCAL_DATE_TIME )
.replace( "T" , " " ) ;
2014-01-07 00:00:00
About java.time
The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.
The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.
To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.
Where to obtain the java.time classes?
- Java SE 8, Java SE 9, and later
- Built-in.
- Part of the standard Java API with a bundled implementation.
- Java 9 adds some minor features and fixes.
- Java SE 6 and Java SE 7
- Much of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport.
- Android
- The ThreeTenABP project adapts ThreeTen-Backport (mentioned above) for Android specifically.
- See How to use ThreeTenABP….
The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.
Renaming columns in Pandas
RENAME SPECIFIC COLUMNS
Use the df.rename() function and refer the columns to be renamed. Not all the columns have to be renamed:
df = df.rename(columns={'oldName1': 'newName1', 'oldName2': 'newName2'})
# Or rename the existing DataFrame (rather than creating a copy)
df.rename(columns={'oldName1': 'newName1', 'oldName2': 'newName2'}, inplace=True)
Minimal Code Example
df = pd.DataFrame('x', index=range(3), columns=list('abcde'))
df
a b c d e
0 x x x x x
1 x x x x x
2 x x x x x
The following methods all work and produce the same output:
df2 = df.rename({'a': 'X', 'b': 'Y'}, axis=1) # new method
df2 = df.rename({'a': 'X', 'b': 'Y'}, axis='columns')
df2 = df.rename(columns={'a': 'X', 'b': 'Y'}) # old method
df2
X Y c d e
0 x x x x x
1 x x x x x
2 x x x x x
Remember to assign the result back, as the modification is not-inplace. Alternatively, specify inplace=True:
df.rename({'a': 'X', 'b': 'Y'}, axis=1, inplace=True)
df
X Y c d e
0 x x x x x
1 x x x x x
2 x x x x x
From v0.25, you can also specify errors='raise' to raise errors if an invalid column-to-rename is specified. See v0.25 rename() docs.
REASSIGN COLUMN HEADERS
Use df.set_axis() with axis=1 and inplace=False (to return a copy).
df2 = df.set_axis(['V', 'W', 'X', 'Y', 'Z'], axis=1, inplace=False)
df2
V W X Y Z
0 x x x x x
1 x x x x x
2 x x x x x
This returns a copy, but you can modify the DataFrame in-place by setting inplace=True (this is the default behaviour for versions <=0.24 but is likely to change in the future).
You can also assign headers directly:
df.columns = ['V', 'W', 'X', 'Y', 'Z']
df
V W X Y Z
0 x x x x x
1 x x x x x
2 x x x x x
How to get the top 10 values in postgresql?
(SELECT <some columns>
FROM mytable
<maybe some joins here>
WHERE <various conditions>
ORDER BY date DESC
LIMIT 10)
UNION ALL
(SELECT <some columns>
FROM mytable
<maybe some joins here>
WHERE <various conditions>
ORDER BY date ASC
LIMIT 10)
how to assign a block of html code to a javascript variable
I recommend to use mustache templating frame work. https://github.com/janl/mustache.js/.
<body>
....................
<!--Put your html variable in a script and set the type to "x-tmpl-mustache"-->
<script id="template" type="x-tmpl-mustache">
<div class='saved' >
<div >test.test</div> <div class='remove'>[Remove]</div></div>
</script>
</body>
//You can use it without jquery.
var template = $('#template').html();
var rendered = Mustache.render(template);
$('#target').html(rendered);
Why I recommend this?
Soon or latter you will try to replace some part of the HTML variable and make it dynamic. Dealing with this as an HTML String will be a headache. Here is where Mustache magic can help you.
<script id="template" type="x-tmpl-mustache">
<div class='remove'> {{ name }}! </div> ....
</script>
and
var template = $('#template').html();
// You can pass dynamic template values
var rendered = Mustache.render(template, {name: "Luke"});
$('#target').html(rendered);
There are lot more features.
How can I hide the Adobe Reader toolbar when displaying a PDF in the .NET WebBrowser control?
It appears the default setting for Adobe Reader X is for the toolbars not to be shown by default unless they are explicitly turned on by the user. And even when I turn them back on during a session, they don't show up automatically next time. As such, I suspect you have a preference set contrary to the default.
The state you desire, with the top and left toolbars not shown, is called "Read Mode". If you right-click on the document itself, and then click "Page Display Preferences" in the context menu that is shown, you'll be presented with the Adobe Reader Preferences dialog. (This is the same dialog you can access by opening the Adobe Reader application, and selecting "Preferences" from the "Edit" menu.) In the list shown in the left-hand column of the Preferences dialog, select "Internet". Finally, on the right, ensure that you have the "Display in Read Mode by default" box checked:
You can also turn off the toolbars temporarily by clicking the button at the right of the top toolbar that depicts arrows pointing to opposing corners:
Finally, if you have "Display in Read Mode by default" turned off, but want to instruct the page you're loading not to display the toolbars (i.e., override the user's current preferences), you can append the following to the URL:
#toolbar=0&navpanes=0
So, for example, the following code will disable both the top toolbar (called "toolbar") and the left-hand toolbar (called "navpane"). However, if the user knows the keyboard combination (F8, and perhaps other methods as well), they will still be able to turn them back on.
string url = @"http://www.domain.com/file.pdf#toolbar=0&navpanes=0";
this._WebBrowser.Navigate(url);
You can read more about the parameters that are available for customizing the way PDF files open here on Adobe's developer website.
Checking if a number is a prime number in Python
Here is my take on the problem:
from math import sqrt
from itertools import count, islice
def is_prime(n):
return n > 1 and all(n % i for i in islice(count(2), int(sqrt(n)-1)))
This is a really simple and concise algorithm, and therefore it is not meant to be anything near the fastest or the most optimal primality check algorithm. It has a time complexity of O(sqrt(n)). Head over here to learn more about primality tests done right and their history.
Explanation
I'm gonna give you some insides about that almost esoteric single line of code that will check for prime numbers:
First of all, using
range()in Python 2 is really a bad idea, because it will create a list of numbers, which uses a lot of memory. Usingxrange()is better, because it creates a generator, which only needs to memorize the initial arguments you provide, and generates every number on-the-fly. If you're using Python 3,range()has been converted to a generator by default. By the way, this is still not the best solution: trying to callxrange(n)for somensuch thatn > 231-1(which is the maximum value for a Clong) raisesOverflowError. Therefore the best way to create a range generator is to useitertools:xrange(2147483647+1) # OverflowError from itertools import count, islice count(1) # Count from 1 to infinity with step=+1 islice(count(1), 2147483648) # Count from 1 to 2^31 with step=+1 islice(count(1, 3), 2147483648) # Count from 1 to 3*2^31 with step=+3You do not actually need to go all the way up to
nif you want to check ifnis a prime number. You can dramatically reduce the tests and only check from 2 tov(n)(square root ofn). Here's an example:Let's find all the divisors of
n = 100, and list them in a table:2 x 50 = 100 4 x 25 = 100 5 x 20 = 100 10 x 10 = 100 <-- sqrt(100) 20 x 5 = 100 25 x 4 = 100 50 x 2 = 100You will easily notice that, after the square root of
n, all the divisors we find were actually already found. For example20was already found doing100/5. The square root of a number is the exact mid-point where the divisors we found begin being duplicated. Therefore, to check if a number is prime, you'll only need to check from 2 tosqrt(n).Why
sqrt(n)-1then, and not justsqrt(n)? That's just because the second argument provided toitertools.islice()is the number of iterations to execute.islice(count(a), b)stops afterbiterations. That's the reason why:for number in islice(count(10), 2): print number, # Will print: 10 11 for number in islice(count(1, 3), 10): print number, # Will print: 1 4 7 10 13 16 19 22 25 28The function
all(...)is the same of the following:def all(iterable): for element in iterable: if not element: return False return TrueIt literally checks for all the elements in the
iterable, returningFalsewhen any of them evaluates toFalse(which for an integer means only if it's zero). Why do we use it then? First of all, we don't need to use an additional index variable (like we would do using a loop), other than that: just for concision, there's no real need of it, but it looks way less bulky to work with only a single line of code instead of several nested lines.
Extended version
I'm including an "unpacked" version of the is_prime() function, to make it easier to understand and read:
from math import sqrt
from itertools import count, islice
def is_prime(n):
if n < 2:
return False
for number in islice(count(2), int(sqrt(n) - 1)):
if n % number == 0:
return False
return True
How to implement the Android ActionBar back button?
If you are using Toolbar, I was facing the same issue. I solved by following these two steps
- In the AndroidManifest.xml
<activity android:name=".activity.SecondActivity" android:parentActivityName=".activity.MainActivity"/>
- In the SecondActivity, add these...
Toolbar toolbar = findViewById(R.id.second_toolbar);
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayShowTitleEnabled(false);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
Cannot open include file: 'stdio.h' - Visual Studio Community 2017 - C++ Error
If you run into this problem with Visual Studio 2019 (VS2019), you can download the build tools from https://visualstudio.microsoft.com/downloads/. And, under Tools for Visual Studio 2019 and download Build Tools for Visual Studios 2019.
When to use in vs ref vs out
Basically both ref and out for passing object/value between methods
The out keyword causes arguments to be passed by reference. This is like the ref keyword, except that ref requires that the variable be initialized before it is passed.
out : Argument is not initialized and it must be initialized in the method
ref : Argument is already initialized and it can be read and updated in the method.
What is the use of “ref” for reference-types ?
You can change the given reference to a different instance.
Did you know?
Although the ref and out keywords cause different run-time behavior, they are not considered part of the method signature at compile time. Therefore, methods cannot be overloaded if the only difference is that one method takes a ref argument and the other takes an out argument.
You can't use the ref and out keywords for the following kinds of methods:
- Async methods, which you define by using the async modifier.
- Iterator methods, which include a yield return or yield break statement.
Properties are not variables and therefore cannot be passed as out parameters.
Inserting string at position x of another string
The Underscore.String library has a function that does Insert
insert(string, index, substring) => string
like so
insert("Hello ", 6, "world");
// => "Hello world"
Break out of a While...Wend loop
A While/Wend loop can only be exited prematurely with a GOTO or by exiting from an outer block (Exit sub/function or another exitable loop)
Change to a Do loop instead:
Do While True
count = count + 1
If count = 10 Then
Exit Do
End If
Loop
Or for looping a set number of times:
for count = 1 to 10
msgbox count
next
(Exit For can be used above to exit prematurely)
SQL Server: convert ((int)year,(int)month,(int)day) to Datetime
Pure datetime solution, does not depend on language or DATEFORMAT, no strings
SELECT
DATEADD(year, [year]-1900, DATEADD(month, [month]-1, DATEADD(day, [day]-1, 0)))
FROM
dbo.Table
How to replace special characters in a string?
You can use basic regular expressions on strings to find all special characters or use pattern and matcher classes to search/modify/delete user defined strings. This link has some simple and easy to understand examples for regular expressions: http://www.vogella.de/articles/JavaRegularExpressions/article.html
Regular expression to get a string between two strings in Javascript
Just use the following regular expression:
(?<=My cow\s).*?(?=\smilk)
Maximum execution time in phpMyadmin
For Xampp version on Windows
Add this line to xampp\phpmyadmin\config.inc.php
$cfg['ExecTimeLimit'] = 6000;
And Change xampp\php\php.ini to
post_max_size = 750M
upload_max_filesize = 750M
max_execution_time = 5000
max_input_time = 5000
memory_limit = 1000M
And change xampp\mysql\bin\my.ini
max_allowed_packet = 200M
Why is it important to override GetHashCode when Equals method is overridden?
We have two problems to cope with.
You cannot provide a sensible
GetHashCode()if any field in the object can be changed. Also often a object will NEVER be used in a collection that depends onGetHashCode(). So the cost of implementingGetHashCode()is often not worth it, or it is not possible.If someone puts your object in a collection that calls
GetHashCode()and you have overridedEquals()without also makingGetHashCode()behave in a correct way, that person may spend days tracking down the problem.
Therefore by default I do.
public class Foo
{
public int FooId { get; set; }
public string FooName { get; set; }
public override bool Equals(object obj)
{
Foo fooItem = obj as Foo;
if (fooItem == null)
{
return false;
}
return fooItem.FooId == this.FooId;
}
public override int GetHashCode()
{
// Some comment to explain if there is a real problem with providing GetHashCode()
// or if I just don't see a need for it for the given class
throw new Exception("Sorry I don't know what GetHashCode should do for this class");
}
}
Disable Proximity Sensor during call
Unfortunately my proximity sensor doesn't work, too (always returns 0.0 cm). I found the way, but not easy one: you need to root your phone, install XPOSED framework and Sensor Disabler (https://play.google.com/store/apps/details?id=com.mrchandler.disableprox). You can mock proximity sensor return value in the app. (e.g. always return 2.0 cm). Then your display will be always on during the call.
Get selected value of a dropdown's item using jQuery
use
$('#dropDownId').find('option:selected').val()
This should work :)
Display tooltip on Label's hover?
You could use the title attribute in html :)
<label title="This is the full title of the label">This is the...</label>
When you keep the mouse over for a brief moment, it should pop up with a box, containing the full title.
If you want more control, I suggest you look into the Tipsy Plugin for jQuery - It can be found at http://onehackoranother.com/projects/jquery/tipsy/ and is fairly simple to get started with.
Seaborn plots not showing up
If you plot in IPython console (where you can't use %matplotlib inline) instead of Jupyter notebook, and don't want to run plt.show() repeatedly, you can start IPython console with ipython --pylab:
$ ipython --pylab
Python 3.6.6 |Anaconda custom (64-bit)| (default, Jun 28 2018, 17:14:51)
Type 'copyright', 'credits' or 'license' for more information
IPython 7.0.1 -- An enhanced Interactive Python. Type '?' for help.
Using matplotlib backend: Qt5Agg
In [1]: import seaborn as sns
In [2]: tips = sns.load_dataset("tips")
In [3]: sns.relplot(x="total_bill", y="tip", data=tips) # you can see the plot now
Using async/await for multiple tasks
int[] ids = new[] { 1, 2, 3, 4, 5 };
Parallel.ForEach(ids, i => DoSomething(1, i, blogClient).Wait());
Although you run the operations in parallel with the above code, this code blocks each thread that each operation runs on. For example, if the network call takes 2 seconds, each thread hangs for 2 seconds w/o doing anything but waiting.
int[] ids = new[] { 1, 2, 3, 4, 5 };
Task.WaitAll(ids.Select(i => DoSomething(1, i, blogClient)).ToArray());
On the other hand, the above code with WaitAll also blocks the threads and your threads won't be free to process any other work till the operation ends.
Recommended Approach
I would prefer WhenAll which will perform your operations asynchronously in Parallel.
public async Task DoWork() {
int[] ids = new[] { 1, 2, 3, 4, 5 };
await Task.WhenAll(ids.Select(i => DoSomething(1, i, blogClient)));
}
In fact, in the above case, you don't even need to
await, you can just directly return from the method as you don't have any continuations:public Task DoWork() { int[] ids = new[] { 1, 2, 3, 4, 5 }; return Task.WhenAll(ids.Select(i => DoSomething(1, i, blogClient))); }
To back this up, here is a detailed blog post going through all the alternatives and their advantages/disadvantages: How and Where Concurrent Asynchronous I/O with ASP.NET Web API
Can't use modulus on doubles?
fmod(x, y) is the function you use.
Check difference in seconds between two times
Assuming dateTime1 and dateTime2 are DateTime values:
var diffInSeconds = (dateTime1 - dateTime2).TotalSeconds;
In your case, you 'd use DateTime.Now as one of the values and the time in the list as the other. Be careful of the order, as the result can be negative if dateTime1 is earlier than dateTime2.
How to convert a NumPy array to PIL image applying matplotlib colormap
- input = numpy_image
- np.unit8 -> converts to integers
- convert('RGB') -> converts to RGB
Image.fromarray -> returns an image object
from PIL import Image import numpy as np PIL_image = Image.fromarray(np.uint8(numpy_image)).convert('RGB') PIL_image = Image.fromarray(numpy_image.astype('uint8'), 'RGB')
How to check in Javascript if one element is contained within another
I came across a wonderful piece of code to check whether or not an element is a child of another element. I have to use this because IE doesn't support the .contains element method. Hope this will help others as well.
Below is the function:
function isChildOf(childObject, containerObject) {
var returnValue = false;
var currentObject;
if (typeof containerObject === 'string') {
containerObject = document.getElementById(containerObject);
}
if (typeof childObject === 'string') {
childObject = document.getElementById(childObject);
}
currentObject = childObject.parentNode;
while (currentObject !== undefined) {
if (currentObject === document.body) {
break;
}
if (currentObject.id == containerObject.id) {
returnValue = true;
break;
}
// Move up the hierarchy
currentObject = currentObject.parentNode;
}
return returnValue;
}
super() in Java
The super keyword can be used to call the superclass constructor and to refer to a member of the superclass
When you call super() with the right arguments, we actually call the constructor Box, which initializes variables width, height and depth, referred to it by using the values of the corresponding parameters. You only remains to initialize its value added weight. If necessary, you can do now class variables Box as private. Put down in the fields of the Box class private modifier and make sure that you can access them without any problems.
At the superclass can be several overloaded versions constructors, so you can call the method super() with different parameters. The program will perform the constructor that matches the specified arguments.
public class Box {
int width;
int height;
int depth;
Box(int w, int h, int d) {
width = w;
height = h;
depth = d;
}
public static void main(String[] args){
HeavyBox heavy = new HeavyBox(12, 32, 23, 13);
}
}
class HeavyBox extends Box {
int weight;
HeavyBox(int w, int h, int d, int m) {
//call the superclass constructor
super(w, h, d);
weight = m;
}
}
How to display a range input slider vertically
Without changing the position to absolute, see below. This supports all recent browsers as well.
.vranger {_x000D_
margin-top: 50px;_x000D_
transform: rotate(270deg);_x000D_
-moz-transform: rotate(270deg); /*do same for other browsers if required*/_x000D_
}<input type="range" class="vranger"/>for very old browsers, you can use -sand-transform: rotate(10deg); from CSS sandpaper
or use
prefix selector such as -ms-transform: rotate(270deg); for IE9
How do I find the number of arguments passed to a Bash script?
Below is the easy one -
cat countvariable.sh
echo "$@" |awk '{for(i=0;i<=NF;i++); print i-1 }'
Output :
#./countvariable.sh 1 2 3 4 5 6
6
#./countvariable.sh 1 2 3 4 5 6 apple orange
8
How can I autoplay a video using the new embed code style for Youtube?
Just add ?autoplay=1 after url in embed code, example :
<iframe width="420" height="315" src="http://www.youtube.com/embed/
oHg5SJYRHA0" frameborder="0"></iframe>
Change it to:
<iframe width="420" height="315" src="http://www.youtube.com/embed/
oHg5SJYRHA0?autoplay=1" frameborder="0"></iframe>
Convert a JSON String to a HashMap
There’s an older answer using javax.json posted here, however it only converts JsonArray and JsonObject, but there are still JsonString, JsonNumber, and JsonValue wrapper classes in the output. If you want to get rid of these, here’s my solution which will unwrap everything.
Beside that, it makes use of Java 8 streams and is contained in a single method.
/**
* Convert a JsonValue into a “plain” Java structure (using Map and List).
*
* @param value The JsonValue, not <code>null</code>.
* @return Map, List, String, Number, Boolean, or <code>null</code>.
*/
public static Object toObject(JsonValue value) {
Objects.requireNonNull(value, "value was null");
switch (value.getValueType()) {
case ARRAY:
return ((JsonArray) value)
.stream()
.map(JsonUtils::toObject)
.collect(Collectors.toList());
case OBJECT:
return ((JsonObject) value)
.entrySet()
.stream()
.collect(Collectors.toMap(
Entry::getKey,
e -> toObject(e.getValue())));
case STRING:
return ((JsonString) value).getString();
case NUMBER:
return ((JsonNumber) value).numberValue();
case TRUE:
return Boolean.TRUE;
case FALSE:
return Boolean.FALSE;
case NULL:
return null;
default:
throw new IllegalArgumentException("Unexpected type: " + value.getValueType());
}
}
Good way of getting the user's location in Android
This is my solution which works fairly well:
private Location bestLocation = null;
private Looper looper;
private boolean networkEnabled = false, gpsEnabled = false;
private synchronized void setLooper(Looper looper) {
this.looper = looper;
}
private synchronized void stopLooper() {
if (looper == null) return;
looper.quit();
}
@Override
protected void runTask() {
final LocationManager locationManager = (LocationManager) service
.getSystemService(Context.LOCATION_SERVICE);
final SharedPreferences prefs = getPreferences();
final int maxPollingTime = Integer.parseInt(prefs.getString(
POLLING_KEY, "0"));
final int desiredAccuracy = Integer.parseInt(prefs.getString(
DESIRED_KEY, "0"));
final int acceptedAccuracy = Integer.parseInt(prefs.getString(
ACCEPTED_KEY, "0"));
final int maxAge = Integer.parseInt(prefs.getString(AGE_KEY, "0"));
final String whichProvider = prefs.getString(PROVIDER_KEY, "any");
final boolean canUseGps = whichProvider.equals("gps")
|| whichProvider.equals("any");
final boolean canUseNetwork = whichProvider.equals("network")
|| whichProvider.equals("any");
if (canUseNetwork)
networkEnabled = locationManager
.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if (canUseGps)
gpsEnabled = locationManager
.isProviderEnabled(LocationManager.GPS_PROVIDER);
// If any provider is enabled now and we displayed a notification clear it.
if (gpsEnabled || networkEnabled) removeErrorNotification();
if (gpsEnabled)
updateBestLocation(locationManager
.getLastKnownLocation(LocationManager.GPS_PROVIDER));
if (networkEnabled)
updateBestLocation(locationManager
.getLastKnownLocation(LocationManager.NETWORK_PROVIDER));
if (desiredAccuracy == 0
|| getLocationQuality(desiredAccuracy, acceptedAccuracy,
maxAge, bestLocation) != LocationQuality.GOOD) {
// Define a listener that responds to location updates
LocationListener locationListener = new LocationListener() {
public void onLocationChanged(Location location) {
updateBestLocation(location);
if (desiredAccuracy != 0
&& getLocationQuality(desiredAccuracy,
acceptedAccuracy, maxAge, bestLocation)
== LocationQuality.GOOD)
stopLooper();
}
public void onProviderEnabled(String provider) {
if (isSameProvider(provider,
LocationManager.NETWORK_PROVIDER))networkEnabled =true;
else if (isSameProvider(provider,
LocationManager.GPS_PROVIDER)) gpsEnabled = true;
// The user has enabled a location, remove any error
// notification
if (canUseGps && gpsEnabled || canUseNetwork
&& networkEnabled) removeErrorNotification();
}
public void onProviderDisabled(String provider) {
if (isSameProvider(provider,
LocationManager.NETWORK_PROVIDER))networkEnabled=false;
else if (isSameProvider(provider,
LocationManager.GPS_PROVIDER)) gpsEnabled = false;
if (!gpsEnabled && !networkEnabled) {
showErrorNotification();
stopLooper();
}
}
public void onStatusChanged(String provider, int status,
Bundle extras) {
Log.i(LOG_TAG, "Provider " + provider + " statusChanged");
if (isSameProvider(provider,
LocationManager.NETWORK_PROVIDER)) networkEnabled =
status == LocationProvider.AVAILABLE
|| status == LocationProvider.TEMPORARILY_UNAVAILABLE;
else if (isSameProvider(provider,
LocationManager.GPS_PROVIDER))
gpsEnabled = status == LocationProvider.AVAILABLE
|| status == LocationProvider.TEMPORARILY_UNAVAILABLE;
// None of them are available, stop listening
if (!networkEnabled && !gpsEnabled) {
showErrorNotification();
stopLooper();
}
// The user has enabled a location, remove any error
// notification
else if (canUseGps && gpsEnabled || canUseNetwork
&& networkEnabled) removeErrorNotification();
}
};
if (networkEnabled || gpsEnabled) {
Looper.prepare();
setLooper(Looper.myLooper());
// Register the listener with the Location Manager to receive
// location updates
if (canUseGps)
locationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER, 1000, 1,
locationListener, Looper.myLooper());
if (canUseNetwork)
locationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER, 1000, 1,
locationListener, Looper.myLooper());
Timer t = new Timer();
t.schedule(new TimerTask() {
@Override
public void run() {
stopLooper();
}
}, maxPollingTime * 1000);
Looper.loop();
t.cancel();
setLooper(null);
locationManager.removeUpdates(locationListener);
} else // No provider is enabled, show a notification
showErrorNotification();
}
if (getLocationQuality(desiredAccuracy, acceptedAccuracy, maxAge,
bestLocation) != LocationQuality.BAD) {
sendUpdate(new Event(EVENT_TYPE, locationToString(desiredAccuracy,
acceptedAccuracy, maxAge, bestLocation)));
} else Log.w(LOG_TAG, "LocationCollector failed to get a location");
}
private synchronized void showErrorNotification() {
if (notifId != 0) return;
ServiceHandler handler = service.getHandler();
NotificationInfo ni = NotificationInfo.createSingleNotification(
R.string.locationcollector_notif_ticker,
R.string.locationcollector_notif_title,
R.string.locationcollector_notif_text,
android.R.drawable.stat_notify_error);
Intent intent = new Intent(
android.provider.Settings.ACTION_LOCATION_SOURCE_SETTINGS);
ni.pendingIntent = PendingIntent.getActivity(service, 0, intent,
PendingIntent.FLAG_UPDATE_CURRENT);
Message msg = handler.obtainMessage(ServiceHandler.SHOW_NOTIFICATION);
msg.obj = ni;
handler.sendMessage(msg);
notifId = ni.id;
}
private void removeErrorNotification() {
if (notifId == 0) return;
ServiceHandler handler = service.getHandler();
if (handler != null) {
Message msg = handler.obtainMessage(
ServiceHandler.CLEAR_NOTIFICATION, notifId, 0);
handler.sendMessage(msg);
notifId = 0;
}
}
@Override
public void interrupt() {
stopLooper();
super.interrupt();
}
private String locationToString(int desiredAccuracy, int acceptedAccuracy,
int maxAge, Location location) {
StringBuilder sb = new StringBuilder();
sb.append(String.format(
"qual=%s time=%d prov=%s acc=%.1f lat=%f long=%f",
getLocationQuality(desiredAccuracy, acceptedAccuracy, maxAge,
location), location.getTime() / 1000, // Millis to
// seconds
location.getProvider(), location.getAccuracy(), location
.getLatitude(), location.getLongitude()));
if (location.hasAltitude())
sb.append(String.format(" alt=%.1f", location.getAltitude()));
if (location.hasBearing())
sb.append(String.format(" bearing=%.2f", location.getBearing()));
return sb.toString();
}
private enum LocationQuality {
BAD, ACCEPTED, GOOD;
public String toString() {
if (this == GOOD) return "Good";
else if (this == ACCEPTED) return "Accepted";
else return "Bad";
}
}
private LocationQuality getLocationQuality(int desiredAccuracy,
int acceptedAccuracy, int maxAge, Location location) {
if (location == null) return LocationQuality.BAD;
if (!location.hasAccuracy()) return LocationQuality.BAD;
long currentTime = System.currentTimeMillis();
if (currentTime - location.getTime() < maxAge * 1000
&& location.getAccuracy() <= desiredAccuracy)
return LocationQuality.GOOD;
if (acceptedAccuracy == -1
|| location.getAccuracy() <= acceptedAccuracy)
return LocationQuality.ACCEPTED;
return LocationQuality.BAD;
}
private synchronized void updateBestLocation(Location location) {
bestLocation = getBestLocation(location, bestLocation);
}
protected Location getBestLocation(Location location,
Location currentBestLocation) {
if (currentBestLocation == null) {
// A new location is always better than no location
return location;
}
if (location == null) return currentBestLocation;
// Check whether the new location fix is newer or older
long timeDelta = location.getTime() - currentBestLocation.getTime();
boolean isSignificantlyNewer = timeDelta > TWO_MINUTES;
boolean isSignificantlyOlder = timeDelta < -TWO_MINUTES;
boolean isNewer = timeDelta > 0;
// If it's been more than two minutes since the current location, use
// the new location
// because the user has likely moved
if (isSignificantlyNewer) {
return location;
// If the new location is more than two minutes older, it must be
// worse
} else if (isSignificantlyOlder) {
return currentBestLocation;
}
// Check whether the new location fix is more or less accurate
int accuracyDelta = (int) (location.getAccuracy() - currentBestLocation
.getAccuracy());
boolean isLessAccurate = accuracyDelta > 0;
boolean isMoreAccurate = accuracyDelta < 0;
boolean isSignificantlyLessAccurate = accuracyDelta > 200;
// Check if the old and new location are from the same provider
boolean isFromSameProvider = isSameProvider(location.getProvider(),
currentBestLocation.getProvider());
// Determine location quality using a combination of timeliness and
// accuracy
if (isMoreAccurate) {
return location;
} else if (isNewer && !isLessAccurate) {
return location;
} else if (isNewer && !isSignificantlyLessAccurate
&& isFromSameProvider) {
return location;
}
return bestLocation;
}
/** Checks whether two providers are the same */
private boolean isSameProvider(String provider1, String provider2) {
if (provider1 == null) return provider2 == null;
return provider1.equals(provider2);
}
When do I use the PHP constant "PHP_EOL"?
PHP_EOL (string) The correct 'End Of Line' symbol for this platform. Available since PHP 4.3.10 and PHP 5.0.2
You can use this constant when you read or write text files on the server's filesystem.
Line endings do not matter in most cases as most software are capable of handling text files regardless of their origin. You ought to be consistent with your code.
If line endings matter, explicitly specify the line endings instead of using the constant. For example:
- HTTP headers must be separated by
\r\n - CSV files should use
\r\nas row separator
Iterating through a List Object in JSP
<c:forEach items="${sessionScope.empL}" var="emp">
<tr>
<td>Employee ID: <c:out value="${emp.eid}"/></td>
<td>Employee Pass: <c:out value="${emp.ename}"/></td>
</tr>
</c:forEach>
How do you configure tomcat to bind to a single ip address (localhost) instead of all addresses?
It may be worth mentioning that running tomcat as a non root user (which you should be doing) will prevent you from using a port below 1024 on *nix. If you want to use TC as a standalone server -- as its performance no longer requires it to be fronted by Apache or the like -- you'll want to bind to port 80 along with whatever IP address you're specifying.
You can do this by using IPTABLES to redirect port 80 to 8080.
Setting active profile and config location from command line in spring boot
I think your problem is likely related to your spring.config.location not ending the path with "/".
Quote the docs
If spring.config.location contains directories (as opposed to files) they should end in / (and will be appended with the names generated from spring.config.name before being loaded).
CSS3 transition events
In Opera 12 when you bind using the plain JavaScript, 'oTransitionEnd' will work:
document.addEventListener("oTransitionEnd", function(){
alert("Transition Ended");
});
however if you bind through jQuery, you need to use 'otransitionend'
$(document).bind("otransitionend", function(){
alert("Transition Ended");
});
In case you are using Modernizr or bootstrap-transition.js you can simply do a change:
var transEndEventNames = {
'WebkitTransition' : 'webkitTransitionEnd',
'MozTransition' : 'transitionend',
'OTransition' : 'oTransitionEnd otransitionend',
'msTransition' : 'MSTransitionEnd',
'transition' : 'transitionend'
},
transEndEventName = transEndEventNames[ Modernizr.prefixed('transition') ];
You can find some info here as well http://www.ianlunn.co.uk/blog/articles/opera-12-otransitionend-bugs-and-workarounds/
How to do URL decoding in Java?
Using java.net.URI class:
public String getDecodedURL(String encodedUrl) {
try {
URI uri = new URI(encodedUrl);
return uri.getScheme() + ":" + uri.getSchemeSpecificPart();
} catch (Exception e) {
return "";
}
}
Please note that exception handling can be better, but it's not much relevant for this example.
Make footer stick to bottom of page correctly
do it using jQuery put inside code on the <head></head> tag
<script type="text/javascript">
$(document).ready(function() {
var docHeight = $(window).height();
var footerHeight = $('#footer').height();
var footerTop = $('#footer').position().top + footerHeight;
if (footerTop < docHeight) {
$('#footer').css('margin-top', 10 + (docHeight - footerTop) + 'px');
}
});
</script>
Can I mask an input text in a bat file?
1.Pure batch solution that (ab)uses XCOPY command and its /P /L switches found here (some improvements on this could be found here ):
:: Hidden.cmd
::Tom Lavedas, 02/05/2013, 02/20/2013
::Carlos, 02/22/2013
::https://groups.google.com/forum/#!topic/alt.msdos.batch.nt/f7mb_f99lYI
@Echo Off
:HInput
SetLocal EnableExtensions EnableDelayedExpansion
Set "FILE=%Temp%.\T"
Set "FILE=.\T"
Keys List >"%File%"
Set /P "=Hidden text ending with Ctrl-C?: " <Nul
Echo.
Set "HInput="
:HInput_
For /F "tokens=1* delims=?" %%A In (
'"Xcopy /P /L "%FILE%" "%FILE%" 2>Nul"'
) Do (
Set "Text=%%B"
If Defined Text (
Set "Char=!Text:~1,1!"
Set "Intro=1"
For /F delims^=^ eol^= %%Z in ("!Char!") Do Set "Intro=0"
Rem If press Intro
If 1 Equ !Intro! Goto :HInput#
Set "HInput=!HInput!!Char!"
)
)
Goto :HInput_
:HInput#
Echo(!HInput!
Goto :Eof
1.2 Another way based on replace command
@Echo Off
SetLocal EnableExtensions EnableDelayedExpansion
Set /P "=Enter a Password:" < Nul
Call :PasswordInput
Echo(Your input was:!Line!
Goto :Eof
:PasswordInput
::Author: Carlos Montiers Aguilera
::Last updated: 20150401. Created: 20150401.
::Set in variable Line a input password
For /F skip^=1^ delims^=^ eol^= %%# in (
'"Echo(|Replace.exe "%~f0" . /U /W"') Do Set "CR=%%#"
For /F %%# In (
'"Prompt $H &For %%_ In (_) Do Rem"') Do Set "BS=%%#"
Set "Line="
:_PasswordInput_Kbd
Set "CHR=" & For /F skip^=1^ delims^=^ eol^= %%# in (
'Replace.exe "%~f0" . /U /W') Do Set "CHR=%%#"
If !CHR!==!CR! Echo(&Goto :Eof
If !CHR!==!BS! (If Defined Line (Set /P "=!BS! !BS!" <Nul
Set "Line=!Line:~0,-1!"
)
) Else (Set /P "=*" <Nul
If !CHR!==! (Set "Line=!Line!^!"
) Else Set "Line=!Line!!CHR!"
)
Goto :_PasswordInput_Kbd
2.Password submitter that uses a HTA pop-up . This is a hybrit .bat/jscript/mshta file and should be saved as a .bat:
<!-- :
:: PasswordSubmitter.bat
@echo off
for /f "tokens=* delims=" %%p in ('mshta.exe "%~f0"') do (
set "pass=%%p"
)
echo your password is %pass%
exit /b
-->
<html>
<head><title>Password submitter</title></head>
<body>
<script language='javascript' >
window.resizeTo(300,150);
function entperPressed(e){
if (e.keyCode == 13) {
pipePass();
}
}
function pipePass() {
var pass=document.getElementById('pass').value;
var fso= new ActiveXObject('Scripting.FileSystemObject').GetStandardStream(1);
close(fso.Write(pass));
}
</script>
<input type='password' name='pass' size='15' onkeypress="return entperPressed(event)" ></input>
<hr>
<button onclick='pipePass()'>Submit</button>
</body>
</html>
3.A self-compiled .net hybrid .Again should be saved as .bat .In difference with other solutions it will create/compile a small .exe file that will be called (if you wish you can delete it). Also requires installed .net framework but that's rather not a problem:
@if (@X)==(@Y) @end /* JScript comment
@echo off
setlocal enableDelayedExpansion
for /f "tokens=* delims=" %%v in ('dir /b /s /a:-d /o:-n "%SystemRoot%\Microsoft.NET\Framework\*jsc.exe"') do (
set "jsc=%%v"
)
if not exist "%~n0.exe" (
"%jsc%" /nologo /out:"%~n0.exe" "%~dpsfnx0"
)
for /f "tokens=* delims=" %%p in ('"%~n0.exe"') do (
set "pass=%%p"
)
echo your password is !pass!
endlocal & exit /b %errorlevel%
*/
import System;
var pwd = "";
var key;
Console.Error.Write("Enter password: ");
do {
key = Console.ReadKey(true);
if ( (key.KeyChar.ToString().charCodeAt(0)) >= 20 && (key.KeyChar.ToString().charCodeAt(0) <= 126) ) {
pwd=pwd+(key.KeyChar.ToString());
Console.Error.Write("*");
}
if ( key.Key == ConsoleKey.Backspace && pwd.Length > 0 ) {
pwd=pwd.Remove(pwd.Length-1);
Console.Error.Write("\b \b");
}
} while (key.Key != ConsoleKey.Enter);
Console.Error.WriteLine();
Console.WriteLine(pwd);
How to split long commands over multiple lines in PowerShell
Ah, and if you have a very long string that you want to break up, say of HTML, you can do it by putting a @ on each side of the outer " - like this:
$mystring = @"
Bob
went
to town
to buy
a fat
pig.
"@
You get exactly this:
Bob
went
to town
to buy
a fat
pig.
And if you are using Notepad++, it will even highlight correctly as a string block.
Now, if you wanted that string to contain double quotes, too, just add them in, like this:
$myvar = "Site"
$mystring = @"
<a href="http://somewhere.com/somelocation">
Bob's $myvar
</a>
"@
You would get exactly this:
<a href="http://somewhere.com/somelocation">
Bob's Site
</a>
However, if you use double-quotes in that @-string like that, Notepad++ doesn't realize that and will switch out the syntax colouring as if it were not quoted or quoted, depending on the case.
And what's better is this: anywhere you insert a $variable, it DOES get interpreted! (If you need the dollar sign in the text, you escape it with a tick mark like this: ``$not-a-variable`.)
NOTICE! If you don't put the final "@ at the very start of the line, it will fail. It took me an hour to figure out that I could not indent that in my code!
Here is MSDN on the subject: Using Windows PowerShell “Here-Strings”
Adding an image to a project in Visual Studio
You just need to have an existing file, open the context menu on your folder , and then choose
Add=>Existing item...
If you have the file already placed within your project structure, but it is not yet included, you can do so by making them visible in the solution explorer
and then include them via the file context menu
CSS hover vs. JavaScript mouseover
EDIT: This answer no longer holds true. CSS is well supportedand Javascript (read: JScript) is now pretty much required for any web experience, and few folks disable javascript.
The original answer, as my opinion in 2009.
Off the top of my head:
With CSS, you may have issues with browser support.
With JScript, people can disable jscript (thats what I do).
I believe the preferred method is to do content in HTML, Layout with CSS, and anything dynamic in JScript. So in this instance, you would probably want to take the CSS approach.
How to implement the Softmax function in Python
Based on all the responses and CS231n notes, allow me to summarise:
def softmax(x, axis):
x -= np.max(x, axis=axis, keepdims=True)
return np.exp(x) / np.exp(x).sum(axis=axis, keepdims=True)
Usage:
x = np.array([[1, 0, 2,-1],
[2, 4, 6, 8],
[3, 2, 1, 0]])
softmax(x, axis=1).round(2)
Output:
array([[0.24, 0.09, 0.64, 0.03],
[0. , 0.02, 0.12, 0.86],
[0.64, 0.24, 0.09, 0.03]])
Click toggle with jQuery
I have a single checkbox named chkDueDate and an HTML object with a click event as follows:
$('#chkDueDate').attr('checked', !$('#chkDueDate').is(':checked'));
Clicking the HTML object (in this case a <span>) toggles the checked property of the checkbox.
Matplotlib make tick labels font size smaller
plt.tick_params(axis='both', which='minor', labelsize=12)
How to access local files of the filesystem in the Android emulator?
In Android Studio 3.0 and later do this:
View > Tool Windows > Device File Explorer
How to switch between python 2.7 to python 3 from command line?
They are 3 ways you can achieve this using the py command (py-launcher) in python 3, virtual environment or configuring your default python system path. For illustration purpose, you may see tutorial https://www.youtube.com/watch?v=ynDlb0n27cw&t=38s
Finding the source code for built-in Python functions?
Here is a cookbook answer to supplement @Chris' answer, CPython has moved to GitHub and the Mercurial repository will no longer be updated:
- Install Git if necessary.
git clone https://github.com/python/cpython.gitCode will checkout to a subdirectory called
cpython->cd cpython- Let's say we are looking for the definition of
print()... egrep --color=always -R 'print' | less -R- Aha! See
Python/bltinmodule.c->builtin_print()
Enjoy.
How to install a gem or update RubyGems if it fails with a permissions error
I found this how-to for sudoless gem:
brew install rbenv ruby-buildsudo gem update --systemadd exports to
.bashrc:export RBENV_ROOT="$(brew --prefix rbenv)" export GEM_HOME="$(brew --prefix)/opt/gems" export GEM_PATH="$(brew --prefix)/opt/gems"And finally add this to your
~/.gemrc:gem: -n/usr/local/bingem update --system
Cross-platform way of getting temp directory in Python
This should do what you want:
print tempfile.gettempdir()
For me on my Windows box, I get:
c:\temp
and on my Linux box I get:
/tmp
Python: Finding differences between elements of a list
My way
>>>v = [1,2,3,4,5]
>>>[v[i] - v[i-1] for i, value in enumerate(v[1:], 1)]
[1, 1, 1, 1]
Manifest merger failed : uses-sdk:minSdkVersion 14
You just change Minimum API Level from Build Settings -> Player Settings -> Other Settings -> Minimum SDK Level to some higher version.
How to solve a pair of nonlinear equations using Python?
from scipy.optimize import fsolve
def double_solve(f1,f2,x0,y0):
func = lambda x: [f1(x[0], x[1]), f2(x[0], x[1])]
return fsolve(func,[x0,y0])
def n_solve(functions,variables):
func = lambda x: [ f(*x) for f in functions]
return fsolve(func, variables)
f1 = lambda x,y : x**2+y**2-1
f2 = lambda x,y : x-y
res = double_solve(f1,f2,1,0)
res = n_solve([f1,f2],[1.0,0.0])
htaccess remove index.php from url
RewriteEngine On
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /(.*)index\.php($|\ |\?)
RewriteRule ^ /%1 [R=301,L]
SQL Query to add a new column after an existing column in SQL Server 2005
It's possible.
First, just add each column the usual way (as the last column).
Secondly, in SQL Server Management Studio Get into Tools => Options.
Under 'Designers' Tab => 'Table and Database Designers' menu, uncheck the option 'Prevent saving changes that require table re-creation'.
Afterwards, right click on your table and choose 'Design'. In 'Design' mode just drag the columns to order them.
Don't forget to save.
How to handle query parameters in angular 2
It seems that RouteParams no longer exists, and is replaced by ActivatedRoute. ActivatedRoute gives us access to the matrix URL notation Parameters. If we want to get Query string ? paramaters we need to use Router.RouterState. The traditional query string paramaters are persisted across routing, which may not be the desired result. Preserving the fragment is now optional in router 3.0.0-rc.1.
import { Router, ActivatedRoute } from '@angular/router';
@Component ({...})
export class paramaterDemo {
private queryParamaterValue: string;
private matrixParamaterValue: string;
private querySub: any;
private matrixSub: any;
constructor(private router: Router, private route: ActivatedRoute) { }
ngOnInit() {
this.router.routerState.snapshot.queryParams["queryParamaterName"];
this.querySub = this.router.routerState.queryParams.subscribe(queryParams =>
this.queryParamaterValue = queryParams["queryParameterName"];
);
this.route.snapshot.params["matrixParameterName"];
this.route.params.subscribe(matrixParams =>
this.matrixParamterValue = matrixParams["matrixParameterName"];
);
}
ngOnDestroy() {
if (this.querySub) {
this.querySub.unsubscribe();
}
if (this.matrixSub) {
this.matrixSub.unsubscribe();
}
}
}
We should be able to manipulate the ? notation upon navigation, as well as the ; notation, but I only gotten the matrix notation to work yet. The plnker that is attached to the latest router documentation shows it should look like this.
let sessionId = 123456789;
let navigationExtras = {
queryParams: { 'session_id': sessionId },
fragment: 'anchor'
};
// Navigate to the login page with extras
this.router.navigate(['/login'], navigationExtras);
What is the best alternative IDE to Visual Studio
I still like Source Insight a lot, but I'm hesitant to recommend it anymore as I'm not sure anybody's still maintaining it. They released a very minor update back in March but haven't had a major release in years. And there seems to be no web community presence. It's a shame because I still like its auto-completion-friendly file open and symbol browsing panels (as well as syntax formatting) better than anything else I've ever used.
How to get the next auto-increment id in mysql
This will return auto increment value for the MySQL database and I didn't check with other databases. Please note that if you are using any other database, the query syntax may be different.
SELECT AUTO_INCREMENT
FROM information_schema.tables
WHERE table_name = 'your_table_name'
and table_schema = 'your_database_name';
SELECT AUTO_INCREMENT
FROM information_schema.tables
WHERE table_name = 'your_table_name'
and table_schema = database();
Specifying java version in maven - differences between properties and compiler plugin
None of the solutions above worked for me straight away. So I followed these steps:
- Add in
pom.xml:
<properties>
<maven.compiler.target>1.8</maven.compiler.target>
<maven.compiler.source>1.8</maven.compiler.source>
</properties>
Go to
Project Properties>Java Build Path, then remove the JRE System Library pointing toJRE1.5.Force updated the project.
Python: Total sum of a list of numbers with the for loop
I think what you mean is how to encapsulate that for general use, e.g. in a function:
def sum_list(l):
sum = 0
for x in l:
sum += x
return sum
Now you can apply this to any list. Examples:
l = [1, 2, 3, 4, 5]
sum_list(l)
l = list(map(int, input("Enter numbers separated by spaces: ").split()))
sum_list(l)
But note that sum is already built in!
Spring Boot not serving static content
I had a similar problem, and it turned out that the simple solution was to have my configuration class extend WebMvcAutoConfiguration:
@Configuration
@EnableWebMvc
@ComponentScan
public class ServerConfiguration extends WebMvcAutoConfiguration{
}
I didn't need any other code to allow my static content to be served, however, I did put a directory called public under src/main/webapp and configured maven to point to src/main/webapp as a resource directory. This means that public is copied into target/classes, and is therefore on the classpath at runtime for spring-boot/tomcat to find.
No module named 'openpyxl' - Python 3.4 - Ubuntu
@zetysz and @Manish already fixed the problem. I am just putting this in an answer for future reference:
piprefers to Python 2 as a default in Ubuntu, this means thatpip install xwill install the module for Python 2 and not for 3pip3refers to Python 3, it will install the module for Python 3
How do I check if a string contains a specific word?
You need to use identical/not identical operators because strpos can return 0 as it's index value. If you like ternary operators, consider using the following (seems a little backwards I'll admit):
echo FALSE === strpos($a,'are') ? 'false': 'true';
Use FontAwesome or Glyphicons with css :before
Re: using icon in :before –
recent Font Awesome builds include the .fa-icon() mixin for SASS and LESS. This will automatically include the font-family as well as some rendering tweaks (e.g. -webkit-font-smoothing). Thus you can do, e.g.:
// Add "?" icon to header.
h1:before {
.fa-icon();
content: "\f059";
}
Can't operator == be applied to generic types in C#?
"...by default == behaves as described above for both predefined and user-defined reference types."
Type T is not necessarily a reference type, so the compiler can't make that assumption.
However, this will compile because it is more explicit:
bool Compare<T>(T x, T y) where T : class
{
return x == y;
}
Follow up to additional question, "But, in case I'm using a reference type, would the the == operator use the predefined reference comparison, or would it use the overloaded version of the operator if a type defined one?"
I would have thought that == on the Generics would use the overloaded version, but the following test demonstrates otherwise. Interesting... I'd love to know why! If someone knows please share.
namespace TestProject
{
class Program
{
static void Main(string[] args)
{
Test a = new Test();
Test b = new Test();
Console.WriteLine("Inline:");
bool x = a == b;
Console.WriteLine("Generic:");
Compare<Test>(a, b);
}
static bool Compare<T>(T x, T y) where T : class
{
return x == y;
}
}
class Test
{
public static bool operator ==(Test a, Test b)
{
Console.WriteLine("Overloaded == called");
return a.Equals(b);
}
public static bool operator !=(Test a, Test b)
{
Console.WriteLine("Overloaded != called");
return a.Equals(b);
}
}
}
Output
Inline: Overloaded == called
Generic:
Press any key to continue . . .
Follow Up 2
I do want to point out that changing my compare method to
static bool Compare<T>(T x, T y) where T : Test
{
return x == y;
}
causes the overloaded == operator to be called. I guess without specifying the type (as a where), the compiler can't infer that it should use the overloaded operator... though I'd think that it would have enough information to make that decision even without specifying the type.
How do I get a specific range of numbers from rand()?
if you care about the quality of your random numbers don't use rand()
use some other prng like http://en.wikipedia.org/wiki/Mersenne_twister or one of the other high quality prng's out there
then just go with the modulus.
Authentication failed to bitbucket
Tools -> options -> git and selecting 'use system git' did the magic for me.
Making a Bootstrap table column fit to content
Kind of an old question, but I arrived here looking for this. I wanted the table to be as small as possible, fitting to it's contents. The solution was to simply set the table width to an arbitrary small number (1px for example). I even created a CSS class to handle it:
.table-fit {
width: 1px;
}
And use it like so:
<table class="table table-fit">
Example: JSFiddle
window.history.pushState refreshing the browser
As others have suggested, you are not clearly explaining your problem, what you are trying to do, or what your expectations are as to what this function is actually supposed to do.
If I have understood correctly, then you are expecting this function to refresh the page for you (you actually use the term "reloads the browser").
But this function is not intended to reload the browser.
All the function does, is to add (push) a new "state" onto the browser history, so that in future, the user will be able to return to this state that the web-page is now in.
Normally, this is used in conjunction with AJAX calls (which refresh only a part of the page).
For example, if a user does a search "CATS" in one of your search boxes, and the results of the search (presumably cute pictures of cats) are loaded back via AJAX, into the lower-right of your page -- then your page state will not be changed. In other words, in the near future, when the user decides that he wants to go back to his search for "CATS", he won't be able to, because the state doesn't exist in his history. He will only be able to click back to your blank search box.
Hence the need for the function
history.pushState({},"Results for `Cats`",'url.html?s=cats');
It is intended as a way to allow the programmer to specifically define his search into the user's history trail. That's all it is intended to do.
When the function is working properly, the only thing you should expect to see, is the address in your browser's address-bar change to whatever you specify in your URL.
If you already understand this, then sorry for this long preamble. But it sounds from the way you pose the question, that you have not.
As an aside, I have also found some contradictions between the way that the function is described in the documentation, and the way it works in reality. I find that it is not a good idea to use blank or empty values as parameters.
See my answer to this SO question. So I would recommend putting a description in your second parameter. From memory, this is the description that the user sees in the drop-down, when he clicks-and-holds his mouse over "back" button.
How do I get ruby to print a full backtrace instead of a truncated one?
IRB has a setting for this awful "feature", which you can customize.
Create a file called ~/.irbrc that includes the following line:
IRB.conf[:BACK_TRACE_LIMIT] = 100
This will allow you to see 100 stack frames in irb, at least. I haven't been able to find an equivalent setting for the non-interactive runtime.
Detailed information about IRB customization can be found in the Pickaxe book.
How can I set selected option selected in vue.js 2?
You simply need to remove v-bind (:) from selected and required attributes. Like this :-
<template>_x000D_
<select class="form-control" v-model="selected" required @change="changeLocation">_x000D_
<option selected>Choose Province</option>_x000D_
<option v-for="option in options" v-bind:value="option.id" >{{ option.name }}</option>_x000D_
</select>_x000D_
</template>You are not binding anything to the vue instance through these attributes thats why it is giving error.
how to redirect to external url from c# controller
If you are using MVC then it would be more appropriate to use RedirectResult instead of using Response.Redirect.
public ActionResult Index() {
return new RedirectResult("http://www.website.com");
}
Reference - https://blogs.msdn.microsoft.com/rickandy/2012/03/01/response-redirect-and-asp-net-mvc-do-not-mix/
How to find MySQL process list and to kill those processes?
select GROUP_CONCAT(stat SEPARATOR ' ') from (select concat('KILL ',id,';') as stat from information_schema.processlist) as stats;
Then copy and paste the result back into the terminal. Something like:
KILL 2871; KILL 2879; KILL 2874; KILL 2872; KILL 2866;
How to Import .bson file format on mongodb
If your access remotely you can do it
for bson:
mongorestore --host m2.mongodb.net --port 27016 --ssl --username $user --password $password --authenticationDatabase $authdb -d test -c people "/home/${USER}/people.bson"
for bson compressed in .gz (gzip) format:
mongorestore --host m2.mongodb.net --port 27016 --ssl --username $user --password $password --authenticationDatabase $authdb -d test -c people --gzip --dir "/home/${USER}/people.bson.gz"
How to link external javascript file onclick of button
You can load all your scripts in the head tag, and whatever your script is doing in function braces. But make sure you change the scope of the variables if you are using those variables outside the script.
Git credential helper - update password
Just cd in the directory where you have installed git-credential-winstore. If you don't know where, just run this in Git Bash:
cat ~/.gitconfig
It should print something looking like:
[credential]
helper = !'C:\\ProgramFile\\GitCredStore\\git-credential-winstore.exe'
In this case, you repository is C:\ProgramFile\GitCredStore. Once you are inside this folder using Git Bash or the Windows command, just type:
git-credential-winstore.exe erase
host=github.com
protocol=https
Don't forget to press Enter twice after protocol=https.
Remove spaces from a string in VB.NET
What about Regex.Replace solution?
myStr = Regex.Replace(myStr, "\s", "")
TypeScript static classes
This is one way:
class SomeClass {
private static myStaticVariable = "whatever";
private static __static_ctor = (() => { /* do static constructor stuff :) */ })();
}
__static_ctor here is an immediately invoked function expression. Typescript will output code to call it at the end of the generated class.
Update: For generic types in static constructors, which are no longer allowed to be referenced by static members, you will need an extra step now:
class SomeClass<T> {
static myStaticVariable = "whatever";
private ___static_ctor = (() => { var someClass:SomeClass<T> ; /* do static constructor stuff :) */ })();
private static __static_ctor = SomeClass.prototype.___static_ctor();
}
In any case, of course, you could just call the generic type static constructor after the class, such as:
class SomeClass<T> {
static myStaticVariable = "whatever";
private __static_ctor = (() => { var example: SomeClass<T>; /* do static constructor stuff :) */ })();
}
SomeClass.prototype.__static_ctor();
Just remember to NEVER use this in __static_ctor above (obviously).
Difference between break and continue in PHP?
Break ends the current loop/control structure and skips to the end of it, no matter how many more times the loop otherwise would have repeated.
Continue skips to the beginning of the next iteration of the loop.
POST Multipart Form Data using Retrofit 2.0 including image
Kotlin version with update for deprication of RequestBody.create :
Retrofit interface
@Multipart
@POST("uploadPhoto")
fun uploadFile(@Part file: MultipartBody.Part): Call<FileResponse>
and to Upload
fun uploadFile(fileUrl: String){
val file = File(fileUrl)
val fileUploadService = RetrofitClientInstance.retrofitInstance.create(FileUploadService::class.java)
val requestBody = file.asRequestBody(file.extension.toMediaTypeOrNull())
val filePart = MultipartBody.Part.createFormData(
"blob",file.name,requestBody
)
val call = fileUploadService.uploadFile(filePart)
call.enqueue(object: Callback<FileResponse>{
override fun onFailure(call: Call<FileResponse>, t: Throwable) {
Log.d(TAG,"Fckd")
}
override fun onResponse(call: Call<FileResponse>, response: Response<FileResponse>) {
Log.d(TAG,"success"+response.toString()+" "+response.body().toString()+" "+response.body()?.status)
}
})
}
Thanks to @jimmy0251
When should we implement Serializable interface?
The answer to this question is, perhaps surprisingly, never, or more realistically, only when you are forced to for interoperability with legacy code. This is the recommendation in Effective Java, 3rd Edition by Joshua Bloch:
There is no reason to use Java serialization in any new system you write
Oracle's chief architect, Mark Reinhold, is on record as saying removing the current Java serialization mechanism is a long-term goal.
Why Java serialization is flawed
Java provides as part of the language a serialization scheme you can opt in to, by using the Serializable interface. This scheme however has several intractable flaws and should be treated as a failed experiment by the Java language designers.
- It fundamentally pretends that one can talk about the serialized form of an object. But there are infinitely many serialization schemes, resulting in infinitely many serialized forms. By imposing one scheme, without any way of changing the scheme, applications can not use a scheme most appropriate for them.
- It is implemented as an additional means of constructing objects, which bypasses any precondition checks your constructors or factory methods perform. Unless tricky, error prone, and difficult to test extra deserialization code is written, your code probably has a gaping security weakness.
- Testing interoperability of different versions of the serialized form is very difficult.
- Handling of immutable objects is troublesome.
What to do instead
Instead, use a serialization scheme that you can explicitly control. Such as Protocol Buffers, JSON, XML, or your own custom scheme.
How can I set a css border on one side only?
You can specify border separately for all borders, for example:
#testdiv{
border-left: 1px solid #000;
border-right: 2px solid #FF0;
}
You can also specify the look of the border, and use separate style for the top, right, bottom and left borders. for example:
#testdiv{
border: 1px #000;
border-style: none solid none solid;
}
Sending XML data using HTTP POST with PHP
Another option would be file_get_contents():
// $xml_str = your xml
// $url = target url
$post_data = array('xml' => $xml_str);
$stream_options = array(
'http' => array(
'method' => 'POST',
'header' => 'Content-type: application/x-www-form-urlencoded' . "\r\n",
'content' => http_build_query($post_data)));
$context = stream_context_create($stream_options);
$response = file_get_contents($url, null, $context);
IFrame: This content cannot be displayed in a frame
Use target="_top" attribute in anchor tag that will really work.
How can I get name of element with jQuery?
To read a property of an object you use .propertyName or ["propertyName"] notation.
This is no different for elements.
var name = $('#item')[0].name;
var name = $('#item')[0]["name"];
If you specifically want to use jQuery methods, then you'd use the .prop() method.
var name = $('#item').prop('name');
Please note that attributes and properties are not necessarily the same.
How do I access my webcam in Python?
import cv2 as cv
capture = cv.VideoCapture(0)
while True:
isTrue,frame = capture.read()
cv.imshow('Video',frame)
if cv.waitKey(20) & 0xFF==ord('d'):
break
capture.release()
cv.destroyAllWindows()
0 <-- refers to the camera , replace it with file path to read a video file
cv.waitKey(20) & 0xFF==ord('d') <-- to destroy window when key is pressed
Adding a custom header to HTTP request using angular.js
my suggestion will be add a function call settings like this inside the function check the header which is appropriate for it. I am sure it will definitely work. it is perfectly working for me.
function getSettings(requestData) {
return {
url: requestData.url,
dataType: requestData.dataType || "json",
data: requestData.data || {},
headers: requestData.headers || {
"accept": "application/json; charset=utf-8",
'Authorization': 'Bearer ' + requestData.token
},
async: requestData.async || "false",
cache: requestData.cache || "false",
success: requestData.success || {},
error: requestData.error || {},
complete: requestData.complete || {},
fail: requestData.fail || {}
};
}
then call your data like this
var requestData = {
url: 'API end point',
data: Your Request Data,
token: Your Token
};
var settings = getSettings(requestData);
settings.method = "POST"; //("Your request type")
return $http(settings);
Decode Base64 data in Java
As an alternative to sun.misc.BASE64Decoder or non-core libraries, look at javax.mail.internet.MimeUtility.decode().
public static byte[] encode(byte[] b) throws Exception {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
OutputStream b64os = MimeUtility.encode(baos, "base64");
b64os.write(b);
b64os.close();
return baos.toByteArray();
}
public static byte[] decode(byte[] b) throws Exception {
ByteArrayInputStream bais = new ByteArrayInputStream(b);
InputStream b64is = MimeUtility.decode(bais, "base64");
byte[] tmp = new byte[b.length];
int n = b64is.read(tmp);
byte[] res = new byte[n];
System.arraycopy(tmp, 0, res, 0, n);
return res;
}
Link with full code: Encode/Decode to/from Base64
What is the meaning of ImagePullBackOff status on a Kubernetes pod?
I had the same problem what caused it was that I already had created a pod from the docker image via the .yml file, however I mistyped the name, i.e test-app:1.0.1 when I needed test-app:1.0.2 in my .yml file. So I did kubectl delete pods --all to remove the faulty pod then redid the kubectl create -f name_of_file.yml which solved my problem.
How to measure elapsed time
From Java 8 onward you can try the following:
import java.time.*;
import java.time.temporal.ChronoUnit;
Instant start_time = Instant.now();
// Your code
Instant stop_time = Instant.now();
System.out.println(Duration.between(start_time, stop_time).toMillis());
//or
System.out.println(ChronoUnit.MILLIS.between(start_time, stop_time));
Convert char * to LPWSTR
This version, using the Windows API function MultiByteToWideChar(), handles the memory allocation for arbitrarily long input strings.
int lenA = lstrlenA(input);
int lenW = ::MultiByteToWideChar(CP_ACP, 0, input, lenA, NULL, 0);
if (lenW>0)
{
output = new wchar_t[lenW];
::MultiByteToWideChar(CP_ACP, 0, input, lenA, output, lenW);
}
Why does Date.parse give incorrect results?
The accepted answer from CMS is correct, I have just added some features :
- trim and clean input spaces
- parse slashes, dashes, colons and spaces
- has default day and time
// parse a date time that can contains spaces, dashes, slashes, colons
function parseDate(input) {
// trimes and remove multiple spaces and split by expected characters
var parts = input.trim().replace(/ +(?= )/g,'').split(/[\s-\/:]/)
// new Date(year, month [, day [, hours[, minutes[, seconds[, ms]]]]])
return new Date(parts[0], parts[1]-1, parts[2] || 1, parts[3] || 0, parts[4] || 0, parts[5] || 0); // Note: months are 0-based
}
How to get a list of column names
Yes, you can achieve this by using the following commands:
sqlite> .headers on
sqlite> .mode column
The result of a select on your table will then look like:
id foo bar age street address
---------- ---------- ---------- ---------- ---------- ----------
1 val1 val2 val3 val4 val5
2 val6 val7 val8 val9 val10
Angularjs - ng-cloak/ng-show elements blink
I'm using ionic framework, adding css style might not work for certain circumstances, you can try using ng-if instead of ng-show / ng-hide
How to check if a string starts with one of several prefixes?
Besides the solutions presented already, you could use the Apache Commons Lang library:
if(StringUtils.startsWithAny(newStr4, new String[] {"Mon","Tues",...})) {
//whatever
}
Update: the introduction of varargs at some point makes the call simpler now:
StringUtils.startsWithAny(newStr4, "Mon", "Tues",...)
How do you do Impersonation in .NET?
"Impersonation" in the .NET space generally means running code under a specific user account. It is a somewhat separate concept than getting access to that user account via a username and password, although these two ideas pair together frequently. I will describe them both, and then explain how to use my SimpleImpersonation library, which uses them internally.
Impersonation
The APIs for impersonation are provided in .NET via the System.Security.Principal namespace:
Newer code (.NET 4.6+, .NET Core, etc.) should generally use
WindowsIdentity.RunImpersonated, which accepts a handle to the token of the user account, and then either anActionorFunc<T>for the code to execute.WindowsIdentity.RunImpersonated(tokenHandle, () => { // do whatever you want as this user. });or
var result = WindowsIdentity.RunImpersonated(tokenHandle, () => { // do whatever you want as this user. return result; });Older code used the
WindowsIdentity.Impersonatemethod to retrieve aWindowsImpersonationContextobject. This object implementsIDisposable, so generally should be called from ausingblock.using (WindowsImpersonationContext context = WindowsIdentity.Impersonate(tokenHandle)) { // do whatever you want as this user. }While this API still exists in .NET Framework, it should generally be avoided, and is not available in .NET Core or .NET Standard.
Accessing the User Account
The API for using a username and password to gain access to a user account in Windows is LogonUser - which is a Win32 native API. There is not currently a built-in .NET API for calling it, so one must resort to P/Invoke.
[DllImport("advapi32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
internal static extern bool LogonUser(String lpszUsername, String lpszDomain, String lpszPassword, int dwLogonType, int dwLogonProvider, out IntPtr phToken);
This is the basic call definition, however there is a lot more to consider to actually using it in production:
- Obtaining a handle with the "safe" access pattern.
- Closing the native handles appropriately
- Code access security (CAS) trust levels (in .NET Framework only)
- Passing
SecureStringwhen you can collect one safely via user keystrokes.
The amount of code to write to illustrate all of this is beyond what should be in a StackOverflow answer, IMHO.
A Combined and Easier Approach
Instead of writing all of this yourself, consider using my SimpleImpersonation library, which combines impersonation and user access into a single API. It works well in both modern and older code bases, with the same simple API:
var credentials = new UserCredentials(domain, username, password);
Impersonation.RunAsUser(credentials, logonType, () =>
{
// do whatever you want as this user.
});
or
var credentials = new UserCredentials(domain, username, password);
var result = Impersonation.RunAsUser(credentials, logonType, () =>
{
// do whatever you want as this user.
return something;
});
Note that it is very similar to the WindowsIdentity.RunImpersonated API, but doesn't require you know anything about token handles.
This is the API as of version 3.0.0. See the project readme for more details. Also note that a previous version of the library used an API with the IDisposable pattern, similar to WindowsIdentity.Impersonate. The newer version is much safer, and both are still used internally.
'pip install' fails for every package ("Could not find a version that satisfies the requirement")
Support for TLS 1.0 and 1.1 was dropped for PyPI. If your system does not use a more recent version, it could explain your error.
Could you try reinstalling pip system-wide, to update your system dependencies to a newer version of TLS?
This seems to be related to Unable to install Python libraries
See Dominique Barton's answer:
Apparently pip is trying to access PyPI via HTTPS (which is encrypted and fine), but with an old (insecure) SSL version. Your system seems to be out of date. It might help if you update your packages.
On Debian-based systems I'd try:
apt-get update && apt-get upgrade python-pipOn Red Hat Linux-based systems:
yum update python-pip # (or python2-pip, at least on Red Hat Linux 7)On Mac:
sudo easy_install -U pipYou can also try to update
opensslseparately.
C# string replace
Use of the replace() method
Here I'm replacing an old value to a new value:
string actual = "Hello World";
string Result = actual.Replace("World", "Stack Overflow");
----------------------
Output : "Hello Stack Overflow"
Reinitialize Slick js after successful ajax call
Note: I am not sure if this is correct but you can give it a try and see if this works.
There is a unslick method which de-initializes the carousel, so you might try using that before re-initializing it.
$.ajax({
type: 'get',
url: '/public/index',
dataType: 'script',
data: data_send,
success: function() {
$('.skills_section').unslick(); // destroy the previous instance
slickCarousel();
}
});
Hope this helps.
Foreign Key to multiple tables
Yet another option is to have, in Ticket, one column specifying the owning entity type (User or Group), second column with referenced User or Group id and NOT to use Foreign Keys but instead rely on a Trigger to enforce referential integrity.
Two advantages I see here over Nathan's excellent model (above):
- More immediate clarity and simplicity.
- Simpler queries to write.
How to check if BigDecimal variable == 0 in java?
A simple and better way for your exemple is:
BigDecimal price;
if(BigDecimal.ZERO.compareTo(price) == 0){
//Returns TRUE
}
How do I correctly use "Not Equal" in MS Access?
I have struggled to get a query to return fields from Table 1 that do not exist in Table 2 and tried most of the answers above until I found a very simple way to obtain the results that I wanted.
I set the join properties between table 1 and table 2 to the third setting (3) (All fields from Table 1 and only those records from Table 2 where the joined fields are equal) and placed a Is Null in the criteria field of the query in Table 2 in the field that I was testing for. It works perfectly.
Thanks to all above though.
What is the best method of handling currency/money?
Just a little update and a cohesion of all the answers for some aspiring juniors/beginners in RoR development that will surely come here for some explanations.
Working with money
Use :decimal to store money in the DB, as @molf suggested (and what my company uses as a golden standard when working with money).
# precision is the total number of digits
# scale is the number of digits to the right of the decimal point
add_column :items, :price, :decimal, precision: 8, scale: 2
Few points:
:decimalis going to be used asBigDecimalwhich solves a lot of issues.precisionandscaleshould be adjusted, depending on what you are representingIf you work with receiving and sending payments,
precision: 8andscale: 2gives you999,999.99as the highest amount, which is fine in 90% of cases.If you need to represent the value of a property or a rare car, you should use a higher
precision.If you work with coordinates (longitude and latitude), you will surely need a higher
scale.
How to generate a migration
To generate the migration with the above content, run in terminal:
bin/rails g migration AddPriceToItems price:decimal{8-2}
or
bin/rails g migration AddPriceToItems 'price:decimal{5,2}'
as explained in this blog post.
Currency formatting
KISS the extra libraries goodbye and use built-in helpers. Use number_to_currency as @molf and @facundofarias suggested.
To play with number_to_currency helper in Rails console, send a call to the ActiveSupport's NumberHelper class in order to access the helper.
For example:
ActiveSupport::NumberHelper.number_to_currency(2_500_000.61, unit: '€', precision: 2, separator: ',', delimiter: '', format: "%n%u")
gives the following output
2500000,61€
Check the other options of number_to_currency helper.
Where to put it
You can put it in an application helper and use it inside views for any amount.
module ApplicationHelper
def format_currency(amount)
number_to_currency(amount, unit: '€', precision: 2, separator: ',', delimiter: '', format: "%n%u")
end
end
Or you can put it in the Item model as an instance method, and call it where you need to format the price (in views or helpers).
class Item < ActiveRecord::Base
def format_price
number_to_currency(price, unit: '€', precision: 2, separator: ',', delimiter: '', format: "%n%u")
end
end
And, an example how I use the number_to_currency inside a contrroler (notice the negative_format option, used to represent refunds)
def refund_information
amount_formatted =
ActionController::Base.helpers.number_to_currency(@refund.amount, negative_format: '(%u%n)')
{
# ...
amount_formatted: amount_formatted,
# ...
}
end
download csv file from web api in angular js
None of those worked for me in Chrome 42...
Instead my directive now uses this link function (base64 made it work):
link: function(scope, element, attrs) {
var downloadFile = function downloadFile() {
var filename = scope.getFilename();
var link = angular.element('<a/>');
link.attr({
href: 'data:attachment/csv;base64,' + encodeURI($window.btoa(scope.csv)),
target: '_blank',
download: filename
})[0].click();
$timeout(function(){
link.remove();
}, 50);
};
element.bind('click', function(e) {
scope.buildCSV().then(function(csv) {
downloadFile();
});
scope.$apply();
});
}
How to install Java SDK on CentOS?
@Sventeck, perfecto.
redhat docs are always a great source - good tutorial that explains how to install JDK via yum and then setting the path can be found here (have fun!) - Install OpenJDK and set $JAVA_HOME path
OpenJDK 6:
yum install java-1.6.0-openjdk-devel
OpenJDK 7:
yum install java-1.7.0-openjdk-devel
To list all available java openjdk-devel packages try:
yum list "java-*-openjdk-devel"
Mapping list in Yaml to list of objects in Spring Boot
The reason must be somewhere else. Using only Spring Boot 1.2.2 out of the box with no configuration, it Just Works. Have a look at this repo - can you get it to break?
https://github.com/konrad-garus/so-yaml
Are you sure the YAML file looks exactly the way you pasted? No extra whitespace, characters, special characters, mis-indentation or something of that sort? Is it possible you have another file elsewhere in the search path that is used instead of the one you're expecting?
Automated Python to Java translation
Yes Jython does this, but it may or may not be what you want
How to name an object within a PowerPoint slide?
Yes. Click on the object (textbox, shape, etc.) to select the object and in the Drawing Tools | Format tab, click on Selection Pane in the Arrange group. From there, you'll see names of objects - you can double click (or press F2) on any name and rename it. By deselecting it, it becomes renamed. You can also get to this from the Home tab -> Drawing group -> Arrange drop-down -> Selection pane or by pressing ALT + F10.
Best way to select random rows PostgreSQL
One lesson from my experience:
offset floor(random() * N) limit 1 is not faster than order by random() limit 1.
I thought the offset approach would be faster because it should save the time of sorting in Postgres. Turns out it wasn't.
Convert int to char in java
Nobody has answered the real "question" here: you ARE converting int to char correctly; in the ASCII table a decimal value of 01 is "start of heading", a non-printing character. Try looking up an ASCII table and converting an int value between 33 and 7E; that will give you characters to look at.
Convert seconds into days, hours, minutes and seconds
I don't know why some of these answers are ridiculously long or complex. Here's one using the DateTime Class. Kind of similar to radzserg's answer. This will only display the units necessary, and negative times will have the 'ago' suffix...
function calctime($seconds = 0) {
$datetime1 = date_create("@0");
$datetime2 = date_create("@$seconds");
$interval = date_diff($datetime1, $datetime2);
if ( $interval->y >= 1 ) $thetime[] = pluralize( $interval->y, 'year' );
if ( $interval->m >= 1 ) $thetime[] = pluralize( $interval->m, 'month' );
if ( $interval->d >= 1 ) $thetime[] = pluralize( $interval->d, 'day' );
if ( $interval->h >= 1 ) $thetime[] = pluralize( $interval->h, 'hour' );
if ( $interval->i >= 1 ) $thetime[] = pluralize( $interval->i, 'minute' );
if ( $interval->s >= 1 ) $thetime[] = pluralize( $interval->s, 'second' );
return isset($thetime) ? implode(' ', $thetime) . ($interval->invert ? ' ago' : '') : NULL;
}
function pluralize($count, $text) {
return $count . ($count == 1 ? " $text" : " ${text}s");
}
// Examples:
// -86400 = 1 day ago
// 12345 = 3 hours 25 minutes 45 seconds
// 987654321 = 31 years 3 months 18 days 4 hours 25 minutes 21 seconds
EDIT: If you want to condense the above example down to use less variables / space (at the expense of legibility), here is an alternate version that does the same thing:
function calctime($seconds = 0) {
$interval = date_diff(date_create("@0"),date_create("@$seconds"));
foreach (array('y'=>'year','m'=>'month','d'=>'day','h'=>'hour','i'=>'minute','s'=>'second') as $format=>$desc) {
if ($interval->$format >= 1) $thetime[] = $interval->$format . ($interval->$format == 1 ? " $desc" : " {$desc}s");
}
return isset($thetime) ? implode(' ', $thetime) . ($interval->invert ? ' ago' : '') : NULL;
}
Force browser to download image files on click
<html>
<head>
<script type="text/javascript">
function prepHref(linkElement) {
var myDiv = document.getElementById('Div_contain_image');
var myImage = myDiv.children[0];
linkElement.href = myImage.src;
}
</script>
</head>
<body>
<div id="Div_contain_image"><img src="YourImage.jpg" alt='MyImage'></div>
<a href="#" onclick="prepHref(this)" download>Click here to download image</a>
</body>
</html>
How do I display images from Google Drive on a website?
Update 18/02/2017 Google had depreciated free hosting feature on Google drive and now you cannot host your static website on Google drive for free.
But if you want to host your JavaScript and CSS and Images file on Google drive then you can still do so. You just need to obtain the permalink of the file. following updated tutorial (2017).
http://www.bloggerseolab.com/2017/02/host-images-javascript-and-css-on-google-drive.html
Must JDBC Resultsets and Statements be closed separately although the Connection is closed afterwards?
Java 1.7 makes our lives much easier thanks to the try-with-resources statement.
try (Connection connection = dataSource.getConnection();
Statement statement = connection.createStatement()) {
try (ResultSet resultSet = statement.executeQuery("some query")) {
// Do stuff with the result set.
}
try (ResultSet resultSet = statement.executeQuery("some query")) {
// Do more stuff with the second result set.
}
}
This syntax is quite brief and elegant. And connection will indeed be closed even when the statement couldn't be created.
JSON and XML comparison
Before answering when to use which one, a little background:
edit: I should mention that this comparison is really from the perspective of using them in a browser with JavaScript. It's not the way either data format has to be used, and there are plenty of good parsers which will change the details to make what I'm saying not quite valid.
JSON is both more compact and (in my view) more readable - in transmission it can be "faster" simply because less data is transferred.
In parsing, it depends on your parser. A parser turning the code (be it JSON or XML) into a data structure (like a map) may benefit from the strict nature of XML (XML Schemas disambiguate the data structure nicely) - however in JSON the type of an item (String/Number/Nested JSON Object) can be inferred syntactically, e.g:
myJSON = {"age" : 12,
"name" : "Danielle"}
The parser doesn't need to be intelligent enough to realise that 12 represents a number, (and Danielle is a string like any other). So in javascript we can do:
anObject = JSON.parse(myJSON);
anObject.age === 12 // True
anObject.name == "Danielle" // True
anObject.age === "12" // False
In XML we'd have to do something like the following:
<person>
<age>12</age>
<name>Danielle</name>
</person>
(as an aside, this illustrates the point that XML is rather more verbose; a concern for data transmission). To use this data, we'd run it through a parser, then we'd have to call something like:
myObject = parseThatXMLPlease();
thePeople = myObject.getChildren("person");
thePerson = thePeople[0];
thePerson.getChildren("name")[0].value() == "Danielle" // True
thePerson.getChildren("age")[0].value() == "12" // True
Actually, a good parser might well type the age for you (on the other hand, you might well not want it to). What's going on when we access this data is - instead of doing an attribute lookup like in the JSON example above - we're doing a map lookup on the key name. It might be more intuitive to form the XML like this:
<person name="Danielle" age="12" />
But we'd still have to do map lookups to access our data:
myObject = parseThatXMLPlease();
age = myObject.getChildren("person")[0].getAttr("age");
EDIT: Original:
In most programming languages (not all, by any stretch) a map lookup such as this will be more costly than an attribute lookup (like we got above when we parsed the JSON).
This is misleading: remember that in JavaScript (and other dynamic languages) there's no difference between a map lookup and a field lookup. In fact, a field lookup is just a map lookup.
If you want a really worthwhile comparison, the best is to benchmark it - do the benchmarks in the context where you plan to use the data.
As I have been typing, Felix Kling has already put up a fairly succinct answer comparing them in terms of when to use each one, so I won't go on any further.
How to convert string to date to string in Swift iOS?
//String to Date Convert
var dateString = "2014-01-12"
var dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd"
let s = dateFormatter.dateFromString(dateString)
println(s)
//CONVERT FROM NSDate to String
let date = NSDate()
var dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd"
var dateString = dateFormatter.stringFromDate(date)
println(dateString)
Converting BitmapImage to Bitmap and vice versa
If you just need to go from BitmapImage to Bitmap it's quite easy,
private Bitmap BitmapImage2Bitmap(BitmapImage bitmapImage)
{
return new Bitmap(bitmapImage.StreamSource);
}
IIS: Display all sites and bindings in PowerShell
If you just want to list all the sites (ie. to find a binding)
Change the working directory to "C:\Windows\system32\inetsrv"
cd c:\Windows\system32\inetsrv
Next run "appcmd list sites" (plural) and output to a file. e.g c:\IISSiteBindings.txt
appcmd list sites > c:\IISSiteBindings.txt
Now open with notepad from your command prompt.
notepad c:\IISSiteBindings.txt
How can I get nth element from a list?
You can use !!, but if you want to do it recursively then below is one way to do it:
dataAt :: Int -> [a] -> a
dataAt _ [] = error "Empty List!"
dataAt y (x:xs) | y <= 0 = x
| otherwise = dataAt (y-1) xs
Install / upgrade gradle on Mac OS X
And using ports:
port install gradle
Ports , tested on El Capitan
End of File (EOF) in C
EOF is -1 because that's how it's defined. The name is provided by the standard library headers that you #include. They make it equal to -1 because it has to be something that can't be mistaken for an actual byte read by getchar(). getchar() reports the values of actual bytes using positive number (0 up to 255 inclusive), so -1 works fine for this.
The != operator means "not equal". 0 stands for false, and anything else stands for true. So what happens is, we call the getchar() function, and compare the result to -1 (EOF). If the result was not equal to EOF, then the result is true, because things that are not equal are not equal. If the result was equal to EOF, then the result is false, because things that are equal are not (not equal).
The call to getchar() returns EOF when you reach the "end of file". As far as C is concerned, the 'standard input' (the data you are giving to your program by typing in the command window) is just like a file. Of course, you can always type more, so you need an explicit way to say "I'm done". On Windows systems, this is control-Z. On Unix systems, this is control-D.
The example in the book is not "wrong". It depends on what you actually want to do. Reading until EOF means that you read everything, until the user says "I'm done", and then you can't read any more. Reading until '\n' means that you read a line of input. Reading until '\0' is a bad idea if you expect the user to type the input, because it is either hard or impossible to produce this byte with a keyboard at the command prompt :)
How to install Java 8 on Mac
brew cask install caskroom/versions/java8
Using any() and all() to check if a list contains one set of values or another
Generally speaking:
all and any are functions that take some iterable and return True, if
- in the case of
all(), no values in the iterable are falsy; - in the case of
any(), at least one value is truthy.
A value x is falsy iff bool(x) == False.
A value x is truthy iff bool(x) == True.
Any non-booleans in the iterable will be fine — bool(x) will coerce any x according to these rules: 0, 0.0, None, [], (), [], set(), and other empty collections will yield False, anything else True. The docstring for bool uses the terms 'true'/'false' for 'truthy'/'falsy', and True/False for the concrete boolean values.
In your specific code samples:
You misunderstood a little bit how these functions work. Hence, the following does something completely not what you thought:
if any(foobars) == big_foobar:
...because any(foobars) would first be evaluated to either True or False, and then that boolean value would be compared to big_foobar, which generally always gives you False (unless big_foobar coincidentally happened to be the same boolean value).
Note: the iterable can be a list, but it can also be a generator/generator expression (˜ lazily evaluated/generated list) or any other iterator.
What you want instead is:
if any(x == big_foobar for x in foobars):
which basically first constructs an iterable that yields a sequence of booleans—for each item in foobars, it compares the item to big_foobar and emits the resulting boolean into the resulting sequence:
tmp = (x == big_foobar for x in foobars)
then any walks over all items in tmp and returns True as soon as it finds the first truthy element. It's as if you did the following:
In [1]: foobars = ['big', 'small', 'medium', 'nice', 'ugly']
In [2]: big_foobar = 'big'
In [3]: any(['big' == big_foobar, 'small' == big_foobar, 'medium' == big_foobar, 'nice' == big_foobar, 'ugly' == big_foobar])
Out[3]: True
Note: As DSM pointed out, any(x == y for x in xs) is equivalent to y in xs but the latter is more readable, quicker to write and runs faster.
Some examples:
In [1]: any(x > 5 for x in range(4))
Out[1]: False
In [2]: all(isinstance(x, int) for x in range(10))
Out[2]: True
In [3]: any(x == 'Erik' for x in ['Erik', 'John', 'Jane', 'Jim'])
Out[3]: True
In [4]: all([True, True, True, False, True])
Out[4]: False
See also: http://docs.python.org/2/library/functions.html#all
Error In PHP5 ..Unable to load dynamic library
If you are using 5.6 php,
sudo apt-get install php5.6-curl
Escape double quotes in Java
Yes you will have to escape all double quotes by a backslash.
Clearfix with twitter bootstrap
clearfix should contain the floating elements but in your html you have added clearfix only after floating right that is your pull-right so you should do like this:
<div class="clearfix">
<div id="sidebar">
<ul>
<li>A</li>
<li>A</li>
<li>C</li>
<li>D</li>
<li>E</li>
<li>F</li>
<li>...</li>
<li>Z</li>
</ul>
</div>
<div id="main">
<div>
<div class="pull-right">
<a>RIGHT</a>
</div>
</div>
<div>MOVED BELOW Z</div>
</div>
Happy to know you solved the problem by setting overflow properties. However this is also good idea to clear the float. Where you have floated your elements you could add overflow: hidden; as you have done in your main.
How to remove special characters from a string?
As described here http://developer.android.com/reference/java/util/regex/Pattern.html
Patterns are compiled regular expressions. In many cases, convenience methods such as
String.matches,String.replaceAllandString.splitwill be preferable, but if you need to do a lot of work with the same regular expression, it may be more efficient to compile it once and reuse it. The Pattern class and its companion, Matcher, also offer more functionality than the small amount exposed by String.
public class RegularExpressionTest {
public static void main(String[] args) {
System.out.println("String is = "+getOnlyStrings("!&(*^*(^(+one(&(^()(*)(*&^%$#@!#$%^&*()("));
System.out.println("Number is = "+getOnlyDigits("&(*^*(^(+91-&*9hi-639-0097(&(^("));
}
public static String getOnlyDigits(String s) {
Pattern pattern = Pattern.compile("[^0-9]");
Matcher matcher = pattern.matcher(s);
String number = matcher.replaceAll("");
return number;
}
public static String getOnlyStrings(String s) {
Pattern pattern = Pattern.compile("[^a-z A-Z]");
Matcher matcher = pattern.matcher(s);
String number = matcher.replaceAll("");
return number;
}
}
Result
String is = one
Number is = 9196390097
ECMAScript 6 class destructor
"A destructor wouldn't even help you here. It's the event listeners themselves that still reference your object, so it would not be able to get garbage-collected before they are unregistered."
Not so. The purpose of a destructor is to allow the item that registered the listeners to unregister them. Once an object has no other references to it, it will be garbage collected.
For instance, in AngularJS, when a controller is destroyed, it can listen for a destroy event and respond to it. This isn't the same as having a destructor automatically called, but it's close, and gives us the opportunity to remove listeners that were set when the controller was initialized.
// Set event listeners, hanging onto the returned listener removal functions
function initialize() {
$scope.listenerCleanup = [];
$scope.listenerCleanup.push( $scope.$on( EVENTS.DESTROY, instance.onDestroy) );
$scope.listenerCleanup.push( $scope.$on( AUTH_SERVICE_RESPONSES.CREATE_USER.SUCCESS, instance.onCreateUserResponse ) );
$scope.listenerCleanup.push( $scope.$on( AUTH_SERVICE_RESPONSES.CREATE_USER.FAILURE, instance.onCreateUserResponse ) );
}
// Remove event listeners when the controller is destroyed
function onDestroy(){
$scope.listenerCleanup.forEach( remove => remove() );
}
Dynamically add item to jQuery Select2 control that uses AJAX
I did it this way and it worked for me like a charm.
var data = [{ id: 0, text: 'enhancement' }, { id: 1, text: 'bug' }, { id: 2,
text: 'duplicate' }, { id: 3, text: 'invalid' }, { id: 4, text: 'wontfix' }];
$(".js-example-data-array").select2({
data: data
})
How can I directly view blobs in MySQL Workbench
Doesn't seem to be possible I'm afraid, its listed as a bug in workbench: http://bugs.mysql.com/bug.php?id=50692 It would be very useful though!
How to get response status code from jQuery.ajax?
You can check your respone content, just console.log it and you will see whitch property have a status code. If you do not understand jsons, please refer to the video: https://www.youtube.com/watch?v=Bv_5Zv5c-Ts
It explains very basic knowledge that let you feel more comfortable with javascript.
You can do it with shorter version of ajax request, please see code above:
$.get("example.url.com", function(data) {
console.log(data);
}).done(function() {
// TO DO ON DONE
}).fail(function(data, textStatus, xhr) {
//This shows status code eg. 403
console.log("error", data.status);
//This shows status message eg. Forbidden
console.log("STATUS: "+xhr);
}).always(function() {
//TO-DO after fail/done request.
console.log("ended");
});
Example console output:
error 403
STATUS: Forbidden
ended
How do I use brew installed Python as the default Python?
python formula now uses python3(v3.6.5 for now), brew will link the directory:
/usr/local/opt/python -> ../Cellar/python/3.6.5
it will also link the binary:
/usr/local/bin/python3 -> ../Cellar/python/3.6.5/bin/python3
If you still need to use python2.x, use:
brew install python@2
To use homebrew's python, just put its directory in PATH, for bash:
export PATH="/usr/local/opt/python/libexec/bin:$PATH"
for fish:
set -x PATH /usr/local/opt/python/libexec/bin $PATH
Note:
- doing this will shadow the system default version of
python - homebrew used to link python to
/usr/local/share/pythonin older versions.
How to create an array from a CSV file using PHP and the fgetcsv function
Try this..
function getdata($csvFile){
$file_handle = fopen($csvFile, 'r');
while (!feof($file_handle) ) {
$line_of_text[] = fgetcsv($file_handle, 1024);
}
fclose($file_handle);
return $line_of_text;
}
// Set path to CSV file
$csvFile = 'test.csv';
$csv = getdata($csvFile);
echo '<pre>';
print_r($csv);
echo '</pre>';
Array
(
[0] => Array
(
[0] => Project
[1] => Date
[2] => User
[3] => Activity
[4] => Issue
[5] => Comment
[6] => Hours
)
[1] => Array
(
[0] => test
[1] => 04/30/2015
[2] => test
[3] => test
[4] => test
[5] =>
[6] => 6.00
));
Select values of checkbox group with jQuery
You can have a javascript variable which stores the number of checkboxes that are emitted, i.e in the <head> of the page:
<script type="text/javascript">
var num_cboxes=<?php echo $number_of_checkboxes;?>;
</script>
So if there are 10 checkboxes, starting from user_group-1 to user_group-10, in the javascript code you would get their value in this way:
var values=new Array();
for (x=1; x<=num_cboxes; x++)
{
values[x]=$("#user_group-" + x).val();
}
How to get a variable from a file to another file in Node.js
File FileOne.js:
module.exports = { ClientIDUnsplash : 'SuperSecretKey' };
File FileTwo.js:
var { ClientIDUnsplash } = require('./FileOne');
This example works best for React.
What's the difference between using "let" and "var"?
Scoping rules
Main difference is scoping rules. Variables declared by var keyword are scoped to the immediate function body (hence the function scope) while let variables are scoped to the immediate enclosing block denoted by { } (hence the block scope).
function run() {
var foo = "Foo";
let bar = "Bar";
console.log(foo, bar); // Foo Bar
{
var moo = "Mooo"
let baz = "Bazz";
console.log(moo, baz); // Mooo Bazz
}
console.log(moo); // Mooo
console.log(baz); // ReferenceError
}
run();
The reason why let keyword was introduced to the language was function scope is confusing and was one of the main sources of bugs in JavaScript.
Take a look at this example from another stackoverflow question:
var funcs = [];
// let's create 3 functions
for (var i = 0; i < 3; i++) {
// and store them in funcs
funcs[i] = function() {
// each should log its value.
console.log("My value: " + i);
};
}
for (var j = 0; j < 3; j++) {
// and now let's run each one to see
funcs[j]();
}
My value: 3 was output to console each time funcs[j](); was invoked since anonymous functions were bound to the same variable.
People had to create immediately invoked functions to capture correct value from the loops but that was also hairy.
Hoisting
While variables declared with var keyword are hoisted (initialized with undefined before the code is run) which means they are accessible in their enclosing scope even before they are declared:
function run() {
console.log(foo); // undefined
var foo = "Foo";
console.log(foo); // Foo
}
run();
let variables are not initialized until their definition is evaluated. Accessing them before the initialization results in a ReferenceError. Variable said to be in "temporal dead zone" from the start of the block until the initialization is processed.
function checkHoisting() {
console.log(foo); // ReferenceError
let foo = "Foo";
console.log(foo); // Foo
}
checkHoisting();
Creating global object property
At the top level, let, unlike var, does not create a property on the global object:
var foo = "Foo"; // globally scoped
let bar = "Bar"; // globally scoped
console.log(window.foo); // Foo
console.log(window.bar); // undefined
Redeclaration
In strict mode, var will let you re-declare the same variable in the same scope while let raises a SyntaxError.
'use strict';
var foo = "foo1";
var foo = "foo2"; // No problem, 'foo' is replaced.
let bar = "bar1";
let bar = "bar2"; // SyntaxError: Identifier 'bar' has already been declared
php Replacing multiple spaces with a single space
$output = preg_replace('/\s+/', ' ',$input);
\s is shorthand for [ \t\n\r]. Multiple spaces will be replaced with single space.
What is the difference between CMD and ENTRYPOINT in a Dockerfile?
Comments on EntryPoint function in code
// ENTRYPOINT /usr/sbin/nginx.
// Set the entrypoint (which defaults to sh -c) to /usr/sbin/nginx.
// Will accept the CMD as the arguments to /usr/sbin/nginx.
Another reference from documents
You can use the exec form of ENTRYPOINT to set fairly stable default commands and arguments and then use CMD to set additional defaults that are more likely to be changed.
Example:
FROM ubuntu:14.04.3
ENTRYPOINT ["/bin/ping"]
CMD ["localhost", "-c", "2"]
Build: sudo docker build -t ent_cmd .
CMD arguments are easy to override.
NO argument (sudo docker -it ent_cmd) : ping localhost
argument (sudo docker run -it ent_cmd google.com) : ping google.com
.
To override EntryPoint argument, you need to supply entrypoint
sudo docker run -it --entrypoint="/bin/bash" ent_cmdd
p.s: In presence of EntryPoint, CMD will hold arguments to fed to EntryPoint. In absense of EntryPoint, CMD will be the command which will be run.