Sending mass email using PHP
First off, using the mail() function that comes with PHP is not an optimal solution. It is easily marked as spammed, and you need to set up header to ensure that you are sending HTML emails correctly. As for whether the code snippet will work, it would, but I doubt you will get HTML code inside it correctly without specifying extra headers
I'll suggest you take a look at SwiftMailer, which has HTML support, support for different mime types and SMTP authentication (which is less likely to mark your mail as spam).
Import CSV file into SQL Server
2) If the client create the csv from excel then the data that have
comma are enclosed within " ... " (double quotes) [as the below
example] so how do the import can handle this?
You should use FORMAT = 'CSV', FIELDQUOTE = '"' options:
BULK INSERT SchoolsTemp
FROM 'C:\CSVData\Schools.csv'
WITH
(
FORMAT = 'CSV',
FIELDQUOTE = '"',
FIRSTROW = 2,
FIELDTERMINATOR = ',', --CSV field delimiter
ROWTERMINATOR = '\n', --Use to shift the control to next row
TABLOCK
)
mysql update query with sub query
Thanks, I didn't have the idea of an UPDATE with INNER JOIN.
In the original query, the mistake was to name the subquery, which must return a value and can't therefore be aliased.
UPDATE Competition
SET Competition.NumberOfTeams =
(SELECT count(*) -- no column alias
FROM PicksPoints
WHERE UserCompetitionID is not NULL
-- put the join condition INSIDE the subquery :
AND CompetitionID = Competition.CompetitionID
group by CompetitionID
) -- no table alias
should do the trick for every record of Competition.
To be noticed :
The effect is NOT EXACTLY the same as the query proposed by mellamokb, which won't update Competition records with no corresponding PickPoints.
Since SELECT id, COUNT(*) GROUP BY id
will only count for existing values of ids,
whereas a SELECT COUNT(*)
will always return a value, being 0 if no records are selected.
This may, or may not, be a problem for you.
0-aware version of mellamokb query would be :
Update Competition as C
LEFT join (
select CompetitionId, count(*) as NumberOfTeams
from PicksPoints as p
where UserCompetitionID is not NULL
group by CompetitionID
) as A on C.CompetitionID = A.CompetitionID
set C.NumberOfTeams = IFNULL(A.NumberOfTeams, 0)
In other words, if no corresponding PickPoints are found, set Competition.NumberOfTeams to zero.
How to find a value in an array and remove it by using PHP array functions?
You can use array_filter
to filter out elements of an array based on a callback function. The callback function takes each element of the array as an argument and you simply return false
if that element should be removed. This also has the benefit of removing duplicate values since it scans the entire array.
You can use it like this:
$myArray = array('apple', 'orange', 'banana', 'plum', 'banana');
$output = array_filter($myArray, function($value) { return $value !== 'banana'; });
// content of $output after previous line:
// $output = array('apple', 'orange', 'plum');
And if you want to re-index the array, you can pass the result to array_values
like this:
$output = array_values($output);
Get the element with the highest occurrence in an array
This is just the mode. Here's a quick, non-optimized solution. It should be O(n).
function mode(array)
{
if(array.length == 0)
return null;
var modeMap = {};
var maxEl = array[0], maxCount = 1;
for(var i = 0; i < array.length; i++)
{
var el = array[i];
if(modeMap[el] == null)
modeMap[el] = 1;
else
modeMap[el]++;
if(modeMap[el] > maxCount)
{
maxEl = el;
maxCount = modeMap[el];
}
}
return maxEl;
}
How to include multiple js files using jQuery $.getScript() method
This works for me:
function getScripts(scripts) {
var prArr = [];
scripts.forEach(function(script) {
(function(script){
prArr .push(new Promise(function(resolve){
$.getScript(script, function () {
resolve();
});
}));
})(script);
});
return Promise.all(prArr, function(){
return true;
});
}
And use it:
var jsarr = ['script1.js','script2.js'];
getScripts(jsarr).then(function(){
...
});
Is it possible to use argsort in descending order?
With your example:
avgDists = np.array([1, 8, 6, 9, 4])
Obtain indexes of n maximal values:
ids = np.argpartition(avgDists, -n)[-n:]
Sort them in descending order:
ids = ids[np.argsort(avgDists[ids])[::-1]]
Obtain results (for n=4):
>>> avgDists[ids]
array([9, 8, 6, 4])
How can one display images side by side in a GitHub README.md?
To piggyback off of @Maruf Hassan
# Title
<table>
<tr>
<td>First Screen Page</td>
<td>Holiday Mention</td>
<td>Present day in purple and selected day in pink</td>
</tr>
<tr>
<td valign="top"><img src="screenshots/Screenshot_1582745092.png"></td>
<td valign="top"><img src="screenshots/Screenshot_1582745125.png"></td>
<td valign="top"><img src="screenshots/Screenshot_1582745139.png"></td>
</tr>
</table>
<td valign="top">...</td>
is supported by GitHub Markdown. Images with varying heights may not vertically align near the top of the cell. This property handles it for you.
How I can check whether a page is loaded completely or not in web driver?
Selenium does it for you. Or at least it tries its best. Sometimes it falls short, and you must help it a little bit. The usual solution is Implicit Wait
which solves most of the problems.
If you really know what you're doing, and why you're doing it, you could try to write a generic method which would check whether the page is completely loaded. However, it can't be done for every web and for every situation.
Related question: Selenium WebDriver : Wait for complex page with JavaScript(JS) to load, see my answer there.
Shorter version: You'll never be sure.
The "normal" load is easy - document.readyState
. This one is implemented by Selenium, of course. The problematic thing are asynchronous requests, AJAX, because you can never tell whether it's done for good or not. Most of today's webpages have scripts that run forever and poll the server all the time.
The various things you could do are under the link above. Or, like 95% of other people, use Implicit Wait
implicity and Explicit Wait
+ ExpectedConditions
where needed.
E.g. after a click, some element on the page should become visible and you need to wait for it:
WebDriverWait wait = new WebDriverWait(driver, 10); // you can reuse this one
WebElement elem = driver.findElement(By.id("myInvisibleElement"));
elem.click();
wait.until(ExpectedConditions.visibilityOf(elem));
PYTHONPATH vs. sys.path
If the only reason to modify the path is for developers working from their working tree, then you should use an installation tool to set up your environment for you. virtualenv is very popular, and if you are using setuptools, you can simply run setup.py develop
to semi-install the working tree in your current Python installation.
How to disable scrolling temporarily?
Do it simply by adding a class to the body:
.stop-scrolling {
height: 100%;
overflow: hidden;
}
Add the class then remove when you want to re-enable scrolling, tested in IE, FF, Safari and Chrome.
$('body').addClass('stop-scrolling')
For mobile devices, you'll need to handle the touchmove
event:
$('body').bind('touchmove', function(e){e.preventDefault()})
And unbind to re-enable scrolling. Tested in iOS6 and Android 2.3.3
$('body').unbind('touchmove')
What's wrong with overridable method calls in constructors?
On invoking overridable method from constructors
Simply put, this is wrong because it unnecessarily opens up possibilities to MANY bugs. When the @Override
is invoked, the state of the object may be inconsistent and/or incomplete.
A quote from Effective Java 2nd Edition, Item 17: Design and document for inheritance, or else prohibit it:
There are a few more restrictions that a class must obey to allow inheritance. Constructors must not invoke overridable methods, directly or indirectly. If you violate this rule, program failure will result. The superclass constructor runs before the subclass constructor, so the overriding method in the subclass will be invoked before the subclass constructor has run. If the overriding method depends on any initialization performed by the subclass constructor, the method will not behave as expected.
Here's an example to illustrate:
public class ConstructorCallsOverride {
public static void main(String[] args) {
abstract class Base {
Base() {
overrideMe();
}
abstract void overrideMe();
}
class Child extends Base {
final int x;
Child(int x) {
this.x = x;
}
@Override
void overrideMe() {
System.out.println(x);
}
}
new Child(42); // prints "0"
}
}
Here, when Base
constructor calls overrideMe
, Child
has not finished initializing the final int x
, and the method gets the wrong value. This will almost certainly lead to bugs and errors.
Related questions
See also
On object construction with many parameters
Constructors with many parameters can lead to poor readability, and better alternatives exist.
Here's a quote from Effective Java 2nd Edition, Item 2: Consider a builder pattern when faced with many constructor parameters:
Traditionally, programmers have used the telescoping constructor pattern, in which you provide a constructor with only the required parameters, another with a single optional parameters, a third with two optional parameters, and so on...
The telescoping constructor pattern is essentially something like this:
public class Telescope {
final String name;
final int levels;
final boolean isAdjustable;
public Telescope(String name) {
this(name, 5);
}
public Telescope(String name, int levels) {
this(name, levels, false);
}
public Telescope(String name, int levels, boolean isAdjustable) {
this.name = name;
this.levels = levels;
this.isAdjustable = isAdjustable;
}
}
And now you can do any of the following:
new Telescope("X/1999");
new Telescope("X/1999", 13);
new Telescope("X/1999", 13, true);
You can't, however, currently set only the name
and isAdjustable
, and leaving levels
at default. You can provide more constructor overloads, but obviously the number would explode as the number of parameters grow, and you may even have multiple boolean
and int
arguments, which would really make a mess out of things.
As you can see, this isn't a pleasant pattern to write, and even less pleasant to use (What does "true" mean here? What's 13?).
Bloch recommends using a builder pattern, which would allow you to write something like this instead:
Telescope telly = new Telescope.Builder("X/1999").setAdjustable(true).build();
Note that now the parameters are named, and you can set them in any order you want, and you can skip the ones that you want to keep at default values. This is certainly much better than telescoping constructors, especially when there's a huge number of parameters that belong to many of the same types.
See also
Related questions
How can I submit a POST form using the <a href="..."> tag?
In case you use MVC to accomplish it - you will have to do something like this
<form action="/ControllerName/ActionName" method="post">
<a href="javascript:;" onclick="parentNode.submit();"><%=n%></a>
<input type="hidden" name="mess" value=<%=n%>/>
</form>
I just went through some examples here and did not see the MVC one figured it won't hurt to post it.
Then on your Action in the Controller I would just put <HTTPPost>
On the top of it.
I believe if you don't have <HTTPGET>
on the top of it it would still work but explicitly putting it there feels a bit safer.
What's the better (cleaner) way to ignore output in PowerShell?
Personally, I use ... | Out-Null
because, as others have commented, that looks like the more "PowerShellish" approach compared to ... > $null
and [void] ...
. $null = ...
is exploiting a specific automatic variable and can be easy to overlook, whereas the other methods make it obvious with additional syntax that you intend to discard the output of an expression. Because ... | Out-Null
and ... > $null
come at the end of the expression I think they effectively communicate "take everything we've done up to this point and throw it away", plus you can comment them out easier for debugging purposes (e.g. ... # | Out-Null
), compared to putting $null =
or [void]
before the expression to determine what happens after executing it.
Let's look at a different benchmark, though: not the amount of time it takes to execute each option, but the amount of time it takes to figure out what each option does. Having worked in environments with colleagues who were not experienced with PowerShell or even scripting at all, I tend to try to write my scripts in a way that someone coming along years later that might not even understand the language they're looking at can have a fighting chance at figuring out what it's doing since they might be in a position of having to support or replace it. This has never occurred to me as a reason to use one method over the others until now, but imagine you're in that position and you use the help
command or your favorite search engine to try to find out what Out-Null
does. You get a useful result immediately, right? Now try to do the same with [void]
and $null =
. Not so easy, is it?
Granted, suppressing the output of a value is a pretty minor detail compared to understanding the overall logic of a script, and you can only try to "dumb down" your code so much before you're trading your ability to write good code for a novice's ability to read...not-so-good code. My point is, it's possible that some who are fluent in PowerShell aren't even familiar with [void]
, $null =
, etc., and just because those may execute faster or take less keystrokes to type, doesn't mean they're the best way to do what you're trying to do, and just because a language gives you quirky syntax doesn't mean you should use it instead of something clearer and better-known.*
* I am presuming that Out-Null
is clear and well-known, which I don't know to be $true
. Whichever option you feel is clearest and most accessible to future readers and editors of your code (yourself included), regardless of time-to-type or time-to-execute, that's the option I'm recommending you use.
How to assert two list contain the same elements in Python?
Converting your lists to sets will tell you that they contain the same elements. But this method cannot confirm that they contain the same number of all elements. For example, your method will fail in this case:
L1 = [1,2,2,3]
L2 = [1,2,3,3]
You are likely better off sorting the two lists and comparing them:
def checkEqual(L1, L2):
if sorted(L1) == sorted(L2):
print "the two lists are the same"
return True
else:
print "the two lists are not the same"
return False
Note that this does not alter the structure/contents of the two lists. Rather, the sorting creates two new lists
Redirect all output to file in Bash
That part is written to stderr, use 2>
to redirect it. For example:
foo > stdout.txt 2> stderr.txt
or if you want in same file:
foo > allout.txt 2>&1
Note: this works in (ba)sh, check your shell for proper syntax
jQuery: How can I create a simple overlay?
Here's a fully encapsulated version which adds an overlay (including a share button) to any IMG element where data-photo-overlay='true.
JSFiddle
http://jsfiddle.net/wloescher/7y6UX/19/
HTML
<img id="my-photo-id" src="http://cdn.sstatic.net/stackexchange/img/logos/so/so-logo.png" alt="Photo" data-photo-overlay="true" />
CSS
#photoOverlay {
background: #ccc;
background: rgba(0, 0, 0, .5);
display: none;
height: 50px;
left: 0;
position: absolute;
text-align: center;
top: 0;
width: 50px;
z-index: 1000;
}
#photoOverlayShare {
background: #fff;
border: solid 3px #ccc;
color: #ff6a00;
cursor: pointer;
display: inline-block;
font-size: 14px;
margin-left: auto;
margin: 15px;
padding: 5px;
position: absolute;
left: calc(100% - 100px);
text-transform: uppercase;
width: 50px;
}
JavaScript
(function () {
// Add photo overlay hover behavior to selected images
$("img[data-photo-overlay='true']").mouseenter(showPhotoOverlay);
// Create photo overlay elements
var _isPhotoOverlayDisplayed = false;
var _photoId;
var _photoOverlay = $("<div id='photoOverlay'></div>");
var _photoOverlayShareButton = $("<div id='photoOverlayShare'>Share</div>");
// Add photo overlay events
_photoOverlay.mouseleave(hidePhotoOverlay);
_photoOverlayShareButton.click(sharePhoto);
// Add photo overlay elements to document
_photoOverlay.append(_photoOverlayShareButton);
_photoOverlay.appendTo(document.body);
// Show photo overlay
function showPhotoOverlay(e) {
// Get sender
var sender = $(e.target || e.srcElement);
// Check to see if overlay is already displayed
if (!_isPhotoOverlayDisplayed) {
// Set overlay properties based on sender
_photoOverlay.width(sender.width());
_photoOverlay.height(sender.height());
// Position overlay on top of photo
if (sender[0].x) {
_photoOverlay.css("left", sender[0].x + "px");
_photoOverlay.css("top", sender[0].y) + "px";
}
else {
// Handle IE incompatibility
_photoOverlay.css("left", sender.offset().left);
_photoOverlay.css("top", sender.offset().top);
}
// Get photo Id
_photoId = sender.attr("id");
// Show overlay
_photoOverlay.animate({ opacity: "toggle" });
_isPhotoOverlayDisplayed = true;
}
}
// Hide photo overlay
function hidePhotoOverlay(e) {
if (_isPhotoOverlayDisplayed) {
_photoOverlay.animate({ opacity: "toggle" });
_isPhotoOverlayDisplayed = false;
}
}
// Share photo
function sharePhoto() {
alert("TODO: Share photo. [PhotoId = " + _photoId + "]");
}
}
)();
Permutation of array
Here is one using arrays and Java 8+
import java.util.Arrays;
import java.util.stream.IntStream;
public class HelloWorld {
public static void main(String[] args) {
int[] arr = {1, 2, 3, 5};
permutation(arr, new int[]{});
}
static void permutation(int[] arr, int[] prefix) {
if (arr.length == 0) {
System.out.println(Arrays.toString(prefix));
}
for (int i = 0; i < arr.length; i++) {
int i2 = i;
int[] pre = IntStream.concat(Arrays.stream(prefix), IntStream.of(arr[i])).toArray();
int[] post = IntStream.range(0, arr.length).filter(i1 -> i1 != i2).map(v -> arr[v]).toArray();
permutation(post, pre);
}
}
}
Close/kill the session when the browser or tab is closed
Not perfect but best solution for now :
var spcKey = false;
var hover = true;
var contextMenu = false;
function spc(e) {
return ((e.altKey || e.ctrlKey || e.keyCode == 91 || e.keyCode==87) && e.keyCode!=82 && e.keyCode!=116);
}
$(document).hover(function () {
hover = true;
contextMenu = false;
spcKey = false;
}, function () {
hover = false;
}).keydown(function (e) {
if (spc(e) == false) {
hover = true;
spcKey = false;
}
else {
spcKey = true;
}
}).keyup(function (e) {
if (spc(e)) {
spcKey = false;
}
}).contextmenu(function (e) {
contextMenu = true;
}).click(function () {
hover = true;
contextMenu = false;
});
window.addEventListener('focus', function () {
spcKey = false;
});
window.addEventListener('blur', function () {
hover = false;
});
window.onbeforeunload = function (e) {
if ((hover == false || spcKey == true) && contextMenu==false) {
window.setTimeout(goToLoginPage, 100);
$.ajax({
url: "/Account/Logoff",
type: 'post',
data: $("#logoutForm").serialize(),
});
return "Oturumunuz kapatildi.";
}
return;
};
function goToLoginPage() {
hover = true;
spcKey = false;
contextMenu = false;
location.href = "/Account/Login";
}
Simplest PHP example for retrieving user_timeline with Twitter API version 1.1
This question helped me a lot but didn't get me all the way in understanding what needs to happen. This blog post did an amazing job of walking me through it.
Here are the important bits all in one place:
- As pointed out above, you MUST sign your 1.1 API requests. If you are doing something like getting public statuses, you'll want an application key rather than a user key. The full link to the page you want is: https://dev.twitter.com/apps
- You must hash ALL the parameters, both the oauth ones AND the get parameters (or POST parameters) together.
- You must SORT the parameters before reducing them to the url encoded form that gets hashed.
- You must encode some things multiple times - for example, you create a query string from the parameters' url-encoded values, and then you url encode THAT and concatenate with the method type and the url.
I sympathize with all the headaches, so here's some code to wrap it all up:
$token = 'YOUR TOKEN';
$token_secret = 'TOKEN SECRET';
$consumer_key = 'YOUR KEY';
$consumer_secret = 'KEY SECRET';
$host = 'api.twitter.com';
$method = 'GET';
$path = '/1.1/statuses/user_timeline.json'; // api call path
$query = array( // query parameters
'screen_name' => 'twitterapi',
'count' => '2'
);
$oauth = array(
'oauth_consumer_key' => $consumer_key,
'oauth_token' => $token,
'oauth_nonce' => (string)mt_rand(), // a stronger nonce is recommended
'oauth_timestamp' => time(),
'oauth_signature_method' => 'HMAC-SHA1',
'oauth_version' => '1.0'
);
$oauth = array_map("rawurlencode", $oauth); // must be encoded before sorting
$query = array_map("rawurlencode", $query);
$arr = array_merge($oauth, $query); // combine the values THEN sort
asort($arr); // secondary sort (value)
ksort($arr); // primary sort (key)
// http_build_query automatically encodes, but our parameters
// are already encoded, and must be by this point, so we undo
// the encoding step
$querystring = urldecode(http_build_query($arr, '', '&'));
$url = "https://$host$path";
// mash everything together for the text to hash
$base_string = $method."&".rawurlencode($url)."&".rawurlencode($querystring);
// same with the key
$key = rawurlencode($consumer_secret)."&".rawurlencode($token_secret);
// generate the hash
$signature = rawurlencode(base64_encode(hash_hmac('sha1', $base_string, $key, true)));
// this time we're using a normal GET query, and we're only encoding the query params
// (without the oauth params)
$url .= "?".http_build_query($query);
$oauth['oauth_signature'] = $signature; // don't want to abandon all that work!
ksort($oauth); // probably not necessary, but twitter's demo does it
// also not necessary, but twitter's demo does this too
function add_quotes($str) { return '"'.$str.'"'; }
$oauth = array_map("add_quotes", $oauth);
// this is the full value of the Authorization line
$auth = "OAuth " . urldecode(http_build_query($oauth, '', ', '));
// if you're doing post, you need to skip the GET building above
// and instead supply query parameters to CURLOPT_POSTFIELDS
$options = array( CURLOPT_HTTPHEADER => array("Authorization: $auth"),
//CURLOPT_POSTFIELDS => $postfields,
CURLOPT_HEADER => false,
CURLOPT_URL => $url,
CURLOPT_RETURNTRANSFER => true,
CURLOPT_SSL_VERIFYPEER => false);
// do our business
$feed = curl_init();
curl_setopt_array($feed, $options);
$json = curl_exec($feed);
curl_close($feed);
$twitter_data = json_decode($json);
C++ Dynamic Shared Library on Linux
Basically, you should include the class' header file in the code where you want to use the class in the shared library. Then, when you link, use the '-l' flag to link your code with the shared library. Of course, this requires the .so to be where the OS can find it. See 3.5. Installing and Using a Shared Library
Using dlsym is for when you don't know at compile time which library you want to use. That doesn't sound like it's the case here. Maybe the confusion is that Windows calls the dynamically loaded libraries whether you do the linking at compile or run-time (with analogous methods)? If so, then you can think of dlsym as the equivalent of LoadLibrary.
If you really do need to dynamically load the libraries (i.e., they're plug-ins), then this FAQ should help.
fastest way to export blobs from table into individual files
For me what worked by combining all the posts I have read is:
1.Enable OLE automation - if not enabled
sp_configure 'show advanced options', 1;
GO
RECONFIGURE;
GO
sp_configure 'Ole Automation Procedures', 1;
GO
RECONFIGURE;
GO
2.Create a folder where the generated files will be stored:
C:\GREGTESTING
3.Create DocTable that will be used for file generation and store there the blobs in Doc_Content
CREATE TABLE [dbo].[Document](
[Doc_Num] [numeric](18, 0) IDENTITY(1,1) NOT NULL,
[Extension] [varchar](50) NULL,
[FileName] [varchar](200) NULL,
[Doc_Content] [varbinary](max) NULL
) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]
INSERT [dbo].[Document] ([Extension] ,[FileName] , [Doc_Content] )
SELECT 'pdf', 'SHTP Notional hire - January 2019.pdf', 0x....(varbinary blob)
Important note!
Don't forget to add in Doc_Content column the varbinary of file you want to generate!
4.Run the below script
DECLARE @outPutPath varchar(50) = 'C:\GREGTESTING'
, @i bigint
, @init int
, @data varbinary(max)
, @fPath varchar(max)
, @folderPath varchar(max)
--Get Data into temp Table variable so that we can iterate over it
DECLARE @Doctable TABLE (id int identity(1,1), [Doc_Num] varchar(100) , [FileName] varchar(100), [Doc_Content] varBinary(max) )
INSERT INTO @Doctable([Doc_Num] , [FileName],[Doc_Content])
Select [Doc_Num] , [FileName],[Doc_Content] FROM [dbo].[Document]
SELECT @i = COUNT(1) FROM @Doctable
WHILE @i >= 1
BEGIN
SELECT
@data = [Doc_Content],
@fPath = @outPutPath + '\' + [Doc_Num] +'_' +[FileName],
@folderPath = @outPutPath + '\'+ [Doc_Num]
FROM @Doctable WHERE id = @i
EXEC sp_OACreate 'ADODB.Stream', @init OUTPUT; -- An instace created
EXEC sp_OASetProperty @init, 'Type', 1;
EXEC sp_OAMethod @init, 'Open'; -- Calling a method
EXEC sp_OAMethod @init, 'Write', NULL, @data; -- Calling a method
EXEC sp_OAMethod @init, 'SaveToFile', NULL, @fPath, 2; -- Calling a method
EXEC sp_OAMethod @init, 'Close'; -- Calling a method
EXEC sp_OADestroy @init; -- Closed the resources
print 'Document Generated at - '+ @fPath
--Reset the variables for next use
SELECT @data = NULL
, @init = NULL
, @fPath = NULL
, @folderPath = NULL
SET @i -= 1
END
5.The results is shown below:
SQL Server equivalent of MySQL's NOW()?
You can also use CURRENT_TIMESTAMP
, if you feel like being more ANSI compliant (though if you're porting code between database vendors, that'll be the least of your worries). It's exactly the same as GetDate()
under the covers (see this question for more on that).
There's no ANSI equivalent for GetUTCDate()
, however, which is probably the one you should be using if your app operates in more than a single time zone ...
How can I make a countdown with NSTimer?
Swift 3
private let NUMBER_COUNT_DOWN = 3
var countDownLabel = UILabel()
var countDown = NUMBER_COUNT_DOWN
var timer:Timer?
private func countDown(time: Double)
{
countDownLabel.frame = CGRect(x: 0, y: 0, width: 300, height: 300)
countDownLabel.font = UIFont.systemFont(ofSize: 300)
countDownLabel.textColor = .black
countDownLabel.center = CGPoint(x: self.view.frame.width / 2, y: self.view.frame.height / 2)
countDownLabel.textAlignment = .center
self.view.addSubview(countDownLabel)
view.bringSubview(toFront: countDownLabel)
timer = Timer.scheduledTimer(timeInterval: time, target: self, selector: #selector(updateCountDown), userInfo: nil, repeats: true)
}
func updateCountDown() {
if(countDown > 0) {
countDownLabel.text = String(countDown)
countDown = countDown - 1
} else {
removeCountDownLable()
}
}
private func removeCountDownLable() {
countDown = NUMBER_COUNT_DOWN
countDownLabel.text = ""
countDownLabel.removeFromSuperview()
timer?.invalidate()
timer = nil
}
Sqlite convert string to date
convert a string
into date
little issue think with indexing mmm 3,3 but works added a month on to the date string
SELECT substr('12Jan20',1,2) as dday,
date(substr('12Jan20',6,7) ||'00-' || case substr('12Jan20',3,3) when 'Jan' then '01'
when 'Feb' then '02'
when 'Mar' then '03'
when 'Apr' then '04'
when 'May' then '05'
when 'Jun' then '06'
when 'Jul' then '07'
when 'Aug' then '08'
when 'Sep' then '09'
when 'Oct' then '10'
when 'Nov' then '11'
when 'Dec' then '12' end || '-'||substr('12Jan20',1,2), '+1 month') as tt
How can I use the HTML5 canvas element in IE?
Currently, ExplorerCanvas is the only option to emulate HTML5 canvas for IE6, 7, and 8. You're also right about its performance, which is pretty poor.
I found a particle simulatior that benchmarks the difference between true HTML5 canvas handling in Google Chrome, Safari, and Firefox, vs ExplorerCanvas in IE. The results show that the major browsers that do support the canvas tag run about 20 to 30 times faster than the emulated HTML5 in IE with ExplorerCanvas.
I doubt that anyone will go through the effort of creating an alternative because 1) excanvas.js is about as cleanly coded as it gets and 2) when IE9 is released all of the major browsers will finally support the canvas object. Hopefully, We'll get IE9 within a year
Eric @ www.webkrunk.com
Infinity symbol with HTML
You can use the following:
- literal:
8
(if the encoding you use can encode it — UTF-8 can, for example)
- character reference:
∞
(decimal), ∞
(hexadecimal)
- entity reference:
∞
But whether it is displayed correctly does also depend on the font the text is displayed with.
PHPDoc type hinting for array of objects?
PSR-5: PHPDoc proposes a form of Generics-style notation.
Syntax
Type[]
Type<Type>
Type<Type[, Type]...>
Type<Type[|Type]...>
Values in a Collection MAY even be another array and even another Collection.
Type<Type<Type>>
Type<Type<Type[, Type]...>>
Type<Type<Type[|Type]...>>
Examples
<?php
$x = [new Name()];
/* @var $x Name[] */
$y = new Collection([new Name()]);
/* @var $y Collection<Name> */
$a = new Collection();
$a[] = new Model_User();
$a->resetChanges();
$a[0]->name = "George";
$a->echoChanges();
/* @var $a Collection<Model_User> */
Note: If you are expecting an IDE to do code assist then it's another question about if the IDE supports PHPDoc Generic-style collections notation.
From my answer to this question.
SQL: capitalize first letter only
select replace(wm_concat(new),',','-') exp_res from (select distinct initcap(substr(name,decode(level,1,1,instr(name,'-',1,level-1)+1),decode(level,(length(name)-length(replace(name,'-','')))+1,9999,instr(name,'-',1,level)-1-decode(level,1,0,instr(name,'-',1,level-1))))) new from table;
connect by level<= (select (length(name)-length(replace(name,'-','')))+1 from table));
Difference between CR LF, LF and CR line break types?
Jeff Atwood has a recent blog post about this: The Great Newline Schism
Here is the essence from Wikipedia:
The sequence CR+LF was in common use
on many early computer systems that
had adopted teletype machines,
typically an ASR33, as a console
device, because this sequence was
required to position those printers at
the start of a new line. On these
systems, text was often routinely
composed to be compatible with these
printers, since the concept of device
drivers hiding such hardware details
from the application was not yet well
developed; applications had to talk
directly to the teletype machine and
follow its conventions. The separation
of the two functions concealed the
fact that the print head could not
return from the far right to the
beginning of the next line in
one-character time. That is why the
sequence was always sent with the CR
first. In fact, it was often necessary
to send extra characters (extraneous
CRs or NULs, which are ignored) to
give the print head time to move to
the left margin. Even after teletypes
were replaced by computer terminals
with higher baud rates, many operating
systems still supported automatic
sending of these fill characters, for
compatibility with cheaper terminals
that required multiple character times
to scroll the display.
Truststore and Keystore Definitions
A keystore contains private keys, and the certificates with their corresponding public keys.
A truststore contains certificates from other parties that you expect to communicate with, or from Certificate Authorities that you trust to identify other parties.
getting integer values from textfield
As You're getting values from textfield as jTextField3.getText();
.
As it is a textField
it will return you string format as its format says:
String getText()
Returns the text contained in this TextComponent.
So, convert your String
to Integer
as:
int jml = Integer.parseInt(jTextField3.getText());
instead of directly setting
int jml = jTextField3.getText();
What is an unsigned char?
signed char
and unsigned char
both represent 1byte, but they have different ranges.
Type | range
-------------------------------
signed char | -128 to +127
unsigned char | 0 to 255
In signed char
if we consider char letter = 'A'
, 'A' is represent binary of 65 in ASCII/Unicode
, If 65 can be stored, -65 also can be stored. There are no negative binary values in ASCII/Unicode
there for no need to worry about negative values.
Example
#include <stdio.h>
int main()
{
signed char char1 = 255;
signed char char2 = -128;
unsigned char char3 = 255;
unsigned char char4 = -128;
printf("Signed char(255) : %d\n",char1);
printf("Unsigned char(255) : %d\n",char3);
printf("\nSigned char(-128) : %d\n",char2);
printf("Unsigned char(-128) : %d\n",char4);
return 0;
}
Output -:
Signed char(255) : -1
Unsigned char(255) : 255
Signed char(-128) : -128
Unsigned char(-128) : 128
Sorting hashmap based on keys
Just use a TreeMap
. It implements the SortedMap
interface, and thus automatically sorts the keys it contains. Your keys can just be sorted alphabetically to get the desired result, so you don't even need to provide a comparator.
HashMaps are never sorted. The only thing you coulkd do with a HashMap is get all the keys, and store them in a sorted set or in a List and sort the List.
CSS overflow-x: visible; and overflow-y: hidden; causing scrollbar issue
I used the content+wrapper
approach ... but I did something different than mentioned so far: I made sure that my wrapper's boundaries did NOT line up with the content's boundaries in the direction that I wanted to be visible.
Important NOTE: It was easy enough to get the content+wrapper, same-bounds
approach to work on one browser or another depending on various css combinations of position
, overflow-*
, etc ... but I never could use that approach to get them all correct (Edge, Chrome, Safari, ...).
But when I had something like:
<div id="hack_wrapper" // created solely for this purpose
style="position:absolute; width:100%; height:100%; overflow-x:hidden;">
<div id="content_wrapper"
style="position:absolute; width:100%; height:15%; overflow:visible;">
... content with too-much horizontal content ...
</div>
</div>
... all browsers were happy.
How to use an array list in Java?
You could either get your strings by index (System.out.println(S.get(0));
) or iterate through it:
for (String s : S) {
System.out.println(s);
}
For other ways to iterate through a list (and their implications) see traditional for loop vs Iterator in Java.
Additionally:
- you shouldn't use variable names starting with upper-case letters
- you should parametrize your array list:
ArrayList<String> list = new ArrayList<String>();
- you should get familiar with Java's extensive API documentation (aka Javadoc), e.g. Java 5, Java 6
AngularJS multiple filter with custom filter function
Try this:
<tr ng-repeat="player in players | filter:{id: player_id, name:player_name} | filter:ageFilter">
$scope.ageFilter = function (player) {
return (player.age > $scope.min_age && player.age < $scope.max_age);
}
What is JavaScript garbage collection?
Beware of circular references when DOM objects are involved:
Memory leak patterns in JavaScript
Keep in mind that memory can only be reclaimed when there are no active references to the object. This is a common pitfall with closures and event handlers, as some JS engines will not check which variables actually are referenced in inner functions and just keep all local variables of the enclosing functions.
Here's a simple example:
function init() {
var bigString = new Array(1000).join('xxx');
var foo = document.getElementById('foo');
foo.onclick = function() {
// this might create a closure over `bigString`,
// even if `bigString` isn't referenced anywhere!
};
}
A naive JS implementation can't collect bigString
as long as the event handler is around. There are several ways to solve this problem, eg setting bigString = null
at the end of init()
(delete
won't work for local variables and function arguments: delete
removes properties from objects, and the variable object is inaccessible - ES5 in strict mode will even throw a ReferenceError
if you try to delete a local variable!).
I recommend to avoid unnecessary closures as much as possible if you care for memory consumption.
A TypeScript GUID class?
I found this https://typescriptbcl.codeplex.com/SourceControl/latest
here is the Guid version they have in case the link does not work later.
module System {
export class Guid {
constructor (public guid: string) {
this._guid = guid;
}
private _guid: string;
public ToString(): string {
return this.guid;
}
// Static member
static MakeNew(): Guid {
var result: string;
var i: string;
var j: number;
result = "";
for (j = 0; j < 32; j++) {
if (j == 8 || j == 12 || j == 16 || j == 20)
result = result + '-';
i = Math.floor(Math.random() * 16).toString(16).toUpperCase();
result = result + i;
}
return new Guid(result);
}
}
}
XAMPP permissions on Mac OS X?
If you use Mac OS X and XAMPP, let's assume that your folder with your site or API located in folder /Applications/XAMPP/xamppfiles/htdocs/API. Then you can grant access like this:
$ chmod 777 /Applications/XAMPP/xamppfiles/htdocs/API
And now open the page inside the folder:
http://localhost/API/index.php
What does "where T : class, new()" mean?
when using the class in constraints it's mean you can only use Reference type, another thing to add is when to use the constraint new(), it's must be the last thing you write in the Constraints terms.
Label on the left side instead above an input field
Put the <label>
outside the form-group
:
<form class="form-inline">
<label for="rg-from">Ab: </label>
<div class="form-group">
<input type="text" id="rg-from" name="rg-from" value="" class="form-control">
</div>
<!-- rest of form -->
</form>
How to access host port from docker container
I've explored the various solution and I find this the least hacky solution:
- Define a static IP address for the bridge gateway IP.
- Add the gateway IP as an extra entry in the
extra_hosts
directive.
The only downside is if you have multiple networks or projects doing this, you have to ensure that their IP address range do not conflict.
Here is a Docker Compose example:
version: '2.3'
services:
redis:
image: "redis"
extra_hosts:
- "dockerhost:172.20.0.1"
networks:
default:
ipam:
driver: default
config:
- subnet: 172.20.0.0/16
gateway: 172.20.0.1
You can then access ports on the host from inside the container using the hostname "dockerhost".
<button> vs. <input type="button" />. Which to use?
Quoting the Forms Page in the HTML manual:
Buttons created with the BUTTON element function just like buttons created with the INPUT element, but they offer richer rendering possibilities: the BUTTON element may have content. For example, a BUTTON element that contains an image functions like and may resemble an INPUT element whose type is set to "image", but the BUTTON element type allows content.
-bash: export: `=': not a valid identifier
You cannot put spaces around the =
sign when you do:
export foo=bar
Remove the spaces you have and you should be good to go.
If you type:
export foo = bar
the shell will interpret that as a request to export three names: foo
, =
and bar
. =
isn't a valid variable name, so the command fails. The variable name, equals sign and it's value must not be separated by spaces for them to be processed as a simultaneous assignment and export.
How to hide a status bar in iOS?
I had the same problem, but its an easy fix! Just set
status bar is initially hidden = YES
then add an row by clicking on the plus right after the text status bar is initially hidden
, then set the text to
view controller-based status bar appearance
by clicking the arrows, and set it to NO
Hope this helps!
How can I make a JPA OneToOne relation lazy
For Kotlin devs: To allow Hibernate to inherit from the @Entity types that you want to be lazy-loadable they have to be inheritable/open
, which they in Kotlin by default are not. To work around this issue we can make use of the all-open
compiler plugin and instruct it to also handle the JPA annotations by adding this to our build.gradle
:
allOpen {
annotation("javax.persistence.Entity")
annotation("javax.persistence.MappedSuperclass")
annotation("javax.persistence.Embeddable")
}
If you are using Kotlin and Spring like me, you are most probably also using the kotlin-jpa
/no-args
and kotlin-spring
/all-open
compiler plugins already. However, you will still need to add the above lines, as that combination of plugins neither makes such classes open
.
Read the great article of Léo Millon for further explanations.
JSON character encoding
The answers here helped me solve my problem, although it's not completely related.
I use the javax.ws.rs API and the @Produces and @Consumes annotations and had this same problem - the JSON I was returning in the webservice was not in UTF-8. I solved it with the following annotations on top of my controller functions :
@Produces(javax.ws.rs.core.MediaType.APPLICATION_JSON + "; charset=UTF-8")
and
@Consumes(javax.ws.rs.core.MediaType.APPLICATION_JSON + "; charset=UTF-8")
On every endpoint's get and post function. I wasn't setting the charset and this solved it. This is part of jersey so maybe you'll have to add a maven dependency.
Already defined in .obj - no double inclusions
This is not a compiler error: the error is coming from the linker. After compilation, the linker will merge the object files resulting from the compilation of each of your translation units (.cpp
files).
The linker finds out that you have the same symbol defined multiple times in different translation units, and complains about it (it is a violation of the One Definition Rule).
The reason is most certainly that main.cpp
includes client.cpp
, and both these files are individually processed by the compiler to produce two separate object files. Therefore, all the symbols defined in the client.cpp
translation unit will be defined also in the main.cpp
translation unit. This is one of the reasons why you do not usually #include
.cpp
files.
Put the definition of your class in a separate client.hpp
file which does not contain also the definitions of the member functions of that class; then, let client.cpp
and main.cpp
include that file (I mean #include
). Finally, leave in client.cpp
the definitions of your class's member functions.
client.h
#ifndef SOCKET_CLIENT_CLASS
#define SOCKET_CLIENT_CLASS
#ifndef BOOST_ASIO_HPP
#include <boost/asio.hpp>
#endif
class SocketClient // Or whatever the name is...
{
// ...
bool read(int, char*); // Or whatever the name is...
// ...
};
#endif
client.cpp
#include "Client.h"
// ...
bool SocketClient::read(int, char*)
{
// Implementation goes here...
}
// ... (add the definitions for all other member functions)
main.h
#include <iostream>
#include <string>
#include <sstream>
#include <boost/asio.hpp>
#include <boost/thread/thread.hpp>
#include "client.h"
// ^^ Notice this!
main.cpp
#include "main.h"
How do I clear my Jenkins/Hudson build history?
Go to the %HUDSON_HOME%\jobs\<projectname>
remove builds
dir and remove lastStable, lastSuccessful
links, and remove nextBuildNumber
file.
After doing above steps go to below link from UI
Jenkins-> Manage Jenkins -> Reload Configuration from Disk
It will do as you need
Java ArrayList clear() function
If you in any doubt, have a look at JDK source code
ArrayList.clear()
source code:
public void clear() {
modCount++;
// Let gc do its work
for (int i = 0; i < size; i++)
elementData[i] = null;
size = 0;
}
You will see that size
is set to 0 so you start from 0 position.
Please note that when adding elements to ArrayList
, the backend array is extended (i.e. array data is copied to bigger array if needed) in order to be able to add new items. When performing ArrayList.clear()
you only remove references to array elements and sets size
to 0, however, capacity
stays as it was.
fopen deprecated warning
If you want it to be used on many platforms, you could as commented use defines like:
#if defined(_MSC_VER) || defined(WIN32) || defined(_WIN32) || defined(__WIN32__) \
|| defined(WIN64) || defined(_WIN64) || defined(__WIN64__)
errno_t err = fopen_s(&stream,name, "w");
#endif
#if defined(unix) || defined(__unix) || defined(__unix__) \
|| defined(linux) || defined(__linux) || defined(__linux__) \
|| defined(sun) || defined(__sun) \
|| defined(BSD) || defined(__OpenBSD__) || defined(__NetBSD__) \
|| defined(__FreeBSD__) || defined __DragonFly__ \
|| defined(sgi) || defined(__sgi) \
|| defined(__MACOSX__) || defined(__APPLE__) \
|| defined(__CYGWIN__)
stream = fopen(name, "w");
#endif
Javascript to set hidden form value on drop down change
Here you can set hidden's value at onchange event of dropdown list :
$('#myDropDown').bind('change', function () {
$('#myHidden').val('setted value');
});
your hidden and drop down list :
<input type="hidden" id="myHidden" />
<select id="myDropDown">
<option value="opt 1">Option 1</option>
<option value="opt 2">Option 2</option>
<option value="opt 3">Option 3</option>
</ select>
Local Storage vs Cookies
Cookies and local storage serve different purposes. Cookies are primarily for reading server-side, local storage can only be read by the client-side. So the question is, in your app, who needs this data — the client or the server?
If it's your client (your JavaScript), then by all means switch. You're wasting bandwidth by sending all the data in each HTTP header.
If it's your server, local storage isn't so useful because you'd have to forward the data along somehow (with Ajax or hidden form fields or something). This might be okay if the server only needs a small subset of the total data for each request.
You'll want to leave your session cookie as a cookie either way though.
As per the technical difference, and also my understanding:
Apart from being an old way of saving data, Cookies give you a limit of 4096 bytes (4095, actually) — it's per cookie. Local Storage is as big as 5MB per domain — SO Question also mentions it.
localStorage
is an implementation of the Storage
Interface. It stores data with no expiration date, and gets cleared only through JavaScript, or clearing the Browser Cache / Locally Stored Data — unlike cookie expiry.
How to run Visual Studio post-build events for debug build only
You can pass the configuration name to the post-build script and check it in there to see if it should run.
Pass the configuration name with $(ConfigurationName)
.
Checking it is based on how you are implementing the post-build step -- it will be a command-line argument.
HTML5 File API read as text and binary
Note in 2018: readAsBinaryString
is outdated. For use cases where previously you'd have used it, these days you'd use readAsArrayBuffer
(or in some cases, readAsDataURL
) instead.
readAsBinaryString
says that the data must be represented as a binary string, where:
...every byte is represented by an integer in the range [0..255].
JavaScript originally didn't have a "binary" type (until ECMAScript 5's WebGL support of Typed Array* (details below) -- it has been superseded by ECMAScript 2015's ArrayBuffer) and so they went with a String with the guarantee that no character stored in the String would be outside the range 0..255. (They could have gone with an array of Numbers instead, but they didn't; perhaps large Strings are more memory-efficient than large arrays of Numbers, since Numbers are floating-point.)
If you're reading a file that's mostly text in a western script (mostly English, for instance), then that string is going to look a lot like text. If you read a file with Unicode characters in it, you should notice a difference, since JavaScript strings are UTF-16** (details below) and so some characters will have values above 255, whereas a "binary string" according to the File API spec wouldn't have any values above 255 (you'd have two individual "characters" for the two bytes of the Unicode code point).
If you're reading a file that's not text at all (an image, perhaps), you'll probably still get a very similar result between readAsText
and readAsBinaryString
, but with readAsBinaryString
you know that there won't be any attempt to interpret multi-byte sequences as characters. You don't know that if you use readAsText
, because readAsText
will use an encoding determination to try to figure out what the file's encoding is and then map it to JavaScript's UTF-16 strings.
You can see the effect if you create a file and store it in something other than ASCII or UTF-8. (In Windows you can do this via Notepad; the "Save As" as an encoding drop-down with "Unicode" on it, by which looking at the data they seem to mean UTF-16; I'm sure Mac OS and *nix editors have a similar feature.) Here's a page that dumps the result of reading a file both ways:
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-type" content="text/html;charset=UTF-8">
<title>Show File Data</title>
<style type='text/css'>
body {
font-family: sans-serif;
}
</style>
<script type='text/javascript'>
function loadFile() {
var input, file, fr;
if (typeof window.FileReader !== 'function') {
bodyAppend("p", "The file API isn't supported on this browser yet.");
return;
}
input = document.getElementById('fileinput');
if (!input) {
bodyAppend("p", "Um, couldn't find the fileinput element.");
}
else if (!input.files) {
bodyAppend("p", "This browser doesn't seem to support the `files` property of file inputs.");
}
else if (!input.files[0]) {
bodyAppend("p", "Please select a file before clicking 'Load'");
}
else {
file = input.files[0];
fr = new FileReader();
fr.onload = receivedText;
fr.readAsText(file);
}
function receivedText() {
showResult(fr, "Text");
fr = new FileReader();
fr.onload = receivedBinary;
fr.readAsBinaryString(file);
}
function receivedBinary() {
showResult(fr, "Binary");
}
}
function showResult(fr, label) {
var markup, result, n, aByte, byteStr;
markup = [];
result = fr.result;
for (n = 0; n < result.length; ++n) {
aByte = result.charCodeAt(n);
byteStr = aByte.toString(16);
if (byteStr.length < 2) {
byteStr = "0" + byteStr;
}
markup.push(byteStr);
}
bodyAppend("p", label + " (" + result.length + "):");
bodyAppend("pre", markup.join(" "));
}
function bodyAppend(tagName, innerHTML) {
var elm;
elm = document.createElement(tagName);
elm.innerHTML = innerHTML;
document.body.appendChild(elm);
}
</script>
</head>
<body>
<form action='#' onsubmit="return false;">
<input type='file' id='fileinput'>
<input type='button' id='btnLoad' value='Load' onclick='loadFile();'>
</form>
</body>
</html>
If I use that with a "Testing 1 2 3" file stored in UTF-16, here are the results I get:
Text (13):
54 65 73 74 69 6e 67 20 31 20 32 20 33
Binary (28):
ff fe 54 00 65 00 73 00 74 00 69 00 6e 00 67 00 20 00 31 00 20 00 32 00 20 00 33 00
As you can see, readAsText
interpreted the characters and so I got 13 (the length of "Testing 1 2 3"), and readAsBinaryString
didn't, and so I got 28 (the two-byte BOM plus two bytes for each character).
* XMLHttpRequest.response with responseType = "arraybuffer"
is supported in HTML 5.
** "JavaScript strings are UTF-16" may seem like an odd statement; aren't they just Unicode? No, a JavaScript string is a series of UTF-16 code units; you see surrogate pairs as two individual JavaScript "characters" even though, in fact, the surrogate pair as a whole is just one character. See the link for details.
How To have Dynamic SQL in MySQL Stored Procedure
I don't believe MySQL supports dynamic sql. You can do "prepared" statements which is similar, but different.
Here is an example:
mysql> PREPARE stmt FROM
-> 'select count(*)
-> from information_schema.schemata
-> where schema_name = ? or schema_name = ?'
;
Query OK, 0 rows affected (0.00 sec)
Statement prepared
mysql> EXECUTE stmt
-> USING @schema1,@schema2
+----------+
| count(*) |
+----------+
| 2 |
+----------+
1 row in set (0.00 sec)
mysql> DEALLOCATE PREPARE stmt;
The prepared statements are often used to see an execution plan for a given query. Since they are executed with the execute command and the sql can be assigned to a variable you can approximate the some of the same behavior as dynamic sql.
Here is a good link about this:
Don't forget to deallocate the stmt
using the last line!
Good Luck!
When you use 'badidea' or 'thisisunsafe' to bypass a Chrome certificate/HSTS error, does it only apply for the current site?
This is specific for each site. So if you type that once, you will only get through that site and all other sites will need a similar type-through.
It is also remembered for that site and you have to click on the padlock to reset it (so you can type it again):
Needless to say use of this "feature" is a bad idea and is unsafe - hence the name.
You should find out why the site is showing the error and/or stop using it until they fix it. HSTS specifically adds protections for bad certs to prevent you clicking through them. The fact it's needed suggests there is something wrong with the https connection - like the site or your connection to it has been hacked.
The chrome developers also do change this periodically. They changed it recently from badidea
to thisisunsafe
so everyone using badidea
, suddenly stopped being able to use it. You should not depend on it. As Steffen pointed out in the comments below, it is available in the code should it change again though they now base64 encode it to make it more obscure. The last time they changed they put this comment in the commit:
Rotate the interstitial bypass keyword
The security interstitial bypass keyword hasn't changed in two years
and awareness of the bypass has been increased in blogs and social
media. Rotate the keyword to help prevent misuse.
I think the message from the Chrome team is clear - you should not use it. It would not surprise me if they removed it completely in future.
If you are using this when using a self-signed certificate for local testing then why not just add your self-signed certificate certificate to your computer's certificate store so you get a green padlock and do not have to type this? Note Chrome insists on a SAN
field in certificates now so if just using the old subject
field then even adding it to the certificate store will not result in a green padlock.
If you leave the certificate untrusted then certain things do not work. Caching for example is completely ignored for untrusted certificates. As is HTTP/2 Push.
HTTPS is here to stay and we need to get used to using it properly - and not bypassing the warnings with a hack that is liable to change and doesn't work the same as a full HTTPS solution.
Normalize data in pandas
This is how you do it column-wise:
[df[col].update((df[col] - df[col].min()) / (df[col].max() - df[col].min())) for col in df.columns]
What are database normal forms and can you give examples?
Here's a quick, admittedly butchered response, but in a sentence:
1NF : Your table is organized as an unordered set of data, and there are no repeating columns.
2NF: You don't repeat data in one column of your table because of another column.
3NF: Every column in your table relates only to your table's key -- you wouldn't have a column in a table that describes another column in your table which isn't the key.
For more detail, see wikipedia...
What is SaaS, PaaS and IaaS? With examples
When you are a simple client who wants to make use of a software but you have nothing in hand then you use SaaS.
When you have a software developed by you, but you want to deploy and run on a publicly available platform then you use PaaS.
When you have the software and the platform ready but you want the hardware to run then you use IaaS.
The matching wildcard is strict, but no declaration can be found for element 'context:component-scan
It's too late but somewhat may useful to others
The matching wildcard is strict, but no declaration can be found for
element 'context:component-scan
which Means you have Missed some Declarations or The Required Declarations Not Found in Your XML
In my case i forgot to add the follwoing
After Adding this the Problem Gone away
<?xml version="1.0" encoding="UTF-8"?>
<beans:beans xmlns="http://www.springframework.org/schema/mvc"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:beans="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd">
Converting a SimpleXML Object to an Array
Just (array)
is missing in your code before the simplexml object:
...
$xml = simplexml_load_string($string, 'SimpleXMLElement', LIBXML_NOCDATA);
$array = json_decode(json_encode((array)$xml), TRUE);
^^^^^^^
...
How to plot multiple functions on the same figure, in Matplotlib?
To plot multiple graphs on the same figure you will have to do:
from numpy import *
import math
import matplotlib.pyplot as plt
t = linspace(0, 2*math.pi, 400)
a = sin(t)
b = cos(t)
c = a + b
plt.plot(t, a, 'r') # plotting t, a separately
plt.plot(t, b, 'b') # plotting t, b separately
plt.plot(t, c, 'g') # plotting t, c separately
plt.show()
The "backspace" escape character '\b': unexpected behavior?
Not too hard to explain... This is like typing hello worl
, hitting the left-arrow key twice, typing d
, and hitting the down-arrow key.
At least, that is how I infer your terminal is interpeting the \b
and \n
codes.
Redirect the output to a file and I bet you get something else entirely. Although you may have to look at the file's bytes to see the difference.
[edit]
To elaborate a bit, this printf
emits a sequence of bytes: hello worl^H^Hd^J
, where ^H
is ASCII character #8 and ^J
is ASCII character #10. What you see on your screen depends on how your terminal interprets those control codes.
How to set Java SDK path in AndroidStudio?
Generally speaking, it is set in the "Project Structure" dialog.
Go to File > Project Structure > SDK Location. The third field is "JDK Location" where you can set it. This will set it for the current project.
To set the default for new projects, go to File > Other Settings > Default Project Structure > SDK Location and set the "JDK Location".
Older Versions
Go to File > Project Structure > [Platform Settings] > SDKs. You'll need to either update you current SDK configuration to use the new directory, or define a new one and then change your project's settings to use the new one. This will set it for the current project.
To set the default for new projects, go to File > Other Settings > Structure for New Projects > [Platform Settings] > SDKs and set the SDK to use when creating a new project.
How to validate domain credentials?
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Security;
using System.DirectoryServices.AccountManagement;
public struct Credentials
{
public string Username;
public string Password;
}
public class Domain_Authentication
{
public Credentials Credentials;
public string Domain;
public Domain_Authentication(string Username, string Password, string SDomain)
{
Credentials.Username = Username;
Credentials.Password = Password;
Domain = SDomain;
}
public bool IsValid()
{
using (PrincipalContext pc = new PrincipalContext(ContextType.Domain, Domain))
{
// validate the credentials
return pc.ValidateCredentials(Credentials.Username, Credentials.Password);
}
}
}
Merge two Excel tables Based on matching data in Columns
Put the table in the second image on Sheet2, columns D to F.
In Sheet1, cell D2 use the formula
=iferror(vlookup($A2,Sheet2!$D$1:$F$100,column(A1),false),"")
copy across and down.
Edit: here is a picture. The data is in two sheets. On Sheet1, enter the formula into cell D2. Then copy the formula across to F2 and then down as many rows as you need.
How to detect READ_COMMITTED_SNAPSHOT is enabled?
Neither on SQL2005 nor 2012 does DBCC USEROPTIONS
show is_read_committed_snapshot_on
:
Set Option Value
textsize 2147483647
language us_english
dateformat mdy
datefirst 7
lock_timeout -1
quoted_identifier SET
arithabort SET
ansi_null_dflt_on SET
ansi_warnings SET
ansi_padding SET
ansi_nulls SET
concat_null_yields_null SET
isolation level read committed
Trust Anchor not found for Android SSL Connection
**Set proper alias name**
CertificateFactory certificateFactory = CertificateFactory.getInstance("X.509","BC");
X509Certificate cert = (X509Certificate) certificateFactory.generateCertificate(derInputStream);
String alias = cert.getSubjectX500Principal().getName();
KeyStore trustStore = KeyStore.getInstance(KeyStore.getDefaultType());
trustStore.load(null);
trustStore.setCertificateEntry(alias, cert);
best practice font size for mobile
The font sizes in your question are an example of what ratio each header should be in comparison to each other, rather than what size they should be themselves (in pixels).
So in response to your question "Is there a 'best practice' for these for mobile phones? - say iphone screen size?", yes there probably is - but you might find what someone says is "best practice" does not work for your layout.
However, to help get you on the right track, this article about building responsive layouts provides a good example of how to calculate the base font-size
in pixels in relation to device screen sizes.
The suggested font-sizes for screen resolutions suggested from that article are as follows:
@media (min-width: 858px) {
html {
font-size: 12px;
}
}
@media (min-width: 780px) {
html {
font-size: 11px;
}
}
@media (min-width: 702px) {
html {
font-size: 10px;
}
}
@media (min-width: 724px) {
html {
font-size: 9px;
}
}
@media (max-width: 623px) {
html {
font-size: 8px;
}
}
How to determine if a number is odd in JavaScript
I'd implement this to return a boolean:
function isOdd (n) {
return !!(n % 2);
// or ((n % 2) !== 0).
}
It'll work on both unsigned and signed numbers. When the modulus return -1
or 1
it'll get translated to true
.
Non-modulus solution:
var is_finite = isFinite;
var is_nan = isNaN;
function isOdd (discriminant) {
if (is_nan(discriminant) && !is_finite(discriminant)) {
return false;
}
// Unsigned numbers
if (discriminant >= 0) {
while (discriminant >= 1) discriminant -= 2;
// Signed numbers
} else {
if (discriminant === -1) return true;
while (discriminant <= -1) discriminant += 2;
}
return !!discriminant;
}
Node.js Mongoose.js string to ObjectId function
I couldn't resolve this method (admittedly I didn't search for long)
mongoose.mongo.BSONPure.ObjectID.fromHexString
If your schema expects the property to be of type ObjectId, the conversion is implicit, at least this seems to be the case in 4.7.8.
You could use something like this however, which gives a bit more flex:
function toObjectId(ids) {
if (ids.constructor === Array) {
return ids.map(mongoose.Types.ObjectId);
}
return mongoose.Types.ObjectId(ids);
}
Comparing user-inputted characters in C
Because comparison doesn't work that way. 'Y' || 'y'
is a logical-or operator; it returns 1
(true) if either of its arguments is true. Since 'Y'
and 'y'
are both true, you're comparing *answer
with 1.
What you want is if(*answer == 'Y' || *answer == 'y')
or perhaps:
switch (*answer) {
case 'Y':
case 'y':
/* Code for Y */
break;
default:
/* Code for anything else */
}
How to go to a specific element on page?
here is a simple javascript for that
call this when you need to scroll the screen to an element which has id="yourSpecificElementId"
window.scroll(0,findPos(document.getElementById("yourSpecificElementId")));
and you need this function for the working:
//Finds y value of given object
function findPos(obj) {
var curtop = 0;
if (obj.offsetParent) {
do {
curtop += obj.offsetTop;
} while (obj = obj.offsetParent);
return [curtop];
}
}
the screen will be scrolled to your specific element.
Redirect Windows cmd stdout and stderr to a single file
In a batch file (Windows 7 and above) I found this method most reliable
Call :logging >"C:\Temp\NAME_Your_Log_File.txt" 2>&1
:logging
TITLE "Logging Commands"
ECHO "Read this output in your log file"
ECHO ..
Prompt $_
COLOR 0F
Obviously, use whatever commands you want and the output will be directed to the text file.
Using this method is reliable HOWEVER there is NO output on the screen.
Accessing the last entry in a Map
To answer your question in one sentence:
Per default, Maps don't have a last entry, it's not part of their contract.
And a side note: it's good practice to code against interfaces, not the implementation classes (see Effective Java by Joshua Bloch, Chapter 8, Item 52: Refer to objects by their interfaces).
So your declaration should read:
Map<String,Integer> map = new HashMap<String,Integer>();
(All maps share a common contract, so the client need not know what kind of map it is, unless he specifies a sub interface with an extended contract).
Possible Solutions
Sorted Maps:
There is a sub interface SortedMap that extends the map interface with order-based lookup methods and it has a sub interface NavigableMap that extends it even further. The standard implementation of this interface, TreeMap, allows you to sort entries either by natural ordering (if they implement the Comparable interface) or by a supplied Comparator.
You can access the last entry through the lastEntry method:
NavigableMap<String,Integer> map = new TreeMap<String, Integer>();
// add some entries
Entry<String, Integer> lastEntry = map.lastEntry();
Linked maps:
There is also the special case of LinkedHashMap, a HashMap implementation that stores the order in which keys are inserted. There is however no interface to back up this functionality, nor is there a direct way to access the last key. You can only do it through tricks such as using a List in between:
Map<String,String> map = new LinkedHashMap<String, Integer>();
// add some entries
List<Entry<String,Integer>> entryList =
new ArrayList<Map.Entry<String, Integer>>(map.entrySet());
Entry<String, Integer> lastEntry =
entryList.get(entryList.size()-1);
Proper Solution:
Since you don't control the insertion order, you should go with the NavigableMap interface, i.e. you would write a comparator that positions the Not-Specified
entry last.
Here is an example:
final NavigableMap<String,Integer> map =
new TreeMap<String, Integer>(new Comparator<String>() {
public int compare(final String o1, final String o2) {
int result;
if("Not-Specified".equals(o1)) {
result=1;
} else if("Not-Specified".equals(o2)) {
result=-1;
} else {
result =o1.compareTo(o2);
}
return result;
}
});
map.put("test", Integer.valueOf(2));
map.put("Not-Specified", Integer.valueOf(1));
map.put("testtest", Integer.valueOf(3));
final Entry<String, Integer> lastEntry = map.lastEntry();
System.out.println("Last key: "+lastEntry.getKey()
+ ", last value: "+lastEntry.getValue());
Output:
Last key: Not-Specified, last value: 1
Solution using HashMap:
If you must rely on HashMaps, there is still a solution, using a) a modified version of the above comparator, b) a List initialized with the Map's entrySet and c) the Collections.sort() helper method:
final Map<String, Integer> map = new HashMap<String, Integer>();
map.put("test", Integer.valueOf(2));
map.put("Not-Specified", Integer.valueOf(1));
map.put("testtest", Integer.valueOf(3));
final List<Entry<String, Integer>> entries =
new ArrayList<Entry<String, Integer>>(map.entrySet());
Collections.sort(entries, new Comparator<Entry<String, Integer>>(){
public int compareKeys(final String o1, final String o2){
int result;
if("Not-Specified".equals(o1)){
result = 1;
} else if("Not-Specified".equals(o2)){
result = -1;
} else{
result = o1.compareTo(o2);
}
return result;
}
@Override
public int compare(final Entry<String, Integer> o1,
final Entry<String, Integer> o2){
return this.compareKeys(o1.getKey(), o2.getKey());
}
});
final Entry<String, Integer> lastEntry =
entries.get(entries.size() - 1);
System.out.println("Last key: " + lastEntry.getKey() + ", last value: "
+ lastEntry.getValue());
}
Output:
Last key: Not-Specified, last value: 1
How to make HTML Text unselectable
No one here posted an answer with all of the correct CSS variations, so here it is:
-webkit-touch-callout: none;
-webkit-user-select: none;
-khtml-user-select: none;
-moz-user-select: none;
-ms-user-select: none;
user-select: none;
How do I set Tomcat Manager Application User Name and Password for NetBeans?
When you're launching tomcat server from netbeans IDE you need to check in menu "tools->servers" on connection tab for tomcat server - there is catalina base directory. And you need to include something like:
<role rolename="manager"/>
<user username="admin" password="admin" roles="manager"/>
at file
\CATALINA_BASE\conf\tomcat-users.xml
or use username automatically generated by IDE with description already placed in this file or on connection tab
For Manager Apps : GUI access:
<role rolename="manager-gui"/>
<user username="tomcat" password="s3cret" roles="manager-gui"/>
jQuery - simple input validation - "empty" and "not empty"
jQuery("#input").live('change', function() {
// since we check more than once against the value, place it in a var.
var inputvalue = $("#input").attr("value");
// if it's value **IS NOT** ""
if(inputvalue !== "") {
jQuery(this).css('outline', 'solid 1px red');
}
// else if it's value **IS** ""
else if(inputvalue === "") {
alert('empty');
}
});
How can I undo a `git commit` locally and on a remote after `git push`
First of all, Relax.
"Nothing is under our control. Our control is mere illusion.", "To err is human"
I get that you've unintentionally pushed your code to remote-master
. THIS is going to be alright.
1. At first, get the SHA-1
value of the commit you are trying to return, e.g. commit to master branch. run this:
git log
you'll see bunch of 'f650a9e398ad9ca606b25513bd4af9fe...' like strings along with each of the commits. copy that number from the commit that you want to return back.
2. Now, type in below command:
git reset --hard your_that_copied_string_but_without_quote_mark
you should see message like "HEAD is now at ". you are on clear. What it just have done is to reflect that change locally.
3. Now, type in below command:
git push -f
you should see like
"warning: push.default is unset; its implicit value has changed
in..... ... Total 0 (delta 0), reused 0 (delta 0) ...
...your_branch_name -> master (forced update)."
Now, you are all clear. Check the master with "git log" again, your fixed_destination_commit should be on top of the list.
You are welcome (in advance ;))
UPDATE:
Now, the changes you had made before all these began, are now gone.
If you want to bring those hard-works back again, it's possible. Thanks to git reflog, and git cherry-pick commands.
For that, i would suggest to please follow this blog or this post.
How to create an XML document using XmlDocument?
Working with a dictionary ->level2 above comes from a dictionary in my case (just in case anybody will find it useful)
Trying the first example I stumbled over this error:
"This document already has a 'DocumentElement' node."
I was inspired by the answer here
and edited my code: (xmlDoc.DocumentElement.AppendChild(body))
//a dictionary:
Dictionary<string, string> Level2Data
{
{"level2", "text"},
{"level2", "other text"},
{"same_level2", "more text"}
}
//xml Decalration:
XmlDocument xmlDoc = new XmlDocument();
XmlDeclaration xmlDeclaration = xmlDoc.CreateXmlDeclaration("1.0", "UTF-8", null);
XmlElement root = xmlDoc.DocumentElement;
xmlDoc.InsertBefore(xmlDeclaration, root);
// add body
XmlElement body = xmlDoc.CreateElement(string.Empty, "body", string.Empty);
xmlDoc.AppendChild(body);
XmlElement body = xmlDoc.CreateElement(string.Empty, "body", string.Empty);
xmlDoc.DocumentElement.AppendChild(body); //without DocumentElement ->ERR
foreach (KeyValuePair<string, string> entry in Level2Data)
{
//write to xml: - it works version 1.
XmlNode keyNode = xmlDoc.CreateElement(entry.Key); //open TAB
keyNode.InnerText = entry.Value;
body.AppendChild(keyNode); //close TAB
//Write to xmml verdion 2: (uncomment the next 4 lines and comment the above 3 - version 1
//XmlElement key = xmlDoc.CreateElement(string.Empty, entry.Key, string.Empty);
//XmlText value = xmlDoc.CreateTextNode(entry.Value);
//key.AppendChild(value);
//body.AppendChild(key);
}
Both versions (1 and 2 inside foreach loop) give the output:
<?xml version="1.0" encoding="UTF-8"?>
<body>
<level1>
<level2>text</level2>
<level2>ther text</level2>
<same_level2>more text</same_level2>
</level1>
</body>
(Note: third line "same level2" in dictionary can be also level2 as the others but I wanted to ilustrate the advantage of the dictionary - in my case I needed level2 with different names.
How to view table contents in Mysql Workbench GUI?
To get the convenient list of tables on the left panel below each database you have to click the tiny icon on the top right of the left panel. At least in MySQL Workbench 6.3 CE on Win7 this worked to get the full list of tables.
See my screenshot to explain.
Sadly this icon not even has a mouseover title attribute, so it was a lucky guess that I found it.
Android refresh current activity
this is what worked for me as seen here.
Just use it or add it to a static class helper and just call it from anywher in your project.
/**
Current Activity instance will go through its lifecycle to onDestroy() and a new instance then created after it.
*/
@SuppressLint("NewApi")
public static final void recreateActivityCompat(final Activity a) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
a.recreate();
} else {
final Intent intent = a.getIntent();
intent.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);
a.finish();
a.overridePendingTransition(0, 0);
a.startActivity(intent);
a.overridePendingTransition(0, 0);
}
}
Observable.of is not a function
I am using Angular 5.2 and RxJS 5.5.6
This code did not work:
import { Observable,of } from 'rxjs/Observable';
getHeroes(): Observable<Hero[]> {
return of(Hero[]) HEROES;
}
Below code worked:
import { Observable } from 'rxjs/Observable';
import { Subscriber } from 'rxjs/Subscriber';
getHeroes(): Observable<Hero[]>
{
return Observable.create((observer: Subscriber<any>) => {
observer.next(HEROES);
observer.complete();
});
}
Calling method:
this.heroService.getHeroes()
.subscribe(heroes => this.heroes = heroes);
I think they might moved/changed of() functionality in RxJS 5.5.2
How to calculate the 95% confidence interval for the slope in a linear regression model in R
Let's fit the model:
> library(ISwR)
> fit <- lm(metabolic.rate ~ body.weight, rmr)
> summary(fit)
Call:
lm(formula = metabolic.rate ~ body.weight, data = rmr)
Residuals:
Min 1Q Median 3Q Max
-245.74 -113.99 -32.05 104.96 484.81
Coefficients:
Estimate Std. Error t value Pr(>|t|)
(Intercept) 811.2267 76.9755 10.539 2.29e-13 ***
body.weight 7.0595 0.9776 7.221 7.03e-09 ***
---
Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
Residual standard error: 157.9 on 42 degrees of freedom
Multiple R-squared: 0.5539, Adjusted R-squared: 0.5433
F-statistic: 52.15 on 1 and 42 DF, p-value: 7.025e-09
The 95% confidence interval for the slope is the estimated coefficient (7.0595) ± two standard errors (0.9776).
This can be computed using confint
:
> confint(fit, 'body.weight', level=0.95)
2.5 % 97.5 %
body.weight 5.086656 9.0324
curl: (6) Could not resolve host: google.com; Name or service not known
Issues were:
- IPV6 enabled
- Wrong DNS server
Here is how I fixed it:
IPV6 Disabling
- Open Terminal
- Type
su
and enter to log in as the super user
- Enter the root password
- Type
cd /etc/modprobe.d/
to change directory to /etc/modprobe.d/
- Type
vi disableipv6.conf
to create a new file there
- Press
Esc + i
to insert data to file
- Type
install ipv6 /bin/true
on the file to avoid loading IPV6 related modules
- Type
Esc + :
and then wq
for save and exit
- Type
reboot
to restart fedora
- After reboot open terminal and type
lsmod | grep ipv6
- If no result, it means you properly disabled IPV6
Add Google DNS server
- Open Terminal
- Type
su
and enter to log in as the super user
- Enter the root password
- Type
cat /etc/resolv.conf
to check what DNS server your Fedora using. Mostly this will be your Modem IP address.
- Now we have to Find a powerful DNS server. Luckily there is a open DNS server maintain by Google.
- Go to this page and find out what are the "Google Public DNS IP addresses"
- Today those are
8.8.8.8
and 8.8.4.4
. But in future those may change.
- Type
vi /etc/resolv.conf
to edit the resolv.conf
file
- Press
Esc + i
for insert data to file
- Comment all the things in the file by inserting # at the begin of the each line. Do not delete anything because can be useful in future.
Type below two lines in the file
nameserver 8.8.8.8
nameserver 8.8.4.4
-Type Esc + :
and then wq
for save and exit
- Now you are done and everything works fine (Not necessary to restart).
- But every time when you restart the computer your /etc/resolv.conf will be replaced by default. So I'll let you find a way to avoid that.
Here is my blog post about this:
http://codeketchup.blogspot.sg/2014/07/how-to-fix-curl-6-could-not-resolve.html
Fastest JavaScript summation
The fastest loop, according to this test is a while loop in reverse
var i = arr.length; while (i--) { }
So, this code might be the fastest you can get
Array.prototype.sum = function () {
var total = 0;
var i = this.length;
while (i--) {
total += this[i];
}
return total;
}
Array.prototype.sum
adds a sum method to the array class... you could easily make it a helper function instead.
Border Height on CSS
Yes, you can set the line height after defining the border like this:
border-right: 1px solid;
line-height: 10px;
How to embed a SWF file in an HTML page?
This is suitable for application from root environment.
<object type="application/x-shockwave-flash" data="/dir/application.swf"
id="applicationID" style="margin:0 10px;width:auto;height:auto;">
<param name="movie" value="/dir/application.swf" />
<param name="wmode" value="transparent" /> <!-- Or opaque, etc. -->
<!-- ? Required paramter or not, depends on application -->
<param name="FlashVars" value="" />
<param name="quality" value="high" />
<param name="menu" value="false" />
</object>
Additional parameters should be/can be added which depends on .swf it self. No embed, just object and parameters within, so, it remains valid, working and usable everywhere, it doesn't matter which !DOCTYPE is all about. :)
@JsonProperty annotation on field as well as getter/setter
My observations based on a few tests has been that whichever name differs from the property name is one which takes effect:
For eg. consider a slight modification of your case:
@JsonProperty("fileName")
private String fileName;
@JsonProperty("fileName")
public String getFileName()
{
return fileName;
}
@JsonProperty("fileName1")
public void setFileName(String fileName)
{
this.fileName = fileName;
}
Both fileName
field, and method getFileName
, have the correct property name of fileName
and setFileName
has a different one fileName1
, in this case Jackson will look for a fileName1
attribute in json at the point of deserialization and will create a attribute called fileName1
at the point of serialization.
Now, coming to your case, where all the three @JsonProperty differ from the default propertyname of fileName
, it would just pick one of them as the attribute(FILENAME
), and had any on of the three differed, it would have thrown an exception:
java.lang.IllegalStateException: Conflicting property name definitions
Make an image width 100% of parent div, but not bigger than its own width
Setting a width of 100% is the full width of the div it's in, not the original full-sized image. There is no way to do that without JavaScript or some other scripting language that can measure the image. If you can have a fixed width or fixed height of the div (like 200px wide) then it shouldn't be too hard to give the image a range to fill. But if you put a 20x20 pixel image in a 200x300 pixel box it will still be distorted.
HEAD and ORIG_HEAD in Git
HEAD
is (direct or indirect, i.e. symbolic) reference to the current commit. It is a commit that you have checked in the working directory (unless you made some changes, or equivalent), and it is a commit on top of which "git commit" would make a new one. Usually HEAD
is symbolic reference to some other named branch; this branch is currently checked out branch, or current branch. HEAD
can also point directly to a commit; this state is called "detached HEAD", and can be understood as being on unnamed, anonymous branch.
And @
alone is a shortcut for HEAD
, since Git 1.8.5
ORIG_HEAD
is previous state of HEAD
, set by commands that have possibly dangerous behavior, to be easy to revert them. It is less useful now that Git has reflog: HEAD@{1}
is roughly equivalent to ORIG_HEAD
(HEAD@{1}
is always last value of HEAD
, ORIG_HEAD
is last value of HEAD
before dangerous operation).
For more information read git(1) manpage / [gitrevisions(7) manpage][git-revisions], Git User's Manual, the Git Community Book and Git Glossary
Summarizing multiple columns with dplyr?
The dplyr
package contains summarise_all
for this aim:
library(dplyr)
# summarise_all was replaced with the summarise(acrosss(..)) syntax dplyr >=1.00
df %>% group_by(grp) %>% summarise(across(everything(), list(mean)))
#> # A tibble: 3 x 5
#> grp a b c d
#> <int> <dbl> <dbl> <dbl> <dbl>
#> 1 1 3.08 2.98 2.98 2.91
#> 2 2 3.03 3.04 2.97 2.87
#> 3 3 2.85 2.95 2.95 3.06
Alternatively, the purrrlyr
package provides the same functionality:
library(purrrlyr)
df %>% slice_rows("grp") %>% dmap(mean)
#> # A tibble: 3 x 5
#> grp a b c d
#> <int> <dbl> <dbl> <dbl> <dbl>
#> 1 1 3.08 2.98 2.98 2.91
#> 2 2 3.03 3.04 2.97 2.87
#> 3 3 2.85 2.95 2.95 3.06
Also don't forget about data.table
(use keyby
to sort sort groups):
library(data.table)
setDT(df)[, lapply(.SD, mean), keyby = grp]
#> grp a b c d
#> 1: 1 3.079412 2.979412 2.979412 2.914706
#> 2: 2 3.029126 3.038835 2.967638 2.873786
#> 3: 3 2.854701 2.948718 2.951567 3.062678
Let's try to compare performance.
library(dplyr)
library(purrrlyr)
library(data.table)
library(bench)
set.seed(123)
n <- 10000
df <- data.frame(
a = sample(1:5, n, replace = TRUE),
b = sample(1:5, n, replace = TRUE),
c = sample(1:5, n, replace = TRUE),
d = sample(1:5, n, replace = TRUE),
grp = sample(1:3, n, replace = TRUE)
)
dt <- setDT(df)
mark(
dplyr = df %>% group_by(grp) %>% summarise(across(everything(), list(mean))),
purrrlyr = df %>% slice_rows("grp") %>% dmap(mean),
data.table = dt[, lapply(.SD, mean), keyby = grp],
check = FALSE
)
#> # A tibble: 3 x 6
#> expression min median `itr/sec` mem_alloc `gc/sec`
#> <bch:expr> <bch:tm> <bch:tm> <dbl> <bch:byt> <dbl>
#> 1 dplyr 2.81ms 2.85ms 328. NA 17.3
#> 2 purrrlyr 7.96ms 8.04ms 123. NA 24.5
#> 3 data.table 596.33µs 707.91µs 1409. NA 10.3
Accessing private member variables from prototype-defined functions
In current JavaScript, I'm fairly certain that there is one and only one way to have private state, accessible from prototype functions, without adding anything public to this
. The answer is to use the "weak map" pattern.
To sum it up: The Person
class has a single weak map, where the keys are the instances of Person, and the values are plain objects that are used for private storage.
Here is a fully functional example: (play at http://jsfiddle.net/ScottRippey/BLNVr/)
var Person = (function() {
var _ = weakMap();
// Now, _(this) returns an object, used for private storage.
var Person = function(first, last) {
// Assign private storage:
_(this).firstName = first;
_(this).lastName = last;
}
Person.prototype = {
fullName: function() {
// Retrieve private storage:
return _(this).firstName + _(this).lastName;
},
firstName: function() {
return _(this).firstName;
},
destroy: function() {
// Free up the private storage:
_(this, true);
}
};
return Person;
})();
function weakMap() {
var instances=[], values=[];
return function(instance, destroy) {
var index = instances.indexOf(instance);
if (destroy) {
// Delete the private state:
instances.splice(index, 1);
return values.splice(index, 1)[0];
} else if (index === -1) {
// Create the private state:
instances.push(instance);
values.push({});
return values[values.length - 1];
} else {
// Return the private state:
return values[index];
}
};
}
Like I said, this is really the only way to achieve all 3 parts.
There are two caveats, however. First, this costs performance -- every time you access the private data, it's an O(n)
operation, where n
is the number of instances. So you won't want to do this if you have a large number of instances.
Second, when you're done with an instance, you must call destroy
; otherwise, the instance and the data will not be garbage collected, and you'll end up with a memory leak.
And that's why my original answer, "You shouldn't", is something I'd like to stick to.
MySql Inner Join with WHERE clause
You could only write one where clause.
SELECT table1.f_id FROM table1
INNER JOIN table2
ON table2.f_id = table1.f_id
where table1.f_com_id = '430' AND
table1.f_status = 'Submitted' AND table2.f_type = 'InProcess'
Calling async method synchronously
I need to call this method from a synchronously method.
It's possible with GenerateCodeAsync().Result
or GenerateCodeAsync().Wait()
, as the other answer suggests. This would block the current thread until GenerateCodeAsync
has completed.
However, your question is tagged with asp.net, and you also left the comment:
I was hoping for a simpler solution, thinking that asp.net handled
this much easier than writing so many lines of code
My point is, you should not be blocking on an asynchronous method in ASP.NET. This will reduce the scalability of your web app, and may create a deadlock (when an await
continuation inside GenerateCodeAsync
is posted to AspNetSynchronizationContext
). Using Task.Run(...).Result
to offload something to a pool thread and then block will hurt the scalability even more, as it incurs +1 more thread to process a given HTTP request.
ASP.NET has built-in support for asynchronous methods, either through asynchronous controllers (in ASP.NET MVC and Web API) or directly via AsyncManager
and PageAsyncTask
in classic ASP.NET. You should use it. For more details, check this answer.
vba listbox multicolumn add
Simplified example (with counter):
With Me.lstbox
.ColumnCount = 2
.ColumnWidths = "60;60"
.AddItem
.List(i, 0) = Company_ID
.List(i, 1) = Company_name
i = i + 1
end with
Make sure to start the counter with 0, not 1 to fill up a listbox.
Why Does OAuth v2 Have Both Access and Refresh Tokens?
This answer is from Justin Richer via the OAuth 2 standard body email list. This is posted with his permission.
The lifetime of a refresh token is up to the (AS) authorization server — they can expire, be revoked, etc. The difference between a refresh token and an access token is the audience: the refresh token only goes back to the authorization server, the access token goes to the (RS) resource server.
Also, just getting an access token doesn’t mean the user’s logged in. In fact, the user might not even be there anymore, which is actually the intended use case of the refresh token. Refreshing the access token will give you access to an API on the user’s behalf, it will not tell you if the user’s there.
OpenID Connect doesn’t just give you user information from an access token, it also gives you an ID token. This is a separate piece of data that’s directed at the client itself, not the AS or the RS. In OIDC, you should only consider someone actually “logged in” by the protocol if you can get a fresh ID token. Refreshing it is not likely to be enough.
For more information please read http://oauth.net/articles/authentication/
How to Completely Uninstall Xcode and Clear All Settings
For complete removal old Xcode 7 you should remove
/Applications/Xcode.app
/Library/Preferences/com.apple.dt.Xcode.plist
~/Library/Preferences/com.apple.dt.Xcode.plist
~/Library/Caches/com.apple.dt.Xcode
~/Library/Application Support/Xcode
~/Library/Developer/Xcode
~/Library/Developer/CoreSimulator
How do you split and unsplit a window/view in Eclipse IDE?
This is possible with the menu items Window>Editor>Toggle Split Editor.
Current shortcut for splitting is:
Azerty keyboard:
- Ctrl + _ for split horizontally, and
- Ctrl + { for split vertically.
Qwerty US keyboard:
- Ctrl + Shift + - (accessing _) for split horizontally, and
- Ctrl + Shift + [ (accessing {) for split vertically.
MacOS - Qwerty US keyboard:
- ⌘ + Shift + - (accessing _) for split horizontally, and
- ⌘ + Shift + [ (accessing {) for split vertically.
On any other keyboard if a required key is unavailable (like { on a german Qwertz keyboard), the following generic approach may work:
- Alt + ASCII code + Ctrl then release Alt
Example: ASCII for '{' = 123, so press 'Alt', '1', '2', '3', 'Ctrl' and release 'Alt', effectively typing '{' while 'Ctrl' is pressed, to split vertically.
Example of vertical split:
PS:
- The menu items Window>Editor>Toggle Split Editor were added with Eclipse Luna 4.4 M4, as mentioned by Lars Vogel in "Split editor implemented in Eclipse M4 Luna"
- The split editor is one of the oldest and most upvoted Eclipse bug! Bug 8009
- The split editor functionality has been developed in Bug 378298, and will be available as of Eclipse Luna M4. The Note & Newsworthy of Eclipse Luna M4 will contain the announcement.
Is it a good idea to index datetime field in mysql?
MySQL recommends using indexes for a variety of reasons including elimination of rows between conditions: http://dev.mysql.com/doc/refman/5.0/en/mysql-indexes.html
This makes your datetime column an excellent candidate for an index if you are going to be using it in conditions frequently in queries. If your only condition is BETWEEN NOW() AND DATE_ADD(NOW(), INTERVAL 30 DAY)
and you have no other index in the condition, MySQL will have to do a full table scan on every query. I'm not sure how many rows are generated in 30 days, but as long as it's less than about 1/3 of the total rows it will be more efficient to use an index on the column.
Your question about creating an efficient database is very broad. I'd say to just make sure that it's normalized and all appropriate columns are indexed (i.e. ones used in joins and where clauses).
Python Linked List
Here is some list functions based on Martin v. Löwis's representation:
cons = lambda el, lst: (el, lst)
mklist = lambda *args: reduce(lambda lst, el: cons(el, lst), reversed(args), None)
car = lambda lst: lst[0] if lst else lst
cdr = lambda lst: lst[1] if lst else lst
nth = lambda n, lst: nth(n-1, cdr(lst)) if n > 0 else car(lst)
length = lambda lst, count=0: length(cdr(lst), count+1) if lst else count
begin = lambda *args: args[-1]
display = lambda lst: begin(w("%s " % car(lst)), display(cdr(lst))) if lst else w("nil\n")
where w = sys.stdout.write
Although doubly linked lists are famously used in Raymond Hettinger's ordered set recipe, singly linked lists have no practical value in Python.
I've never used a singly linked list in Python for any problem except educational.
Thomas Watnedal suggested a good educational resource How to Think Like a Computer Scientist, Chapter 17: Linked lists:
A linked list is either:
- the empty list, represented by None, or
a node that contains a cargo object and a reference to a linked list.
class Node:
def __init__(self, cargo=None, next=None):
self.car = cargo
self.cdr = next
def __str__(self):
return str(self.car)
def display(lst):
if lst:
w("%s " % lst)
display(lst.cdr)
else:
w("nil\n")
Set timeout for ajax (jQuery)
You could use the timeout
setting in the ajax options like this:
$.ajax({
url: "test.html",
timeout: 3000,
error: function(){
//do something
},
success: function(){
//do something
}
});
Read all about the ajax options here: http://api.jquery.com/jQuery.ajax/
Remember that when a timeout occurs, the error
handler is triggered and not the success
handler :)
XAMPP installation on Win 8.1 with UAC Warning
As ivan.sim writes in his answer
- Ensure that your user account has administrator privilege.
- Disable UAC(User Account Control) as it restricts certain administrative function needed to run a web server.
- Install in C://xampp.
Problem with the correct answer is in the explanation of point 2., and magicandre1981 writes more about it
Moving the slider down doesn't completely disable UAC since Windows 8.
This is changed compared to Windows 7, because the new Store apps
require an active UAC. With UAC off, they no longer run.
How can we then disable UAC and install XAMPP?
Easy. Go to Registry Editor and navigate to
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System
Right click EnableLUA and modify the Value data to 0.
Then restart your computer and you're ready to install XAMPP.
How can I connect to Android with ADB over TCP?
From adb --help
:
connect <host>:<port> - Connect to a device via TCP/IP
That's a command-line option by the way.
You should try connecting the phone to your Wi-Fi, and then get its IP address from your router. It's not going to work on the cell network.
The port is 5554.
Java integer to byte array
How about:
public static final byte[] intToByteArray(int value) {
return new byte[] {
(byte)(value >>> 24),
(byte)(value >>> 16),
(byte)(value >>> 8),
(byte)value};
}
The idea is not mine. I've taken it from some post on dzone.com.
How to use filesaver.js
For people who want to load it in the console :
var s = document.createElement('script');
s.type = 'text/javascript';
s.src = 'https://cdnjs.cloudflare.com/ajax/libs/FileSaver.js/1.3.8/FileSaver.min.js';
document.body.appendChild(s);
Then :
saveAs(new Blob([data], {type: "application/octet-stream ;charset=utf-8"}), "video.ts")
File will be save when you're out of a breakpoint (at least on Chrome)
What is an OS kernel ? How does it differ from an operating system?
The Operating System is a generic name given to all of the elements (user interface, libraries, resources) which make up the system as a whole.
The kernel is "brain" of the operating system, which controls everything from access to the hard disk to memory management. Whenever you want to do anything, it goes though the kernel.
How to Solve Max Connection Pool Error
Check against any long running queries in your database.
Increasing your pool size will only make your webapp live a little longer (and probably get a lot slower)
You can use sql server profiler and filter on duration / reads to see which querys need optimization.
I also see you're probably keeping a global connection?
blnMainConnectionIsCreatedLocal
Let .net do the pooling for you and open / close your connection with a using statement.
Suggestions:
Always open and close a connection like this, so .net can manage your connections and you won't run out of connections:
using (SqlConnection conn = new SqlConnection(connectionString))
{
conn.Open();
// do some stuff
} //conn disposed
As I mentioned, check your query with sql server profiler and see if you can optimize it. Having a slow query with many requests in a web app can give these timeouts too.
How to split a delimited string in Ruby and convert it to an array?
For String Integer
without space as String
arr = "12345"
arr.split('')
output: ["1","2","3","4","5"]
For String Integer
with space as String
arr = "1 2 3 4 5"
arr.split(' ')
output: ["1","2","3","4","5"]
For String Integer
without space as Integer
arr = "12345"
arr.split('').map(&:to_i)
output: [1,2,3,4,5]
For String
arr = "abc"
arr.split('')
output: ["a","b","c"]
Explanation:
arr
-> string which you're going to perform any action.
split()
-> is an method, which split the input and store it as array.
''
or ' '
or ','
-> is an value, which is needed to be removed from given string.
How can I lookup a Java enum from its String value?
In case it helps others, the option I prefer, which is not listed here, uses Guava's Maps functionality:
public enum Vebosity {
BRIEF("BRIEF"),
NORMAL("NORMAL"),
FULL("FULL");
private String value;
private Verbosity(final String value) {
this.value = value;
}
public String getValue() {
return this.value;
}
private static ImmutableMap<String, Verbosity> reverseLookup =
Maps.uniqueIndex(Arrays.asList(Verbosity.values()), Verbosity::getValue);
public static Verbosity fromString(final String id) {
return reverseLookup.getOrDefault(id, NORMAL);
}
}
With the default you can use null
, you can throw IllegalArgumentException
or your fromString
could return an Optional
, whatever behavior you prefer.
Get month name from date in Oracle
select to_char(sysdate, 'Month') from dual
in your example will be:
select to_char(to_date('15-11-2010', 'DD-MM-YYYY'), 'Month') from dual
Moment.js - two dates difference in number of days
the diff
method returns the difference in milliseconds. Instantiating moment(diff)
isn't meaningful.
You can define a variable :
var dayInMilliseconds = 1000 * 60 * 60 * 24;
and then use it like so :
diff / dayInMilliseconds // --> 15
Edit
actually, this is built into the diff
method, dubes' answer is better
Differences between socket.io and websockets
Even if modern browsers support WebSockets now, I think there is no need to throw SocketIO away and it still has its place in any nowadays project. It's easy to understand, and personally, I learned how WebSockets work thanks to SocketIO.
As said in this topic, there's a plenty of integration libraries for Angular, React, etc. and definition types for TypeScript and other programming languages.
The other point I would add to the differences between Socket.io and WebSockets is that clustering with Socket.io is not a big deal. Socket.io offers Adapters that can be used to link it with Redis to enhance scalability. You have ioredis and socket.io-redis for example.
Yes I know, SocketCluster exists, but that's off-topic.
Run javascript function when user finishes typing instead of on key up?
I don't think keyDown event is necessary in this case (please tell me why if I'm wrong). In my (non-jquery) script similar solution looks like that:
var _timer, _timeOut = 2000;
function _onKeyUp(e) {
clearTimeout(_timer);
if (e.keyCode == 13) { // close on ENTER key
_onCloseClick();
} else { // send xhr requests
_timer = window.setTimeout(function() {
_onInputChange();
}, _timeOut)
}
}
It's my first reply on Stack Overflow, so I hope this helps someone, someday:)
Display PDF within web browser
I recently needed to provide a more mobile-friendly, responsive version of a .pdf document, because narrow phone screens required scrolling right and left a lot. To allow just vertical scrolling and avoid horizontal scrolling, the following steps worked for me:
- Open the .pdf in Chrome browser
- Click Open with Google Docs
- Click File > Download > Web Page
- Click on the downloaded document to unzip it
- Click on the unzipped HTML document to open it in Chrome browser
- Press fn F12 to open Chrome Dev Tools
- Paste copy(document.documentElement.outerHTML.replace(/padding:72pt 72pt 72pt 72pt;/, '').replace(/margin-right:.*?pt/g, '')) into the Console, and press Enter to copy the tweaked document to the clipboard
- Open a text editor (e.g., Notepad), or in my case VSCode, paste, and save with a .html extension.
The result looked good and was usable in both desktop and mobile environments.
How to Convert date into MM/DD/YY format in C#
DateTime.Today.ToString("MM/dd/yy")
Look at the docs for custom date and time format strings for more info.
(Oh, and I hope this app isn't destined for other cultures. That format could really confuse a lot of people... I've never understood the whole month/day/year thing, to be honest. It just seems weird to go "middle/low/high" in terms of scale like that.)
How to set label size in Bootstrap
You'll have to do 2 things to make a Bootstrap label (or anything really) adjust sizes based on screen size:
- Use a media query per display size range to adjust the CSS.
- Override CSS sizing set by Bootstrap. You do this by making your CSS rules more specific than Bootstrap's. By default, Bootstrap sets
.label { font-size: 75% }
. So any extra selector on your CSS rule will make it more specific.
Here's an example CSS listing to accomplish what you are asking, using the default 4 sizes in Bootstrap:
@media (max-width: 767) {
/* your custom css class on a parent will increase specificity */
/* so this rule will override Bootstrap's font size setting */
.autosized .label { font-size: 14px; }
}
@media (min-width: 768px) and (max-width: 991px) {
.autosized .label { font-size: 16px; }
}
@media (min-width: 992px) and (max-width: 1199px) {
.autosized .label { font-size: 18px; }
}
@media (min-width: 1200px) {
.autosized .label { font-size: 20px; }
}
Here is how it could be used in the HTML:
<!-- any ancestor could be set to autosized -->
<div class="autosized">
...
...
<span class="label label-primary">Label 1</span>
</div>
How add spaces between Slick carousel item
The slick-slide has inner wrapping div which you can use to create spacing between slides without breaking the design:
.slick-list {margin: 0 -5px;}
.slick-slide>div {padding: 0 5px;}
Operand type clash: uniqueidentifier is incompatible with int
Sounds to me like at least one of those tables has defined UserID
as a uniqueidentifier
, not an int
. Did you check the data in each table? What does SELECT TOP 1 UserID FROM
each table yield? An int
or a GUID
?
EDIT
I think you have built a procedure based on all tables that contain a column named UserID. I think you should not have included the aspnet_Membership
table in your script, since it's not really one of "your" tables.
If you meant to design your tables around the aspnet_Membership
database, then why are the rest of the columns int
when that table clearly uses a uniqueidentifier
for the UserID
column?
Throw HttpResponseException or return Request.CreateErrorResponse?
If you are not returning HttpResponseMessage and instead are returning entity/model classes directly, an approach which I have found useful is to add the following utility function to my controller
private void ThrowResponseException(HttpStatusCode statusCode, string message)
{
var errorResponse = Request.CreateErrorResponse(statusCode, message);
throw new HttpResponseException(errorResponse);
}
and simply call it with the appropriate status code and message
Find a class somewhere inside dozens of JAR files?
user1207523's script works fine for me. Here is a variant that searches for jar files recusively using find instead of simple expansion;
#!/bin/bash
for i in `find . -name '*.jar'`; do jar -tf "$i" | grep $1 | xargs -I{} echo -e "$i : {}" ; done
Check mySQL version on Mac 10.8.5
To check your MySQL version on your mac, navigate to the directory where you installed it (default is usr/local/mysql/bin) and issue this command:
./mysql --version
Alternatively, to avoid needing to navigate to that specific dir to run the command, add its location to your path ($PATH). There's more than one way to add a dir to your $PATH (with explanations on stackoverflow and other places on how to do so), such as adding it to your ./bash_profile.
After adding the mysql bin dir to your $PATH, verify it's there by executing:
echo $PATH
Thereafter you can check your mysql version from anywhere by running (note no "./"):
mysql --version
Application Loader stuck at "Authenticating with the iTunes store" when uploading an iOS app
Found the solution:
I was uploading the build, Every activity went well except “Authenticating with the iTunes store”.
I disconnected my LAN cable and Connected my MAC with my mobile hotspot. and authentication problem was solved. If you have a limited internet plan then as soon as you pass authentication stage, again connect your LAN so that it will upload the app from you LAN cable's internet connection.
Windows.history.back() + location.reload() jquery
window.history.back() does not support reload or refresh of the page. But you can use following if you are okay with an extra refresh
window.history.back()
window.location.reload()
However a real complete solution would be as follows:
I wrote a service to keep track of previous page and then navigate to that page with reload:true
Here is how i did it.
'use strict';
angular.module('tryme5App')
.factory('RouterTracker', function RouterTracker($rootScope) {
var routeHistory = [];
var service = {
getRouteHistory: getRouteHistory
};
$rootScope.$on('$stateChangeSuccess', function (ev, to, toParams, from, fromParams) {
routeHistory = [];
routeHistory.push({route: from, routeParams: fromParams});
});
function getRouteHistory() {
return routeHistory;
}
return service;
});
Make sure you have included this js file from you index.html
<script src="scripts/components/util/route.service.js"></script>
Now from you stateprovider or controller you can access this service and navigate
var routeHistory = RouterTracker.getRouteHistory();
console.log(routeHistory[0].route.name)
$state.go(routeHistory[0].route.name, null, { reload: true });
or alternatively even perform checks and conditional routing
var routeHistory = RouterTracker.getRouteHistory();
console.log(routeHistory[0].route.name)
if(routeHistory[0].route.name == 'seat') {
$state.go('seat', null, { reload: true });
} else {
window.history.back()
}
Make sure you have added RouterTracker as an argument in your function
in my case it was :
.state('seat.new', {
parent: 'seat',
url: '/new',
data: {
authorities: ['ROLE_USER'],
},
onEnter: ['$stateParams', '$state', '$uibModal', 'RouterTracker', function($stateParams, $state, $uibModal, RouterTracker) {
$uibModal.open({
//....Open dialog.....
}).result.then(function(result) {
var routeHistory = RouterTracker.getRouteHistory();
console.log(routeHistory[0].route.name)
$state.go(routeHistory[0].route.name, null, { reload: true });
}, function() {
$state.go('^');
})
Read file data without saving it in Flask
If you want to use standard Flask stuff - there's no way to avoid saving a temporary file if the uploaded file size is > 500kb. If it's smaller than 500kb - it will use "BytesIO", which stores the file content in memory, and if it's more than 500kb - it stores the contents in TemporaryFile() (as stated in the werkzeug documentation). In both cases your script will block until the entirety of uploaded file is received.
The easiest way to work around this that I have found is:
1) Create your own file-like IO class where you do all the processing of the incoming data
2) In your script, override Request class with your own:
class MyRequest( Request ):
def _get_file_stream( self, total_content_length, content_type, filename=None, content_length=None ):
return MyAwesomeIO( filename, 'w' )
3) Replace Flask's request_class with your own:
app.request_class = MyRequest
4) Go have some beer :)
Python Pandas User Warning: Sorting because non-concatenation axis is not aligned
tl;dr:
concat
and append
currently sort the non-concatenation index (e.g. columns if you're adding rows) if the columns don't match. In pandas 0.23 this started generating a warning; pass the parameter sort=True
to silence it. In the future the default will change to not sort, so it's best to specify either sort=True
or False
now, or better yet ensure that your non-concatenation indices match.
The warning is new in pandas 0.23.0:
In a future version of pandas pandas.concat()
and DataFrame.append()
will no longer sort the non-concatenation axis when it is not already aligned. The current behavior is the same as the previous (sorting), but now a warning is issued when sort is not specified and the non-concatenation axis is not aligned,
link.
More information from linked very old github issue, comment by smcinerney :
When concat'ing DataFrames, the column names get alphanumerically sorted if there are any differences between them. If they're identical across DataFrames, they don't get sorted.
This sort is undocumented and unwanted. Certainly the default behavior should be no-sort.
After some time the parameter sort
was implemented in pandas.concat
and DataFrame.append
:
sort : boolean, default None
Sort non-concatenation axis if it is not already aligned when join is 'outer'. The current default of sorting is deprecated and will change to not-sorting in a future version of pandas.
Explicitly pass sort=True to silence the warning and sort. Explicitly pass sort=False to silence the warning and not sort.
This has no effect when join='inner', which already preserves the order of the non-concatenation axis.
So if both DataFrames have the same columns in the same order, there is no warning and no sorting:
df1 = pd.DataFrame({"a": [1, 2], "b": [0, 8]}, columns=['a', 'b'])
df2 = pd.DataFrame({"a": [4, 5], "b": [7, 3]}, columns=['a', 'b'])
print (pd.concat([df1, df2]))
a b
0 1 0
1 2 8
0 4 7
1 5 3
df1 = pd.DataFrame({"a": [1, 2], "b": [0, 8]}, columns=['b', 'a'])
df2 = pd.DataFrame({"a": [4, 5], "b": [7, 3]}, columns=['b', 'a'])
print (pd.concat([df1, df2]))
b a
0 0 1
1 8 2
0 7 4
1 3 5
But if the DataFrames have different columns, or the same columns in a different order, pandas returns a warning if no parameter sort
is explicitly set (sort=None
is the default value):
df1 = pd.DataFrame({"a": [1, 2], "b": [0, 8]}, columns=['b', 'a'])
df2 = pd.DataFrame({"a": [4, 5], "b": [7, 3]}, columns=['a', 'b'])
print (pd.concat([df1, df2]))
FutureWarning: Sorting because non-concatenation axis is not aligned.
a b
0 1 0
1 2 8
0 4 7
1 5 3
print (pd.concat([df1, df2], sort=True))
a b
0 1 0
1 2 8
0 4 7
1 5 3
print (pd.concat([df1, df2], sort=False))
b a
0 0 1
1 8 2
0 7 4
1 3 5
If the DataFrames have different columns, but the first columns are aligned - they will be correctly assigned to each other (columns a
and b
from df1
with a
and b
from df2
in the example below) because they exist in both. For other columns that exist in one but not both DataFrames, missing values are created.
Lastly, if you pass sort=True
, columns are sorted alphanumerically. If sort=False
and the second DafaFrame has columns that are not in the first, they are appended to the end with no sorting:
df1 = pd.DataFrame({"a": [1, 2], "b": [0, 8], 'e':[5, 0]},
columns=['b', 'a','e'])
df2 = pd.DataFrame({"a": [4, 5], "b": [7, 3], 'c':[2, 8], 'd':[7, 0]},
columns=['c','b','a','d'])
print (pd.concat([df1, df2]))
FutureWarning: Sorting because non-concatenation axis is not aligned.
a b c d e
0 1 0 NaN NaN 5.0
1 2 8 NaN NaN 0.0
0 4 7 2.0 7.0 NaN
1 5 3 8.0 0.0 NaN
print (pd.concat([df1, df2], sort=True))
a b c d e
0 1 0 NaN NaN 5.0
1 2 8 NaN NaN 0.0
0 4 7 2.0 7.0 NaN
1 5 3 8.0 0.0 NaN
print (pd.concat([df1, df2], sort=False))
b a e c d
0 0 1 5.0 NaN NaN
1 8 2 0.0 NaN NaN
0 7 4 NaN 2.0 7.0
1 3 5 NaN 8.0 0.0
In your code:
placement_by_video_summary = placement_by_video_summary.drop(placement_by_video_summary_new.index)
.append(placement_by_video_summary_new, sort=True)
.sort_index()
Integer to hex string in C++
For those of you who figured out that many/most of the ios::fmtflags
don't work with std::stringstream
yet like the template idea that Kornel posted way back when, the following works and is relatively clean:
#include <iomanip>
#include <sstream>
template< typename T >
std::string hexify(T i)
{
std::stringbuf buf;
std::ostream os(&buf);
os << "0x" << std::setfill('0') << std::setw(sizeof(T) * 2)
<< std::hex << i;
return buf.str().c_str();
}
int someNumber = 314159265;
std::string hexified = hexify< int >(someNumber);
Angular 2 / 4 / 5 - Set base href dynamically
I use the current working directory ./
when building several apps off the same domain:
<base href="./">
On a side note, I use .htaccess
to assist with my routing on page reload:
RewriteEngine on
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule .* index.html [L]
node.js: cannot find module 'request'
Go to directory of your project
mkdir TestProject
cd TestProject
Make this directory a root of your project (this will create a default package.json
file)
npm init --yes
Install required npm module and save it as a project dependency (it will appear in package.json
)
npm install request --save
Create a test.js
file in project directory with code from package example
var request = require('request');
request('http://www.google.com', function (error, response, body) {
if (!error && response.statusCode == 200) {
console.log(body); // Print the google web page.
}
});
Your project directory should look like this
TestProject/
- node_modules/
- package.json
- test.js
Now just run node inside your project directory
node test.js
Shortcut to create properties in Visual Studio?
After typing "prop" + Tab + Tab as suggested by Amra,
you can immediately type the property's type (which will replace the default int
), type another tab and type the property name (which will replace the default MyProperty). Finish by pressing Enter.
Can anyone explain me StandardScaler?
The answers above are great, but I needed a simple example to alleviate some concerns that I have had in the past. I wanted to make sure it was indeed treating each column separately. I am now reassured and can't find what example had caused me concern. All columns ARE scaled separately as described by those above.
CODE
import pandas as pd
import scipy.stats as ss
from sklearn.preprocessing import StandardScaler
data= [[1, 1, 1, 1, 1],[2, 5, 10, 50, 100],[3, 10, 20, 150, 200],[4, 15, 40, 200, 300]]
df = pd.DataFrame(data, columns=['N0', 'N1', 'N2', 'N3', 'N4']).astype('float64')
sc_X = StandardScaler()
df = sc_X.fit_transform(df)
num_cols = len(df[0,:])
for i in range(num_cols):
col = df[:,i]
col_stats = ss.describe(col)
print(col_stats)
OUTPUT
DescribeResult(nobs=4, minmax=(-1.3416407864998738, 1.3416407864998738), mean=0.0, variance=1.3333333333333333, skewness=0.0, kurtosis=-1.3599999999999999)
DescribeResult(nobs=4, minmax=(-1.2828087129930659, 1.3778315806221817), mean=-5.551115123125783e-17, variance=1.3333333333333337, skewness=0.11003776770595125, kurtosis=-1.394993095506219)
DescribeResult(nobs=4, minmax=(-1.155344148338584, 1.53471088361394), mean=0.0, variance=1.3333333333333333, skewness=0.48089217736510326, kurtosis=-1.1471008824318165)
DescribeResult(nobs=4, minmax=(-1.2604572012883055, 1.2668071116222517), mean=-5.551115123125783e-17, variance=1.3333333333333333, skewness=0.0056842140599118185, kurtosis=-1.6438177182479734)
DescribeResult(nobs=4, minmax=(-1.338945389819976, 1.3434309690153527), mean=5.551115123125783e-17, variance=1.3333333333333333, skewness=0.005374558840039456, kurtosis=-1.3619131970819205)
NOTE:
The scipy.stats module is correctly reporting the "sample" variance, which uses (n - 1) in the denominator. The "population" variance would use n in the denominator for the calculation of variance. To understand better, please see the code below that uses scaled data from the first column of the data set above:
Code
import scipy.stats as ss
sc_Data = [[-1.34164079], [-0.4472136], [0.4472136], [1.34164079]]
col_stats = ss.describe([-1.34164079, -0.4472136, 0.4472136, 1.34164079])
print(col_stats)
print()
mean_by_hand = 0
for row in sc_Data:
for element in row:
mean_by_hand += element
mean_by_hand /= 4
variance_by_hand = 0
for row in sc_Data:
for element in row:
variance_by_hand += (mean_by_hand - element)**2
sample_variance_by_hand = variance_by_hand / 3
sample_std_dev_by_hand = sample_variance_by_hand ** 0.5
pop_variance_by_hand = variance_by_hand / 4
pop_std_dev_by_hand = pop_variance_by_hand ** 0.5
print("Sample of Population Calcs:")
print(mean_by_hand, sample_variance_by_hand, sample_std_dev_by_hand, '\n')
print("Population Calcs:")
print(mean_by_hand, pop_variance_by_hand, pop_std_dev_by_hand)
Output
DescribeResult(nobs=4, minmax=(-1.34164079, 1.34164079), mean=0.0, variance=1.3333333422778562, skewness=0.0, kurtosis=-1.36000000429325)
Sample of Population Calcs:
0.0 1.3333333422778562 1.1547005422523435
Population Calcs:
0.0 1.000000006708392 1.000000003354196
Edit line thickness of CSS 'underline' attribute
Thanks to the magic of new css options this is now possible natively:
a {
text-decoration: underline;
text-decoration-thickness: 5px;
text-decoration-skip-ink: auto;
text-underline-offset: 3px;
}
As of yet support is relatively poor. But it'll land in other browsers than ff eventually.
What is an efficient way to implement a singleton pattern in Java?
This is how to implement a simple singleton:
public class Singleton {
// It must be static and final to prevent later modification
private static final Singleton INSTANCE = new Singleton();
/** The constructor must be private to prevent external instantiation */
private Singleton(){}
/** The public static method allowing to get the instance */
public static Singleton getInstance() {
return INSTANCE;
}
}
This is how to properly lazy create your singleton:
public class Singleton {
// The constructor must be private to prevent external instantiation
private Singleton(){}
/** The public static method allowing to get the instance */
public static Singleton getInstance() {
return SingletonHolder.INSTANCE;
}
/**
* The static inner class responsible for creating your instance only on demand,
* because the static fields of a class are only initialized when the class
* is explicitly called and a class initialization is synchronized such that only
* one thread can perform it, this rule is also applicable to inner static class
* So here INSTANCE will be created only when SingletonHolder.INSTANCE
* will be called
*/
private static class SingletonHolder {
private static final Singleton INSTANCE = new Singleton();
}
}
Dynamically select data frame columns using $ and a character value
too late.. but I guess I have the answer -
Here's my sample study.df dataframe -
>study.df
study sample collection_dt other_column
1 DS-111 ES768098 2019-01-21:04:00:30 <NA>
2 DS-111 ES768099 2018-12-20:08:00:30 some_value
3 DS-111 ES768100 <NA> some_value
And then -
> ## Selecting Columns in an Given order
> ## Create ColNames vector as per your Preference
>
> selectCols <- c('study','collection_dt','sample')
>
> ## Select data from Study.df with help of selection vector
> selectCols %>% select(.data=study.df,.)
study collection_dt sample
1 DS-111 2019-01-21:04:00:30 ES768098
2 DS-111 2018-12-20:08:00:30 ES768099
3 DS-111 <NA> ES768100
>
How can I solve ORA-00911: invalid character error?
I'm using a 3rd party program that executes Oracle SQL and I encountered this error. Prior to a SELECT
statement, I had some commented notes that included special characters. Removing the comments resolved the issue.
DLL and LIB files - what and why?
There are static libraries (LIB) and dynamic libraries (DLL) - but note that .LIB files can be either static libraries (containing object files) or import libraries (containing symbols to allow the linker to link to a DLL).
Libraries are used because you may have code that you want to use in many programs. For example if you write a function that counts the number of characters in a string, that function will be useful in lots of programs. Once you get that function working correctly you don't want to have to recompile the code every time you use it, so you put the executable code for that function in a library, and the linker can extract and insert the compiled code into your program. Static libraries are sometimes called 'archives' for this reason.
Dynamic libraries take this one step further. It seems wasteful to have multiple copies of the library functions taking up space in each of the programs. Why can't they all share one copy of the function? This is what dynamic libraries are for. Rather than building the library code into your program when it is compiled, it can be run by mapping it into your program as it is loaded into memory. Multiple programs running at the same time that use the same functions can all share one copy, saving memory. In fact, you can load dynamic libraries only as needed, depending on the path through your code. No point in having the printer routines taking up memory if you aren't doing any printing. On the other hand, this means you have to have a copy of the dynamic library installed on every machine your program runs on. This creates its own set of problems.
As an example, almost every program written in 'C' will need functions from a library called the 'C runtime library, though few programs will need all of the functions. The C runtime comes in both static and dynamic versions, so you can determine which version your program uses depending on particular needs.
SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry '1922-1' for key 'IDX_STOCK_PRODUCT'
the message means you are doing another insert with the same combination of columns that are part of the IDX_STOCK_PRODUCT, which seams to be defined as UNIQUE. If it is so, it doesn't allow to enter same combination (it seems like it consists of two fields) twice.
If you are inserting records, make sure you are picking brand new record id or that the combination of record id and the other column is unique.
Without detailed table structure and your code, we can hardly guess whats going wrong.
C# "as" cast vs classic cast
With the "classic" method, if the cast fails, an InvalidCastException
is thrown. With the as
method, it results in null
, which can be checked for, and avoid an exception being thrown.
Also, you can only use as
with reference types, so if you are typecasting to a value type, you must still use the "classic" method.
Note:
The as
method can only be used for types that can be assigned a null
value. That use to only mean reference types, but when .NET 2.0 came out, it introduced the concept of a nullable value type. Since these types can be assigned a null
value, they are valid to use with the as
operator.