How to make an Android device vibrate? with different frequency?
I struggled understanding how to do this on my first implementation - make sure you have the following:
1) Your device supports vibration (my Samsung tablet did not work so I kept re-checking the code - the original code worked perfectly on my CM Touchpad
2) You have declared above the application level in your AndroidManifest.xml file to give the code permission to run.
3) Have imported both of the following in to your MainActivity.java with the other imports: import android.content.Context; import android.os.Vibrator;
4) Call your vibration (discussed extensively in this thread already) - I did it in a separate function and call this in the code at other points - depending on what you want to use to call the vibration you may need an image (Android: long click on a button -> perform actions) or button listener, or a clickable object as defined in XML (Clickable image - android):
public void vibrate(int duration)
{
Vibrator vibs = (Vibrator) getSystemService(Context.VIBRATOR_SERVICE);
vibs.vibrate(duration);
}
How to call URL action in MVC with javascript function?
try:
var url = '/Home/Index/' + e.value;
window.location = window.location.host + url;
That should get you where you want.
Why do I get TypeError: can't multiply sequence by non-int of type 'float'?
Maybe this will help others in the future - I had the same error while trying to multiple a float and a list of floats. The thing is that everyone here talked about multiplying a float with a string (but here all my element were floats all along) so the problem was actually using the * operator on a list.
For example:
import math
import numpy as np
alpha = 0.2
beta=1-alpha
C = (-math.log(1-beta))/alpha
coff = [0.0,0.01,0.0,0.35,0.98,0.001,0.0]
coff *= C
The error:
coff *= C
TypeError: can't multiply sequence by non-int of type 'float'
The solution - convert the list to numpy array:
coff = np.asarray(coff) * C
Where's the DateTime 'Z' format specifier?
I was dealing with DateTimeOffset and unfortunately the "o" prints out "+0000" not "Z".
So I ended up with:
dateTimeOffset.UtcDateTime.ToString("o")
JQuery/Javascript: check if var exists
It is impossible to determine whether a variable has been declared or not other than using try..catch to cause an error if it hasn't been declared. Test like:
if (typeof varName == 'undefined')
do not tell you if varName is a variable in scope, only that testing with typeof returned undefined. e.g.
var foo;
typeof foo == 'undefined'; // true
typeof bar == 'undefined'; // true
In the above, you can't tell that foo was declared but bar wasn't. You can test for global variables using in:
var global = this;
...
'bar' in global; // false
But the global object is the only variable object* you can access, you can't access the variable object of any other execution context.
The solution is to always declare variables in an appropriate context.
- The global object isn't really a variable object, it just has properties that match global variables and provide access to them so it just appears to be one.
How to display image with JavaScript?
You could make use of the Javascript DOM API. In particular, look at the createElement() method.
You could create a re-usable function that will create an image like so...
function show_image(src, width, height, alt) {
var img = document.createElement("img");
img.src = src;
img.width = width;
img.height = height;
img.alt = alt;
// This next line will just add it to the <body> tag
document.body.appendChild(img);
}
Then you could use it like this...
<button onclick=
"show_image('http://google.com/images/logo.gif',
276,
110,
'Google Logo');">Add Google Logo</button>
See a working example on jsFiddle: http://jsfiddle.net/Bc6Et/
How to define Typescript Map of key value pair. where key is a number and value is an array of objects
you can also skip creating dictionary altogether. i used below approach to same problem .
mappedItems: {};
items.forEach(item => {
if (mappedItems[item.key]) {
mappedItems[item.key].push({productId : item.productId , price : item.price , discount : item.discount});
} else {
mappedItems[item.key] = [];
mappedItems[item.key].push({productId : item.productId , price : item.price , discount : item.discount}));
}
});
In what situations would AJAX long/short polling be preferred over HTML5 WebSockets?
One contending technology you've omitted is Server-Sent Events / Event Source. What are Long-Polling, Websockets, Server-Sent Events (SSE) and Comet? has a good discussion of all of these. Keep in mind that some of these are easier than others to integrate with on the server side.
Border color on default input style
I would have thought this would have been answered already - but surely what you want is this: box-shadow: 0 0 3px #CC0000;
Example: http://jsfiddle.net/vmzLW/
MySQL DISTINCT on a GROUP_CONCAT()
GROUP_CONCAT has DISTINCT attribute:
SELECT GROUP_CONCAT(DISTINCT categories ORDER BY categories ASC SEPARATOR ' ') FROM table
Things possible in IntelliJ that aren't possible in Eclipse?
There are many things that idea solves in a much simpler way, or there's no equivalent:
Autocomplete actions: Doing ctrl+shift+a you can call any idea action from the keyboard without remembering its key combination... Think about gnome-do or launchy in windows, and you've got the idea! Also, this feature supports CamelCasing abbreviations ;)
Shelf: Lets you keep easily some pieces of code apart, and then review them through the diff viewer.
Local history: It's far better managed, and simpler.
SVN annotations and history: simpler to inspect, and also you can easily see the history only for such a part of a whole source file.
Autocomplete everywhere, such as the evaluate expression and breakpoint condition windows.
Maven integration... much, much simpler, and well integrated.
Refactors much closer to the hand, such as loops insertion, wrapping/casting, renaming, and add variables.
Find much powerful and well organized. Even in big projects
Much stable to work with several branches of a big project at the same time (as a former bugfixer of 1.5Gb by branch sources, and the need to working in them simultaneously, idea shown its rock-solid capabilities)
Cleaner and simpler interface...
And, simpler to use only with the keyboard, letting apart the need of using the mouse for lots of simple taks, saving you time and giving you more focus on the code... where it matters!
And now, being opensource... the Idea user base will grow exponentially.
Two inline-block, width 50% elements wrap to second line
inline and inline-block elements are affected by whitespace in the HTML.
The simplest way to fix your problem is to remove the whitespace between </div> and <div id="col2">, see: http://jsfiddle.net/XCDsu/15/
There are other possible solutions, see: bikeshedding CSS3 property alternative?
Simple pthread! C++
When compiling with G++, remember to put the -lpthread flag :)
make image( not background img) in div repeat?
It would probably be easier to just fake it by using a div. Just make sure you set the height if its empty so that it can actually appear. Say for instance you want it to be 50px tall set the div height to 50px.
<div id="rightflower">
<div id="divImg"></div>
</div>
And in your style sheet just add the background and its properties, height and width, and what ever positioning you had in mind.
How do I tell CMake to link in a static library in the source directory?
I found this helpful...
http://www.cmake.org/pipermail/cmake/2011-June/045222.html
From their example:
ADD_LIBRARY(boost_unit_test_framework STATIC IMPORTED)
SET_TARGET_PROPERTIES(boost_unit_test_framework PROPERTIES IMPORTED_LOCATION /usr/lib/libboost_unit_test_framework.a)
TARGET_LINK_LIBRARIES(mytarget A boost_unit_test_framework C)
How to Animate Addition or Removal of Android ListView Rows
The RecyclerView takes care of adding, removing, and re-ordering animations!
This simple AndroidStudio project features a RecyclerView. take a look at the commits:
How to replace a character by a newline in Vim
\r can do the work here for you.
How to create a horizontal loading progress bar?
For using the new progress bar
style="?android:attr/progressBarStyleHorizontal"
for the old grey color progress bar use
style="@android:style/Widget.ProgressBar.Horizontal"
in this one you have the option of changing the height by setting minHeight
The complete XML code is:
<ProgressBar
android:id="@+id/pbProcessing"
style="?android:attr/progressBarStyleHorizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@+id/tvProcessing"
android:indeterminateOnly="true"/>
indeterminateOnly is set to true for getting indeterminate horizontal progress bar
Getting Git to work with a proxy server - fails with "Request timed out"
Command to use:
git config --global http.proxy http://proxyuser:[email protected]:8080
- change
proxyuserto your proxy user - change
proxypwdto your proxy password - change
proxy.server.comto the URL of your proxy server - change
8080to the proxy port configured on your proxy server
Note that this works for both http and https repos.
If you decide at any time to reset this proxy and work without proxy:
Command to use:
git config --global --unset http.proxy
Finally, to check the currently set proxy:
git config --global --get http.proxy
Start/Stop and Restart Jenkins service on Windows
To stop Jenkins Please avoid shutting down the Java process or the Windows service. These are not usual commands. Use those only if your Jenkins is causing problems.
Use Jenkins' way to stop that protects from data loss.
http://[jenkins-server]/[command]
where [command] can be any one of the following
- exit
- restart
- reload
Example: if my local PC is running Jenkins at port 8080, it will be
http://localhost:8080/exit
How to make a TextBox accept only alphabetic characters?
private void textBox2_KeyPress(object sender, KeyPressEventArgs e)
{
if (e.KeyChar >= '0' && e.KeyChar <= '9')
e.Handled = true;
else
e.Handled = false;
}
Zipping a file in bash fails
Run dos2unix or similar utility on it to remove the carriage returns (^M).
This message indicates that your file has dos-style lineendings:
-bash: /backup/backup.sh: /bin/bash^M: bad interpreter: No such file or directory Utilities like dos2unix will fix it:
dos2unix <backup.bash >improved-backup.sh Or, if no such utility is installed, you can accomplish the same thing with translate:
tr -d "\015\032" <backup.bash >improved-backup.sh As for how those characters got there in the first place, @MadPhysicist had some good comments.
How do I create a local database inside of Microsoft SQL Server 2014?
Warning! SQL Server 14 Express, SQL Server Management Studio, and SQL 2014 LocalDB are separate downloads, make sure you actually installed SQL Server and not just the Management Studio! SQL Server 14 express with LocalDB download link
Youtube video about entire process.
Writeup with pictures about installing SQL Server
How to select a local server:
When you are asked to connect to a 'database server' right when you open up SQL Server Management Studio do this:
1) Make sure you have Server Type: Database
2) Make sure you have Authentication: Windows Authentication (no username & password)
3) For the server name field look to the right and select the drop down arrow, click 'browse for more'
4) New window pops up 'Browse for Servers', make sure to pick 'Local Servers' tab and under 'Database Engine' you will have the local server you set up during installation of SQL Server 14
How do I create a local database inside of Microsoft SQL Server 2014?
1) After you have connected to a server, bring up the Object Explorer toolbar under 'View' (Should open by default)
2) Now simply right click on 'Databases' and then 'Create new Database' to be taken through the database creation tools!
New to unit testing, how to write great tests?
tests are supposed to improve maintainability. If you change a method and a test breaks that can be a good thing. On the other hand, if you look at your method as a black box then it shouldn't matter what is inside the method. The fact is you need to mock things for some tests, and in those cases you really can't treat the method as a black box. The only thing you can do is to write an integration test -- you load up a fully instantiated instance of the service under test and have it do its thing like it would running in your app. Then you can treat it as a black box.
When I'm writing tests for a method, I have the feeling of rewriting a second time what I
already wrote in the method itself.
My tests just seems so tightly bound to the method (testing all codepath, expecting some
inner methods to be called a number of times, with certain arguments), that it seems that
if I ever refactor the method, the tests will fail even if the final behavior of the
method did not change.
This is because you are writing your tests after you wrote your code. If you did it the other way around (wrote the tests first) it wouldnt feel this way.
What's the difference between subprocess Popen and call (how can I use them)?
There are two ways to do the redirect. Both apply to either subprocess.Popen or subprocess.call.
Set the keyword argument
shell = Trueorexecutable = /path/to/the/shelland specify the command just as you have it there.Since you're just redirecting the output to a file, set the keyword argument
stdout = an_open_writeable_file_objectwhere the object points to the
outputfile.
subprocess.Popen is more general than subprocess.call.
Popen doesn't block, allowing you to interact with the process while it's running, or continue with other things in your Python program. The call to Popen returns a Popen object.
call does block. While it supports all the same arguments as the Popen constructor, so you can still set the process' output, environmental variables, etc., your script waits for the program to complete, and call returns a code representing the process' exit status.
returncode = call(*args, **kwargs)
is basically the same as calling
returncode = Popen(*args, **kwargs).wait()
call is just a convenience function. It's implementation in CPython is in subprocess.py:
def call(*popenargs, timeout=None, **kwargs):
"""Run command with arguments. Wait for command to complete or
timeout, then return the returncode attribute.
The arguments are the same as for the Popen constructor. Example:
retcode = call(["ls", "-l"])
"""
with Popen(*popenargs, **kwargs) as p:
try:
return p.wait(timeout=timeout)
except:
p.kill()
p.wait()
raise
As you can see, it's a thin wrapper around Popen.
How to force Selenium WebDriver to click on element which is not currently visible?
I had the same problem with selenium 2 in internet explorer 9, but my fix is really strange. I was not able to click into inputs inside my form -> selenium repeats, their are not visible.
It occured when my form had curved shadows -> http://www.paulund.co.uk/creating-different-css3-box-shadows-effects: in the concrete "Effect no. 2"
I have no idea, why&how this pseudo element solution's stopped selenium tests, but it works for me.
CSS values using HTML5 data attribute
There is, indeed, prevision for such feature, look http://www.w3.org/TR/css3-values/#attr-notation
This fiddle should work like what you need, but will not for now.
Unfortunately, it's still a draft, and isn't fully implemented on major browsers.
It does work for content on pseudo-elements, though.
How to flush output of print function?
Also as suggested in this blog one can reopen sys.stdout in unbuffered mode:
sys.stdout = os.fdopen(sys.stdout.fileno(), 'w', 0)
Each stdout.write and print operation will be automatically flushed afterwards.
What is the simplest way to get indented XML with line breaks from XmlDocument?
XmlTextWriter xw = new XmlTextWriter(writer);
xw.Formatting = Formatting.Indented;
Invert "if" statement to reduce nesting
It's a matter of opinion.
My normal approach would be to avoid single line ifs, and returns in the middle of a method.
You wouldn't want lines like it suggests everywhere in your method but there is something to be said for checking a bunch of assumptions at the top of your method, and only doing your actual work if they all pass.
Simple and fast method to compare images for similarity
I face the same issues recently, to solve this problem(simple and fast algorithm to compare two images) once and for all, I contribute an img_hash module to opencv_contrib, you can find the details from this link.
img_hash module provide six image hash algorithms, quite easy to use.
Codes example
origin lena
blur lena
resize lena
shift lena
#include <opencv2/core.hpp>
#include <opencv2/core/ocl.hpp>
#include <opencv2/highgui.hpp>
#include <opencv2/img_hash.hpp>
#include <opencv2/imgproc.hpp>
#include <iostream>
void compute(cv::Ptr<cv::img_hash::ImgHashBase> algo)
{
auto input = cv::imread("lena.png");
cv::Mat similar_img;
//detect similiar image after blur attack
cv::GaussianBlur(input, similar_img, {7,7}, 2, 2);
cv::imwrite("lena_blur.png", similar_img);
cv::Mat hash_input, hash_similar;
algo->compute(input, hash_input);
algo->compute(similar_img, hash_similar);
std::cout<<"gaussian blur attack : "<<
algo->compare(hash_input, hash_similar)<<std::endl;
//detect similar image after shift attack
similar_img.setTo(0);
input(cv::Rect(0,10, input.cols,input.rows-10)).
copyTo(similar_img(cv::Rect(0,0,input.cols,input.rows-10)));
cv::imwrite("lena_shift.png", similar_img);
algo->compute(similar_img, hash_similar);
std::cout<<"shift attack : "<<
algo->compare(hash_input, hash_similar)<<std::endl;
//detect similar image after resize
cv::resize(input, similar_img, {120, 40});
cv::imwrite("lena_resize.png", similar_img);
algo->compute(similar_img, hash_similar);
std::cout<<"resize attack : "<<
algo->compare(hash_input, hash_similar)<<std::endl;
}
int main()
{
using namespace cv::img_hash;
//disable opencl acceleration may(or may not) boost up speed of img_hash
cv::ocl::setUseOpenCL(false);
//if the value after compare <= 8, that means the images
//very similar to each other
compute(ColorMomentHash::create());
//there are other algorithms you can try out
//every algorithms have their pros and cons
compute(AverageHash::create());
compute(PHash::create());
compute(MarrHildrethHash::create());
compute(RadialVarianceHash::create());
//BlockMeanHash support mode 0 and mode 1, they associate to
//mode 1 and mode 2 of PHash library
compute(BlockMeanHash::create(0));
compute(BlockMeanHash::create(1));
}
In this case, ColorMomentHash give us best result
- gaussian blur attack : 0.567521
- shift attack : 0.229728
- resize attack : 0.229358
Pros and cons of each algorithm
The performance of img_hash is good too
Speed comparison with PHash library(100 images from ukbench)
If you want to know the recommend thresholds for these algorithms, please check this post(http://qtandopencv.blogspot.my/2016/06/introduction-to-image-hash-module-of.html). If you are interesting about how do I measure the performance of img_hash modules(include speed and different attacks), please check this link(http://qtandopencv.blogspot.my/2016/06/speed-up-image-hashing-of-opencvimghash.html).
Get div tag scroll position using JavaScript
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
<script type="text/javascript">
function scollPos() {
var div = document.getElementById("myDiv").scrollTop;
document.getElementById("pos").innerHTML = div;
}
</script>
</head>
<body>
<form id="form1">
<div id="pos">
</div>
<div id="myDiv" style="overflow: auto; height: 200px; width: 200px;" onscroll="scollPos();">
Place some large content here
</div>
</form>
</body>
</html>
How to read file contents into a variable in a batch file?
To get all the lines of the file loaded into the variable, Delayed Expansion is needed, so do the following:
SETLOCAL EnableDelayedExpansion
for /f "Tokens=* Delims=" %%x in (version.txt) do set Build=!Build!%%x
There is a problem with some special characters, though especially ;, % and !
How to find my realm file?
Finding a Realm File
For Android
How to view my Realm file in the Realm Browser?
For iOS
If your App is on Device
Make sure that your device is connected and go to the devices window in the Xcode menu Window > Devices (??2). There you will be able to choose your device and your app from a list of installed apps with debugging permissions.
After selecting your app, go to the cog in the toolbar at the bottom of the table view and select “Download Container…“. There you will be able to pull the file from the documents location to your Mac. It will be saved as an xcappdata bundle.
When you open the local path in Finder, where you saved it, you can tap into that by selecting “Show Package Contents” in the context menu of the finder, when you select the file. A new finder window will open, where you find your Realm inside in the following path (e.g.): AppData/Documents/default.realm (The directory '/private/var/mobile' is the path, which is used by iOS on the device filesystem.
If your App is on the Simulator
Go to your user’s directory:
/Users/<username>/Library/Developer/CoreSimulator/Devices/<simulator-uuid>/data/Containers/Data/Application/<application-uuid>/Documents/default.realm
Probably the easiest way to get the current path of the default realm is to pause the simulator and enter the following into the LLDB console:
Objective-C:
(lldb) po [RLMRealmConfiguration defaultConfiguration].fileURL
Swift using Realm Objective-C:
(lldb) po RLMRealmConfiguration.defaultConfiguration().fileURL
Swift using Realm Swift:
(lldb) po Realm.Configuration.defaultConfiguration.fileURL
Or if you have an RLMRealm instance at hand, you can use:
(lldb) po myRealm.configuration.fileURL
Then just copy this path, open your terminal, and type open [Pasted path here]
NOTE: Some paths have a space in them so be sure to use "\" before the space to escape it
Helper Tool SimPholders
This is probably the fastest way to find the file of an app in the simulator. Install SimPholders. This will allow you to access your app’s documents directory directly from your menu bar.
Note Some people have mentioned that SimPholders has taken them to the wrong simulator app folder, if that's the case for you, print out your realm path by following the steps above, printing out your realm.path
How do you get the contextPath from JavaScript, the right way?
Reviewer the solution by this Checking the solution of this page, make the following solution I hope it works: Example:
Javascript:
var context = window.location.pathname.substring(0, window.location.pathname.indexOf("/",2));
var url =window.location.protocol+"//"+ window.location.host +context+"/bla/bla";
How to calculate date difference in JavaScript?
this should work just fine if you just need to show what time left, since JavaScript uses frames for its time you'll have get your End Time - The Time RN after that we can divide it by 1000 since apparently 1000 frames = 1 seconds, after that you can use the basic math of time, but there's still a problem to this code, since the calculation is static, it can't compensate for the different day total in a year (360/365/366), the bunch of IF after the calculation is to make it null if the time is lower than 0, hope this helps even though it's not exactly what you're asking :)
var now = new Date();
var end = new Date("End Time");
var total = (end - now) ;
var totalD = Math.abs(Math.floor(total/1000));
var years = Math.floor(totalD / (365*60*60*24));
var months = Math.floor((totalD - years*365*60*60*24) / (30*60*60*24));
var days = Math.floor((totalD - years*365*60*60*24 - months*30*60*60*24)/ (60*60*24));
var hours = Math.floor((totalD - years*365*60*60*24 - months*30*60*60*24 - days*60*60*24)/ (60*60));
var minutes = Math.floor((totalD - years*365*60*60*24 - months*30*60*60*24 - days*60*60*24 - hours*60*60)/ (60));
var seconds = Math.floor(totalD - years*365*60*60*24 - months*30*60*60*24 - days*60*60*24 - hours*60*60 - minutes*60);
var Y = years < 1 ? "" : years + " Years ";
var M = months < 1 ? "" : months + " Months ";
var D = days < 1 ? "" : days + " Days ";
var H = hours < 1 ? "" : hours + " Hours ";
var I = minutes < 1 ? "" : minutes + " Minutes ";
var S = seconds < 1 ? "" : seconds + " Seconds ";
var A = years == 0 && months == 0 && days == 0 && hours == 0 && minutes == 0 && seconds == 0 ? "Sending" : " Remaining";
document.getElementById('txt').innerHTML = Y + M + D + H + I + S + A;
Operation Not Permitted when on root - El Capitan (rootless disabled)
Correct solution is to copy or install to /usr/local/bin not /usr/bin.This is due to System Integrity Protection (SIP). SIP makes /usr/bin read-only but leaves /usr/local as read-write.
SIP should not be disabled as stated in the answer above because it adds another layer of protection against malware gaining root access. Here is a complete explanation of what SIP does and why it is useful.
As suggested in this answer one should not disable SIP (rootless mode) "It is not recommended to disable rootless mode! The best practice is to install custom stuff to "/usr/local" only."
Oracle PL/SQL - Raise User-Defined Exception With Custom SQLERRM
Yes. You just have to use the RAISE_APPLICATION_ERROR function. If you also want to name your exception, you'll need to use the EXCEPTION_INIT pragma in order to associate the error number to the named exception. Something like
SQL> ed
Wrote file afiedt.buf
1 declare
2 ex_custom EXCEPTION;
3 PRAGMA EXCEPTION_INIT( ex_custom, -20001 );
4 begin
5 raise_application_error( -20001, 'This is a custom error' );
6 exception
7 when ex_custom
8 then
9 dbms_output.put_line( sqlerrm );
10* end;
SQL> /
ORA-20001: This is a custom error
PL/SQL procedure successfully completed.
Do fragments really need an empty constructor?
Yes they do.
You shouldn't really be overriding the constructor anyway. You should have a newInstance() static method defined and pass any parameters via arguments (bundle)
For example:
public static final MyFragment newInstance(int title, String message) {
MyFragment f = new MyFragment();
Bundle bdl = new Bundle(2);
bdl.putInt(EXTRA_TITLE, title);
bdl.putString(EXTRA_MESSAGE, message);
f.setArguments(bdl);
return f;
}
And of course grabbing the args this way:
@Override
public void onCreate(Bundle savedInstanceState) {
title = getArguments().getInt(EXTRA_TITLE);
message = getArguments().getString(EXTRA_MESSAGE);
//...
//etc
//...
}
Then you would instantiate from your fragment manager like so:
@Override
public void onCreate(Bundle savedInstanceState) {
if (savedInstanceState == null){
getSupportFragmentManager()
.beginTransaction()
.replace(R.id.content, MyFragment.newInstance(
R.string.alert_title,
"Oh no, an error occurred!")
)
.commit();
}
}
This way if detached and re-attached the object state can be stored through the arguments. Much like bundles attached to Intents.
Reason - Extra reading
I thought I would explain why for people wondering why.
If you check: https://android.googlesource.com/platform/frameworks/base/+/master/core/java/android/app/Fragment.java
You will see the instantiate(..) method in the Fragment class calls the newInstance method:
public static Fragment instantiate(Context context, String fname, @Nullable Bundle args) {
try {
Class<?> clazz = sClassMap.get(fname);
if (clazz == null) {
// Class not found in the cache, see if it's real, and try to add it
clazz = context.getClassLoader().loadClass(fname);
if (!Fragment.class.isAssignableFrom(clazz)) {
throw new InstantiationException("Trying to instantiate a class " + fname
+ " that is not a Fragment", new ClassCastException());
}
sClassMap.put(fname, clazz);
}
Fragment f = (Fragment) clazz.getConstructor().newInstance();
if (args != null) {
args.setClassLoader(f.getClass().getClassLoader());
f.setArguments(args);
}
return f;
} catch (ClassNotFoundException e) {
throw new InstantiationException("Unable to instantiate fragment " + fname
+ ": make sure class name exists, is public, and has an"
+ " empty constructor that is public", e);
} catch (java.lang.InstantiationException e) {
throw new InstantiationException("Unable to instantiate fragment " + fname
+ ": make sure class name exists, is public, and has an"
+ " empty constructor that is public", e);
} catch (IllegalAccessException e) {
throw new InstantiationException("Unable to instantiate fragment " + fname
+ ": make sure class name exists, is public, and has an"
+ " empty constructor that is public", e);
} catch (NoSuchMethodException e) {
throw new InstantiationException("Unable to instantiate fragment " + fname
+ ": could not find Fragment constructor", e);
} catch (InvocationTargetException e) {
throw new InstantiationException("Unable to instantiate fragment " + fname
+ ": calling Fragment constructor caused an exception", e);
}
}
http://docs.oracle.com/javase/6/docs/api/java/lang/Class.html#newInstance() Explains why, upon instantiation it checks that the accessor is public and that that class loader allows access to it.
It's a pretty nasty method all in all, but it allows the FragmentManger to kill and recreate Fragments with states. (The Android subsystem does similar things with Activities).
Example Class
I get asked a lot about calling newInstance. Do not confuse this with the class method. This whole class example should show the usage.
/**
* Created by chris on 21/11/2013
*/
public class StationInfoAccessibilityFragment extends BaseFragment implements JourneyProviderListener {
public static final StationInfoAccessibilityFragment newInstance(String crsCode) {
StationInfoAccessibilityFragment fragment = new StationInfoAccessibilityFragment();
final Bundle args = new Bundle(1);
args.putString(EXTRA_CRS_CODE, crsCode);
fragment.setArguments(args);
return fragment;
}
// Views
LinearLayout mLinearLayout;
/**
* Layout Inflater
*/
private LayoutInflater mInflater;
/**
* Station Crs Code
*/
private String mCrsCode;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mCrsCode = getArguments().getString(EXTRA_CRS_CODE);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
mInflater = inflater;
return inflater.inflate(R.layout.fragment_station_accessibility, container, false);
}
@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
mLinearLayout = (LinearLayout)view.findViewBy(R.id.station_info_accessibility_linear);
//Do stuff
}
@Override
public void onResume() {
super.onResume();
getActivity().getSupportActionBar().setTitle(R.string.station_info_access_mobility_title);
}
// Other methods etc...
}
SVN commit command
To add a file/folder to the project, a good way is:
First of all add your files to /path/to/your/project/my/added/files, and then run following commands:
svn cleanup /path/to/your/project
svn add --force /path/to/your/project/*
svn cleanup /path/to/your/project
svn commit /path/to/your/project -m 'Adding a file'
I used cleanup to prevent any segmentation fault (core dumped), and now the SVN project is updated.
Visual Studio move project to a different folder
- Copy the project folder to new destination
- Remove your project from solution (Right-click the project in "Solution Explorer" and choose "Remove")
- Then add existing project to solution (Right-click the project in "Solution Explorer" and choose "Add" then "Existing project")
- Change path to "packages" folder in "YourProjectName.csproj" file (Open in notepad and change paths for linked packages)
How to add a "confirm delete" option in ASP.Net Gridview?
Try this:
I used for Update and Delete buttons. It doesn't touch Edit button. You can use auto generated buttons.
protected void gvOperators_OnRowDataBound(object sender, GridViewRowEventArgs e)
{
if(e.Row.RowType != DataControlRowType.DataRow) return;
var updateButton = (LinkButton)e.Row.Cells[0].Controls[0];
if (updateButton.Text == "Update")
{
updateButton.OnClientClick = "return confirm('Do you really want to update?');";
}
var deleteButton = (LinkButton)e.Row.Cells[0].Controls[2];
if (deleteButton.Text == "Delete")
{
deleteButton.OnClientClick = "return confirm('Do you really want to delete?');";
}
}
How can I get a collection of keys in a JavaScript dictionary?
As others have said, you could use Object.keys(), but who cares about older browsers, right?
Well, I do.
Try this. array_keys from PHPJS ports PHP's handy array_keys function, so it can be used in JavaScript.
At a glance, it uses Object.keys if supported, but it handles the case where it isn't very easily. It even includes filtering the keys based on values you might be looking for (optional) and a toggle for whether or not to use strict comparison === versus typecasting comparison == (optional).
SQL SELECT from multiple tables
select p.pid, p.cid, c1.name,c2.name
from product p
left outer join customer1 c1 on c1.cid=p.cid
left outer join customer2 c2 on c2.cid=p.cid
set background color: Android
Try this:
li.setBackgroundColor(android.R.color.red); //or which ever color do you want
EDIT: Posting logcat file would also help.
Check if any type of files exist in a directory using BATCH script
You can use this
@echo off
for /F %%i in ('dir /b "c:\test directory\*.*"') do (
echo Folder is NON empty
goto :EOF
)
echo Folder is empty or does not exist
Taken from here.
That should do what you need.
Where's the IE7/8/9/10-emulator in IE11 dev tools?
I posted an answer to this already when someone else asked the same question (see How to bring back "Browser mode" in IE11?).
Read my answer there for a fuller explaination, but in short:
They removed it deliberately, because compat mode is not actually really very good for testing compatibility.
If you really want to test for compatibility with any given version of IE, you need to test in a real copy of that IE version. MS provide free VMs on http://modern.ie/ for you to use for this purpose.
The only way to get compat mode in IE11 is to set the
X-UA-Compatibleheader. When you have this and the site defaults to compat mode, you will be able to set the mode in dev tools, but only between edge or the specified compat mode; other modes will still not be available.
Multidimensional Array [][] vs [,]
One is an array of arrays, and one is a 2d array. The former can be jagged, the latter is uniform.
That is, a double[][] can validly be:
double[][] x = new double[5][];
x[0] = new double[10];
x[1] = new double[5];
x[2] = new double[3];
x[3] = new double[100];
x[4] = new double[1];
Because each entry in the array is a reference to an array of double. With a jagged array, you can do an assignment to an array like you want in your second example:
x[0] = new double[13];
On the second item, because it is a uniform 2d array, you can't assign a 1d array to a row or column, because you must index both the row and column, which gets you down to a single double:
double[,] ServicePoint = new double[10,9];
ServicePoint[0]... // <-- meaningless, a 2d array can't use just one index.
UPDATE:
To clarify based on your question, the reason your #1 had a syntax error is because you had this:
double[][] ServicePoint = new double[10][9];
And you can't specify the second index at the time of construction. The key is that ServicePoint is not a 2d array, but an 1d array (of arrays) and thus since you are creating a 1d array (of arrays), you specify only one index:
double[][] ServicePoint = new double[10][];
Then, when you create each item in the array, each of those are also arrays, so then you can specify their dimensions (which can be different, hence the term jagged array):
ServicePoint[0] = new double[13];
ServicePoint[1] = new double[20];
Hope that helps!
What is causing "Unable to allocate memory for pool" in PHP?
Using a TTL of 0 means that APC will flush all the cache when it runs out of memory. The error don't appear anymore but it makes APC far less efficient. It's a no risk, no trouble, "I don't want to do my job" decision. APC is not meant to be used that way. You should choose a TTL high enough so the most accessed pages won't expire. The best is to give enough memory so APC doesn't need to flush cache.
Just read the manual to understand how ttl is used : http://www.php.net/manual/en/apc.configuration.php#ini.apc.ttl
The solution is to increase memory allocated to APC. Do this by increasing apc.shm_size.
If APC is compiled to use Shared Segment Memory you will be limited by your operating system. Type this command to see your system limit for each segment :
sysctl -a | grep -E "shmall|shmmax"
To alocate more memory you'll have to increase the number of segments with the parameter apc.shm_segments.
If APC is using mmap memory then you have no limit. The amount of memory is still defined by the same option apc.shm_size.
If there's not enough memory on the server, then use filters option to prevent less frequently accessed php files from being cached.
But never use a TTL of 0.
As c33s said, use apc.php to check your config. Copy the file from apc package to a webfolder and point browser to it. You'll see what is really allocated and how it is used. The graphs must remain stable after hours, if they are completly changing at each refresh, then it means that your setup is wrong (APC is flushing everything). Allocate 20% more ram than what APC really use as a security margin, and check it on a regular basis.
The default of allowing only 32MB is ridiculously low. PHP was designed when servers were 64MB and most scripts were using one php file per page. Nowadays solutions like Magento require more than 10k files (~60Mb in APC). You should allow enough memory so most of php files are always cached. It's not a waste, it's more efficient to keep opcode in ram rather than having the corresponding raw php in file cache. Nowadays we can find dedicated servers with 24Gb of memory for as low as $80/month, so don't hesitate to allow several GB to APC. I put 2GB out of 24GB on a server hosting 5Magento stores and ~40 wordpress website, APC uses 1.2GB. Count 64MB for Magento installation, 40MB for a Wordpress with some plugins.
Also, if you have developpment websites on the same server. Exclude them from cache.
How can I disable editing cells in a WPF Datagrid?
If you want to disable editing the entire grid, you can set IsReadOnly to true on the grid. If you want to disable user to add new rows, you set the property CanUserAddRows="False"
<DataGrid IsReadOnly="True" CanUserAddRows="False" />
Further more you can set IsReadOnly on individual columns to disable editing.
Using 'starts with' selector on individual class names
Try this:
$("div[class]").filter(function() {
var classNames = this.className.split(/\s+/);
for (var i=0; i<classNames.length; ++i) {
if (classNames[i].substr(0, 6) === "apple-") {
return true;
}
}
return false;
})
Hive: how to show all partitions of a table?
You can see Hive MetaStore tables,Partitions information in table of "PARTITIONS". You could use "TBLS" join "Partition" to query special table partitions.
Is there a float input type in HTML5?
This topic (e.g. step="0.01") relates to stepMismatch and is supported by all browsers as follows:
How do I update a Mongo document after inserting it?
I will use collection.save(the_changed_dict) this way. I've just tested this, and it still works for me. The following is quoted directly from pymongo doc.:
save(to_save[, manipulate=True[, safe=False[, **kwargs]]])
Save a document in this collection.
If to_save already has an "_id" then an update() (upsert) operation is performed and any existing document with that "_id" is overwritten. Otherwise an insert() operation is performed. In this case if manipulate is True an "_id" will be added to to_save and this method returns the "_id" of the saved document. If manipulate is False the "_id" will be added by the server but this method will return None.
How to export database schema in Oracle to a dump file
It depends on which version of Oracle? Older versions require exp (export), newer versions use expdp (data pump); exp was deprecated but still works most of the time.
Before starting, note that Data Pump exports to the server-side Oracle "directory", which is an Oracle symbolic location mapped in the database to a physical location. There may be a default directory (DATA_PUMP_DIR), check by querying DBA_DIRECTORIES:
SQL> select * from dba_directories;
... and if not, create one
SQL> create directory DATA_PUMP_DIR as '/oracle/dumps';
SQL> grant all on directory DATA_PUMP_DIR to myuser; -- DBAs dont need this grant
Assuming you can connect as the SYSTEM user, or another DBA, you can export any schema like so, to the default directory:
$ expdp system/manager schemas=user1 dumpfile=user1.dpdmp
Or specifying a specific directory, add directory=<directory name>:
C:\> expdp system/manager schemas=user1 dumpfile=user1.dpdmp directory=DUMPDIR
With older export utility, you can export to your working directory, and even on a client machine that is remote from the server, using:
$ exp system/manager owner=user1 file=user1.dmp
Make sure the export is done in the correct charset. If you haven't setup your environment, the Oracle client charset may not match the DB charset, and Oracle will do charset conversion, which may not be what you want. You'll see a warning, if so, then you'll want to repeat the export after setting NLS_LANG environment variable so the client charset matches the database charset. This will cause Oracle to skip charset conversion.
Example for American UTF8 (UNIX):
$ export NLS_LANG=AMERICAN_AMERICA.AL32UTF8
Windows uses SET, example using Japanese UTF8:
C:\> set NLS_LANG=Japanese_Japan.AL32UTF8
More info on Data Pump here: http://docs.oracle.com/cd/B28359_01/server.111/b28319/dp_export.htm#g1022624
how to load CSS file into jsp
I use this version
<style><%@include file="/WEB-INF/css/style.css"%></style>
The container 'Maven Dependencies' references non existing library - STS
Although it's too late , But here is my experience .
Whenever you get your maven project from a source controller or just copying your project from one machine to another , you need to update the dependencies .
For this Right-click on Project on project explorer -> Maven -> Update Project.
Please consider checking the "Force update of snapshot/releases" checkbox.
If you have not your dependencies in m2/repository then you need internet connection to get from the remote maven repository.
In case you have get from the source controller and you have not any unit test , It's probably your test folder does not include in the source controller in the first place , so you don't have those in the new repository.so you need to create those folders manually.
I have had both these cases .
My Routes are Returning a 404, How can I Fix Them?
You could try to move root/public/.htaccess to root/.htaccess and it should work
How to find the last field using 'cut'
This is the only solution possible for using nothing but cut:
echo "s.t.r.i.n.g." | cut -d'.' -f2- [repeat_following_part_forever_or_until_out_of_memory:] | cut -d'.' -f2-
Using this solution, the number of fields can indeed be unknown and vary from time to time. However as line length must not exceed LINE_MAX characters or fields, including the new-line character, then an arbitrary number of fields can never be part as a real condition of this solution.
Yes, a very silly solution but the only one that meets the criterias I think.
Using "margin: 0 auto;" in Internet Explorer 8
Add <!doctype html> at the top of your HTML output.
Solving SharePoint Server 2010 - 503. The service is unavailable, After installation
Thanks for sharing this. It helped a lot. The one difference in my applicationHost.config was
<add name="SharePoint14Module" image="C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\isapi\owssvr.dll" preCondition="appPoolName=SharePoint Central Administration v4,bitness64;SharePoint - 80" />
Note the multiple semicolon seperated entries. This is probably because I have a single box install of SPS.
Python os.path.join on Windows
For a system-agnostic solution that works on both Windows and Linux, no matter what the input path, one could use os.path.join(os.sep, rootdir + os.sep, targetdir)
On WIndows:
>>> os.path.join(os.sep, "C:" + os.sep, "Windows")
'C:\\Windows'
On Linux:
>>> os.path.join(os.sep, "usr" + os.sep, "lib")
'/usr/lib'
SQL 'LIKE' query using '%' where the search criteria contains '%'
You need to escape it: on many databases this is done by preceding it with backslash, \%.
So abc becomes abc\%.
Your programming language will have a database-specific function to do this for you. For example, PHP has mysql_escape_string() for the MySQL database.
How to break lines in PowerShell?
I think I found it. All you have to do is type in "`n" (WITH THE QUOTATION MARKS!)
Thanks!
What is the difference between BIT and TINYINT in MySQL?
From Overview of Numeric Types;
BIT[(M)]
A bit-field type. M indicates the number of bits per value, from 1 to 64. The default is 1 if M is omitted.
This data type was added in MySQL 5.0.3 for MyISAM, and extended in 5.0.5 to MEMORY, InnoDB, BDB, and NDBCLUSTER. Before 5.0.3, BIT is a synonym for TINYINT(1).
TINYINT[(M)] [UNSIGNED] [ZEROFILL]
A very small integer. The signed range is -128 to 127. The unsigned range is 0 to 255.
Additionally consider this;
BOOL, BOOLEAN
These types are synonyms for TINYINT(1). A value of zero is considered false. Non-zero values are considered true.
Ranges of floating point datatype in C?
As dasblinkenlight already answered, the numbers come from the way that floating point numbers are represented in IEEE-754, and Andreas has a nice breakdown of the maths.
However - be careful that the precision of floating point numbers isn't exactly 6 or 15 significant decimal digits as the table suggests, since the precision of IEEE-754 numbers depends on the number of significant binary digits.
floathas 24 significant binary digits - which depending on the number represented translates to 6-8 decimal digits of precision.doublehas 53 significant binary digits, which is approximately 15 decimal digits.
Another answer of mine has further explanation if you're interested.
jQuery Uncaught TypeError: Property '$' of object [object Window] is not a function
This is a syntax issue, the jQuery library included with WordPress loads in "no conflict" mode. This is to prevent compatibility problems with other javascript libraries that WordPress can load. In "no-confict" mode, the $ shortcut is not available and the longer jQuery is used, i.e.
jQuery(document).ready(function ($) {
By including the $ in parenthesis after the function call you can then use this shortcut within the code block.
For full details see WordPress Codex
Can I have two JavaScript onclick events in one element?
You could try something like this as well
<a href="#" onclick="one(); two();" >click</a>
<script type="text/javascript">
function one(){
alert('test');
}
function two(){
alert('test2');
}
</script>
What is the correct XPath for choosing attributes that contain "foo"?
John C is the closest, but XPath is case sensitive, so the correct XPath would be:
/bla/a[contains(@prop, 'Foo')]
How do I parse JSON with Objective-C?
JSON parsing using NSJSONSerialization
NSString* path = [[NSBundle mainBundle] pathForResource:@"data" ofType:@"json"];
//Here you can take JSON string from your URL ,I am using json file
NSString* jsonString = [[NSString alloc] initWithContentsOfFile:path encoding:NSUTF8StringEncoding error:nil];
NSData* jsonData = [jsonString dataUsingEncoding:NSUTF8StringEncoding];
NSError *jsonError;
NSArray *jsonDataArray = [NSJSONSerialization JSONObjectWithData:[jsonString dataUsingEncoding:NSUTF8StringEncoding] options:kNilOptions error:&jsonError];
NSLog(@"jsonDataArray: %@",jsonDataArray);
NSDictionary *jsonObject = [NSJSONSerialization JSONObjectWithData:jsonData options:kNilOptions error:&jsonError];
if(jsonObject !=nil){
// NSString *errorCode=[NSMutableString stringWithFormat:@"%@",[jsonObject objectForKey:@"response"]];
if(![[jsonObject objectForKey:@"#data"] isEqual:@""]){
NSMutableArray *array=[jsonObject objectForKey:@"#data"];
// NSLog(@"array: %@",array);
NSLog(@"array: %d",array.count);
int k = 0;
for(int z = 0; z<array.count;z++){
NSString *strfd = [NSString stringWithFormat:@"%d",k];
NSDictionary *dicr = jsonObject[@"#data"][strfd];
k=k+1;
// NSLog(@"dicr: %@",dicr);
NSLog(@"Firstname - Lastname : %@ - %@",
[NSMutableString stringWithFormat:@"%@",[dicr objectForKey:@"user_first_name"]],
[NSMutableString stringWithFormat:@"%@",[dicr objectForKey:@"user_last_name"]]);
}
}
}
You can see the Console output as below :
Firstname - Lastname : Chandra Bhusan - Pandey
Firstname - Lastname : Kalaiyarasan - Balu
Firstname - Lastname : (null) - (null)
Firstname - Lastname : Girija - S
Firstname - Lastname : Girija - S
Firstname - Lastname : (null) - (null)
How to create circular ProgressBar in android?
It's easy to create this yourself
In your layout include the following ProgressBar with a specific drawable (note you should get the width from dimensions instead). The max value is important here:
<ProgressBar
android:id="@+id/progressBar"
style="?android:attr/progressBarStyleHorizontal"
android:layout_width="150dp"
android:layout_height="150dp"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:max="500"
android:progress="0"
android:progressDrawable="@drawable/circular" />
Now create the drawable in your resources with the following shape. Play with the radius (you can use innerRadius instead of innerRadiusRatio) and thickness values.
circular (Pre Lollipop OR API Level < 21)
<shape
android:innerRadiusRatio="2.3"
android:shape="ring"
android:thickness="3.8sp" >
<solid android:color="@color/yourColor" />
</shape>
circular ( >= Lollipop OR API Level >= 21)
<shape
android:useLevel="true"
android:innerRadiusRatio="2.3"
android:shape="ring"
android:thickness="3.8sp" >
<solid android:color="@color/yourColor" />
</shape>
useLevel is "false" by default in API Level 21 (Lollipop) .
Start Animation
Next in your code use an ObjectAnimator to animate the progress field of the ProgessBar of your layout.
ProgressBar progressBar = (ProgressBar) view.findViewById(R.id.progressBar);
ObjectAnimator animation = ObjectAnimator.ofInt(progressBar, "progress", 0, 500); // see this max value coming back here, we animate towards that value
animation.setDuration(5000); // in milliseconds
animation.setInterpolator(new DecelerateInterpolator());
animation.start();
Stop Animation
progressBar.clearAnimation();
P.S. unlike examples above, it give smooth animation.
Using TortoiseSVN how do I merge changes from the trunk to a branch and vice versa?
The behavior depends on which version your repository has. Subversion 1.5 allows 4 types of merge:
- merge sourceURL1[@N] sourceURL2[@M] [WCPATH]
- merge sourceWCPATH1@N sourceWCPATH2@M [WCPATH]
- merge [-c M[,N...] | -r N:M ...] SOURCE[@REV] [WCPATH]
- merge --reintegrate SOURCE[@REV] [WCPATH]
Subversion before 1.5 only allowed the first 2 formats.
Technically you can perform all merges with the first two methods, but the last two enable subversion 1.5's merge tracking.
TortoiseSVN's options merge a range or revisions maps to method 3 when your repository is 1.5+ or to method one when your repository is older.
When merging features over to a release/maintenance branch you should use the 'Merge a range of revisions' command.
Only when you want to merge all features of a branch back to a parent branch (commonly trunk) you should look into using 'Reintegrate a branch'.
And the last command -Merge two different trees- is only usefull when you want to step outside the normal branching behavior. (E.g. Comparing different releases and then merging the differenct to yet another branch)
How does ifstream's eof() work?
-1 is get's way of saying you've reached the end of file. Compare it using the std::char_traits<char>::eof() (or std::istream::traits_type::eof()) - avoid -1, it's a magic number. (Although the other one is a bit verbose - you can always just call istream::eof)
The EOF flag is only set once a read tries to read past the end of the file. If I have a 3 byte file, and I only read 3 bytes, EOF is false, because I've not tried to read past the end of the file yet. While this seems confusing for files, which typically know their size, EOF is not known until a read is attempted on some devices, such as pipes and network sockets.
The second example works as inf >> foo will always return inf, with the side effect of attempt to read something and store it in foo. inf, in an if or while, will evaluate to true if the file is "good": no errors, no EOF. Thus, when a read fails, inf evaulates to false, and your loop properly aborts. However, take this common error:
while(!inf.eof()) // EOF is false here
{
inf >> x; // read fails, EOF becomes true, x is not set
// use x // we use x, despite our read failing.
}
However, this:
while(inf >> x) // Attempt read into x, return false if it fails
{
// will only be entered if read succeeded.
}
Which is what we want.
How to write palindrome in JavaScript
Best Way to check string is palindrome with more criteria like case and special characters...
function checkPalindrom(str) {
var str = str.replace(/[^a-zA-Z0-9]+/gi, '').toLowerCase();
return str == str.split('').reverse().join('');
}
You can test it with following words and strings and gives you more specific result.
1. bob
2. Doc, note, I dissent. A fast never prevents a fatness. I diet on cod
For strings it ignores special characters and convert string to lower case.
Change the "From:" address in Unix "mail"
On CentOS this worked for me:
echo "email body" | mail -s "Subject here" -r from_email_address email_address_to
How to prevent line-break in a column of a table cell (not a single cell)?
Just add
style="white-space:nowrap;"
Example:
<table class="blueTable" style="white-space:nowrap;">
<tr>
<td>My name is good</td>
</tr>
</table>
How to add white spaces in HTML paragraph
If you really need then you can use i.e. entity to do that, but remember that fonts used to render your page are usually proportional, so "aligning" with spaces does not really work and looks ugly.
Rename multiple files in a directory in Python
It seems that your problem is more in determining the new file name rather than the rename itself (for which you could use the os.rename method).
It is not clear from your question what the pattern is that you want to be renaming. There is nothing wrong with string manipulation. A regular expression may be what you need here.
How to make custom error pages work in ASP.NET MVC 4
Here is my solution. Use [ExportModelStateToTempData] / [ImportModelStateFromTempData] is uncomfortable in my opinion.
~/Views/Home/Error.cshtml:
@{
ViewBag.Title = "Error";
Layout = "~/Views/Shared/_Layout.cshtml";
}
<h2>Error</h2>
<hr/>
<div style="min-height: 400px;">
@Html.ValidationMessage("Error")
<br />
<br />
<button onclick="Error_goBack()" class="k-button">Go Back</button>
<script>
function Error_goBack() {
window.history.back()
}
</script>
</div>
~/Controllers/HomeController.sc:
public class HomeController : BaseController
{
public ActionResult Index()
{
return View();
}
public ActionResult Error()
{
return this.View();
}
...
}
~/Controllers/BaseController.sc:
public class BaseController : Controller
{
public BaseController() { }
protected override void OnActionExecuted(ActionExecutedContext filterContext)
{
if (filterContext.Result is ViewResult)
{
if (filterContext.Controller.TempData.ContainsKey("Error"))
{
var modelState = filterContext.Controller.TempData["Error"] as ModelState;
filterContext.Controller.ViewData.ModelState.Merge(new ModelStateDictionary() { new KeyValuePair<string, ModelState>("Error", modelState) });
filterContext.Controller.TempData.Remove("Error");
}
}
if ((filterContext.Result is RedirectResult) || (filterContext.Result is RedirectToRouteResult))
{
if (filterContext.Controller.ViewData.ModelState.ContainsKey("Error"))
{
filterContext.Controller.TempData["Error"] = filterContext.Controller.ViewData.ModelState["Error"];
}
}
base.OnActionExecuted(filterContext);
}
}
~/Controllers/MyController.sc:
public class MyController : BaseController
{
public ActionResult Index()
{
return View();
}
public ActionResult Details(int id)
{
if (id != 5)
{
ModelState.AddModelError("Error", "Specified row does not exist.");
return RedirectToAction("Error", "Home");
}
else
{
return View("Specified row exists.");
}
}
}
I wish you successful projects ;-)
SASS - use variables across multiple files
How about writing some color-based class in a global sass file, thus we don't need to care where variables are. Just like the following:
// base.scss
@import "./_variables.scss";
.background-color{
background: $bg-color;
}
and then, we can use the background-color class in any file.
My point is that I don't need to import variable.scss in any file, just use it.
Timer for Python game
I use this function in my python programs. The input for the function is as example:
value = time.time()
def stopWatch(value):
'''From seconds to Days;Hours:Minutes;Seconds'''
valueD = (((value/365)/24)/60)
Days = int (valueD)
valueH = (valueD-Days)*365
Hours = int(valueH)
valueM = (valueH - Hours)*24
Minutes = int(valueM)
valueS = (valueM - Minutes)*60
Seconds = int(valueS)
print Days,";",Hours,":",Minutes,";",Seconds
start = time.time() # What in other posts is described is
***your code HERE***
end = time.time()
stopWatch(end-start) #Use then my code
How to change the name of an iOS app?
- Select the top most line to the left (with you project name, number of targets, etc).
- Select the target you wish to rename.
- Click on the name of the target again.
- Type the new name.
- Press enter.
How can I change the font size using seaborn FacetGrid?
For the legend, you can use this
plt.setp(g._legend.get_title(), fontsize=20)
Where g is your facetgrid object returned after you call the function making it.
Change color of Button when Mouse is over
<Button Content="Click" Width="200" Height="50">
<Button.Style>
<Style TargetType="{x:Type Button}">
<Setter Property="Background" Value="LightBlue" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type Button}">
<Border x:Name="Border" Background="{TemplateBinding Background}">
<ContentPresenter HorizontalAlignment="Center" VerticalAlignment="Center" />
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="Background" Value="LightGreen" TargetName="Border" />
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</Button.Style>
How to get Selected Text from select2 when using <input>
As of Select2 4.x, it always returns an array, even for non-multi select lists.
var data = $('your-original-element').select2('data')
alert(data[0].text);
alert(data[0].id);
For Select2 3.x and lower
Single select:
var data = $('your-original-element').select2('data');
if(data) {
alert(data.text);
}
Note that when there is no selection, the variable 'data' will be null.
Multi select:
var data = $('your-original-element').select2('data')
alert(data[0].text);
alert(data[0].id);
alert(data[1].text);
alert(data[1].id);
From the 3.x docs:
data Gets or sets the selection. Analogous to val method, but works with objects instead of ids.
data method invoked on a single-select with an unset value will return null, while a data method invoked on an empty multi-select will return [].
PHP XML how to output nice format
Two different issues here:
Set the formatOutput and preserveWhiteSpace attributes to
TRUEto generate formatted XML:$doc->formatOutput = TRUE; $doc->preserveWhiteSpace = TRUE;Many web browsers (namely Internet Explorer and Firefox) format XML when they display it. Use either the View Source feature or a regular text editor to inspect the output.
See also xmlEncoding and encoding.
How to get first and last element in an array in java?
I think there is only one intuitive solution and it is:
int[] someArray = {1,2,3,4,5};
int first = someArray[0];
int last = someArray[someArray.length - 1];
System.out.println("First: " + first + "\n" + "Last: " + last);
Output:
First: 1
Last: 5
Click a button programmatically
in c# this is working :D
protect void button1_Click(object sender, EventArgs e){
button2_Click(button2, null);
}
protect void button2_Click(object sender, EventeArgs e){
//some codes here
}
for vb.net
Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
Button2_Click(Sender, e)
End Sub
Protected Sub Button2_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button2.Click
//some codes here
End Sub
Read contents of a local file into a variable in Rails
data = File.read("/path/to/file")
Create two threads, one display odd & other even numbers
Concurrent Package:
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
//=========== Task1 class prints odd =====
class TaskClass1 implements Runnable
{
private Condition condition;
private Lock lock;
boolean exit = false;
int i;
TaskClass1(Condition condition,Lock lock)
{
this.condition = condition;
this.lock = lock;
}
@Override
public void run() {
try
{
lock.lock();
for(i = 1;i<11;i++)
{
if(i%2 == 0)
{
condition.signal();
condition.await();
}
if(i%2 != 0)
{
System.out.println(Thread.currentThread().getName()+" == "+i);
}
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally
{
lock.unlock();
}
}
}
//==== Task2 : prints even =======
class TaskClass2 implements Runnable
{
private Condition condition;
private Lock lock;
boolean exit = false;
TaskClass2(Condition condition,Lock lock)
{
this.condition = condition;
this.lock = lock;
}
@Override
public void run() {
int i;
// TODO Auto-generated method stub
try
{
lock.lock();
for(i = 2;i<11;i++)
{
if(i%2 != 0)
{
condition.signal();
condition.await();
}
if(i%2 == 0)
{
System.out.println(Thread.currentThread().getName()+" == "+i);
}
}
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally
{
lock.unlock();
}
}
}
public class OddEven {
public static void main(String[] a)
{
Lock lock = new ReentrantLock();
Condition condition = lock.newCondition();
Future future1;
Future future2;
ExecutorService executorService = Executors.newFixedThreadPool(2);
future1 = executorService.submit(new TaskClass1(condition,lock));
future2 = executorService.submit(new TaskClass2(condition,lock));
executorService.shutdown();
}
}
How to Deserialize JSON data?
You can write your own JSON parser and make it more generic based on your requirement. Here is one which served my purpose nicely, hope will help you too.
class JsonParsor
{
public static DataTable JsonParse(String rawJson)
{
DataTable dataTable = new DataTable();
Dictionary<string, string> outdict = new Dictionary<string, string>();
StringBuilder keybufferbuilder = new StringBuilder();
StringBuilder valuebufferbuilder = new StringBuilder();
StringReader bufferreader = new StringReader(rawJson);
int s = 0;
bool reading = false;
bool inside_string = false;
bool reading_value = false;
bool reading_number = false;
while (s >= 0)
{
s = bufferreader.Read();
//open JSON
if (!reading)
{
if ((char)s == '{' && !inside_string && !reading)
{
reading = true;
continue;
}
if ((char)s == '}' && !inside_string && !reading)
break;
if ((char)s == ']' && !inside_string && !reading)
continue;
if ((char)s == ',')
continue;
}
else
{
if (reading_value)
{
if (!inside_string && (char)s >= '0' && (char)s <= '9')
{
reading_number = true;
valuebufferbuilder.Append((char)s);
continue;
}
}
//if we find a quote and we are not yet inside a string, advance and get inside
if (!inside_string)
{
if ((char)s == '\"' && !inside_string)
inside_string = true;
if ((char)s == '[' && !inside_string)
{
keybufferbuilder.Length = 0;
valuebufferbuilder.Length = 0;
reading = false;
inside_string = false;
reading_value = false;
}
if ((char)s == ',' && !inside_string && reading_number)
{
if (!dataTable.Columns.Contains(keybufferbuilder.ToString()))
dataTable.Columns.Add(keybufferbuilder.ToString(), typeof(string));
if (!outdict.ContainsKey(keybufferbuilder.ToString()))
outdict.Add(keybufferbuilder.ToString(), valuebufferbuilder.ToString());
keybufferbuilder.Length = 0;
valuebufferbuilder.Length = 0;
reading_value = false;
reading_number = false;
}
continue;
}
//if we reach end of the string
if (inside_string)
{
if ((char)s == '\"')
{
inside_string = false;
s = bufferreader.Read();
if ((char)s == ':')
{
reading_value = true;
continue;
}
if (reading_value && (char)s == ',')
{
//put the key-value pair into dictionary
if(!dataTable.Columns.Contains(keybufferbuilder.ToString()))
dataTable.Columns.Add(keybufferbuilder.ToString(),typeof(string));
if (!outdict.ContainsKey(keybufferbuilder.ToString()))
outdict.Add(keybufferbuilder.ToString(), valuebufferbuilder.ToString());
keybufferbuilder.Length = 0;
valuebufferbuilder.Length = 0;
reading_value = false;
}
if (reading_value && (char)s == '}')
{
if (!dataTable.Columns.Contains(keybufferbuilder.ToString()))
dataTable.Columns.Add(keybufferbuilder.ToString(), typeof(string));
if (!outdict.ContainsKey(keybufferbuilder.ToString()))
outdict.Add(keybufferbuilder.ToString(), valuebufferbuilder.ToString());
ICollection key = outdict.Keys;
DataRow newrow = dataTable.NewRow();
foreach (string k_loopVariable in key)
{
CommonModule.LogTheMessage(outdict[k_loopVariable],"","","");
newrow[k_loopVariable] = outdict[k_loopVariable];
}
dataTable.Rows.Add(newrow);
CommonModule.LogTheMessage(dataTable.Rows.Count.ToString(), "", "row_count", "");
outdict.Clear();
keybufferbuilder.Length=0;
valuebufferbuilder.Length=0;
reading_value = false;
reading = false;
continue;
}
}
else
{
if (reading_value)
{
valuebufferbuilder.Append((char)s);
continue;
}
else
{
keybufferbuilder.Append((char)s);
continue;
}
}
}
else
{
switch ((char)s)
{
case ':':
reading_value = true;
break;
default:
if (reading_value)
{
valuebufferbuilder.Append((char)s);
}
else
{
keybufferbuilder.Append((char)s);
}
break;
}
}
}
}
return dataTable;
}
}
How to check if a char is equal to an empty space?
To compare Strings you have to use the equals keyword.
if(c.equals(""))
{
}
How to do SELECT MAX in Django?
Django also has the 'latest(field_name = None)' function that finds the latest (max. value) entry. It not only works with date fields but also with strings and integers.
You can give the field name when calling that function:
max_rated_entry = YourModel.objects.latest('rating')
return max_rated_entry.details
Or you can already give that field name in your models meta data:
from django.db import models
class YourModel(models.Model):
#your class definition
class Meta:
get_latest_by = 'rating'
Now you can call 'latest()' without any parameters:
max_rated_entry = YourModel.objects.latest()
return max_rated_entry.details
Return True, False and None in Python
It's impossible to say without seeing your actual code. Likely the reason is a code path through your function that doesn't execute a return statement. When the code goes down that path, the function ends with no value returned, and so returns None.
Updated: It sounds like your code looks like this:
def b(self, p, data):
current = p
if current.data == data:
return True
elif current.data == 1:
return False
else:
self.b(current.next, data)
That else clause is your None path. You need to return the value that the recursive call returns:
else:
return self.b(current.next, data)
BTW: using recursion for iterative programs like this is not a good idea in Python. Use iteration instead. Also, you have no clear termination condition.
Is there a way to 'uniq' by column?
well, simpler than isolating the column with awk, if you need to remove everything with a certain value for a given file, why not just do grep -v:
e.g. to delete everything with the value "col2" in the second place line: col1,col2,col3,col4
grep -v ',col2,' file > file_minus_offending_lines
If this isn't good enough, because some lines may get improperly stripped by possibly having the matching value show up in a different column, you can do something like this:
awk to isolate the offending column: e.g.
awk -F, '{print $2 "|" $line}'
the -F sets the field delimited to ",", $2 means column 2, followed by some custom delimiter and then the entire line. You can then filter by removing lines that begin with the offending value:
awk -F, '{print $2 "|" $line}' | grep -v ^BAD_VALUE
and then strip out the stuff before the delimiter:
awk -F, '{print $2 "|" $line}' | grep -v ^BAD_VALUE | sed 's/.*|//g'
(note -the sed command is sloppy because it doesn't include escaping values. Also the sed pattern should really be something like "[^|]+" (i.e. anything not the delimiter). But hopefully this is clear enough.
How can I check if a key exists in a dictionary?
Another method is has_key() (if still using Python 2.X):
>>> a={"1":"one","2":"two"}
>>> a.has_key("1")
True
See full command of running/stopped container in Docker
Moving Dylan's comment into a full-blown answer because TOO USEFUL:
docker run --rm -v /var/run/docker.sock:/var/run/docker.sock assaflavie/runlike YOUR-CONTAINER
What does it do? Runs https://github.com/lavie/runlike inside a container, gets you the complete docker run command, then removes the container for you.
Attaching click to anchor tag in angular
You just need to add !! before your click method handler call: (click)="!!onGoToPage2()". The !! will prevent the default action from happening by converting the return of your method to a boolean. If it's a void method, then this will become false.
How can I get the latest JRE / JDK as a zip file rather than EXE or MSI installer?
Thanks for asking; the JDK does not seem to interact with the Windows registry.
However, the JRE does in certain instances.
Ruby replace string with captured regex pattern
def get_code(str)
str.sub(/^(Z_.*): .*/, '\1')
end
get_code('Z_foo: bar!') # => "Z_foo"
click command in selenium webdriver does not work
If you know for sure that the element is present, you could try this to simulate the click - if .Click() isn't working
driver.findElement(By.name("submit")).sendKeys(Keys.RETURN);
or
driver.findElement(By.name("submit")).sendKeys(Keys.ENTER);
Python Pandas: How to read only first n rows of CSV files in?
If you only want to read the first 999,999 (non-header) rows:
read_csv(..., nrows=999999)
If you only want to read rows 1,000,000 ... 1,999,999
read_csv(..., skiprows=1000000, nrows=999999)
nrows : int, default None Number of rows of file to read. Useful for reading pieces of large files*
skiprows : list-like or integer Row numbers to skip (0-indexed) or number of rows to skip (int) at the start of the file
and for large files, you'll probably also want to use chunksize:
chunksize : int, default None Return TextFileReader object for iteration
onchange equivalent in angular2
We can use Angular event bindings to respond to any DOM event. The syntax is simple. We surround the DOM event name in parentheses and assign a quoted template statement to it. -- reference
Since change is on the list of standard DOM events, we can use it:
(change)="saverange()"
In your particular case, since you're using NgModel, you could break up the two-way binding like this instead:
[ngModel]="range" (ngModelChange)="saverange($event)"
Then
saverange(newValue) {
this.range = newValue;
this.Platform.ready().then(() => {
this.rootRef.child("users").child(this.UserID).child('range').set(this.range)
})
}
However, with this approach saverange() is called with every keystroke, so you're probably better off using (change).
List vs tuple, when to use each?
Tuples are fixed size in nature whereas lists are dynamic.
In other words, a tuple is immutable whereas a list is mutable.
- You can't add elements to a tuple. Tuples have no append or extend method.
- You can't remove elements from a tuple. Tuples have no remove or pop method.
- You can find elements in a tuple, since this doesn’t change the tuple.
- You can also use the
inoperator to check if an element exists in the tuple.
Tuples are faster than lists. If you're defining a constant set of values and all you're ever going to do with it is iterate through it, use a tuple instead of a list.
It makes your code safer if you “write-protect” data that does not need to be changed. Using a tuple instead of a list is like having an implied assert statement that this data is constant, and that special thought (and a specific function) is required to override that.
Some tuples can be used as dictionary keys (specifically, tuples that contain immutable values like strings, numbers, and other tuples). Lists can never be used as dictionary keys, because lists are not immutable.
Source: Dive into Python 3
How to remove the underline for anchors(links)?
<u>
is a deprecated tag.
Use...
<span class="underline">My text</span>
with a CSS file containing...
span.underline
{
text-decoration: underline;
}
or just...
<span style="text-decoration:underline">My Text</span>
java.lang.VerifyError: Expecting a stackmap frame at branch target JDK 1.7
This ERROR can happen when you use Mockito to mock final classes.
Consider using Mockito inline or Powermock instead.
How to set timeout on python's socket recv method?
As mentioned in previous replies, you can use something like: .settimeout()
For example:
import socket
s = socket.socket()
s.settimeout(1) # Sets the socket to timeout after 1 second of no activity
host, port = "somehost", 4444
s.connect((host, port))
s.send("Hello World!\r\n")
try:
rec = s.recv(100) # try to receive 100 bytes
except socket.timeout: # fail after 1 second of no activity
print("Didn't receive data! [Timeout]")
finally:
s.close()
I hope this helps!!
Java: How to convert String[] to List or Set
It's a old code, anyway, try it:
import java.util.Arrays;
import java.util.List;
import java.util.ArrayList;
public class StringArrayTest
{
public static void main(String[] args)
{
String[] words = {"word1", "word2", "word3", "word4", "word5"};
List<String> wordList = Arrays.asList(words);
for (String e : wordList)
{
System.out.println(e);
}
}
}
sum two columns in R
You can do this :
df <- data.frame("a" = c(1,2,3,4), "b" = c(4,3,2,1), "x_ind" = c(1,0,1,1), "y_ind" = c(0,0,1,1), "z_ind" = c(0,1,1,1) )
df %>% mutate( bi = ifelse((df$x_ind + df$y_ind +df$z_ind)== 3, 1,0 ))
How can I check for NaN values?
Another method if you're stuck on <2.6, you don't have numpy, and you don't have IEEE 754 support:
def isNaN(x):
return str(x) == str(1e400*0)
Formula to check if string is empty in Crystal Reports
if {le_gur_bond.gur1}="" or IsNull({le_gur_bond.gur1}) Then
""
else
"and " + {le_gur_bond.gur2} + " of "+ {le_gur_bond.grr_2_address2}
Qt. get part of QString
If you do not need to modify the substring, then you can use QStringRef. The QStringRef class is a read only wrapper around an existing QString that references a substring within the existing string. This gives much better performance than creating a new QString object to contain the sub-string. E.g.
QString myString("This is a string");
QStringRef subString(&myString, 5, 2); // subString contains "is"
If you do need to modify the substring, then left(), mid() and right() will do what you need...
QString myString("This is a string");
QString subString = myString.mid(5,2); // subString contains "is"
subString.append("n't"); // subString contains "isn't"
Simpler way to check if variable is not equal to multiple string values?
You can make use of in_array() in PHP.
$os = array("uk", "us"); // You can set multiple check conditions here
if (in_array("uk", $os)) //Founds a match !
{
echo "Got you";
}
Access blocked by CORS policy: Response to preflight request doesn't pass access control check
If you are using Spring as Back-End server and especially using Spring Security then i found a solution by putting http.cors(); in the configure method. The method looks like that:
protected void configure(HttpSecurity http) throws Exception {
http
.csrf().disable()
.authorizeRequests() // authorize
.anyRequest().authenticated() // all requests are authenticated
.and()
.httpBasic();
http.cors();
}
Check if a variable exists in a list in Bash
This is almost your original proposal but almost a 1-liner. Not that complicated as other valid answers, and not so depending on bash versions (can work with old bashes).
OK=0 ; MP_FLAVOURS="vanilla lemon hazelnut straciatella"
for FLAV in $MP_FLAVOURS ; do [ $FLAV == $FLAVOR ] && { OK=1 ; break; } ; done
[ $OK -eq 0 ] && { echo "$FLAVOR not a valid value ($MP_FLAVOURS)" ; exit 1 ; }
I guess my proposal can still be improved, both in length and style.
MySQL: #126 - Incorrect key file for table
mysql> set global sql_slave_skip_counter=1; start slave; show slave status\G
Then got error exists :
Error 'Table './openx/f_scraper_banner_details' is marked as crashed and should be repaired' on query. Default database: 'openx'. Query: 'INSERT INTO f_scraper_banner_details(job_details_id, ad_id, client_id, zone_id, affiliateid, comments, pct_to_report, publisher_currency, sanity_check_enabled, status, error_code, report_date) VALUES (10274859, 321264, 0, 31926, 0, '', -1, 'USD', 1, 'FAILURE', 'INACTIVE_BANNER', '2016-06-28 04:00:00')'
mysql> repair table f_scraper_banner_details;
This worked for me
Best way to select random rows PostgreSQL
postgresql order by random(), select rows in random order:
select your_columns from your_table ORDER BY random()
postgresql order by random() with a distinct:
select * from
(select distinct your_columns from your_table) table_alias
ORDER BY random()
postgresql order by random limit one row:
select your_columns from your_table ORDER BY random() limit 1
React-Native Button style not work
Try This one
<TouchableOpacity onPress={() => this._onPressAppoimentButton()} style={styles.Btn}>
<Button title="Order Online" style={styles.Btn} > </Button>
</TouchableOpacity>
How do I control how Emacs makes backup files?
Another way of configuring backup options is via the Customize interface. Enter:
M-x customize-group
And then at the Customize group: prompt enter backup.
If you scroll to the bottom of the buffer you'll see Backup Directory Alist. Click Show Value and set the first entry of the list as follows:
Regexp matching filename: .*
Backup directory name: /path/to/your/backup/dir
Alternatively, you can turn backups off my setting Make Backup Files to off.
If you don't want Emacs to automatically edit your .emacs file you'll want to set up a customisations file.
How to get current moment in ISO 8601 format with date, hour, and minute?
For Java version 7
You can follow Oracle documentation: http://docs.oracle.com/javase/7/docs/api/java/text/SimpleDateFormat.html
X - is used for ISO 8601 time zone
TimeZone tz = TimeZone.getTimeZone("UTC");
DateFormat df = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssX");
df.setTimeZone(tz);
String nowAsISO = df.format(new Date());
System.out.println(nowAsISO);
DateFormat df1 = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssX");
//nowAsISO = "2013-05-31T00:00:00Z";
Date finalResult = df1.parse(nowAsISO);
System.out.println(finalResult);
Java math function to convert positive int to negative and negative to positive?
Yes, as was already noted by Jeffrey Bosboom (Sorry Jeffrey, I hadn't noticed your comment when I answered), there is such a function: Math.negateExact.
and
No, you probably shouldn't be using it. Not unless you need a method reference.
How can I get a count of the total number of digits in a number?
dividing a number by 10 will give you the left most digit then doing a mod 10 on the number gives the number without the first digit and repeat that till you have all the digits
How to remove provisioning profiles from Xcode
Provisioning profiles are stored under settings > accounts. Just press the "View details..." for the developer account you want and the provisioning profiles will be listed there.
How can I pad an integer with zeros on the left?
Found this example... Will test...
import java.text.DecimalFormat;
class TestingAndQualityAssuranceDepartment
{
public static void main(String [] args)
{
int x=1;
DecimalFormat df = new DecimalFormat("00");
System.out.println(df.format(x));
}
}
Tested this and:
String.format("%05d",number);
Both work, for my purposes I think String.Format is better and more succinct.
How to solve privileges issues when restore PostgreSQL Database
For me, I was setting up a database with pgAdmin and it seems setting the owner during database creation was not enough. I had to navigate down to the 'public' schema and set the owner there as well (was originally 'postgres').
How to increase storage for Android Emulator? (INSTALL_FAILED_INSUFFICIENT_STORAGE)
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.android.junkfoodian"
android:installLocation="preferExternal" // this line can work for Installation error: // // INSTALL_FAILED_INSUFFICIENT_STORAGE
Check if DataRow exists by column name in c#?
You should try
if (row.Table.Columns.Contains("US_OTHERFRIEND"))
I don't believe that row has a columns property itself.
Named regular expression group "(?P<group_name>regexp)": what does "P" stand for?
Since we're all guessing, I might as well give mine: I've always thought it stood for Python. That may sound pretty stupid -- what, P for Python?! -- but in my defense, I vaguely remembered this thread [emphasis mine]:
Subject: Claiming (?P...) regex syntax extensions
From: Guido van Rossum ([email protected])
Date: Dec 10, 1997 3:36:19 pm
I have an unusual request for the Perl developers (those that develop the Perl language). I hope this (perl5-porters) is the right list. I am cc'ing the Python string-sig because it is the origin of most of the work I'm discussing here.
You are probably aware of Python. I am Python's creator; I am planning to release a next "major" version, Python 1.5, by the end of this year. I hope that Python and Perl can co-exist in years to come; cross-pollination can be good for both languages. (I believe Larry had a good look at Python when he added objects to Perl 5; O'Reilly publishes books about both languages.)
As you may know, Python 1.5 adds a new regular expression module that more closely matches Perl's syntax. We've tried to be as close to the Perl syntax as possible within Python's syntax. However, the regex syntax has some Python-specific extensions, which all begin with (?P . Currently there are two of them:
(?P<foo>...)Similar to regular grouping parentheses, but the text
matched by the group is accessible after the match has been performed, via the symbolic group name "foo".
(?P=foo)Matches the same string as that matched by the group named "foo". Equivalent to \1, \2, etc. except that the group is referred
to by name, not number.I hope that this Python-specific extension won't conflict with any future Perl extensions to the Perl regex syntax. If you have plans to use (?P, please let us know as soon as possible so we can resolve the conflict. Otherwise, it would be nice if the (?P syntax could be permanently reserved for Python-specific syntax extensions. (Is there some kind of registry of extensions?)
to which Larry Wall replied:
[...] There's no registry as of now--yours is the first request from outside perl5-porters, so it's a pretty low-bandwidth activity. (Sorry it was even lower last week--I was off in New York at Internet World.)
Anyway, as far as I'm concerned, you may certainly have 'P' with my blessing. (Obviously Perl doesn't need the 'P' at this point. :-) [...]
So I don't know what the original choice of P was motivated by -- pattern? placeholder? penguins? -- but you can understand why I've always associated it with Python. Which considering that (1) I don't like regular expressions and avoid them wherever possible, and (2) this thread happened fifteen years ago, is kind of odd.
Changing navigation bar color in Swift
If you have customized navigation controller, you can use above code snippet. So in my case, I've used as following code pieces.
Swift 3.0, XCode 8.1 version
navigationController.navigationBar.barTintColor = UIColor.green
Navigation Bar Text:
navigationController.navigationBar.titleTextAttributes = [NSForegroundColorAttributeName: UIColor.orange]
It is very helpful talks.
Excel error HRESULT: 0x800A03EC while trying to get range with cell's name
The error code 0x800A03EC (or -2146827284) means NAME_NOT_FOUND; in other words, you've asked for something, and Excel can't find it.
This is a generic code, which can apply to lots of things it can't find e.g. using properties which aren't valid at that time like PivotItem.SourceNameStandard throws this when a PivotItem doesn't have a filter applied. Worksheets["BLAHBLAH"] throws this, when the sheet doesn't exist etc. In general, you are asking for something with a specific name and it doesn't exist. As for why, that will taking some digging on your part.
Check your sheet definitely does have the Range you are asking for, or that the .CellName is definitely giving back the name of the range you are asking for.
How to return an array from an AJAX call?
Have a look at json_encode (http://php.net/manual/en/function.json-encode.php). It is available as of PHP 5.2. Use the parameter dataType: 'json' to have it parsed for you. You'll have the Object as the first argument in success then. For further information have a look at the jQuery-documentation: http://api.jquery.com/jQuery.ajax/
Change Select List Option background colour on hover
I realise this is an older question, but I recently came across this need and came up with the following solution using jQuery and CSS:
jQuery('select[name*="lstDestinations"] option').hover(
function() {
jQuery(this).addClass('highlight');
}, function() {
jQuery(this).removeClass('highlight');
}
);
and the css:
.highlight {
background-color:#333;
cursor:pointer;
}
Perhaps this helps someone else.
Infinite Recursion with Jackson JSON and Hibernate JPA issue
For me the best solution is to use @JsonView and create specific filters for each scenario. You could also use @JsonManagedReference and @JsonBackReference, however it is a hardcoded solution to only one situation, where the owner always references the owning side, and never the opposite. If you have another serialization scenario where you need to re-annotate the attribute differently, you will not be able to.
Problem
Lets use two classes, Company and Employee where you have a cyclic dependency between them:
public class Company {
private Employee employee;
public Company(Employee employee) {
this.employee = employee;
}
public Employee getEmployee() {
return employee;
}
}
public class Employee {
private Company company;
public Company getCompany() {
return company;
}
public void setCompany(Company company) {
this.company = company;
}
}
And the test class that tries to serialize using ObjectMapper (Spring Boot):
@SpringBootTest
@RunWith(SpringRunner.class)
@Transactional
public class CompanyTest {
@Autowired
public ObjectMapper mapper;
@Test
public void shouldSaveCompany() throws JsonProcessingException {
Employee employee = new Employee();
Company company = new Company(employee);
employee.setCompany(company);
String jsonCompany = mapper.writeValueAsString(company);
System.out.println(jsonCompany);
assertTrue(true);
}
}
If you run this code, you'll get the:
org.codehaus.jackson.map.JsonMappingException: Infinite recursion (StackOverflowError)
Solution Using `@JsonView`
@JsonView enables you to use filters and choose what fields should be included while serializing the objects. A filter is just a class reference used as a identifier. So let's first create the filters:
public class Filter {
public static interface EmployeeData {};
public static interface CompanyData extends EmployeeData {};
}
Remember, the filters are dummy classes, just used for specifying the fields with the @JsonView annotation, so you can create as many as you want and need. Let's see it in action, but first we need to annotate our Company class:
public class Company {
@JsonView(Filter.CompanyData.class)
private Employee employee;
public Company(Employee employee) {
this.employee = employee;
}
public Employee getEmployee() {
return employee;
}
}
and change the Test in order for the serializer to use the View:
@SpringBootTest
@RunWith(SpringRunner.class)
@Transactional
public class CompanyTest {
@Autowired
public ObjectMapper mapper;
@Test
public void shouldSaveCompany() throws JsonProcessingException {
Employee employee = new Employee();
Company company = new Company(employee);
employee.setCompany(company);
ObjectWriter writter = mapper.writerWithView(Filter.CompanyData.class);
String jsonCompany = writter.writeValueAsString(company);
System.out.println(jsonCompany);
assertTrue(true);
}
}
Now if you run this code, the Infinite Recursion problem is solved, because you have explicitly said that you just want to serialize the attributes that were annotated with @JsonView(Filter.CompanyData.class).
When it reaches the back reference for company in the Employee, it checks that it's not annotated and ignore the serialization. You also have a powerful and flexible solution to choose which data you want to send through your REST APIs.
With Spring you can annotate your REST Controllers methods with the desired @JsonView filter and the serialization is applied transparently to the returning object.
Here are the imports used in case you need to check:
import static org.junit.Assert.assertTrue;
import javax.transaction.Transactional;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.ObjectWriter;
import com.fasterxml.jackson.annotation.JsonView;
How to truncate a foreign key constrained table?
Tested on MYSQL Database
Solution 1:
SET FOREIGN_KEY_CHECKS = 0;
TRUNCATE table1;
Solution 2:
DELETE FROM table1;
ALTER TABLE table1 AUTO_INCREMENT = 1;
TRUNCATE table1;
This works for me. I hope, this will help you also. Thanks for asking this question.
how to add background image to activity?
We can easily place the background image in PercentFrameLayout using the ImageView. We have to set the scaleType attribute value="fitXY" and in the foreground we can also display other view's like textview or button.
<android.support.percent.PercentFrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
>
<ImageView
android:src="@drawable/logo"
android:id="@+id/im1"
android:scaleType="fitXY"
android:layout_height="match_parent"
android:layout_width="match_parent"/>
<EditText android:layout_gravity="center_horizontal"
android:hint="Enter Username"
android:id="@+id/et1"
android:layout_height="wrap_content"
app:layout_widthPercent="50%"
app:layout_marginTopPercent="30%"
/>
<Button
android:layout_gravity="center_horizontal"
android:text="Login"
android:id="@+id/b1"
android:layout_height="wrap_content"
app:layout_widthPercent="50%"
app:layout_marginTopPercent="40%"/>
</android.support.percent.PercentFrameLayout>
Where are SQL Server connection attempts logged?
Another way to check on connection attempts is to look at the server's event log. On my Windows 2008 R2 Enterprise machine I opened the server manager (right-click on Computer and select Manage. Then choose Diagnostics -> Event Viewer -> Windows Logs -> Applcation. You can filter the log to isolate the MSSQLSERVER events. I found a number that looked like this
Login failed for user 'bogus'. The user is not associated with a trusted SQL Server connection. [CLIENT: 10.12.3.126]
Is it possible to have different Git configuration for different projects?
I had an error when trying to git stash my local changes. The error from git said "Please tell me who you are" and then told me to "Run git config --global user.email "[email protected] and git config --global user.name "Your name" to set your account's default identity." However, you must Omit --global to set the identity only in your current repository.
Is it possible to assign a base class object to a derived class reference with an explicit typecast?
I disagree that it is not possible. You can do it like this:
public class Auto
{
public string Make {get; set;}
public string Model {get; set;}
}
public class Sedan : Auto
{
public int NumberOfDoors {get; set;}
}
public static T ConvertAuto<T>(Sedan sedan) where T : class
{
object auto = sedan;
return (T)loc;
}
Usage:
var sedan = new Sedan();
sedan.NumberOfDoors = 4;
var auto = ConvertAuto<Auto>(sedan);
How can I get the current page name in WordPress?
This seems to be the easiest to use:
<?php single_post_title(); ?>
Priority queue in .Net
Use a Java to C# translator on the Java implementation (java.util.PriorityQueue) in the Java Collections framework, or more intelligently use the algorithm and core code and plug it into a C# class of your own making that adheres to the C# Collections framework API for Queues, or at least Collections.
Maven: Failed to retrieve plugin descriptor error
For me, the solution given on the page maven is not able to download anything from central because ssl don't work worked, when running Mint 19 in a VM:
sudo apt install ca-certificates-java
sudo update-ca-certificates -f
How can I represent an infinite number in Python?
In python2.x there was a dirty hack that served this purpose (NEVER use it unless absolutely necessary):
None < any integer < any string
Thus the check i < '' holds True for any integer i.
It has been reasonably deprecated in python3. Now such comparisons end up with
TypeError: unorderable types: str() < int()
Responsive dropdown navbar with angular-ui bootstrap (done in the correct angular kind of way)
Update 2015-06
Based on antoinepairet's comment/example:
Using uib-collapse attribute provides animations: http://plnkr.co/edit/omyoOxYnCdWJP8ANmTc6?p=preview
<nav class="navbar navbar-default" role="navigation">
<div class="navbar-header">
<!-- note the ng-init and ng-click here: -->
<button type="button" class="navbar-toggle" ng-init="navCollapsed = true" ng-click="navCollapsed = !navCollapsed">
<span class="sr-only">Toggle navigation</span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
</button>
<a class="navbar-brand" href="#">Brand</a>
</div>
<div class="collapse navbar-collapse" uib-collapse="navCollapsed">
<ul class="nav navbar-nav">
...
</ul>
</div>
</nav>
Ancient..
I see that the question is framed around BS2, but I thought I'd pitch in with a solution for Bootstrap 3 using ng-class solution based on suggestions in ui.bootstrap issue 394:
The only variation from the official bootstrap example is the addition of ng- attributes noted by comments, below:
<nav class="navbar navbar-default" role="navigation">
<div class="navbar-header">
<!-- note the ng-init and ng-click here: -->
<button type="button" class="navbar-toggle" ng-init="navCollapsed = true" ng-click="navCollapsed = !navCollapsed">
<span class="sr-only">Toggle navigation</span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
</button>
<a class="navbar-brand" href="#">Brand</a>
</div>
<!-- note the ng-class here -->
<div class="collapse navbar-collapse" ng-class="{'in':!navCollapsed}">
<ul class="nav navbar-nav">
...
Here is an updated working example: http://plnkr.co/edit/OlCCnbGlYWeO7Nxwfj5G?p=preview (hat tip Lars)
This seems to works for me in simple use cases, but you'll note in the example that the second dropdown is cut off… good luck!
JQuery - Get select value
val() returns the value of the <select> element, i.e. the value attribute of the selected <option> element.
Since you actually want the inner text of the selected <option> element, you should match that element and use text() instead:
var nationality = $("#dancerCountry option:selected").text();
Reversing a string in C
If you want to practice advanced features of C, how about pointers? We can toss in macros and xor-swap for fun too!
#include <string.h> // for strlen()
// reverse the given null-terminated string in place
void inplace_reverse(char * str)
{
if (str)
{
char * end = str + strlen(str) - 1;
// swap the values in the two given variables
// XXX: fails when a and b refer to same memory location
# define XOR_SWAP(a,b) do\
{\
a ^= b;\
b ^= a;\
a ^= b;\
} while (0)
// walk inwards from both ends of the string,
// swapping until we get to the middle
while (str < end)
{
XOR_SWAP(*str, *end);
str++;
end--;
}
# undef XOR_SWAP
}
}
A pointer (e.g. char *, read from right-to-left as a pointer to a char) is a data type in C that is used
to refer to location in memory of another value. In this case,
the location where a char is stored. We can dereference
pointers by prefixing them with an *, which gives us the value
stored at that location. So the value stored at str is *str.
We can do simple arithmetic with pointers. When we increment (or decrement) a pointer, we simply move it to refer to the next (or previous) memory location for that type of value. Incrementing pointers of different types may move the pointer by a different number of bytes because different values have different byte sizes in C.
Here, we use one pointer to refer to the first unprocessed
char of the string (str) and another to refer to the last (end).
We swap their values (*str and *end), and move the pointers
inwards to the middle of the string. Once str >= end, either
they both point to the same char, which means our original string had an
odd length (and the middle char doesn't need to be reversed), or
we've processed everything.
To do the swapping, I've defined a macro. Macros are text substitution done by the C preprocessor. They are very different from functions, and it's important to know the difference. When you call a function, the function operates on a copy of the values you give it. When you call a macro, it simply does a textual substitution - so the arguments you give it are used directly.
Since I only used the XOR_SWAP macro once, it was probably overkill to define it,
but it made more clear what I was doing. After the C preprocessor expands the macro,
the while loop looks like this:
while (str < end)
{
do { *str ^= *end; *end ^= *str; *str ^= *end; } while (0);
str++;
end--;
}
Note that the macro arguments show up once for each time they're used in the macro definition. This can be very useful - but can also break your code if used incorrectly. For example, if I had compressed the increment/decrement instructions and the macro call into a single line, like
XOR_SWAP(*str++, *end--);
Then this would expand to
do { *str++ ^= *end--; *end-- ^= *str++; *str++ ^= *end--; } while (0);
Which has triple the increment/decrement operations, and doesn't actually do the swap it's supposed to do.
While we're on the subject, you should know what xor (^) means. It's a basic
arithmetic operation - like addition, subtraction, multiplication, division, except
it's not usually taught in elementary school. It combines two integers bit by bit
- like addition, but we don't care about the carry-overs. 1^1 = 0, 1^0 = 1,
0^1 = 1, 0^0 = 0.
A well known trick is to use xor to swap two values. This works because of three basic
properties of xor: x ^ 0 = x, x ^ x = 0 and x ^ y = y ^ x for all values x and y. So say we have two
variables a and b that are initially storing two values
va and vb.
// initially: // a == va // b == vb a ^= b; // now: a == va ^ vb b ^= a; // now: b == vb ^ (va ^ vb) // == va ^ (vb ^ vb) // == va ^ 0 // == va a ^= b; // now: a == (va ^ vb) ^ va // == (va ^ va) ^ vb // == 0 ^ vb // == vb
So the values are swapped. This does have one bug - when a and b are the same variable:
// initially: // a == va a ^= a; // now: a == va ^ va // == 0 a ^= a; // now: a == 0 ^ 0 // == 0 a ^= a; // now: a == 0 ^ 0 // == 0
Since we str < end, this never happens in the above code, so we're okay.
While we're concerned about correctness we should check our edge cases. The if (str) line should make sure we weren't given a NULL pointer for string. What about the empty string ""? Well strlen("") == 0, so we'll initialize end as str - 1, which means that the while (str < end) condition is never true, so we don't do anything. Which is correct.
There's a bunch of C to explore. Have fun with it!
Update: mmw brings up a good point, which is you do have to be slightly careful how you invoke this, as it does operate in-place.
char stack_string[] = "This string is copied onto the stack.";
inplace_reverse(stack_string);
This works fine, since stack_string is an array, whose contents are initialized to the given string constant. However
char * string_literal = "This string is part of the executable.";
inplace_reverse(string_literal);
Will cause your code to flame and die at runtime. That's because string_literal merely points to the string that is stored as part of your executable - which is normally memory that you are not allowed to edit by the OS. In a happier world, your compiler would know this, and cough an error when you tried to compile, telling you that string_literal needs to be of type char const * since you can't modify the contents. However, this is not the world my compiler lives in.
There are some hacks you could try to make sure that some memory is on the stack or in the heap (and is therefore editable), but they're not necessarily portable, and it could be pretty ugly. However, I'm more than happy to throw responsibility for this to the function invoker. I've told them that this function does in place memory manipulation, it's their responsibility to give me an argument that allows that.
What are all the uses of an underscore in Scala?
There is a specific example that "_" be used:
type StringMatcher = String => (String => Boolean)
def starts: StringMatcher = (prefix:String) => _ startsWith prefix
may be equal to :
def starts: StringMatcher = (prefix:String) => (s)=>s startsWith prefix
Applying “_” in some scenarios will automatically convert to “(x$n) => x$n ”
Set scroll position
Also worth noting window.scrollBy(dx,dy) (ref)
Understanding the map function
The map() function is there to apply the same procedure to every item in an iterable data structure, like lists, generators, strings, and other stuff.
Let's look at an example:
map() can iterate over every item in a list and apply a function to each item, than it will return (give you back) the new list.
Imagine you have a function that takes a number, adds 1 to that number and returns it:
def add_one(num):
new_num = num + 1
return new_num
You also have a list of numbers:
my_list = [1, 3, 6, 7, 8, 10]
if you want to increment every number in the list, you can do the following:
>>> map(add_one, my_list)
[2, 4, 7, 8, 9, 11]
Note: At minimum map() needs two arguments. First a function name and second something like a list.
Let's see some other cool things map() can do.
map() can take multiple iterables (lists, strings, etc.) and pass an element from each iterable to a function as an argument.
We have three lists:
list_one = [1, 2, 3, 4, 5]
list_two = [11, 12, 13, 14, 15]
list_three = [21, 22, 23, 24, 25]
map() can make you a new list that holds the addition of elements at a specific index.
Now remember map(), needs a function. This time we'll use the builtin sum() function. Running map() gives the following result:
>>> map(sum, list_one, list_two, list_three)
[33, 36, 39, 42, 45]
REMEMBER:
In Python 2 map(), will iterate (go through the elements of the lists) according to the longest list, and pass None to the function for the shorter lists, so your function should look for None and handle them, otherwise you will get errors. In Python 3 map() will stop after finishing with the shortest list. Also, in Python 3, map() returns an iterator, not a list.
React Native Error: ENOSPC: System limit for number of file watchers reached
Firstly you can run every time with root privileges
sudo npm start
Or you can delete node_modules folder and use
npm installto install againor you can get permanent solution
echo fs.inotify.max_user_watches=524288 | sudo tee -a /etc/sysctl.conf && sudo sysctl -p
How to get text of an input text box during onKeyPress?
the value of the input text box, during onKeyPress is always the value before the change
This is on purpose: This allows the event listener to cancel the keypress.
If the event listeners cancels the event, the value is not updated. If the event is not canceled, the value is updated, but after the event listener was called.
To get the value after the field value has been updated, schedule a function to run on the next event loop. The usual way to do this is to call setTimeout with a timeout of 0:
$('#field').keyup(function() {
var $field = $(this);
// this is the value before the keypress
var beforeVal = $field.val();
setTimeout(function() {
// this is the value after the keypress
var afterVal = $field.val();
}, 0);
});
Try here: http://jsfiddle.net/Q57gY/2/
Edit: Some browsers (e.g. Chrome) do not trigger keypress events for backspace; changed keypress to keyup in code.
Why is vertical-align:text-top; not working in CSS
something like
position:relative;
top:-5px;
just on the inline element itself works for me. Have to play with the top to get it centered vertically...
Passing a Bundle on startActivity()?
You can pass values from one activity to another activity using the Bundle. In your current activity, create a bundle and set the bundle for the particular value and pass that bundle to the intent.
Intent intent = new Intent(this,NewActivity.class);
Bundle bundle = new Bundle();
bundle.putString(key,value);
intent.putExtras(bundle);
startActivity(intent);
Now in your NewActivity, you can get this bundle and retrive your value.
Bundle bundle = getArguments();
String value = bundle.getString(key);
You can also pass data through the intent. In your current activity, set intent like this,
Intent intent = new Intent(this,NewActivity.class);
intent.putExtra(key,value);
startActivity(intent);
Now in your NewActivity, you can get that value from intent like this,
String value = getIntent().getExtras().getString(key);
iOS9 Untrusted Enterprise Developer with no option to trust
In iOS 9.1 and lower, go to Settings - General - Profiles - tap on your Profile - tap on Trust button.
In iOS 9.2+ & iOS 11+ go to: Settings - General - Profiles & Device Management - tap on your Profile - tap on Trust button.
In iOS 10+, go to: Settings - General - Device Management - tap on your Profile - tap on Trust button.
Text in Border CSS HTML
Text in Border with transparent text background
.box{
background-image: url("https://i.stack.imgur.com/N39wV.jpg");
width: 350px;
padding: 10px;
}
/*begin first box*/
.first{
width: 300px;
height: 100px;
margin: 10px;
border-width: 0 2px 0 2px;
border-color: #333;
border-style: solid;
position: relative;
}
.first span {
position: absolute;
display: flex;
right: 0;
left: 0;
align-items: center;
}
.first .foo{
top: -8px;
}
.first .bar{
bottom: -8.5px;
}
.first span:before{
margin-right: 15px;
}
.first span:after {
margin-left: 15px;
}
.first span:before , .first span:after {
content: ' ';
height: 2px;
background: #333;
display: block;
width: 50%;
}
/*begin second box*/
.second{
width: 300px;
height: 100px;
margin: 10px;
border-width: 2px 0 2px 0;
border-color: #333;
border-style: solid;
position: relative;
}
.second span {
position: absolute;
top: 0;
bottom: 0;
display: flex;
flex-direction: column;
align-items: center;
}
.second .foo{
left: -15px;
}
.second .bar{
right: -15.5px;
}
.second span:before{
margin-bottom: 15px;
}
.second span:after {
margin-top: 15px;
}
.second span:before , .second span:after {
content: ' ';
width: 2px;
background: #333;
display: block;
height: 50%;
}<div class="box">
<div class="first">
<span class="foo">FOO</span>
<span class="bar">BAR</span>
</div>
<br>
<div class="second">
<span class="foo">FOO</span>
<span class="bar">BAR</span>
</div>
</div>Summarizing count and conditional aggregate functions on the same factor
Assuming that your original dataset is similar to the one you created (i.e. with NA as character. You could specify na.strings while reading the data using read.table. But, I guess NAs would be detected automatically.
The price column is factor which needs to be converted to numeric class. When you use as.numeric, all the non-numeric elements (i.e. "NA", FALSE) gets coerced to NA) with a warning.
library(dplyr)
df %>%
mutate(price=as.numeric(as.character(price))) %>%
group_by(company, year, product) %>%
summarise(total.count=n(),
count=sum(is.na(price)),
avg.price=mean(price,na.rm=TRUE),
max.price=max(price, na.rm=TRUE))
data
I am using the same dataset (except the ... row) that was showed.
df = tbl_df(data.frame(company=c("Acme", "Meca", "Emca", "Acme", "Meca","Emca"),
year=c("2011", "2010", "2009", "2011", "2010", "2013"), product=c("Wrench", "Hammer",
"Sonic Screwdriver", "Fairy Dust", "Kindness", "Helping Hand"), price=c("5.67",
"7.12", "12.99", "10.99", "NA",FALSE)))
ios simulator: how to close an app
You can use this command to quit an app in iOS Simulator
xcrun simctl terminate booted com.apple.mobilesafari
You will need to know the bundle id of the app you have installed in the simulator. You can refer to this link
Advantages of using display:inline-block vs float:left in CSS
If you want to align the div with pixel accurate, then use float. inline-block seems to always requires you to chop off a few pixels (at least in IE)
How to convert datetime to timestamp using C#/.NET (ignoring current timezone)
Find timestamp from DateTime:
private long ConvertToTimestamp(DateTime value)
{
TimeZoneInfo NYTimeZone = TimeZoneInfo.FindSystemTimeZoneById("Eastern Standard Time");
DateTime NyTime = TimeZoneInfo.ConvertTime(value, NYTimeZone);
TimeZone localZone = TimeZone.CurrentTimeZone;
System.Globalization.DaylightTime dst = localZone.GetDaylightChanges(NyTime.Year);
NyTime = NyTime.AddHours(-1);
DateTime epoch = new DateTime(1970, 1, 1, 0, 0, 0, 0).ToLocalTime();
TimeSpan span = (NyTime - epoch);
return (long)Convert.ToDouble(span.TotalSeconds);
}
Difference between Eclipse Europa, Helios, Galileo
To see a list of the Eclipse release name and it's corresponding version number go to this website. http://en.wikipedia.org/wiki/Eclipse_%28software%29#Release
- Release Date Platform version
- Juno ?? June 2012 4.2?
- Indigo 22 June 2011 3.7
- Helios 23 June 2010 3.6
- Galileo 24 June 2009 3.5
- Ganymede 25 June 2008 3.4
- Europa 29 June 2007 3.3
- Callisto 30 June 2006 3.2
- Eclipse 3.1 28 June 2005 3.1
- Eclipse 3.0 21 June 2004 3.0
I too dislike the way that the Eclipse foundation DOES NOT use the version number for their downloads or on the Help -> About Eclipse dialog. They do display the version on the download webpage, but the actual file name is something like:
- eclipse-java-indigo-SR1-linux-gtk.tar.gz
- eclipse-java-helios-linux-gtk.tar.gz
But over time, you forget what release name goes with what version number. I would much prefer a file naming convention like:
- eclipse-3.7.1-java-indigo-SR1-linux-gtk.tar.gz
- eclipse-3.6-java-helios-linux-gtk.tar.gz
This way you get BOTH from the file name and it is sortable in a directory listing. Fortunately, they mostly choose names are alphabetically after the previous one (except for 3.4-Ganymede vs the newer 3.5-Galileo).
How to test that a registered variable is not empty?
You can check for empty string (when stderr is empty)
- name: Check script
shell: . {{ venv_name }}/bin/activate && myscritp.py
args:
chdir: "{{ home }}"
sudo_user: "{{ user }}"
register: test_myscript
- debug: msg='myscritp is Ok'
when: test_myscript.stderr == ""
If you want to check for fail:
- debug: msg='myscritp has error: {{test_myscript.stderr}}'
when: test_myscript.stderr != ""
Also look at this stackoverflow question
MySQL SELECT query string matching
Just turn the LIKE around
SELECT * FROM customers
WHERE 'Robert Bob Smith III, PhD.' LIKE CONCAT('%',name,'%')
How do I pass options to the Selenium Chrome driver using Python?
Code which disable chrome extensions for ones, who uses DesiredCapabilities to set browser flags :
desired_capabilities['chromeOptions'] = {
"args": ["--disable-extensions"],
"extensions": []
}
webdriver.Chrome(desired_capabilities=desired_capabilities)
How to check if an object is an array?
You can try this:
var arr = []; (or) arr = new Array();
var obj = {}; (or) arr = new Object();
arr.constructor.prototype.hasOwnProperty('push') //true
obj.constructor.prototype.hasOwnProperty('push') // false
What's the meaning of "=>" (an arrow formed from equals & greater than) in JavaScript?
ES6 Arrow functions:
In javascript the => is the symbol of an arrow function expression. A arrow function expression does not have its own this binding and therefore cannot be used as a constructor function. for example:
var words = 'hi from outside object';_x000D_
_x000D_
let obj = {_x000D_
words: 'hi from inside object',_x000D_
talk1: () => {console.log(this.words)},_x000D_
talk2: function () {console.log(this.words)}_x000D_
}_x000D_
_x000D_
obj.talk1(); // doesn't have its own this binding, this === window_x000D_
obj.talk2(); // does have its own this binding, this is objRules of using arrow functions:
- If there is exactly one argument you can omit the parentheses of the argument.
- If you return an expression and do this on the same line you can omit the
{}and thereturnstatement
For example:
let times2 = val => val * 2; _x000D_
// It is on the same line and returns an expression therefore the {} are ommited and the expression returns implictly_x000D_
// there also is only one argument, therefore the parentheses around the argument are omitted_x000D_
_x000D_
console.log(times2(3));To show error message without alert box in Java Script
First you are trying to write to the innerHTML of the input field. This will not work. You need to have a div or span to write to. Try something like:
First_Name
<input type=text id=fname name=fname onblur="validate()"> </input>
<div id="fname_error"></div>
Then change your validate function to read
if(myform.fname.value.length==0)
{
document.getElementById("fname_error").innerHTML="this is invalid name ";
}
Second, I'm always hesitant about using onBlur for this kind of thing. It is possible to submit a form without exiting the field (e.g. return key) in which case your validation code will not be executed. I prefer to run the validation from the button that submits the form and then call the submit() from within the function only if the document has passed validation.
How can I execute PHP code from the command line?
If you're using Laravel, you can use php artisan tinker to get an amazing interactive shell to interact with your Laravel app. However, Tinker works with "Psysh" under the hood which is a popular PHP REPL and you can use it even if you're not using Laravel (bare PHP):
// Bare PHP:
>>> preg_match("/hell/", "hello");
=> 1
// Laravel Stuff:
>>> Str::slug("How to get the job done?!!?!", "_");
=> "how_to_get_the_job_done"
One great feature I really like about Psysh is that it provides a quick way for directly looking up the PHP docs from the command line. To get it to work, you only have to take the following simple steps:
apt install php-sqlite3
And then get the required PHP documentation database and move it to the proper location:
wget http://psysh.org/manual/en/php_manual.sqlite
mkdir -p /usr/local/share/psysh/ && mv php_manual.sqlite /usr/local/share/psysh/
Now for instance:
Adding to the classpath on OSX
To specify a classpath for a single Java process, you can add a classpath option when you run the Java command.
In you command line. Use
java -cp "path/to/your/jar:." main
rather than just
java main
The option tells Java where to search for libraries.
OracleCommand SQL Parameters Binding
You need to use something like this:
OracleCommand oraCommand = new OracleCommand("SELECT fullname FROM sup_sys.user_profile
WHERE domain_user_name = :userName", db);
More can be found in this MSDN article: http://msdn.microsoft.com/en-us/library/system.data.oracleclient.oraclecommand.parameters%28v=vs.100%29.aspx
It is advised you use the : character instead of @ for Oracle.
How can I truncate a datetime in SQL Server?
This query should give you result equivalent to trunc(sysdate) in Oracle.
SELECT *
FROM your_table
WHERE CONVERT(varchar(12), your_column_name, 101)
= CONVERT(varchar(12), GETDATE(), 101)
Hope this helps!
Automatic confirmation of deletion in powershell
Add -recurse after the remove-item, also the -force parameter helps remove hidden files e.g.:
gci C:\temp\ -exclude *.svn-base,".svn" -recurse | %{ri $_ -force -recurse}
How to find the .NET framework version of a Visual Studio project?
You can also search the Visual Studio project files for the XML tag RequiredTargetFramework. This tag seems to exist on .NET 3.5 and higher.
For example: <RequiredTargetFramework>3.5</RequiredTargetFramework>
Eclipse 3.5 Unable to install plugins
I was getting the error while trying to connect for updates. Just did as in the above answer -
Window-> Preferences-> General-> Network
There the default provider was set as Native. I changed it to direct as my laptop didn't need to connect to any proxy.
Applied and it is working fine.
Prime numbers between 1 to 100 in C Programming Language
The condition i==j+1 will not be true for i==2. This can be fixed by a couple of changes to the inner loop:
#include <stdio.h>
int main(void)
{
for (int i=2; i<100; i++)
{
for (int j=2; j<=i; j++) // Changed upper bound
{
if (i == j) // Changed condition and reversed order of if:s
printf("%d\n",i);
else if (i%j == 0)
break;
}
}
}
create multiple tag docker image
How not to do it:
When building an image, you could also tag it this way.
docker build -t ubuntu:14.04 .
Then you build it again with another tag:
docker build -t ubuntu:latest .
If your Dockerfile makes good use of the cache, the same image should come out, and it effectively does the same as retagging the same image. If you do docker images then you will see that they have the same ID.
There's probably a case where this goes wrong though... But like @david-braun said, you can't create tags with Dockerfiles themselves, just with the docker command.
Regular expression to extract numbers from a string
we can use \b as a word boundary and then; \b\d+\b
Background color not showing in print preview
if you are using Bootstrap.just use this code in your custom css file. Bootstrap removes all your colors in print preview.
@media print{
.box-text {
font-size: 27px !important;
color: blue !important;
-webkit-print-color-adjust: exact !important;
}
}
How do I link to a library with Code::Blocks?
At a guess, you used Code::Blocks to create a Console Application project. Such a project does not link in the GDI stuff, because console applications are generally not intended to do graphics, and TextOut is a graphics function. If you want to use the features of the GDI, you should create a Win32 Gui Project, which will be set up to link in the GDI for you.
Hibernate: best practice to pull all lazy collections
It's probably not anywhere approaching a best practice, but I usually call a SIZE on the collection to load the children in the same transaction, like you have suggested. It's clean, immune to any changes in the structure of the child elements, and yields SQL with low overhead.
Bootstrap 3 Slide in Menu / Navbar on Mobile
Bootstrap 4
Create a responsive navbar sidebar "drawer" in Bootstrap 4?
Bootstrap horizontal menu collapse to sidemenu
Bootstrap 3
I think what you're looking for is generally known as an "off-canvas" layout. Here is the standard off-canvas example from the official Bootstrap docs: http://getbootstrap.com/examples/offcanvas/
The "official" example uses a right-side sidebar the toggle off and on separately from the top navbar menu. I also found these off-canvas variations that slide in from the left and may be closer to what you're looking for..
http://www.bootstrapzero.com/bootstrap-template/off-canvas-sidebar http://www.bootstrapzero.com/bootstrap-template/facebook
How to extract the year from a Python datetime object?
The other answers to this question seem to hit it spot on. Now how would you figure this out for yourself without stack overflow? Check out IPython, an interactive Python shell that has tab auto-complete.
> ipython
import Python 2.5 (r25:51908, Nov 6 2007, 16:54:01)
Type "copyright", "credits" or "license" for more information.
IPython 0.8.2.svn.r2750 -- An enhanced Interactive Python.
? -> Introduction and overview of IPython's features.
%quickref -> Quick reference.
help -> Python's own help system.
object? -> Details about 'object'. ?object also works, ?? prints more.
In [1]: import datetime
In [2]: now=datetime.datetime.now()
In [3]: now.
press tab a few times and you'll be prompted with the members of the "now" object:
now.__add__ now.__gt__ now.__radd__ now.__sub__ now.fromordinal now.microsecond now.second now.toordinal now.weekday
now.__class__ now.__hash__ now.__reduce__ now.astimezone now.fromtimestamp now.min now.strftime now.tzinfo now.year
now.__delattr__ now.__init__ now.__reduce_ex__ now.combine now.hour now.minute now.strptime now.tzname
now.__doc__ now.__le__ now.__repr__ now.ctime now.isocalendar now.month now.time now.utcfromtimestamp
now.__eq__ now.__lt__ now.__rsub__ now.date now.isoformat now.now now.timetuple now.utcnow
now.__ge__ now.__ne__ now.__setattr__ now.day now.isoweekday now.replace now.timetz now.utcoffset
now.__getattribute__ now.__new__ now.__str__ now.dst now.max now.resolution now.today now.utctimetuple
and you'll see that now.year is a member of the "now" object.
Entity Framework: One Database, Multiple DbContexts. Is this a bad idea?
You can have multiple contexts for single database. It can be useful for example if your database contains multiple database schemas and you want to handle each of them as separate self contained area.
The problem is when you want to use code first to create your database - only single context in your application can do that. The trick for this is usually one additional context containing all your entities which is used only for database creation. Your real application contexts containing only subsets of your entities must have database initializer set to null.
There are other issues you will see when using multiple context types - for example shared entity types and their passing from one context to another, etc. Generally it is possible, it can make your design much cleaner and separate different functional areas but it has its costs in additional complexity.
How to make Bootstrap Panel body with fixed height
You can use max-height in an inline style attribute, as below:
<div class="panel panel-primary">
<div class="panel-heading">jhdsahfjhdfhs</div>
<div class="panel-body" style="max-height: 10;">fdoinfds sdofjohisdfj</div>
</div>
To use scrolling with content that overflows a given max-height, you can alternatively try the following:
<div class="panel panel-primary">
<div class="panel-heading">jhdsahfjhdfhs</div>
<div class="panel-body" style="max-height: 10;overflow-y: scroll;">fdoinfds sdofjohisdfj</div>
</div>
To restrict the height to a fixed value you can use something like this.
<div class="panel panel-primary">
<div class="panel-heading">jhdsahfjhdfhs</div>
<div class="panel-body" style="min-height: 10; max-height: 10;">fdoinfds sdofjohisdfj</div>
</div>
Specify the same value for both max-height and min-height (either in pixels or in points – as long as it’s consistent).
You can also put the same styles in css class in a stylesheet (or a style tag as shown below) and then include the same in your tag. See below:
Style Code:
.fixed-panel {
min-height: 10;
max-height: 10;
overflow-y: scroll;
}
Apply Style :
<div class="panel panel-primary">
<div class="panel-heading">jhdsahfjhdfhs</div>
<div class="panel-body fixed-panel">fdoinfds sdofjohisdfj</div>
</div>
Hope this helps with your need.
stringstream, string, and char* conversion confusion
stringstream.str() returns a temporary string object that's destroyed at the end of the full expression. If you get a pointer to a C string from that (stringstream.str().c_str()), it will point to a string which is deleted where the statement ends. That's why your code prints garbage.
You could copy that temporary string object to some other string object and take the C string from that one:
const std::string tmp = stringstream.str();
const char* cstr = tmp.c_str();
Note that I made the temporary string const, because any changes to it might cause it to re-allocate and thus render cstr invalid. It is therefor safer to not to store the result of the call to str() at all and use cstr only until the end of the full expression:
use_c_str( stringstream.str().c_str() );
Of course, the latter might not be easy and copying might be too expensive. What you can do instead is to bind the temporary to a const reference. This will extend its lifetime to the lifetime of the reference:
{
const std::string& tmp = stringstream.str();
const char* cstr = tmp.c_str();
}
IMO that's the best solution. Unfortunately it's not very well known.
Proper way to initialize C++ structs
I write some test code:
#include <string>
#include <iostream>
#include <stdio.h>
using namespace std;
struct sc {
int x;
string y;
int* z;
};
int main(int argc, char** argv)
{
int* r = new int[128];
for(int i = 0; i < 128; i++ ) {
r[i] = i+32;
}
cout << r[100] << endl;
delete r;
sc* a = new sc;
sc* aa = new sc[2];
sc* b = new sc();
sc* ba = new sc[2]();
cout << "az:" << a->z << endl;
cout << "bz:" << b->z << endl;
cout << "a:" << a->x << " y" << a->y << "end" << endl;
cout << "b:" << b->x << " y" << b->y << "end" <<endl;
cout << "aa:" << aa->x << " y" << aa->y << "end" <<endl;
cout << "ba:" << ba->x << " y" << ba->y << "end" <<endl;
}
g++ compile and run:
./a.out
132
az:0x2b0000002a
bz:0
a:854191480 yend
b:0 yend
aa:854190968 yend
ba:0 yend
Auto-refreshing div with jQuery - setTimeout or another method?
$(document).ready(function() {
$.ajaxSetup({ cache: false }); // This part addresses an IE bug. without it, IE will only load the first number and will never refresh
setInterval(function() {
$('#notice_div').load('response.php');
}, 3000); // the "3000"
});
Download image with JavaScript
As @Ian explained, the problem is that jQuery's click() is not the same as the native one.
Therefore, consider using vanilla-js instead of jQuery:
var a = document.createElement('a');
a.href = "img.png";
a.download = "output.png";
document.body.appendChild(a);
a.click();
document.body.removeChild(a);
Should I declare Jackson's ObjectMapper as a static field?
Yes, that is safe and recommended.
The only caveat from the page you referred is that you can't be modifying configuration of the mapper once it is shared; but you are not changing configuration so that is fine. If you did need to change configuration, you would do that from the static block and it would be fine as well.
EDIT: (2013/10)
With 2.0 and above, above can be augmented by noting that there is an even better way: use ObjectWriter and ObjectReader objects, which can be constructed by ObjectMapper.
They are fully immutable, thread-safe, meaning that it is not even theoretically possible to cause thread-safety issues (which can occur with ObjectMapper if code tries to re-configure instance).
iOS - Build fails with CocoaPods cannot find header files
None of the answers helped me (I had my pods linked with all targets, build configurations setup properly, correclty set search paths "$(inherited)", etc...).
Problem disappeared by itself after I updated cocoapods to the newest, debug version using standard install / update command:
gem install cocoapods --pre
or:
sudo gem install cocoapods --pre
(if sudo was used during installation).
It must have been cocoapods bug.
BootStrap : Uncaught TypeError: $(...).datetimepicker is not a function
You guys copied the wrong code.
Go into the "/build" folder and grab the jquery.datetimepicker.full.js or jquery.datetimepicker.full.min.js if you want the minified version. It should fix it! :)
Get lengths of a list in a jinja2 template
Alex' comment looks good but I was still confused with using range. The following worked for me while working on a for condition using length within range.
{% for i in range(0,(nums['list_users_response']['list_users_result']['users'])| length) %}
<li> {{ nums['list_users_response']['list_users_result']['users'][i]['user_name'] }} </li>
{% endfor %}
DateTime.Now.ToString("yyyy-MM-dd hh:mm:ss") is returning AM time instead of PM time?
Use HH for 24 hour hours format:
DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss")
Or the tt format specifier for the AM/PM part:
DateTime.Now.ToString("yyyy-MM-dd hh:mm:ss tt")
Take a look at the custom Date and Time format strings documentation.
Objective-C - Remove last character from string
If it's an NSMutableString (which I would recommend since you're changing it dynamically), you can use:
[myString deleteCharactersInRange:NSMakeRange([myRequestString length]-1, 1)];
How to add custom validation to an AngularJS form?
@synergetic I think @blesh suppose to put function validate as below
function validate(value) {
var valid = blacklist.indexOf(value) === -1;
ngModel.$setValidity('blacklist', valid);
return valid ? value : undefined;
}
ngModel.$formatters.unshift(validate);
ngModel.$parsers.unshift(validate);
SqlException from Entity Framework - New transaction is not allowed because there are other threads running in the session
In my case, the problem appeared when I called Stored Procedure via EF and then later SaveChanges throw this exception. The problem was in calling the procedure, the enumerator was not disposed. I fixed the code following way:
public bool IsUserInRole(string username, string roleName, DataContext context)
{
var result = context.aspnet_UsersInRoles_IsUserInRoleEF("/", username, roleName);
//using here solved the issue
using (var en = result.GetEnumerator())
{
if (!en.MoveNext())
throw new Exception("emty result of aspnet_UsersInRoles_IsUserInRoleEF");
int? resultData = en.Current;
return resultData == 1;//1 = success, see T-SQL for return codes
}
}
How to loop through an array containing objects and access their properties
var c = {_x000D_
myProperty: [_x000D_
{ name: 'this' },_x000D_
{ name: 'can' },_x000D_
{ name: 'get' },_x000D_
{ name: 'crazy' }_x000D_
]_x000D_
};_x000D_
_x000D_
c.myProperty.forEach(function(myProperty_element) {_x000D_
var x = myProperty_element.name;_x000D_
console.log('the name of the member is : ' + x);_x000D_
})This is one of the ways how I was able to achieve it.
Please explain the exec() function and its family
The exec(3,3p) functions replace the current process with another. That is, the current process stops, and another runs instead, taking over some of the resources the original program had.
fopen deprecated warning
It looks like Microsoft has deprecated lots of calls which use buffers to improve code security. However, the solutions they're providing aren't portable. Anyway, if you aren't interested in using the secure version of their calls (like fopen_s), you need to place a definition of _CRT_SECURE_NO_DEPRECATE before your included header files. For example:
#define _CRT_SECURE_NO_DEPRECATE
#include <stdio.h>
The preprocessor directive can also be added to your project settings to effect it on all the files under the project. To do this add _CRT_SECURE_NO_DEPRECATE to Project Properties -> Configuration Properties -> C/C++ -> Preprocessor -> Preprocessor Definitions.
Mongoose and multiple database in single node.js project
Pretty late but this might help someone. The current answers assumes you are using the same file for your connections and models.
In real life, there is a high chance that you are splitting your models into different files. You can use something like this in your main file:
mongoose.connect('mongodb://localhost/default');
const db = mongoose.connection;
db.on('error', console.error.bind(console, 'connection error:'));
db.once('open', () => {
console.log('connected');
});
which is just how it is described in the docs. And then in your model files, do something like the following:
import mongoose, { Schema } from 'mongoose';
const userInfoSchema = new Schema({
createdAt: {
type: Date,
required: true,
default: new Date(),
},
// ...other fields
});
const myDB = mongoose.connection.useDb('myDB');
const UserInfo = myDB.model('userInfo', userInfoSchema);
export default UserInfo;
Where myDB is your database name.