SyntaxFix

Programs & Examples On #Repository pattern

The repository pattern provides a way to provide isolation between the data access layer of your application with the business layer. When using this tag on implementation heavy questions - tag the code language the implementation is written in.

What's an Aggregate Root?

The aggregate root is a complex name for a simple idea.

General idea

Well designed class diagram encapsulates its internals. Point through which you access this structure is called aggregate root.

enter image description here

Internals of your solution may be very complicated, but users of this hierarchy will just use root.doSomethingWhichHasBusinessMeaning().

Example

Check this simple class hierarchy enter image description here

How do you want to ride your car? Chose better API

Option A (it just somehow works):

car.ride();

Option B (user has access to class inernals):

if(car.getTires().getUsageLevel()< Car.ACCEPTABLE_TIRE_USAGE)
    for (Wheel w: car:getWheels()){
        w.spin();
    }
}

If you think that option A is better then congratulations. You get the main reason behind aggregate root.

Aggregate root encapsulates multiple classes. you can manipulate the whole hierarchy only through the main object.

What is the difference between DAO and Repository patterns?

OK, think I can explain better what I've put in comments :). So, basically, you can see both those as the same, though DAO is a more flexible pattern than Repository. If you want to use both, you would use the Repository in your DAO-s. I'll explain each of them below:

REPOSITORY:

It's a repository of a specific type of objects - it allows you to search for a specific type of objects as well as store them. Usually it will ONLY handle one type of objects. E.g. AppleRepository would allow you to do AppleRepository.findAll(criteria) or AppleRepository.save(juicyApple). Note that the Repository is using Domain Model terms (not DB terms - nothing related to how data is persisted anywhere).

A repository will most likely store all data in the same table, whereas the pattern doesn't require that. The fact that it only handles one type of data though, makes it logically connected to one main table (if used for DB persistence).

DAO - data access object (in other words - object used to access data)

A DAO is a class that locates data for you (it is mostly a finder, but it's commonly used to also store the data). The pattern doesn't restrict you to store data of the same type, thus you can easily have a DAO that locates/stores related objects.

E.g. you can easily have UserDao that exposes methods like

Collection<Permission> findPermissionsForUser(String userId)
User findUser(String userId)
Collection<User> findUsersForPermission(Permission permission)

All those are related to User (and security) and can be specified under then same DAO. This is not the case for Repository.

Finally

Note that both patterns really mean the same (they store data and they abstract the access to it and they are both expressed closer to the domain model and hardly contain any DB reference), but the way they are used can be slightly different, DAO being a bit more flexible/generic, while Repository is a bit more specific and restrictive to a type only.

using stored procedure in entity framework

You need to create a model class that contains all stored procedure properties like below. Also because Entity Framework model class needs primary key, you can create a fake key by using Guid.

public class GetFunctionByID
{
    [Key]
    public Guid? GetFunctionByID { get; set; }

    // All the other properties.
}

then register the GetFunctionByID model class in your DbContext.

public class FunctionsContext : BaseContext<FunctionsContext>
{
    public DbSet<App_Functions> Functions { get; set; }
    public DbSet<GetFunctionByID> GetFunctionByIds {get;set;}
}

When you call your stored procedure, just see below: 

var functionId = yourIdParameter;
var result =  db.Database.SqlQuery<GetFunctionByID>("GetFunctionByID @FunctionId", new SqlParameter("@FunctionId", functionId)).ToList());

Converting an int to std::string

You can use std::to_string in C++11

int i = 3;
std::string str = std::to_string(i);

Sorting arrays in javascript by object key value

Use Array's sort() method, eg

myArray.sort(function(a, b) {
    return a.distance - b.distance;
});

Correlation between two vectors?

To perform a linear regression between two vectors x and y follow these steps:

[p,err] = polyfit(x,y,1);   % First order polynomial
y_fit = polyval(p,x,err);   % Values on a line
y_dif = y - y_fit;          % y value difference (residuals)
SSdif = sum(y_dif.^2);      % Sum square of difference
SStot = (length(y)-1)*var(y);   % Sum square of y taken from variance
rsq = 1-SSdif/SStot;        % Correlation 'r' value. If 1.0 the correlelation is perfect

For x=[10;200;7;150] and y=[0.001;0.45;0.0007;0.2] I get rsq = 0.9181.

Reference URL: http://www.mathworks.com/help/matlab/data_analysis/linear-regression.html

Explain the different tiers of 2 tier & 3 tier architecture?

Wikipedia explains it better then I could

From the article - Top is 1st Tier: alt text

Is it possible to install iOS 6 SDK on Xcode 5?

I was also running the same problem when I updated to xcode 5 it removed older sdk. But I taken the copy of older SDK from another computer and the same you can download from following link.

http://www.4shared.com/zip/NlPgsxz6/iPhoneOS61sdk.html
(www.4shared.com test account [email protected]/test)

There are 2 ways to work with.

1) Unzip and paste this folder to /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs & restart the xcode.

But this might again removed by Xcode if you update xcode.

2) Another way is Unzip and paste where you want and go to /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs and create a symbolic link here, so that the SDK will remain same even if you update the Xcode.

Another change I made, Build Setting > Architectures > standard (not 64) so list all the versions of Deployment Target

No need to download the zip if you only wanted to change the deployment target.

Here are some screenshots. enter image description here enter image description here

Column order manipulation using col-lg-push and col-lg-pull in Twitter Bootstrap 3

Misconception Common misconception with column ordering is that, I should (or could) do the pushing and pulling on mobile devices, and that the desktop views should render in the natural order of the markup. This is wrong.

Reality Bootstrap is a mobile first framework. This means that the order of the columns in your HTML markup should represent the order in which you want them displayed on mobile devices. This mean that the pushing and pulling is done on the larger desktop views. not on mobile devices view..

Brandon Schmalz - Full Stack Web Developer Have a look at full description here

Make Div overlay ENTIRE page (not just viewport)?

The viewport is all that matters, but you likely want the entire website to stay darkened even while scrolling. For this, you want to use position:fixed instead of position:absolute. Fixed will keep the element static on the screen as you scroll, giving the impression that the entire body is darkened.

Example: http://jsbin.com/okabo3/edit

div.fadeMe {
  opacity:    0.5; 
  background: #000; 
  width:      100%;
  height:     100%; 
  z-index:    10;
  top:        0; 
  left:       0; 
  position:   fixed; 
}

<body>
  <div class="fadeMe"></div>
  <p>A bunch of content here...</p>
</body>

fatal error LNK1112: module machine type 'x64' conflicts with target machine type 'X86'

This problem may also happen if your project set up to have the same intermediate directories in Project Properties -> Configuration Properties -> General

How to append output to the end of a text file

I would use printf instead of echo because it's more reliable and processes formatting such as new line \n properly.

This example produces an output similar to echo in previous examples:

printf "hello world"  >> read.txt   
cat read.txt
hello world

However if you were to replace printf with echo in this example, echo would treat \n as a string, thus ignoring the intent

printf "hello\nworld"  >> read.txt   
cat read.txt
hello
world

How can I add a string to the end of each line in Vim?

 
%s/\s*$/\*/g

this will do the trick, and ensure leading spaces are ignored.

The openssl extension is required for SSL/TLS protection

enter image description here You are running Composer with SSL/TLS protection disabled.

 composer config --global disable-tls true
 composer config --global disable-tls false

How to initialize HashSet values by construction?

With the release of and the convenience factory methods this is possible in a cleaner way:

Set set = Set.of("a", "b", "c");

How can get the text of a div tag using only javascript (no jQuery)

Actually you dont need to call document.getElementById() function to get access to your div.

You can use this object directly by id:

text = test.textContent || test.innerText;
alert(text);

How do you execute an arbitrary native command from a string?

Please also see this Microsoft Connect report on essentially, how blummin' difficult it is to use PowerShell to run shell commands (oh, the irony).

http://connect.microsoft.com/PowerShell/feedback/details/376207/

They suggest using --% as a way to force PowerShell to stop trying to interpret the text to the right.

For example:

MSBuild /t:Publish --% /p:TargetDatabaseName="MyDatabase";TargetConnectionString="Data Source=.\;Integrated Security=True" /p:SqlPublishProfilePath="Deploy.publish.xml" Database.sqlproj

JSON date to Java date?

That DateTime format is actually ISO 8601 DateTime. JSON does not specify any particular format for dates/times. If you Google a bit, you will find plenty of implementations to parse it in Java.

Here's one

If you are open to using something other than Java's built-in Date/Time/Calendar classes, I would also suggest Joda Time. They offer (among many things) a ISODateTimeFormat to parse these kinds of strings.

Rerouting stdin and stdout from C

 
freopen("/my/newstdin", "r", stdin);
freopen("/my/newstdout", "w", stdout);
freopen("/my/newstderr", "w", stderr);

... do your stuff

freopen("/dev/stdin", "r", stdin);
...
...

This peaks the needle on my round-peg-square-hole-o-meter, what are you trying to accomplish?

Edit:

Remember that stdin, stdout and stderr are file descriptors 0, 1 and 2 for every newly created process. freopen() should keep the same fd's, just assign new streams to them.

So, a good way to ensure that this is actually doing what you want it to do would be:

printf("Stdout is descriptor %d\n", fileno(stdout));
freopen("/tmp/newstdout", "w", stdout);
printf("Stdout is now /tmp/newstdout and hopefully still fd %d\n",
   fileno(stdout));
freopen("/dev/stdout", "w", stdout);
printf("Now we put it back, hopefully its still fd %d\n",
   fileno(stdout));

I believe this is the expected behavior of freopen(), as you can see, you're still only using three file descriptors (and associated streams).

This would override any shell redirection, as there would be nothing for the shell to redirect. However, its probably going to break pipes. You might want to be sure to set up a handler for SIGPIPE, in case your program finds itself on the blocking end of a pipe (not FIFO, pipe).

So, ./your_program --stdout /tmp/stdout.txt --stderr /tmp/stderr.txt should be easily accomplished with freopen() and keeping the same actual file descriptors. What I don't understand is why you'd need to put them back once changing them? Surely, if someone passed either option, they would want it to persist until the program terminated?

jQuery selector first td of each row

$('td:first-child') will return a collection of the elements that you want.

var text = $('td:first-child').map(function() {
  return $(this).html();
}).get();

Modify table: How to change 'Allow Nulls' attribute from not null to allow null

 
-- replace NVARCHAR(42) with the actual type of your column
ALTER TABLE your_table
ALTER COLUMN your_column NVARCHAR(42) NULL

What's a concise way to check that environment variables are set in a Unix shell script?

Rather than using external shell scripts I tend to load in functions in my login shell. I use something like this as a helper function to check for environment variables rather than any set variable:

is_this_an_env_variable ()
    local var="$1"
    if env |grep -q "^$var"; then
       return 0
    else
       return 1
    fi
 }

Understanding ibeacon distancing

Distances to the source of iBeacon-formatted advertisement packets are estimated from the signal path attenuation calculated by comparing the measured received signal strength to the claimed transmit power which the transmitter is supposed to encode in the advertising data.

A path loss based scheme like this is only approximate and is subject to variation with things like antenna angles, intervening objects, and presumably a noisy RF environment. In comparison, systems really designed for distance measurement (GPS, Radar, etc) rely on precise measurements of propagation time, in same cases even examining the phase of the signal.

As Jiaru points out, 160 ft is probably beyond the intended range, but that doesn't necessarily mean that a packet will never get through, only that one shouldn't expect it to work at that distance.

How to POST JSON data with Python Requests?

From requests 2.4.2 (https://pypi.python.org/pypi/requests), the "json" parameter is supported. No need to specify "Content-Type". So the shorter version:

requests.post('http://httpbin.org/post', json={'test': 'cheers'})

Move an array element from one array position to another

You can implement some basic Calculus and create a universal function for moving array element from one position to the other.

For JavaScript it looks like this:

function magicFunction (targetArray, indexFrom, indexTo) { 

    targetElement = targetArray[indexFrom]; 
    magicIncrement = (indexTo - indexFrom) / Math.abs (indexTo - indexFrom); 

    for (Element = indexFrom; Element != indexTo; Element += magicIncrement){ 
        targetArray[Element] = targetArray[Element + magicIncrement]; 
    } 

    targetArray[indexTo] = targetElement; 

}

Check out "moving array elements" at "gloommatter" for detailed explanation.

http://www.gloommatter.com/DDesign/programming/moving-any-array-elements-universal-function.html

How do I change Bootstrap 3's glyphicons to white?

You can just create your own .white class and add it to the glyphicon element.

.white, .white a {
  color: #fff;
}

<i class="glyphicon glyphicon-home white"></i>

Message: Trying to access array offset on value of type null

This happens because $cOTLdata is not null but the index 'char_data' does not exist. Previous versions of PHP may have been less strict on such mistakes and silently swallowed the error / notice while 7.4 does not do this anymore.

To check whether the index exists or not you can use isset():

isset($cOTLdata['char_data'])

Which means the line should look something like this:

$len = isset($cOTLdata['char_data']) ? count($cOTLdata['char_data']) : 0;

Note I switched the then and else cases of the ternary operator since === null is essentially what isset already does (but in the positive case).

an htop-like tool to display disk activity in linux

It is not htop-like, but you could use atop. However, to display disk activity per process, it needs a kernel patch (available from the site). These kernel patches are now obsoleted, only to show per-process network activity an optional module is provided.

Bootstrap 3 only for mobile

If you're looking to make the elements be 33.3% only on small devices and lower:

This is backwards from what Bootstrap is designed for, but you can do this:

<div class="row">
    <div class="col-xs-4 col-md-12">.col-xs-4 .col-md-12</div>
    <div class="col-xs-4 col-md-12">.col-xs-4 .col-md-12</div>
    <div class="col-xs-4 col-md-12">.col-xs-4 .col-md-12</div>
</div>

This will make each element 33.3% wide on small and extra small devices but 100% wide on medium and larger devices.

JSFiddle: http://jsfiddle.net/jdwire/sggt8/embedded/result/

If you're only looking to hide elements for smaller devices:

I think you're looking for the visible-xs and/or visible-sm classes. These will let you make certain elements only visible to small screen devices.

For example, if you want a element to only be visible to small and extra-small devices, do this:

<div class="visible-xs visible-sm">You're using a fairly small device.</div>

To show it only for larger screens, use this:

<div class="hidden-xs hidden-sm">You're probably not using a phone.</div>

See http://getbootstrap.com/css/#responsive-utilities-classes for more information.

Predefined type 'System.ValueTuple´2´ is not defined or imported

It's part of the .NET Framework 4.7.

As long as you don't target the above framework or higher (or .NET Core 2.0 / .NET Standard 2.0), you'll need to reference ValueTuple. Do this by adding the System.ValueTuple NuGet Package

Await operator can only be used within an Async method

You can only use await in an async method, and Main cannot be async.

You'll have to use your own async-compatible context, call Wait on the returned Task in the Main method, or just ignore the returned Task and just block on the call to Read. Note that Wait will wrap any exceptions in an AggregateException.

If you want a good intro, see my async/await intro post.

ImportError: No module named xlsxwriter

I have the same issue. It seems that pip is the problem. Try 

pip uninstall xlsxwriter
easy_install xlsxwriter

Printing Lists as Tabular Data

I think this is what you are looking for.

It's a simple module that just computes the maximum required width for the table entries and then just uses rjust and ljust to do a pretty print of the data.

If you want your left heading right aligned just change this call:

 print >> out, row[0].ljust(col_paddings[0] + 1),

From line 53 with:

 print >> out, row[0].rjust(col_paddings[0] + 1),

How can I get a user's media from Instagram without authenticating as a user?

Just want to add to @350D answer, since it was hard for me to understand.

My logic in code is next:

When calling API first time, i'm calling only https://www.instagram.com/_vull_ /media/. When I receive response, I check boolean value of more_available. If its true, I get the last photo from the array, get its id and then call Instagram API again but this time https://www.instagram.com/_vull_/media/?max_id=1400286183132701451_1642962433.

Important thing to know here, this Id is the Id of the last picture in the array. So when asking for maxId with the last id of the picture in the array, you will get next 20 pictures, and so on.

Hope this clarify things.

How do I search for an object by its ObjectId in the mongo console?

If you're using Node.js:

> var ObjectId = require('mongodb').ObjectId; 
> var id = req.params.gonderi_id;       
> var o_id = new ObjectId(id);
> db.test.find({_id:o_id})

Edit: corrected to new ObjectId(id), not new ObjectID(id)

What does 'var that = this;' mean in JavaScript?

From Crockford

By convention, we make a private that variable. This is used to make the object available to the private methods. This is a workaround for an error in the ECMAScript Language Specification which causes this to be set incorrectly for inner functions.

JS Fiddle

function usesThis(name) {
    this.myName = name;

    function returnMe() {
        return this;        //scope is lost because of the inner function
    }

    return {
        returnMe : returnMe
    }
}

function usesThat(name) {
    var that = this;
    this.myName = name;

    function returnMe() {
        return that;            //scope is baked in with 'that' to the "class"
    }

    return {
        returnMe : returnMe
    }
}

var usesthat = new usesThat('Dave');
var usesthis = new usesThis('John');
alert("UsesThat thinks it's called " + usesthat.returnMe().myName + '\r\n' +
      "UsesThis thinks it's called " + usesthis.returnMe().myName);

This alerts...

UsesThat thinks it's called Dave

UsesThis thinks it's called undefined

Slice indices must be integers or None or have __index__ method

Your debut and fin values are floating point values, not integers, because taille is a float.

Make those values integers instead:

item = plateau[int(debut):int(fin)]

Alternatively, make taille an integer:

taille = int(sqrt(len(plateau)))

Simplest way to form a union of two lists

Using LINQ's Union

Enumerable.Union(ListA,ListB);

or

ListA.Union(ListB);

String date to xmlgregoriancalendar conversion

Found the solution as below.... posting it as it could help somebody else too :)

DateFormat format = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
Date date = format.parse("2014-04-24 11:15:00");

GregorianCalendar cal = new GregorianCalendar();
cal.setTime(date);

XMLGregorianCalendar xmlGregCal =  DatatypeFactory.newInstance().newXMLGregorianCalendar(cal);

System.out.println(xmlGregCal);

Output:

2014-04-24T11:15:00.000+02:00

Install dependencies globally and locally using package.json

All modules from package.json are installed to ./node_modules/

I couldn't find this explicitly stated but this is the package.json reference for NPM.

cURL not working (Error #77) for SSL connections on CentOS for non-root users

I just had a similar problem with Error#77 on CentOS7. I was missing the softlink /etc/pki/tls/certs/ca-bundle.crt that is installed with the ca-certificates RPM.

'curl' was attempting to open this path to get the Certificate Authorities. I discovered with:

strace curl https://example.com

and saw clearly that the open failed on that link.

My fix was:

yum reinstall ca-certificates

That should setup everything again. If you have private CAs for Corporate or self-signed use make sure they are in /etc/pki/ca-trust/source/anchors so that they are re-added.

Cannot kill Python script with Ctrl-C

Ctrl+C terminates the main thread, but because your threads aren't in daemon mode, they keep running, and that keeps the process alive. We can make them daemons:

f = FirstThread()
f.daemon = True
f.start()
s = SecondThread()
s.daemon = True
s.start()

But then there's another problem - once the main thread has started your threads, there's nothing else for it to do. So it exits, and the threads are destroyed instantly. So let's keep the main thread alive:

import time
while True:
    time.sleep(1)

Now it will keep print 'first' and 'second' until you hit Ctrl+C.

Edit: as commenters have pointed out, the daemon threads may not get a chance to clean up things like temporary files. If you need that, then catch the KeyboardInterrupt on the main thread and have it co-ordinate cleanup and shutdown. But in many cases, letting daemon threads die suddenly is probably good enough.

'cannot find or open the pdb file' Visual Studio C++ 2013

It worked for me. Go to Tools-> Options -> Debugger -> Native and check the Load DLL exports. Hope this helps

How to change column datatype from character to numeric in PostgreSQL 8.4

If your VARCHAR column contains empty strings (which are not the same as NULL for PostgreSQL as you might recall) you will have to use something in the line of the following to set a default:

ALTER TABLE presales ALTER COLUMN code TYPE NUMERIC(10,0)
            USING COALESCE(NULLIF(code, '')::NUMERIC, 0);

(found with the help of this answer)

Does file_get_contents() have a timeout setting?

The default timeout is defined by default_socket_timeout ini-setting, which is 60 seconds. You can also change it on the fly:

ini_set('default_socket_timeout', 900); // 900 Seconds = 15 Minutes

Another way to set a timeout, would be to use stream_context_create to set the timeout as HTTP context options of the HTTP stream wrapper in use:

$ctx = stream_context_create(array('http'=>
    array(
        'timeout' => 1200,  //1200 Seconds is 20 Minutes
    )
));

echo file_get_contents('http://example.com/', false, $ctx);

JQuery confirm dialog

Try this one

$('<div></div>').appendTo('body')
  .html('<div><h6>Yes or No?</h6></div>')
  .dialog({
      modal: true, title: 'message', zIndex: 10000, autoOpen: true,
      width: 'auto', resizable: false,
      buttons: {
          Yes: function () {
              doFunctionForYes();
              $(this).dialog("close");
          },
          No: function () {
              doFunctionForNo();
              $(this).dialog("close");
          }
      },
      close: function (event, ui) {
          $(this).remove();
      }
});

Fiddle

Change navbar text color Bootstrap

In fact, we can simply use the standard bootstrap text colors, instead of hacking the CSS formats.

Standard Color examples: text-primary, text-secondary, text-success, text-danger, text-warning, text-info

In the Navbar code sample bellow, the text Homepage would be in the orange color (text-warning).

<a class="navbar-brand text-warning" href="/" > Homepage </a>

In the Navbar menu item sample bellow, the text Menu Item would be in the blue color (text-primary).

<a class="dropdown-item text-primary" href="/my-link">Menu Item</a>

How to prove that a problem is NP complete?

First, you show that it lies in NP at all.

Then you find another problem that you already know is NP complete and show how you polynomially reduce NP Hard problem to your problem.

Two decimal places using printf( )

What you want is %.2f, not 2%f.

Also, you might want to replace your %d with a %f ;)

#include <cstdio>
int main()
{
printf("When this number: %f is assigned to 2 dp, it will be: %.2f ", 94.9456, 94.9456);
return 0;
}

This will output:

When this number: 94.945600 is assigned to 2 dp, it will be: 94.95

See here for a full description of the printf formatting options: printf

Make UINavigationBar transparent

Try the following piece of code:

self.navigationController.navigationBar.translucent = YES;

Combining COUNT IF AND VLOOK UP EXCEL

If your are referring to two worksheets please use this formula 

=COUNTIF(Worksheet2!$A$1:$A$50,Worksheet1cellA1)

In case referring to to more than two worksheets please use this formula

=COUNTIF(Worksheet2!$A$1:$A$50,Worksheet1cellA1)+=COUNTIF
(Worksheet3!$A$1:$A$50,Worksheet1cellA1)+=
               COUNTIF(Worksheet4!$A$1:$A$50,Worksheet1cellA1)

Why does the JFrame setSize() method not set the size correctly?

The top border of frame is of size 30.You can write code for printing the coordinate of any point on the frame using MouseInputAdapter.You will find when the cursor is just below the top border of the frame the y coordinate is not zero , its close to 30.Hence if you give size to frame 300 * 300 , the size available for putting the components on the frame is only 300 * 270.So if you need to have size 300 * 300 ,give 300 * 330 size of the frame.

How to specify the download location with wget?

man wget: -O file --output-document=file

wget "url" -O /tmp/cron_test/<file>

What is the ultimate postal code and zip regex?

This looks like a good reference although it's not in Regex.

Really, unless you're actually shipping something to your users, I don't think it's worth the effort. And if you are shipping it, there are address cleaning tools/services you can look into to make it way easier on yourself.

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...
}

conversion from string to json object android

Remove the slashes:

String json = {"phonetype":"N95","cat":"WP"};

try {

    JSONObject obj = new JSONObject(json);

    Log.d("My App", obj.toString());

} catch (Throwable t) {
    Log.e("My App", "Could not parse malformed JSON: \"" + json + "\"");
}

Change image source with JavaScript

You've got a few changes (this assumes you indeed still want to change the image with an ID of IMG, if not use Shadow Wizard's solution).

Remove a.src and replace with a:

<script type="text/javascript">
function changeImage(a) {
    document.getElementById("img").src=a;
}
</script>

Change your onclick attributes to include a string of the new image source instead of a literal:

onclick='changeImage( "1772031_29_b.jpg" );'

working with negative numbers in python

Try this on your TA:

# Simulate multiplying two N-bit two's-complement numbers
# into a 2N-bit accumulator
# Use shift-add so that it's O(base_2_log(N)) not O(N)

for numa, numb in ((3, 5), (-3, 5), (3, -5), (-3, -5), (-127, -127)):
    print numa, numb,
    accum = 0
    negate = False
    if numa < 0:
        negate = True
        numa = -numa
    while numa:
        if numa & 1:
            accum += numb
        numa >>= 1
        numb <<= 1
    if negate:
        accum = -accum
    print accum

output:

3 5 15
-3 5 -15
3 -5 -15
-3 -5 15
-127 -127 16129

How do I accomplish an if/else in mustache.js?

Note, you can use {{.}} to render the current context item.

{{#avatar}}{{.}}{{/avatar}}

{{^avatar}}missing{{/avatar}}

Export table data from one SQL Server to another

There is script table option in Tasks/Generate scripts! I also missed it at beginning! But you can generate insert scripts there (very nice feature, but in very un-intuitive place).

When you get to step "Set Scripting Options" go to "Advanced" tab.

Steps described here (pictures can understand, but i do write in latvian there).

How to change UIPickerView height

Advantages:

  1. Makes setFrame of UIPickerView behave like it should
  2. No transform code within your UIViewController
  3. Works within viewWillLayoutSubviews to rescale/position the UIPickerView
  4. Works on the iPad without UIPopover
  5. The superclass always receives a valid height
  6. Works with iOS 5

Disadvantages:

  1. Requires you to subclass UIPickerView
  2. Requires the use of pickerView viewForRow to undo the transformation for the subViews
  3. UIAnimations might not work

Solution:

Subclass UIPickerView and overwrite the two methods using the following code. It combines subclassing, fixed height and the transformation approach.

#define FIXED_PICKER_HEIGHT 216.0f
- (void) setFrame:(CGRect)frame
{
    CGFloat targetHeight = frame.size.height;
    CGFloat scaleFactor = targetHeight / FIXED_PICKER_HEIGHT;
    frame.size.height = FIXED_PICKER_HEIGHT;//fake normal conditions for super
    self.transform = CGAffineTransformIdentity;//fake normal conditions for super
    [super setFrame:frame];
    frame.size.height = targetHeight;
    CGFloat dX=self.bounds.size.width/2, dY=self.bounds.size.height/2;
    self.transform = CGAffineTransformTranslate(CGAffineTransformScale(CGAffineTransformMakeTranslation(-dX, -dY), 1, scaleFactor), dX, dY);
}

- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view
{
    //Your code goes here

    CGFloat inverseScaleFactor = FIXED_PICKER_HEIGHT/self.frame.size.height;
    CGAffineTransform scale = CGAffineTransformMakeScale(1, inverseScaleFactor);
    view.transform = scale;
    return view;
}

How to check if my string is equal to null?

Exception may also help:

try {
   //define your myString
}
catch (Exception e) {
   //in that case, you may affect "" to myString
   myString="";
}

Hiding button using jQuery

jQuery offers the .hide() method for this purpose. Simply select the element of your choice and call this method afterward. For example:

$('#comanda').hide();

One can also determine how fast the transition runs by providing a duration parameter in miliseconds or string (possible values being 'fast', and 'slow'):

$('#comanda').hide('fast');

In case you want to do something just after the element hid, you must provide a callback as a parameter too:

$('#comanda').hide('fast', function() {
  alert('It is hidden now!');
});

-XX:MaxPermSize with or without -XX:PermSize

If you're doing some performance tuning it's often recommended to set both -XX:PermSize and -XX:MaxPermSize to the same value to increase JVM efficiency.

Here is some information:

  1. Support for large page heap on x86 and amd64 platforms
  2. Java Support for Large Memory Pages
  3. Setting the Permanent Generation Size

You can also specify -XX:+CMSClassUnloadingEnabled to enable class unloading option if you are using CMS GC. It may help to decrease the probability of Java.lang.OutOfMemoryError: PermGen space

How should I copy Strings in Java?

Strings are immutable objects so you can copy them just coping the reference to them, because the object referenced can't change ...

So you can copy as in your first example without any problem : 

String s = "hello";
String backup_of_s = s;
s = "bye";

Is optimisation level -O3 dangerous in g++?

Recently I experienced a problem using optimization with g++. The problem was related to a PCI card, where the registers (for command and data) were repreented by a memory address. My driver mapped the physical address to a pointer within the application and gave it to the called process, which worked with it like this:

unsigned int * pciMemory;
askDriverForMapping( & pciMemory );
...
pciMemory[ 0 ] = someCommandIdx;
pciMemory[ 0 ] = someCommandLength;
for ( int i = 0; i < sizeof( someCommand ); i++ )
    pciMemory[ 0 ] = someCommand[ i ];

The card didn't act as expected. When I saw the assembly I understood that the compiler only wrote someCommand[ the last ] into pciMemory, omitting all preceding writes.

In conclusion: be accurate and attentive with optimization.

offsetting an html anchor to adjust for fixed header

My solution combines the target and before selectors for our CMS. Other techniques don't account for text in the anchor. Adjust the height and the negative margin to the offset you need...

:target::before {
    content: '';
    display: block;
    height:      180px;
    margin-top: -180px;
}

Why does background-color have no effect on this DIV?

Change it to:

<div style="background-color:black; overflow:hidden;" onmouseover="this.bgColor='white'">
<div style="float:left">hello</div>
<div style="float:right">world</div>
</div>

Basically the outer div only contains floats. Floats are removed from the normal flow. As such the outer div really contains nothing and thus has no height. It really is black but you just can't see it.

The overflow:hidden property basically makes the outer div enclose the floats. The other way to do this is:

<div style="background-color:black" onmouseover="this.bgColor='white'">
<div style="float:left">hello</div>
<div style="float:right">world</div>
<div style="clear:both></div>
</div>

Oh and just for completeness, you should really prefer classes to direct CSS styles.

How to initialize a struct in accordance with C programming language standards

In (ANSI) C99, you can use a designated initializer to initialize a structure: 

MY_TYPE a = { .flag = true, .value = 123, .stuff = 0.456 };

Edit: Other members are initialized as zero: "Omitted field members are implicitly initialized the same as objects that have static storage duration." (https://gcc.gnu.org/onlinedocs/gcc/Designated-Inits.html)

Is it possible to make Font Awesome icons larger than 'fa-5x'?

Font awesome use SVG icons. So, you can resize it for your requirment.

just use CSS class for that,

    .large-icon{
       font-size:10em;
       //or
      font-size:200%;
      //or
      font-size:50px;
    }

How do I create a right click context menu in Java Swing?

There's a section on Bringing Up a Popup Menu in the How to Use Menus article of The Java Tutorials which explains how to use the JPopupMenu class.

The example code in the tutorial shows how to add MouseListeners to the components which should display a pop-up menu, and displays the menu accordingly.

(The method you describe is fairly similar to the way the tutorial presents the way to show a pop-up menu on a component.)

How to convert an integer (time) to HH:MM:SS::00 in SQL Server 2008?

This will work:

DECLARE @MS INT = 235216
select cast(dateadd(ms, @MS, '00:00:00') AS TIME(3))

(where ms is just a number of seconds not a timeformat)

Use of True, False, and None as return values in Python functions

Use if foo or if not foo. There isn't any need for either == or is for that.

For checking against None, is None and is not None are recommended. This allows you to distinguish it from False (or things that evaluate to False, like "" and []).

Whether get_attr should return None would depend on the context. You might have an attribute where the value is None, and you wouldn't be able to do that. I would interpret None as meaning "unset", and a KeyError would mean the key does not exist in the file.

How to output HTML from JSP <%! ... %> block?

 
<%!
private void myFunc(String Bits, javax.servlet.jsp.JspWriter myOut)
{  
  try{ myOut.println("<div>"+Bits+"</div>"); } 
  catch(Exception eek) { }
}
%>
...
<%
  myFunc("more difficult than it should be",out);
%>

Try this, it worked for me!

Date Comparison using Java

This is one of the ways:

String toDate = "05/11/2010";

if (new SimpleDateFormat("MM/dd/yyyy").parse(toDate).getTime() / (1000 * 60 * 60 * 24) >= System.currentTimeMillis() / (1000 * 60 * 60 * 24)) {
    System.out.println("Display report.");
} else {
    System.out.println("Don't display report.");
}

A bit more easy interpretable:

String toDateAsString = "05/11/2010";
Date toDate = new SimpleDateFormat("MM/dd/yyyy").parse(toDateAsString);
long toDateAsTimestamp = toDate.getTime();
long currentTimestamp = System.currentTimeMillis();
long getRidOfTime = 1000 * 60 * 60 * 24;
long toDateAsTimestampWithoutTime = toDateAsTimestamp / getRidOfTime;
long currentTimestampWithoutTime = currentTimestamp / getRidOfTime;

if (toDateAsTimestampWithoutTime >= currentTimestampWithoutTime) {
    System.out.println("Display report.");
} else {
    System.out.println("Don't display report.");
}

Oh, as a bonus, the JodaTime's variant:

String toDateAsString = "05/11/2010";
DateTime toDate = DateTimeFormat.forPattern("MM/dd/yyyy").parseDateTime(toDateAsString);
DateTime now = new DateTime();

if (!toDate.toLocalDate().isBefore(now.toLocalDate())) {
    System.out.println("Display report.");
} else {
    System.out.println("Don't display report.");
}

How to get Chrome to allow mixed content?

On OSX using the current Chrome build (2/20/2020, 79.0.3945.130), you can:

Click on the 'i' info icon on the left side of address bar.

Click Site Settings

Scroll down to Insecure content

Change it from Blocked (Default) to Allow

Reload the page and try your action again.

How do I break out of nested loops in Java?

Below is an example where "break" statement pushes the cursor out of the for loop whenever the condition is met.

public class Practice3_FindDuplicateNumber {

    public static void main(String[] args) {
        Integer[] inp = { 2, 3, 4, 3, 3 };
        Integer[] aux_arr = new Integer[inp.length];
        boolean isduplicate = false;
        for (int i = 0; i < aux_arr.length; i++) {

            aux_arr[i] = -1;

        }
        outer: for (int i = 0; i < inp.length; i++) {
            if (aux_arr[inp[i]] == -200) {
                System.out.println("Duplicate Found at index: " + i + " Carrying value: " + inp[i]);
                isduplicate = true;
                break outer;
            } else {
                aux_arr[inp[i]] = -200;
            }
        }

        for (Integer integer : aux_arr) {
            System.out.println(integer);
        }

        if (isduplicate == false) {
            System.out.println("No Duplicates!!!!!");
        } else {
            System.out.println("Duplicates!!!!!");
        }
    }

}

ReSharper "Cannot resolve symbol" even when project builds

I my case, I tried all the suggestions above. But, at some point I realized that the problem persists even if Resharper is suspended. So, I looked for similar problem in VS itself and found the solution in the comments for the accepted answer in this SO post.

I'm listing my steps for brevity.

  1. VS -> Tools -> Options -> ReSharper Suspend button
  2. Build solution. Notice all references still unresolved
  3. Clean the solution
  4. Restart VS
  5. Build the solution without Resharper. Notice all references resolved
  6. VS -> Tools -> Options -> ReSharper Resume button

How to make an installer for my C# application?

Generally speaking, it's recommended to use MSI-based installations on Windows. Thus, if you're ready to invest a fair bit of time, WiX is the way to go.

If you want something which is much more simpler, go with InnoSetup.

Get HTML inside iframe using jQuery

this works for me because it works fine in ie8.

$('#iframe').contents().find("html").html();

but if you like to use javascript aside for jquery you may use like this

var iframe = document.getElementById('iframecontent');
var innerDoc = iframe.contentDocument || iframe.contentWindow.document;
var val_1 = innerDoc.getElementById('value_1').value;

Using any() and all() to check if a list contains one set of values or another

Generally speaking:

all and any are functions that take some iterable and return True, if

  • in the case of all(), no values in the iterable are falsy;
  • in the case of any(), at least one value is truthy.

A value x is falsy iff bool(x) == False. A value x is truthy iff bool(x) == True.

Any non-booleans in the iterable will be fine — bool(x) will coerce any x according to these rules: 0, 0.0, None, [], (), [], set(), and other empty collections will yield False, anything else True. The docstring for bool uses the terms 'true'/'false' for 'truthy'/'falsy', and True/False for the concrete boolean values.

In your specific code samples:

You misunderstood a little bit how these functions work. Hence, the following does something completely not what you thought:

if any(foobars) == big_foobar:

...because any(foobars) would first be evaluated to either True or False, and then that boolean value would be compared to big_foobar, which generally always gives you False (unless big_foobar coincidentally happened to be the same boolean value).

Note: the iterable can be a list, but it can also be a generator/generator expression (˜ lazily evaluated/generated list) or any other iterator.

What you want instead is:

if any(x == big_foobar for x in foobars):

which basically first constructs an iterable that yields a sequence of booleans—for each item in foobars, it compares the item to big_foobar and emits the resulting boolean into the resulting sequence:

tmp = (x == big_foobar for x in foobars)

then any walks over all items in tmp and returns True as soon as it finds the first truthy element. It's as if you did the following:

In [1]: foobars = ['big', 'small', 'medium', 'nice', 'ugly']                                        

In [2]: big_foobar = 'big'                                                                          

In [3]: any(['big' == big_foobar, 'small' == big_foobar, 'medium' == big_foobar, 'nice' == big_foobar, 'ugly' == big_foobar])        
Out[3]: True

Note: As DSM pointed out, any(x == y for x in xs) is equivalent to y in xs but the latter is more readable, quicker to write and runs faster.

Some examples:

In [1]: any(x > 5 for x in range(4))
Out[1]: False

In [2]: all(isinstance(x, int) for x in range(10))
Out[2]: True

In [3]: any(x == 'Erik' for x in ['Erik', 'John', 'Jane', 'Jim'])
Out[3]: True

In [4]: all([True, True, True, False, True])
Out[4]: False

See also: http://docs.python.org/2/library/functions.html#all

Remove empty space before cells in UITableView

Select the tableview in your storyboard and ensure that the style is set to "Plain", instead of "Grouped". You can find this setting in the attributes Inspector tab.

casting Object array to Integer array error

 When casting is done in Java, Java compiler as well as Java run-time check whether the casting is possible or not and throws errors in case not.

When casting of Object types is involved, the instanceof test should pass in order for the assignment to go through. In your example it results
Object[] a = new Object[1]; boolean isIntegerArr = a instanceof Integer[]
If you do a sysout of the above line, it would return false;
So trying an instance of check before casting would help. So, to fix the error, you can either add 'instanceof' check
OR
use following line of code:
(Arrays.asList(a)).toArray(c);
Please do note that the above code would fail, if the Object array contains any entry that is other than Integer.

Laravel Mail::send() sending to multiple to or bcc addresses

Try this:

$toemail = explode(',', str_replace(' ', '', $request->toemail));

Detecting Enter keypress on VB.NET

In the KeyDown Event:

 If e.KeyCode = Keys.Enter Then
       Messagebox.Show("Enter key pressed")
 end if

Lists in ConfigParser

I landed here seeking to consume this...

[global]
spys = [email protected], [email protected]

The answer is to split it on the comma and strip the spaces:

SPYS = [e.strip() for e in parser.get('global', 'spys').split(',')]

To get a list result:

['[email protected]', '[email protected]']

It may not answer the OP's question exactly but might be the simple answer some people are looking for.

How to create friendly URL in php?

According to this article, you want a mod_rewrite (placed in an .htaccess file) rule that looks something like this:

RewriteEngine on
RewriteRule ^/news/([0-9]+)\.html /news.php?news_id=$1

And this maps requests from

/news.php?news_id=63

to

/news/63.html

Another possibility is doing it with forcetype, which forces anything down a particular path to use php to eval the content. So, in your .htaccess file, put the following:

<Files news>
    ForceType application/x-httpd-php
</Files>

And then the index.php can take action based on the $_SERVER['PATH_INFO'] variable:

<?php
    echo $_SERVER['PATH_INFO'];
    // outputs '/63.html'
?>

Uncaught TypeError: Cannot set property 'onclick' of null

Try to put all your <script ...></script> tags before the </body> tag. Perhaps the js is trying to access an object of the DOM before it's built up.

How to add a ScrollBar to a Stackpanel

If you mean, you want to scroll through multiple items in your stackpanel, try putting a grid around it. By definition, a stackpanel has infinite length.

So try something like this:

   <Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
        <StackPanel Width="311">
              <TextBlock Text="{Binding A}" TextWrapping="Wrap" Style="{StaticResource PhoneTextExtraLargeStyle}" FontStretch="Condensed" FontSize="28" />
              <TextBlock Text="{Binding B}" TextWrapping="Wrap" Margin="12,-6,12,0" Style="{StaticResource PhoneTextSubtleStyle}"/>
        </StackPanel>
    </Grid>

You could even make this work with a ScrollViewer

How do I execute a program from Python? os.system fails due to spaces in path

subprocess.call will avoid problems with having to deal with quoting conventions of various shells. It accepts a list, rather than a string, so arguments are more easily delimited. i.e.

import subprocess
subprocess.call(['C:\\Temp\\a b c\\Notepad.exe', 'C:\\test.txt'])

How to build x86 and/or x64 on Windows from command line with CMAKE?

Besides CMAKE_GENERATOR_PLATFORM variable, there is also the -A switch

cmake -G "Visual Studio 16 2019" -A Win32
cmake -G "Visual Studio 16 2019" -A x64

https://cmake.org/cmake/help/v3.16/generator/Visual%20Studio%2016%202019.html#platform-selection

  -A <platform-name>           = Specify platform name if supported by
                                 generator.

How do I change selected value of select2 dropdown with JqGrid?

do this 

 $('select#id').val(selectYear).select2();

How to define a connection string to a SQL Server 2008 database?

Copy/Paste what is below into your code:

SqlConnection cnTrupp = new SqlConnection("Initial Catalog = Database;Data Source = localhost;Persist Security Info=True;Integrated Security = True;");

Keep in mind that this solution uses your windows account to log in.

As John and Adam have said, this has to do with how you are logging in (or not logging in). Look at the link John provided to get a better explanation.

Are string.Equals() and == operator really same?

Two differences:

  • Equals is polymorphic (i.e. it can be overridden, and the implementation used will depend on the execution-time type of the target object), whereas the implementation of == used is determined based on the compile-time types of the objects:

    // Avoid getting confused by interning
object x = new StringBuilder("hello").ToString();
object y = new StringBuilder("hello").ToString();
if (x.Equals(y)) // Yes

// The compiler doesn't know to call ==(string, string) so it generates
// a reference comparision instead
if (x == y) // No

string xs = (string) x;
string ys = (string) y;

// Now *this* will call ==(string, string), comparing values appropriately
if (xs == ys) // Yes

  • Equals will go bang if you call it on null, == won't

    string x = null;
string y = null;

if (x.Equals(y)) // Bang

if (x == y) // Yes

Note that you can avoid the latter being a problem using object.Equals:

if (object.Equals(x, y)) // Fine even if x or y is null

iText - add content to existing PDF file

Gutch's code is close, but it'll only work right if:

  • There are no annotations (links, fields, etc), no Document Structure/Marked Content, no bookmarks, no document-level script, etc, etc, etc...
  • The page size happens to be A.4 (decent odds, but it won't work on any ol' PDF you happen to come across)
  • You don't mind losing all the original document metadata (producer, creation date, possibly author/title/keywords), and maybe the document ID. You can't copy the creation date and doc ID unless you do some pretty deep hackery on iText itself).

The Approved Method is to do it the other way around. Open the existing document with a PdfStamper, and use the returned PdfContentByte from getOverContent() to write text (and whatever else you might need) directly to the page. No second document needed.

And you can use a ColumnText to handle layout and such for you... no need to get down and dirty with beginText(),setFontAndSize(),drawText(),drawText()...,endText().

Changing the "tick frequency" on x or y axis in matplotlib?

In case anyone is interested in a general one-liner, simply get the current ticks and use it to set the new ticks by sampling every other tick.

ax.set_xticks(ax.get_xticks()[::2])

How may I sort a list alphabetically using jQuery?

 
$(".list li").sort(asc_sort).appendTo('.list');
//$("#debug").text("Output:");
// accending sort
function asc_sort(a, b){
    return ($(b).text()) < ($(a).text()) ? 1 : -1;    
}

// decending sort
function dec_sort(a, b){
    return ($(b).text()) > ($(a).text()) ? 1 : -1;    
}

live demo : http://jsbin.com/eculis/876/edit

How to save picture to iPhone photo library?

In Swift 2.2

UIImageWriteToSavedPhotosAlbum(image: UIImage, _ completionTarget: AnyObject?, _ completionSelector: Selector, _ contextInfo: UnsafeMutablePointer<Void>)

If you do not want to be notified when the image is done saving then you may pass nil in the completionTarget, completionSelector and contextInfo parameters.

Example:

UIImageWriteToSavedPhotosAlbum(image, self, #selector(self.imageSaved(_:didFinishSavingWithError:contextInfo:)), nil)

func imageSaved(image: UIImage!, didFinishSavingWithError error: NSError?, contextInfo: AnyObject?) {
        if (error != nil) {
            // Something wrong happened.
        } else {
            // Everything is alright.
        }
    }

The important thing to note here is that your method that observes the image saving should have these 3 parameters else you will run into NSInvocation errors.

Hope it helps.

How to add google-play-services.jar project dependency so my project will run and present map

Be Careful, Follow these steps and save your time

  1. Right Click on your Project Explorer.

  2. Select New-> Project -> Android Application Project from Existing Code

  3. Browse upto this path only - "C:\Users**your path**\Local\Android\android-sdk\extras\google\google_play_services"

  4. Be careful brose only upto - google_play_services and not upto google_play_services_lib

  5. And this way you are able to import the google play service lib.

Let me know if you have any queries regarding the same.

Thanks

How to refresh Gridview after pressed a button in asp.net

Adding the GridView1.DataBind() to the button click event did not work for me. However, adding it to the SqlDataSource1_Updated event did though.

Protected Sub SqlDataSource1_Updated(sender As Object, e As SqlDataSourceStatusEventArgs) Handles SqlDataSource1.Updated
    GridView1.DataBind()
End Sub

C#: HttpClient with POST parameters

A cleaner alternative would be to use a Dictionary to handle parameters. They are key-value pairs after all.

private static readonly HttpClient httpclient;

static MyClassName()
{
    // HttpClient is intended to be instantiated once and re-used throughout the life of an application. 
    // Instantiating an HttpClient class for every request will exhaust the number of sockets available under heavy loads. 
    // This will result in SocketException errors.
    // https://docs.microsoft.com/en-us/dotnet/api/system.net.http.httpclient?view=netframework-4.7.1
    httpclient = new HttpClient();    
} 

var url = "http://myserver/method";
var parameters = new Dictionary<string, string> { { "param1", "1" }, { "param2", "2" } };
var encodedContent = new FormUrlEncodedContent (parameters);

var response = await httpclient.PostAsync (url, encodedContent).ConfigureAwait (false);
if (response.StatusCode == HttpStatusCode.OK) {
    // Do something with response. Example get content:
    // var responseContent = await response.Content.ReadAsStringAsync ().ConfigureAwait (false);
}

Also dont forget to Dispose() httpclient, if you dont use the keyword using

As stated in the Remarks section of the HttpClient class in the Microsoft docs, HttpClient should be instantiated once and re-used.

Edit:

You may want to look into response.EnsureSuccessStatusCode(); instead of if (response.StatusCode == HttpStatusCode.OK).

You may want to keep your httpclient and dont Dispose() it. See: Do HttpClient and HttpClientHandler have to be disposed?

Edit:

Do not worry about using .ConfigureAwait(false) in .NET Core. For more details look at https://blog.stephencleary.com/2017/03/aspnetcore-synchronization-context.html

SSIS Excel Connection Manager failed to Connect to the Source

I also ran into this problem today, but found a different solution from using Excel 97-2003. According to Maderia, the problem is SSDT (SQL Server Data Tools) is a 32bit application and can only use 32bit providers; but you likely have the 64bit ACE OLE DB provider installed. You could play around with trying to install the 32bit provider, but you can't have both the 64 & 32 version installed at the same time. The solution Maderia suggested (and I found worked for me) was to set the DelayValidation = TRUE on the tasks where I'm importing/exporting the Excel 2007 file.

CharSequence VS String in Java?

CharSequence

A CharSequence is an interface, not an actual class. An interface is just a set of rules (methods) that a class must contain if it implements the interface. In Android a CharSequence is an umbrella for various types of text strings. Here are some of the common ones:

(You can read more about the differences between these here.)

If you have a CharSequence object, then it is actually an object of one of the classes that implement CharSequence. For example:

CharSequence myString = "hello";
CharSequence mySpannableStringBuilder = new SpannableStringBuilder();

The benefit of having a general umbrella type like CharSequence is that you can handle multiple types with a single method. For example, if I have a method that takes a CharSequence as a parameter, I could pass in a String or a SpannableStringBuilder and it would handle either one.

public int getLength(CharSequence text) {
    return text.length();
}

String

You could say that a String is just one kind of CharSequence. However, unlike CharSequence, it is an actual class, so you can make objects from it. So you could do this:

String myString = new String();

but you can't do this:

CharSequence myCharSequence = new CharSequence(); // error: 'CharSequence is abstract; cannot be instantiated

Since CharSequence is just a list of rules that String conforms to, you could do this:

CharSequence myString = new String();

That means that any time a method asks for a CharSequence, it is fine to give it a String. 

String myString = "hello";
getLength(myString); // OK

// ...

public int getLength(CharSequence text) {
    return text.length();
}

However, the opposite is not true. If the method takes a String parameter, you can't pass it something that is only generally known to be a CharSequence, because it might actually be a SpannableString or some other kind of CharSequence.

CharSequence myString = "hello";
getLength(myString); // error

// ...

public int getLength(String text) {
    return text.length();
}

httpd Server not started: (13)Permission denied: make_sock: could not bind to address [::]:88

This is an addition to the answer by Abdull somewhere in this thread:

I had to modify instead of adding a port

semanage port -m -t http_port_t -p tcp 5000

because I get this error on adding the port

ValueError: Port tcp/5000 already defined

How to use code to open a modal in Angular 2?

Include jQuery as usual inside script tags in index.html.

After all the imports but before declaring @Component, add:

declare var $: any;

Now you are free to use jQuery anywhere in your Angular 2 TypeScript code:

$("#myModal").modal('show');

Reference: https://stackoverflow.com/a/38246116/2473022

Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at

The server at x3.chatforyoursite.com needs to output the following header:

Access-Control-Allow-Origin: http://www.example.com

Where http://www.example.com is your website address. You should check your settings on chatforyoursite.com to see if you can enable this - if not their technical support would probably be the best way to resolve this. However to answer your question, you need the remote site to allow your site to access AJAX responses client side.

Image, saved to sdcard, doesn't appear in Android's Gallery app

 
 File folderGIF = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES) + "/newgif2");    //path where gif will be stored
success = folderGIF.mkdir();    //make directory
 String finalPath = folderGIF + "/test1.gif";  //path of file
.....
/* changes in gallery app if any changes in done*/
 MediaScannerConnection.scanFile(this,
                    new String[]{finalPath}, null,
                    new MediaScannerConnection.OnScanCompletedListener() {
                        public void onScanCompleted(String path, Uri uri) {
                            Log.i("ExternalStorage", "Scanned " + path + ":");
                            Log.i("ExternalStorage", "-> uri=" + uri);
                        }
                    });

Using CRON jobs to visit url?

Here is simple example. you can use it like

wget -q -O - http://example.com/backup >/dev/null 2>&1

and in start you can add your option like (*****). Its up to your system requirements either you want to run it every minute or hours etc.

How to break out of a loop from inside a switch?

It amazes me how simple this is considering the depth of explanations... Here's all you need...

bool imLoopin = true;

while(imLoopin) {

    switch(msg->state) {

        case MSGTYPE: // ... 
            break;

        // ... more stuff ...

        case DONE:
            imLoopin = false;
            break;

    }

}

LOL!! Really! That's all you need! One extra variable!

GoogleMaps API KEY for testing

Updated Answer

As of June11, 2018 it is now mandatory to have a billing account to get API key. You can still make keyless calls to the Maps JavaScript API and Street View Static API which will return low-resolution maps that can be used for development. Enabling billing still gives you $200 free credit monthly for your projects.

This answer is no longer valid

As long as you're using a testing API key it is free to register and use. But when you move your app to commercial level you have to pay for it. When you enable billing, google gives you $200 credit free each month that means if your app's map usage is low you can still use it for free even after the billing enabled, if it exceeds the credit limit now you have to pay for it.

How to Change Margin of TextView

Your layout in xml probably already has a layout_margin(Left|Right|etc) attribute in it, which means you need to access the object generated by that xml and modify it.

I found this solution to be very simple: 

ViewGroup.MarginLayoutParams mlp = (ViewGroup.MarginLayoutParams) mTextView
        .getLayoutParams();

mlp.setMargins(adjustmentPxs, 0, 0, 0);

break;

Get the LayoutParams instance of your textview, downcast it to MarginLayoutParams, and use the setMargins method to set the margins.

Eclipse gives “Java was started but returned exit code 13”

Instead of opening eclipse.exe , first open folder named configuration then you will get log file like 1401241141809.log ; open that log (open latest one) detail error will be listed there. Ex: java.lang.UnsatisfiedLinkError: Cannot load 64-bit SWT libraries on 32-bit JVM

means you need to have JVM and SDK of same version.

Replace a value in a data frame based on a conditional (`if`) statement

Short answer is:

junk$nm[junk$nm %in% "B"] <- "b"

Take a look at Index vectors in R Introduction (if you don't read it yet).

EDIT. As noticed in comments this solution works for character vectors so fail on your data.

For factor best way is to change level:

levels(junk$nm)[levels(junk$nm)=="B"] <- "b"

Login failed for user 'DOMAIN\MACHINENAME$'

In my case I had Identity="ApplicationPoolIdentity" for my IIS Application Pool.

After I added IIS APPPOOL\ApplicationName user to SQL Server it works.

Get only records created today in laravel

You can use whereRaw('date(created_at) = curdate()') if timezone is not a concern or whereRaw('date(created_at) = ?', [Carbon::now()->format('Y-m-d')] ) otherwise.

Since the created_at field is a timestamp, you need to get only the date part of it and ignore the time part.

Assigning default value while creating migration file

 
t.integer :retweets_count, :default => 0

... should work.

See the Rails guide on migrations

How do I change the title of the "back" button on a Navigation Bar

Swift 4
iOS 11.2
Xcode 9.2 

TableViewController1  ---segue--->   TableViewController2

You can change the text of the back button in either TableViewController1 or TableViewController2.

Change the back button text inside TableViewController1:

1) In viewWillAppear(): 

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)

    let myBackButton = UIBarButtonItem()
    myBackButton.title = "Custom text"
    navigationItem.backBarButtonItem = myBackButton
}

For some reason, viewDidLoad() is too early to add the back button to the NavigationItem. To connect the two TableViewControllers, in the storyboard control drag from the TableViewCell in TableViewController1 to the middle of TableViewController2 and in the popup menu select Selection Segue > Show.

2) In tableView(_:didSelectRowAt:):

override func tableView(_ tableView: UITableView, didSelectRowAt: IndexPath) {

    let myButton = UIBarButtonItem()
    myButton.title = "Custom text"
    navigationItem.backBarButtonItem = myButton

    performSegue(withIdentifier: "ShowMyCustomBackButton", sender: nil)
}

To connect the two TableViewControllers, in the storyboard control drag from the little yellow circle above TableViewController1 to the middle of TableViewController2 and from the popup menu select Manual Segue > Show. Then select the segue connecting the two TableViewControllers, and in the Attributes Inspector next to "Identifier" enter "ShowMyCustomBackButton".

3) In the storyboard:

If you just need static custom text for the back button, select the NavigationItem for TableViewController1 (it has a < for an icon in the storyboard’s table of contents), then open the Attributes Inspector and in the “Back Button” field enter your custom text (be sure to tab out of that field for the change to take effect).

Change the back button text inside TableViewController2:

1) In viewWillAppear():

class MySecondTableViewController: UITableViewController {

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)

        let myBackButton = UIBarButtonItem(
            title: "<Custom text",
            style: .plain,
            target: self,
            action: #selector(goBack)  //selector() needs to be paired with an @objc label on the method
        )

        navigationItem.leftBarButtonItem = myBackButton
    }

    @objc func goBack() {
        navigationController?.popViewController(animated: true)
    }

To connect the two TableViewControllers, in the storyboard control drag from the TableViewCell in TableViewController1 to the middle of TableViewController2 and in the popup menu select Selection Segue > Show.

Query to select data between two dates with the format m/d/yyyy

 
SELECT * FROM tablename WHERE STR_TO_DATE(columnname, '%d/%m/%Y')
  BETWEEN STR_TO_DATE('29/05/2017', '%d/%m/%Y')
    AND STR_TO_DATE('30/05/2017', '%d/%m/%Y')

It works perfectly :)

How to fix corrupted git repository?

If you are desperate you can try this:

git clone ssh://[email protected]/path/to/project destination --depth=1

It will get your data, but you'll lose the history. I went with trial and error on my repo and --depth=10 worked, but --depth=50 gave me failure.

Java: notify() vs. notifyAll() all over again

This answer is a graphical rewriting and simplification of the excellent answer by xagyg, including comments by eran.

Why use notifyAll, even when each product is intended for a single consumer?

Consider producers and consumers, simplified as follows.

Producer:

while (!empty) {
   wait() // on full
}
put()
notify()

Consumer:

while (empty) {
   wait() // on empty
}
take()
notify()

Assume 2 producers and 2 consumers, sharing a buffer of size 1. The following picture depicts a scenario leading to a deadlock, which would be avoided if all threads used notifyAll.

Each notify is labeled with the thread being woken up.

deadlock due to notify

Git: "Corrupt loose object"

Create a backup and clone the repository into a fresh directory

cp -R foo foo-backup
git clone git@url:foo foo-new

(optional) If you are working on a different branch than master, switch it.

cd foo-new
git checkout -b branch-name origin/branch-name

Sync changes excluding the .git directory

rsync -aP --exclude=.git foo-backup/ foo-new

Node.js for() loop returning the same values at each loop

 
  for(var i = 0; i < BoardMessages.length;i++){
        (function(j){
            console.log("Loading message %d".green, j);
            htmlMessageboardString += MessageToHTMLString(BoardMessages[j]);
        })(i);
  }

That should work; however, you should never create a function in a loop. Therefore,

  for(var i = 0; i < BoardMessages.length;i++){
        composeMessage(BoardMessages[i]);
  }

  function composeMessage(message){
      console.log("Loading message %d".green, message);
      htmlMessageboardString += MessageToHTMLString(message);
  }

How do I extract data from JSON with PHP?

The acepted Answer is very detailed and correct in most of the cases.

I just want to add that i was getting an error while attempting to load a JSON text file encoded with UTF8, i had a well formatted JSON but the 'json_decode' always returned me with NULL, it was due the BOM mark.

To solve it, i made this PHP function:

function load_utf8_file($filePath)
{
    $response = null;
    try
    {
        if (file_exists($filePath)) {
            $text = file_get_contents($filePath);
            $response = preg_replace("/^\xEF\xBB\xBF/", '', $text);          
        }     
    } catch (Exception $e) {
      echo 'ERROR: ',  $e->getMessage(), "\n";
   }
   finally{  }
   return $response;
}

Then i use it like this to load a JSON file and get a value from it:

$str = load_utf8_file('appconfig.json'); 
$json = json_decode($str, true); 
//print_r($json);
echo $json['prod']['deploy']['hostname'];

wait process until all subprocess finish?

A Popen object has a .wait() method exactly defined for this: to wait for the completion of a given subprocess (and, besides, for retuning its exit status).

If you use this method, you'll prevent that the process zombies are lying around for too long.

(Alternatively, you can use subprocess.call() or subprocess.check_call() for calling and waiting. If you don't need IO with the process, that might be enough. But probably this is not an option, because your if the two subprocesses seem to be supposed to run in parallel, which they won't with (check_)call().)

If you have several subprocesses to wait for, you can do

exit_codes = [p.wait() for p in p1, p2]

which returns as soon as all subprocesses have finished. You then have a list of return codes which you maybe can evaluate.

Export to csv in jQuery

Here are two WORKAROUNDS to the problem of triggering downloads from the client only. In later browsers you should look at "blob"

1. Drag and drop the table

Did you know you can simply DRAG your table into excel?

Here is how to select the table to either cut and past or drag

Select a complete table with Javascript (to be copied to clipboard)

2. create a popup page from your div

Although it will not produce a save dialog, if the resulting popup is saved with extension .csv, it will be treated correctly by Excel.

The string could be
w.document.write("row1.1\trow1.2\trow1.3\nrow2.1\trow2.2\trow2.3");
e.g. tab-delimited with a linefeed for the lines.

There are plugins that will create the string for you - such as http://plugins.jquery.com/project/table2csv

var w = window.open('','csvWindow'); // popup, may be blocked though
// the following line does not actually do anything interesting with the 
// parameter given in current browsers, but really should have. 
// Maybe in some browser it will. It does not hurt anyway to give the mime type
w.document.open("text/csv");
w.document.write(csvstring); // the csv string from for example a jquery plugin
w.document.close();

DISCLAIMER: These are workarounds, and does not fully answer the question which currently has the answer for most browser: not possible on the client only

Order columns through Bootstrap4

This can also be achieved with the CSS "Order" property and a media query.

Something like this:

@media only screen and (max-width: 768px) {
    #first {
        order: 2;
    }
    #second {
        order: 4;
    }
    #third {
        order: 1;
    }
    #fourth {
        order: 3;
    }
}

CodePen Link: https://codepen.io/preston206/pen/EwrXqm

How to clear variables in ipython?

%reset seems to clear defined variables.

jQuery UI: Datepicker set year range dropdown to 100 years

You can set the year range using this option per documentation here http://api.jqueryui.com/datepicker/#option-yearRange

yearRange: '1950:2013', // specifying a hard coded year range

or this way

yearRange: "-100:+0", // last hundred years

From the Docs

Default: "c-10:c+10"

The range of years displayed in the year drop-down: either relative to today's year ("-nn:+nn"), relative to the currently selected year ("c-nn:c+nn"), absolute ("nnnn:nnnn"), or combinations of these formats ("nnnn:-nn"). Note that this option only affects what appears in the drop-down, to restrict which dates may be selected use the minDate and/or maxDate options.

Getting the last n elements of a vector. Is there a better way than using the length() function?

Here is a function to do it and seems reasonably fast. 

endv<-function(vec,val) 
{
if(val>length(vec))
{
stop("Length of value greater than length of vector")
}else
{
vec[((length(vec)-val)+1):length(vec)]
}
}

USAGE:

test<-c(0,1,1,0,0,1,1,NA,1,1)
endv(test,5)
endv(LETTERS,5)

BENCHMARK:

                                                    test replications elapsed relative
1                                 expression(tail(x, 5))       100000    5.24    6.469
2 expression(x[seq.int(to = length(x), length.out = 5)])       100000    0.98    1.210
3                       expression(x[length(x) - (4:0)])       100000    0.81    1.000
4                                 expression(endv(x, 5))       100000    1.37    1.691

javascript set cookie with expire time

 
document.cookie = "cookie_name=cookie_value; max-age=31536000; path=/";

Will set the value for a year.

Get connection status on Socket.io client

Track the state of the connection yourself. With a boolean. Set it to false at declaration. Use the various events (connect, disconnect, reconnect, etc.) to reassign the current boolean value. Note: Using undocumented API features (e.g., socket.connected), is not a good idea; the feature could get removed in a subsequent version without the removal being mentioned.

Token Authentication vs. Cookies

One of the primary differences is that cookies are subject to Same Origin Policy whereas tokens are not. This creates all kinds of down stream effects.

Since cookies are only sent to and from a particular host that host must bear the burden of authenticating the user and the user must create an account with security data with that host in order to be verifiable.

Tokens on the other hand are issued and are not subject to same origin policy. The issuer can be literally anybody and it is up to the host to decide which issuers to trust. An issuer like Google and Facebook is typically well trusted so a host can shift the burden of authenticating the user (including storing all user security data) to another party and the user can consolidate their personal data under a specific issuer and not have to remember a bunch of different passwords for each host they interact with.

This allows for single sign on scenarios that reduce overall friction in the user experience. In theory the web also becomes more secure as specialised identity providers emerge to provide auth services instead of having every ma and pa website spinning up their own, likely half baked, auth systems. And as these providers emerge the cost of providing secure web resources for even very basic resources trends towards zero.

So in general tokens reduce the friction and costs associated with providing authentication and shifts the burden of the various aspects of a secure web to centralised parties better able to both implement and maintain security systems.

Oracle 'Partition By' and 'Row_Number' keyword

That selects the row number per country code, account, and currency. So, the rows with country code "US", account "XYZ" and currency "$USD" will each get a row number assigned from 1-n; the same goes for every other combination of those columns in the result set.

This query is kind of funny, because the order by clause does absolutely nothing. All the rows in each partition have the same country code, account, and currency, so there's no point ordering by those columns. The ultimate row numbers assigned in this particular query will therefore be unpredictable.

Hope that helps...

Add views below toolbar in CoordinatorLayout

Take the attribute

app:layout_behavior="@string/appbar_scrolling_view_behavior"

off the RecyclerView and put it on the FrameLayout that you are trying to show under the Toolbar.

I've found that one important thing the scrolling view behavior does is to layout the component below the toolbar. Because the FrameLayout has a descendant that will scroll (RecyclerView), the CoordinatorLayout will get those scrolling events for moving the Toolbar.

One other thing to be aware of: That layout behavior will cause the FrameLayout height to be sized as if the Toolbar is already scrolled, and with the Toolbar fully displayed the entire view is simply pushed down so that the bottom of the view is below the bottom of the CoordinatorLayout.

This was a surprise to me. I was expecting the view to be dynamically resized as the toolbar is scrolled up and down. So if you have a scrolling component with a fixed component at the bottom of your view, you won't see that bottom component until you have fully scrolled the Toolbar.

So when I wanted to anchor a button at the bottom of the UI, I worked around this by putting the button at the bottom of the CoordinatorLayout (android:layout_gravity="bottom") and adding a bottom margin equal to the button's height to the view beneath the toolbar.

How to get value by class name in JavaScript or jquery?

Try this:

$(document).ready(function(){
    var yourArray = [];
    $("span.HOEnZb").find("div").each(function(){
        if(($.trim($(this).text()).length>0)){
         yourArray.push($(this).text());
        }
    });
});

DEMO

Convert UTF-8 with BOM to UTF-8 with no BOM in Python

 
import codecs
import shutil
import sys

s = sys.stdin.read(3)
if s != codecs.BOM_UTF8:
    sys.stdout.write(s)

shutil.copyfileobj(sys.stdin, sys.stdout)

How to update record using Entity Framework 6?

You can use the AddOrUpdate method:

db.Books.AddOrUpdate(book); //requires using System.Data.Entity.Migrations;
db.SaveChanges();

How do you install Google frameworks (Play, Accounts, etc.) on a Genymotion virtual device?

I could flash the ARM translation but not the gapps, using https://stackoverflow.com/a/20013322/98057. I got the 'Ooops, something went wrong while flashing gapps-jb-20121011-signed.zip' error mentioned above. If you read the Genymotion logs and find an entry like:

Sep 16 23:00:02 [Genymotion Player] [Error] [Adb][shell] Unable to finished process:  "Process operation timed out"

Try to apply the flash using adbdirectly:

$ adb -s 192.168.56.101:5555 shell "/system/bin/check-archive.sh /sdcard/Download/gapps-jb-20121011-signed.zip"
$ adb -s 192.168.56.101:5555 shell "/system/bin/flash-archive.sh /sdcard/Download/gapps-jb-20121011-signed.zip"
$ adb reboot

Change these commands according to what your log files say (the path and IP will probably be different).

I found the Genymobile log files in the following folder, by the way:

~/.Genymobile/Genymotion/deployed/<device name>/genymotion-player.log

Does Python have a toString() equivalent, and can I convert a db.Model element to String?

You should define the __unicode__ method on your model, and the template will call it automatically when you reference the instance.

Batch - If, ElseIf, Else

batchfiles perform simple string substitution with variables. so, a simple

goto :language%language%
echo notfound
...

does this without any need for if.

How do I run a terminal inside of Vim?

Someone already suggested https://github.com/Shougo/vimshell.vim, but they didn't mention why. Consequently, when I came away from this question I wasted a lot of other time trying the other (much higher ranked) options.

Shougo/vimshell is the answer. Here's why:

In addition to being a terminal emulator, VimShell allows you to navigate through terminal output in normal and visual mode. Thus, if a command you run results in output that you'd like to copy and paste using the keyboard only...VimShell covers this.

None of the other options mentioned, including the :terminal command in NeoVim do this. Neovim's :terminal comes close, but falls short in at least the following ways as of 2/18/2017:

  • Moves the cursor to the end of the buffer, instead of at the last keeping it in the same spot like VimShell does. Huge waste of time.

  • Doesn't support modifiable = 1 see a discussion on this at Github, so helpful plugins like vim-easymotion can't be used.

  • Doesn't support the display of line numbers like Vimshell does.

Don't waste time on the other options, including Neovim's :terminal. Go with VimShell.

JPA Hibernate One-to-One relationship

I'm not sure you can use a relationship as an Id/PrimaryKey in Hibernate.

Pointers in Python?

I want form.data['field'] and form.field.value to always have the same value

This is feasible, because it involves decorated names and indexing -- i.e., completely different constructs from the barenames a and b that you're asking about, and for with your request is utterly impossible. Why ask for something impossible and totally different from the (possible) thing you actually want?!

Maybe you don't realize how drastically different barenames and decorated names are. When you refer to a barename a, you're getting exactly the object a was last bound to in this scope (or an exception if it wasn't bound in this scope) -- this is such a deep and fundamental aspect of Python that it can't possibly be subverted. When you refer to a decorated name x.y, you're asking an object (the object x refers to) to please supply "the y attribute" -- and in response to that request, the object can perform totally arbitrary computations (and indexing is quite similar: it also allows arbitrary computations to be performed in response).

Now, your "actual desiderata" example is mysterious because in each case two levels of indexing or attribute-getting are involved, so the subtlety you crave could be introduced in many ways. What other attributes is form.field suppose to have, for example, besides value? Without that further .value computations, possibilities would include:

class Form(object):
   ...
   def __getattr__(self, name):
       return self.data[name]

and

class Form(object):
   ...
   @property
   def data(self):
       return self.__dict__

The presence of .value suggests picking the first form, plus a kind-of-useless wrapper:

class KouWrap(object):
   def __init__(self, value):
       self.value = value

class Form(object):
   ...
   def __getattr__(self, name):
       return KouWrap(self.data[name])

If assignments such form.field.value = 23 is also supposed to set the entry in form.data, then the wrapper must become more complex indeed, and not all that useless:

class MciWrap(object):
   def __init__(self, data, k):
       self._data = data
       self._k = k
   @property
   def value(self):
       return self._data[self._k]
   @value.setter
   def value(self, v)
       self._data[self._k] = v

class Form(object):
   ...
   def __getattr__(self, name):
       return MciWrap(self.data, name)

The latter example is roughly as close as it gets, in Python, to the sense of "a pointer" as you seem to want -- but it's crucial to understand that such subtleties can ever only work with indexing and/or decorated names, never with barenames as you originally asked!

Doing HTTP requests FROM Laravel to an external API

You just want to call an external URL and use the results? PHP does this out of the box, if we're talking about a simple GET request to something serving JSON:

$json = json_decode(file_get_contents('http://host.com/api/stuff/1'), true);

If you want to do a post request, it's a little harder but there's loads of examples how to do this with curl.

So I guess the question is; what exactly do you want?

Should Gemfile.lock be included in .gitignore?

Assuming you're not writing a rubygem, Gemfile.lock should be in your repository. It's used as a snapshot of all your required gems and their dependencies. This way bundler doesn't have to recalculate all the gem dependencies each time you deploy, etc.

From cowboycoded's comment below:

If you are working on a gem, then DO NOT check in your Gemfile.lock. If you are working on a Rails app, then DO check in your Gemfile.lock.

Here's a nice article explaining what the lock file is.

ssh script returns 255 error

This error will also occur when using pdsh to hosts which are not contained in your "known_hosts" file.

I was able to correct this by SSH'ing into each host manually and accepting the question "Do you want to add this to known hosts".

Split string into tokens and save them in an array

 
#include <stdio.h>
#include <string.h>

int main ()
{
    char buf[] ="abc/qwe/ccd";
    int i = 0;
    char *p = strtok (buf, "/");
    char *array[3];

    while (p != NULL)
    {
        array[i++] = p;
        p = strtok (NULL, "/");
    }

    for (i = 0; i < 3; ++i) 
        printf("%s\n", array[i]);

    return 0;
}

Get first day of week in SQL Server

Maybe I'm over simplifying here, and that may be the case, but this seems to work for me. Haven't ran into any problems with it yet...

CAST('1/1/' + CAST(YEAR(GETDATE()) AS VARCHAR(30)) AS DATETIME) + (DATEPART(wk, YOUR_DATE) * 7 - 7) as 'FirstDayOfWeek'
CAST('1/1/' + CAST(YEAR(GETDATE()) AS VARCHAR(30)) AS DATETIME) + (DATEPART(wk, YOUR_DATE) * 7) as 'LastDayOfWeek'

Copy/Paste/Calculate Visible Cells from One Column of a Filtered Table

Just to add to Jon's coding if you needed to take it a step further, and do more than just one column you can add something like 

Dim copyRange2 As Range
Dim copyRange3 As Range

Set copyRange2 =src.Range("B2:B" & lastRow)
Set copyRange3 =src.Range("C2:C" & lastRow)

copyRange2.SpecialCells(xlCellTypeVisible).Copy tgt.Range("B12")
copyRange3.SpecialCells(xlCellTypeVisible).Copy tgt.Range("C12")

put these near the other codings that are the same you can easily change the Ranges as you need.

I only add this because it was helpful for me. I'd assume Jon already knows this but for those that are less experienced sometimes it's helpful to see how to change/add/modify these codings. I figured since Ruya didn't know how to manipulate the original coding it could be helpful if one ever needed to copy over only 2 visibile columns, or only 3, etc. You can use this same coding, add in extra lines that are almost the same and then the coding is copying over whatever you need.

I don't have enough reputation to reply to Jon's comment directly so I have to post as a new comment, sorry.

psql: FATAL: Ident authentication failed for user "postgres"

I had similar problem and I fixed it in pg_hba.conf when removing all ident methods even for IP6 address (in spite I have only IP4 on machine).

host all all 127.0.0.1/32 password
host all all ::1/128 password
#for pgAdmin running at local network
host all all 192.168.0.0/24 md5

Spring Boot JPA - configuring auto reconnect

Setting spring.datasource.tomcat.testOnBorrow=true in application.properties didn't work.

Programmatically setting like below worked without any issues. 

import org.apache.tomcat.jdbc.pool.DataSource;
import org.apache.tomcat.jdbc.pool.PoolProperties;    

@Bean
public DataSource dataSource() {
    PoolProperties poolProperties = new PoolProperties();
    poolProperties.setUrl(this.properties.getDatabase().getUrl());         
    poolProperties.setUsername(this.properties.getDatabase().getUsername());            
    poolProperties.setPassword(this.properties.getDatabase().getPassword());

    //here it is
    poolProperties.setTestOnBorrow(true);
    poolProperties.setValidationQuery("SELECT 1");

    return new DataSource(poolProperties);
}

How to check if Location Services are enabled?

 
private boolean isGpsEnabled()
{
    LocationManager service = (LocationManager) getSystemService(LOCATION_SERVICE);
    return service.isProviderEnabled(LocationManager.GPS_PROVIDER)&&service.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
}

Converting UTF-8 to ISO-8859-1 in Java - how to keep it as single byte

Starting with a set of bytes which encode a string using UTF-8, creates a string from that data, then get some bytes encoding the string in a different encoding:

    byte[] utf8bytes = { (byte)0xc3, (byte)0xa2, 0x61, 0x62, 0x63, 0x64 };
    Charset utf8charset = Charset.forName("UTF-8");
    Charset iso88591charset = Charset.forName("ISO-8859-1");

    String string = new String ( utf8bytes, utf8charset );

    System.out.println(string);

    // "When I do a getbytes(encoding) and "
    byte[] iso88591bytes = string.getBytes(iso88591charset);

    for ( byte b : iso88591bytes )
        System.out.printf("%02x ", b);

    System.out.println();

    // "then create a new string with the bytes in ISO-8859-1 encoding"
    String string2 = new String ( iso88591bytes, iso88591charset );

    // "I get a two different chars"
    System.out.println(string2);

this outputs strings and the iso88591 bytes correctly:

âabcd 
e2 61 62 63 64 
âabcd

So your byte array wasn't paired with the correct encoding: 

    String failString = new String ( utf8bytes, iso88591charset );

    System.out.println(failString);

Outputs

âabcd

(either that, or you just wrote the utf8 bytes to a file and read them elsewhere as iso88591)

Hive: Convert String to Integer

If the value is between –2147483648 and 2147483647, cast(string_filed as int) will work. else cast(string_filed as bigint) will work

    hive> select cast('2147483647' as int);
    OK
    2147483647
    
    hive> select cast('2147483648' as int);
    OK
    NULL
    
    hive> select cast('2147483648' as bigint);
    OK
    2147483648

Python - List of unique dictionaries

Pretty straightforward option:

L = [
    {'id':1,'name':'john', 'age':34},
    {'id':1,'name':'john', 'age':34},
    {'id':2,'name':'hanna', 'age':30},
    ]


D = dict()
for l in L: D[l['id']] = l
output = list(D.values())
print output

Laravel Eloquent: How to get only certain columns from joined tables

I know, you ask for Eloquent but you can do it with Fluent Query Builder

$data = DB::table('themes')
    ->join('users', 'users.id', '=', 'themes.user_id')
    ->get(array('themes.*', 'users.username'));

Check file extension in upload form in PHP

Personally,I prefer to use preg_match() function:

if(preg_match("/\.(gif|png|jpg)$/", $filename))

or in_array()

$exts = array('gif', 'png', 'jpg'); 
if(in_array(end(explode('.', $filename)), $exts)

With in_array() can be useful if you have a lot of extensions to validate and perfomance question. Another way to validade file images: you can use @imagecreatefrom*(), if the function fails, this mean the image is not valid.

For example:

function testimage($path)
{
   if(!preg_match("/\.(png|jpg|gif)$/",$path,$ext)) return 0;
   $ret = null;
   switch($ext)
   {
       case 'png': $ret = @imagecreatefrompng($path); break;
       case 'jpeg': $ret = @imagecreatefromjpeg($path); break;
       // ...
       default: $ret = 0;
   }

   return $ret;
}

then:

$valid = testimage('foo.png');

Assuming that foo.png is a PHP-script file with .png extension, the above function fails. It can avoid attacks like shell update and LFI.

How to reload a div without reloading the entire page?

 
$("#div_element").load('script.php');

demo: http://sandbox.phpcode.eu/g/2ecbe/3

whole code:

<div id="submit">ajax</div> 
<div id="div_element"></div> 
<script> 
$('#submit').click(function(event){ 
   $("#div_element").load('script.php?html=some_arguments');  

}); 
</script>

Simplest way to throw an error/exception with a custom message in Swift 2?

Simplest solution without extra extensions, enums, classes and etc.:

NSException(name:NSExceptionName(rawValue: "name"), reason:"reason", userInfo:nil).raise()

Implement paging (skip / take) functionality with this query

 
OFFSET     10 ROWS       -- skip 10 rows
FETCH NEXT 10 ROWS ONLY; -- take 10 rows

use this in the end of your select syntax. =)

Unable to instantiate default tuplizer [org.hibernate.tuple.entity.PojoEntityTuplizer]

I had a similar problem and after going over a lot on stack overflow and spending time on the jar dependencies, I figured out that in my case, I had two sets of asm.jar. I removed one of them and it worked fine...

How to re-enable right click so that I can inspect HTML elements in Chrome?

I built upon @Chema solution and added resetting pointer-events and user-select. If they are set to none for an image, right-clicking it does not invoke the context menu for the image with options to view or save it.

javascript:function enableContextMenu(aggressive = true) { void(document.ondragstart=null); void(document.onselectstart=null); void(document.onclick=null); void(document.onmousedown=null); void(document.onmouseup=null); void(document.body.oncontextmenu=null); enableRightClickLight(document); if (aggressive) { enableRightClick(document); removeContextMenuOnAll('body'); removeContextMenuOnAll('img'); removeContextMenuOnAll('td'); } } function removeContextMenuOnAll(tagName) { var elements = document.getElementsByTagName(tagName); for (var i = 0; i < elements.length; i++) { enableRightClick(elements[i]); enablePointerEvents(elements[i]); } } function enableRightClickLight(el) { el || (el = document); el.addEventListener('contextmenu', bringBackDefault, true); } function enableRightClick(el) { el || (el = document); el.addEventListener('contextmenu', bringBackDefault, true); el.addEventListener('dragstart', bringBackDefault, true); el.addEventListener('selectstart', bringBackDefault, true); el.addEventListener('click', bringBackDefault, true); el.addEventListener('mousedown', bringBackDefault, true); el.addEventListener('mouseup', bringBackDefault, true); } function restoreRightClick(el) { el || (el = document); el.removeEventListener('contextmenu', bringBackDefault, true); el.removeEventListener('dragstart', bringBackDefault, true); el.removeEventListener('selectstart', bringBackDefault, true); el.removeEventListener('click', bringBackDefault, true); el.removeEventListener('mousedown', bringBackDefault, true); el.removeEventListener('mouseup', bringBackDefault, true); } function bringBackDefault(event) { event.returnValue = true; (typeof event.stopPropagation === 'function') && event.stopPropagation(); (typeof event.cancelBubble === 'function') && event.cancelBubble(); } function enablePointerEvents(el) {  if (!el) return; el.style.pointerEvents='auto'; el.style.webkitTouchCallout='default'; el.style.webkitUserSelect='auto'; el.style.MozUserSelect='auto'; el.style.msUserSelect='auto'; el.style.userSelect='auto'; enablePointerEvents(el.parentElement); } enableContextMenu();

Capture Video of Android's Screen

I didn't implement it but still i am giving you an idea to do this.

First of all get the code to take a screenshot of Android device. And Call the same function for creating Images after an interval of times. Add then find the code to create video from frames/images.

Edit

see this link also and modify it according to your screen dimension .The main thing is to divide your work into several small tasks and then combine it as your need.

FFMPEG is the best way to do this. but once i have tried but it is a very long procedure. First you have to download cygwin and Native C++ library and lot of stuff and connect then you are able to work on FFMPEG (it is built in C++).

How can I validate google reCAPTCHA v2 using javascript/jQuery?

This Client side verification of reCaptcha - the following worked for me :

if reCaptcha is not validated on client side grecaptcha.getResponse(); returns null, else is returns a value other than null.

Javascript Code: 

var response = grecaptcha.getResponse();

if(response.length == 0)
    //reCaptcha not verified

else
    //reCaptch verified

Change a Django form field to a hidden field

If you have a custom template and view you may exclude the field and use {{ modelform.instance.field }} to get the value.

also you may prefer to use in the view:

form.fields['field_name'].widget = forms.HiddenInput()

but I'm not sure it will protect save method on post.

Hope it helps.

how to open a jar file in Eclipse

The jar file is just an executable java program. If you want to modify the code, you have to open the .java files.

How to redirect Valgrind's output to a file?

You can also set the options --log-fd if you just want to read your logs with a less. For example :

valgrind --log-fd=1 ls | less

How to convert a double to long without casting?

Simply put, casting is more efficient than creating a Double object.

Combine two integer arrays

use ArrayUtils.addAll(T[], T...):

import org.apache.commons.lang3.ArrayUtils;

AnyObject[] array1 = ...;
AnyObject[] array2 = ...;
AnyObject[] mergedArray = ArrayUtils.addAll(array1, array2);

How do I create an Excel chart that pulls data from multiple sheets?

Use the Chart Wizard.

On Step 2 of 4, there is a tab labeled "Series". There are 3 fields and a list box on this tab. The list box shows the different series you are already including on the chart. Each series has both a "Name" field and a "Values" field that is specific to that series. The final field is the "Category (X) axis labels" field, which is common to all series.

Click on the "Add" button below the list box. This will add a blank series to your list box. Notice that the values for "Name" and for "Values" change when you highlight a series in the list box.

Select your new series.

There is an icon in each field on the right side. This icon allows you to select cells in the workbook to pull the data from. When you click it, the Wizard temporarily hides itself (except for the field you are working in) allowing you to interact with the workbook.

Select the appropriate sheet in the workbook and then select the fields with the data you want to show in the chart. The button on the right of the field can be clicked to unhide the wizard.

Hope that helps.

EDIT: The above applies to 2003 and before. For 2007, when the chart is selected, you should be able to do a similar action using the "Select Data" option on the "Design" tab of the ribbon. This opens up a dialog box listing the Series for the chart. You can select the series just as you could in Excel 2003, but you must use the "Add" and "Edit" buttons to define custom series.

How do I install a JRE or JDK to run the Android Developer Tools on Windows 7?

download jre1.7.0_45 and then extract it into the Eclipse folder and rename folder of jre1.7.0_45 to jre and Eclipse will run

Catch KeyError in Python

If you don't want to handle error just NoneType and use get() e.g.:

manager.connect.get("")

How to solve the “failed to lazily initialize a collection of role” Hibernate exception

One of the best solutions is to add the following in your application.properties file: spring.jpa.properties.hibernate.enable_lazy_load_no_trans=true

Is there are way to make a child DIV's width wider than the parent DIV using CSS?

To make child div as wide as the content, try this:

.child{
    position:absolute;
    left:0;
    overflow:visible;
    white-space:nowrap;
}

Remove final character from string

Simple:

st =  "abcdefghij"
st = st[:-1]

There is also another way that shows how it is done with steps:

list1 = "abcdefghij"
list2 = list(list1)
print(list2)
list3 = list2[:-1]
print(list3)

This is also a way with user input:

list1 = input ("Enter :")
list2 = list(list1)
print(list2)
list3 = list2[:-1]
print(list3)

To make it take away the last word in a list:

list1 = input("Enter :")
list2 = list1.split()
print(list2)
list3 = list2[:-1]
print(list3)

Problem with SMTP authentication in PHP using PHPMailer, with Pear Mail works

Exim 4 requires that AUTH command only be sent after the client issued EHLO - attempts to authenticate without EHLO would be rejected. Some mailservers require that EHLO be issued twice. PHPMailer apparently fails to do so. If PHPMailer does not allow you to force EHLO initiation, you really should switch to SwiftMailer 4.

Shrink to fit content in flexbox, or flex-basis: content workaround?

I want columns One and Two to shrink/grow to fit rather than being fixed.

Have you tried: flex-basis: auto

or this:

flex: 1 1 auto, which is short for:

  • flex-grow: 1 (grow proportionally)
  • flex-shrink: 1 (shrink proportionally)
  • flex-basis: auto (initial size based on content size)

or this:

main > section:first-child {
    flex: 1 1 auto;
    overflow-y: auto;
}

main > section:nth-child(2) {
    flex: 1 1 auto;
    overflow-y: auto;
}

main > section:last-child {
    flex: 20 1 auto;
    display: flex;
    flex-direction: column;  
}

revised demo

Related:

What's the difference between "Request Payload" vs "Form Data" as seen in Chrome dev tools Network tab

In Chrome, request with 'Content-Type:application/json' shows as Request PayedLoad and sends data as json object.

But request with 'Content-Type:application/x-www-form-urlencoded' shows Form Data and sends data as Key:Value Pair, so if you have array of object in one key it flats that key's value:

{ Id: 1, 
name:'john', 
phones:[{title:'home',number:111111,...},
        {title:'office',number:22222,...}]
}

sends 

{ Id: 1, 
name:'john', 
phones:[object object]
phones:[object object]
}

What is the difference between Release and Debug modes in Visual Studio?

Well, it depends on what language you are using, but in general they are 2 separate configurations, each with its own settings. By default, Debug includes debug information in the compiled files (allowing easy debugging) while Release usually has optimizations enabled.

As far as conditional compilation goes, they each define different symbols that can be checked in your program, but they are language-specific macros.

How can I replace every occurrence of a String in a file with PowerShell?

Small correction for the Set-Content command. If the searched string is not found the Set-Content command will blank (empty) the target file.

You can first verify if the string you are looking for exist or not. If not it will not replace anything.

If (select-string -path "c:\Windows\System32\drivers\etc\hosts" -pattern "String to look for") `
    {(Get-Content c:\Windows\System32\drivers\etc\hosts).replace('String to look for', 'String to replace with') | Set-Content c:\Windows\System32\drivers\etc\hosts}
    Else{"Nothing happened"}

SQL Server 2008 Row Insert and Update timestamps

As an alternative to using a trigger, you might like to consider creating a stored procedure to handle the INSERTs that takes most of the columns as arguments and gets the CURRENT_TIMESTAMP which it includes in the final INSERT to the database. You could do the same for the CREATE. You may also be able to set things up so that users cannot execute INSERT and CREATE statements other than via the stored procedures.

I have to admit that I haven't actually done this myself so I'm not at all sure of the details.

How do I get the MAX row with a GROUP BY in LINQ query?

 
        using (DataContext dc = new DataContext())
        {
            var q = from t in dc.TableTests
                    group t by t.SerialNumber
                        into g
                        select new
                        {
                            SerialNumber = g.Key,
                            uid = (from t2 in g select t2.uid).Max()
                        };
        }

Multi value Dictionary

Here is an implementation of a single key to multi value map in C# which uses a set based key type:

https://github.com/ColmBhandal/CsharpExtras/blob/master/CsharpExtras/Dictionary/MultiValueMapImpl.cs

The dictionary behaves like a regular dictionary from the key type onto a set of the value type, but also provides functionality to directly add a single value of the value type, and in the background handles the creation of an underlying set and/or addition to that set.

Bootstrap 4 File Input

In case you want to use it globally on all custom inputs use following jQuery code:

$(document).ready(function () {
    $('.custom-file-input').on('change', function (e) {
         e.target.nextElementSibling.innerHTML = e.target.files[0].name;
    });
});

Generate full SQL script from EF 5 Code First Migrations

To add to Matt wilson's answer I had a bunch of code-first entity classes but no database as I hadn't taken a backup. So I did the following on my Entity Framework project:

Open Package Manager console in Visual Studio and type the following:

Enable-Migrations

Add-Migration

Give your migration a name such as 'Initial' and then create the migration. Finally type the following:

Update-Database

Update-Database -Script -SourceMigration:0

The final command will create your database tables from your entity classes (provided your entity classes are well formed).

How do I make a stored procedure in MS Access?

Access 2010 has both stored procedures, and also has table triggers. And, both features are available even when you not using a server (so, in 100% file based mode).

If you using SQL Server with Access, then of course the stored procedures are built using SQL Server and not Access.

For Access 2010, you open up the table (non-design view), and then choose the table tab. You see options there to create store procedures and table triggers.

For example:

screenshot

Note that the stored procedure language is its own flavor just like Oracle or SQL Server (T-SQL). Here is example code to update an inventory of fruits as a result of an update in the fruit order table alt text

Keep in mind these are true engine-level table triggers. In fact if you open up that table with VB6, VB.NET, FoxPro or even modify the table on a computer WITHOUT Access having been installed, the procedural code and the trigger at the table level will execute. So, this is a new feature of the data engine jet (now called ACE) for Access 2010. As noted, this is procedural code that runs, not just a single statement.

Apache Tomcat Not Showing in Eclipse Server Runtime Environments

In my case I needed to install "JST Server Adapters". I am running Eclipse 3.6 Helios RCP Edition.

Here are the steps I followed:

  1. Help -> Install New Software
  2. Choose "Helios - http://download.eclipse.org/releases/helios" site or kepler - http://download.ecliplse.org/releases/kepler
  3. Expand "Web, XML, and Java EE Development"
  4. Check JST Server Adapters (version 3.2.2)

After that I could define new Server Runtime Environments.

EDIT: With Eclipse 3.7 Indigo Classic, Eclipse Kepler and Luna, the steps are the same (with appropriate update site) but you need both JST Server Adapters and JST Server Adapters Extentions to get the Server Runtime Environment options.

Are global variables bad?

Sooner or later you will need to change how that variable is set or what happens when it is accessed, or you just need to hunt down where it is changed.

It is practically always better to not have global variables. Just write the dam get and set methods, and be gland you when you need them a day, week or month later.

Add column with number of days between dates in DataFrame pandas

A list comprehension is your best bet for the most Pythonic (and fastest) way to do this:

[int(i.days) for i in (df.B - df.A)]
  1. i will return the timedelta(e.g. '-58 days')
  2. i.days will return this value as a long integer value(e.g. -58L)
  3. int(i.days) will give you the -58 you seek.

If your columns aren't in datetime format. The shorter syntax would be: df.A = pd.to_datetime(df.A)

Laravel 5 call a model function in a blade view

want to use model in view as:

{{ Product::find($id) }}

you can use in view:

<?php
$tmp = \App\Product::find($id);
?>
{{ $tmp->name }}

Hope this will help you

max(length(field)) in mysql

Ok, I am not sure what are you using(MySQL, SLQ Server, Oracle, MS Access..) But you can try the code below. It work in W3School example DB. Here try this: 

SELECT city, max(length(city)) FROM Customers;

Hashset vs Treeset

One advantage not yet mentioned of a TreeSet is that its has greater "locality", which is shorthand for saying (1) if two entries are nearby in the order, a TreeSet places them near each other in the data structure, and hence in memory; and (2) this placement takes advantage of the principle of locality, which says that similar data is often accessed by an application with similar frequency.

This is in contrast to a HashSet, which spreads the entries all over memory, no matter what their keys are.

When the latency cost of reading from a hard drive is thousands of times the cost of reading from cache or RAM, and when the data really is accessed with locality, the TreeSet can be a much better choice.

SQL Error: ORA-00933: SQL command not properly ended

Your query should look like

UPDATE table_name
SET column1=value, column2=value2,...
WHERE some_column=some_value

You can check the below question for help

Read url to string in few lines of java code

Or just use Apache Commons IOUtils.toString(URL url), or the variant that also accepts an encoding parameter.

What is @RenderSection in asp.net MVC

If you have a _Layout.cshtml view like this

<html>
    <body>
        @RenderBody()
        @RenderSection("scripts", required: false)
    </body>
</html>

then you can have an index.cshtml content view like this

@section scripts {
     <script type="text/javascript">alert('hello');</script>
}

the required indicates whether or not the view using the layout page must have a scripts section

Return JSON for ResponseEntity<String>

This is a String, not a json structure(key, value), try:

return new ResponseEntity("{"vale" : "This is a String"}", HttpStatus.OK);

Closing WebSocket correctly (HTML5, Javascript)

Very simple, you close it :)

var myWebSocket = new WebSocket("ws://example.org"); 
myWebSocket.send("Hello Web Sockets!"); 
myWebSocket.close();

Did you check also the following site And check the introduction article of Opera

Enum Naming Convention - Plural

Best Practice - use singular. You have a list of items that make up an Enum. Using an item in the list sounds strange when you say Versions.1_0. It makes more sense to say Version.1_0 since there is only one 1_0 Version.

Convert bytes to int?

Assuming you're on at least 3.2, there's a built in for this:

int.from_bytes( bytes, byteorder, *, signed=False )

...

The argument bytes must either be a bytes-like object or an iterable producing bytes.

The byteorder argument determines the byte order used to represent the integer. If byteorder is "big", the most significant byte is at the beginning of the byte array. If byteorder is "little", the most significant byte is at the end of the byte array. To request the native byte order of the host system, use sys.byteorder as the byte order value.

The signed argument indicates whether two’s complement is used to represent the integer.


## Examples:
int.from_bytes(b'\x00\x01', "big")                         # 1
int.from_bytes(b'\x00\x01', "little")                      # 256

int.from_bytes(b'\x00\x10', byteorder='little')            # 4096
int.from_bytes(b'\xfc\x00', byteorder='big', signed=True)  #-1024

In angular $http service, How can I catch the "status" of error?

UPDATED: As of angularjs 1.5, promise methods success and error have been deprecated. (see this answer)

from current docs:

$http.get('/someUrl', config).then(successCallback, errorCallback);
$http.post('/someUrl', data, config).then(successCallback, errorCallback);

you can use the function's other arguments like so:

error(function(data, status, headers, config) {
    console.log(data);
    console.log(status);
}

see $http docs:

// Simple GET request example :
$http.get('/someUrl').
  success(function(data, status, headers, config) {
    // this callback will be called asynchronously
    // when the response is available
  }).
  error(function(data, status, headers, config) {
    // called asynchronously if an error occurs
    // or server returns response with an error status.
  });