Programs & Examples On #Operations

What's the difference between a single precision and double precision floating point operation?

First of all float and double are both used for representation of numbers fractional numbers. So, the difference between the two stems from the fact with how much precision they can store the numbers.

For example: I have to store 123.456789 One may be able to store only 123.4567 while other may be able to store the exact 123.456789.

So, basically we want to know how much accurately can the number be stored and is what we call precision.

Quoting @Alessandro here

The precision indicates the number of decimal digits that are correct, i.e. without any kind of representation error or approximation. In other words, it indicates how many decimal digits one can safely use.

Float can accurately store about 7-8 digits in the fractional part while Double can accurately store about 15-16 digits in the fractional part

So, double can store double the amount of fractional part as of float. That is why Double is called double the float

Java NIO FileChannel versus FileOutputstream performance / usefulness

I tested the performance of FileInputStream vs. FileChannel for decoding base64 encoded files. In my experients I tested rather large file and traditional io was alway a bit faster than nio.

FileChannel might have had an advantage in prior versions of the jvm because of synchonization overhead in several io related classes, but modern jvm are pretty good at removing unneeded locks.

What is a tracking branch?

This was how I added a tracking branch so I can pull from it into my new branch:

git branch --set-upstream-to origin/Development new-branch

How to scroll to bottom in react?

In order to scroll down to the bottom of the page first we have to select an id which resides at the bottom of the page. Then we can use the document.getElementById to select the id and scroll down using scrollIntoView(). Please refer the below code.

   scrollToBottom= async ()=>{
      document.getElementById('bottomID').scrollIntoView();
    }

Merging arrays with the same keys

Two entries in an array can't share a key, you'll need to change the key for the duplicate

Python urllib2 Basic Auth Problem

The problem could be that the Python libraries, per HTTP-Standard, first send an unauthenticated request, and then only if it's answered with a 401 retry, are the correct credentials sent. If the Foursquare servers don't do "totally standard authentication" then the libraries won't work.

Try using headers to do authentication:

import urllib2, base64

request = urllib2.Request("http://api.foursquare.com/v1/user")
base64string = base64.b64encode('%s:%s' % (username, password))
request.add_header("Authorization", "Basic %s" % base64string)   
result = urllib2.urlopen(request)

Had the same problem as you and found the solution from this thread: http://forums.shopify.com/categories/9/posts/27662

Make Bootstrap 3 Tabs Responsive

I prefer a css only scheme based on horizontal scroll, like tabs on android. This's my solution, just wrap with a class nav-tabs-responsive:

<div class="nav-tabs-responsive">
  <ul class="nav nav-tabs" role="tablist">
    <li>...</li>
  </ul>
</div>

And two css lines:

.nav-tabs { min-width: 600px; }
.nav-tabs-responsive { overflow: auto; }

600px is the point over you will be responsive (you can set it using bootstrap variables)

How can I insert data into Database Laravel?

The error MethodNotAllowedHttpException means the route exists, but the HTTP method (GET) is wrong. You have to change it to POST:

Route::post('test/register', array('uses'=>'TestController@create'));

Also, you need to hash your passwords:

public function create()
{
    $user = new User;

    $user->username = Input::get('username');
    $user->email = Input::get('email');
    $user->password = Hash::make(Input::get('password'));
    $user->save();

    return Redirect::back();
}

And I removed the line:

$user= Input::all();

Because in the next command you replace its contents with

$user = new User;

To debug your Input, you can, in the first line of your controller:

dd( Input::all() );

It will display all fields in the input.

fatal error LNK1104: cannot open file 'libboost_system-vc110-mt-gd-1_51.lib'

I had the same problem. It was caused because I compiled the Boost with the Visual C++ 2010(v100) and I tried to use the library with the Visual Studio 2012 (v110) by mistake.

So, I changed the configurations (in Visual Studio 2012) going to Project properties -> General -> Plataform Toolset and change the value from Visual Studio 2012 (v110) to Visual Studio 2010 (v100).

Adb install failure: INSTALL_CANCELED_BY_USER

The problem seems to be with Instant Run feature.Go to "File -> Settings -> Build, Execution, Deployment -> Instant Run" and just disable it.

Hope this works if above answers doesnt work..

JavaScript naming conventions

That's an individual question that could depend on how you're working. Some people like to put the variable type at the begining of the variable, like "str_message". And some people like to use underscore between their words ("my_message") while others like to separate them with upper-case letters ("myMessage").

I'm often working with huge JavaScript libraries with other people, so functions and variables (except the private variables inside functions) got to start with the service's name to avoid conflicts, as "guestbook_message".

In short: english, lower-cased, well-organized variable and function names is preferable according to me. The names should describe their existence rather than being short.

"could not find stored procedure"

I had the same problem. Eventually I found why. I used a code from web to test output of my procedure. At the end it had a call to Drop(procedure) so I deleted it myself.

Xcode error - Thread 1: signal SIGABRT

SIGABRT is, as stated in other answers, a general uncaught exception. You should definitely learn a little bit more about Objective-C. The problem is probably in your UITableViewDelegate method didSelectRowAtIndexPath.

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath

I can't tell you much more until you show us something of the code where you handle the table data source and delegate methods.

Fastest way to check a string contain another substring in JavaScript?

I made a jsben.ch for you http://jsben.ch/#/aWxtF ...seems that indexOf is a bit faster.

How do I check if a directory exists? "is_dir", "file_exists" or both?

A way to check if a path is directory can be following:

function isDirectory($path) {
    $all = @scandir($path);
    return $all !== false;
}

NOTE: It will return false for non-existant path too, but works perfectly for UNIX/Windows

Pass all variables from one shell script to another?

Fatal Error gave a straightforward possibility: source your second script! if you're worried that this second script may alter some of your precious variables, you can always source it in a subshell:

( . ./test2.sh )

The parentheses will make the source happen in a subshell, so that the parent shell will not see the modifications test2.sh could perform.


There's another possibility that should definitely be referenced here: use set -a.

From the POSIX set reference:

-a: When this option is on, the export attribute shall be set for each variable to which an assignment is performed; see the Base Definitions volume of IEEE Std 1003.1-2001, Section 4.21, Variable Assignment. If the assignment precedes a utility name in a command, the export attribute shall not persist in the current execution environment after the utility completes, with the exception that preceding one of the special built-in utilities causes the export attribute to persist after the built-in has completed. If the assignment does not precede a utility name in the command, or if the assignment is a result of the operation of the getopts or read utilities, the export attribute shall persist until the variable is unset.

From the Bash Manual:

-a: Mark variables and function which are modified or created for export to the environment of subsequent commands.

So in your case:

set -a
TESTVARIABLE=hellohelloheloo
# ...
# Here put all the variables that will be marked for export
# and that will be available from within test2 (and all other commands).
# If test2 modifies the variables, the modifications will never be
# seen in the present script!
set +a

./test2.sh

 # Here, even if test2 modifies TESTVARIABLE, you'll still have
 # TESTVARIABLE=hellohelloheloo

Observe that the specs only specify that with set -a the variable is marked for export. That is:

set -a
a=b
set +a
a=c
bash -c 'echo "$a"'

will echo c and not an empty line nor b (that is, set +a doesn't unmark for export, nor does it “save” the value of the assignment only for the exported environment). This is, of course, the most natural behavior.

Conclusion: using set -a/set +a can be less tedious than exporting manually all the variables. It is superior to sourcing the second script, as it will work for any command, not only the ones written in the same shell language.

What is "git remote add ..." and "git push origin master"?

git is like UNIX. User friendly but picky about its friends. It's about as powerful and as user friendly as a shell pipeline.

That being said, once you understand its paradigms and concepts, it has the same zenlike clarity that I've come to expect from UNIX command line tools. You should consider taking some time off to read one of the many good git tutorials available online. The Pro Git book is a good place to start.

To answer your first question.

  1. What is git remote add ...

    As you probably know, git is a distributed version control system. Most operations are done locally. To communicate with the outside world, git uses what are called remotes. These are repositories other than the one on your local disk which you can push your changes into (so that other people can see them) or pull from (so that you can get others changes). The command git remote add origin [email protected]:peter/first_app.gitcreates a new remote called origin located at [email protected]:peter/first_app.git. Once you do this, in your push commands, you can push to origin instead of typing out the whole URL.

  2. What is git push origin master

    This is a command that says "push the commits in the local branch named master to the remote named origin". Once this is executed, all the stuff that you last synchronised with origin will be sent to the remote repository and other people will be able to see them there.

Now about transports (i.e. what git://) means. Remote repository URLs can be of many types (file://, https:// etc.). Git simply relies on the authentication mechanism provided by the transport to take care of permissions and stuff. This means that for file:// URLs, it will be UNIX file permissions, etc. The git:// scheme is asking git to use its own internal transport protocol, which is optimised for sending git changesets around. As for the exact URL, it's the way it is because of the way github has set up its git server.

Now the verbosity. The command you've typed is the general one. It's possible to tell git something like "the branch called master over here is local mirror of the branch called foo on the remote called bar". In git speak, this means that master tracks bar/foo. When you clone for the first time, you will get a branch called master and a remote called origin (where you cloned from) with the local master set to track the master on origin. Once this is set up, you can simply say git push and it'll do it. The longer command is available in case you need it (e.g. git push might push to the official public repo and git push review master can be used to push to a separate remote which your team uses to review code). You can set your branch to be a tracking branch using the --set-upstream option of the git branch command.

I've felt that git (unlike most other apps I've used) is better understood from the inside out. Once you understand how data is stored and maintained inside the repository, the commands and what they do become crystal clear. I do agree with you that there's some elitism amongst many git users but I also found that with UNIX users once upon a time, and it was worth ploughing past them to learn the system. Good luck!

Split large string in n-size chunks in JavaScript

My issue with the above solution is that it beark the string into formal size chunks regardless of the position in the sentences.

I think the following a better approach; although it needs some performance tweaking:

 static chunkString(str, length, size,delimiter='\n' ) {
        const result = [];
        for (let i = 0; i < str.length; i++) {
            const lastIndex = _.lastIndexOf(str, delimiter,size + i);
            result.push(str.substr(i, lastIndex - i));
            i = lastIndex;
        }
        return result;
    }

How to rollback a specific migration?

rake db:migrate:down VERSION=20100905201547

will roll back the specific file.


To find the version of all migrations, you can use this command:

rake db:migrate:status

Or, simply the prefix of the migration's file name is the version you need to rollback.


See the Ruby on Rails guide entry on migrations.

Get img thumbnails from Vimeo?

It seems like api/v2 is dead.
In order to use the new API, you need to register your application, and base64 encode the client_id and client_secret as an Authorization header.

$.ajax({
    type:'GET',
    url: 'https://api.vimeo.com/videos/' + video_id,
    dataType: 'json',
    headers: {
        'Authorization': 'Basic ' + window.btoa(client_id + ":" + client_secret);
    },
    success: function(data) {
        var thumbnail_src = data.pictures.sizes[2].link;
        $('#thumbImg').attr('src', thumbnail_src);
    }
});

For security, you can return the client_id and client_secret already encoded from the server.

CSS I want a div to be on top of everything

You need to add position:relative; to the menu. Z-index only works when you have a non static positioning scheme.

How can I convert byte size into a human-readable format in Java?

public String humanReadable(long size) {
    long limit = 10 * 1024;
    long limit2 = limit * 2 - 1;
    String negative = "";
    if(size < 0) {
        negative = "-";
        size = Math.abs(size);
    }

    if(size < limit) {
        return String.format("%s%s bytes", negative, size);
    } else {
        size = Math.round((double) size / 1024);
        if (size < limit2) {
            return String.format("%s%s kB", negative, size);
        } else {
            size = Math.round((double)size / 1024);
            if (size < limit2) {
                return String.format("%s%s MB", negative, size);
            } else {
                size = Math.round((double)size / 1024);
                if (size < limit2) {
                    return String.format("%s%s GB", negative, size);
                } else {
                    size = Math.round((double)size / 1024);
                        return String.format("%s%s TB", negative, size);
                }
            }
        }
    }
}

Load local javascript file in chrome for testing?

The easiest workaround I have found is to use Firefox. Not only does it work with no extra steps (drag and drop - no muss no fuss), but blackboxing works better than Chrome.

Extracting just Month and Year separately from Pandas Datetime column

There is two steps to extract year for all the dataframe without using method apply.

Step1

convert the column to datetime :

df['ArrivalDate']=pd.to_datetime(df['ArrivalDate'], format='%Y-%m-%d')

Step2

extract the year or the month using DatetimeIndex() method

 pd.DatetimeIndex(df['ArrivalDate']).year

Remove leading zeros from a number in Javascript

We can use four methods for this conversion

  1. parseInt with radix 10
  2. Number Constructor
  3. Unary Plus Operator
  4. Using mathematical functions (subtraction)

_x000D_
_x000D_
const numString = "065";_x000D_
_x000D_
//parseInt with radix=10_x000D_
let number = parseInt(numString, 10);_x000D_
console.log(number);_x000D_
_x000D_
// Number constructor_x000D_
number = Number(numString);_x000D_
console.log(number);_x000D_
_x000D_
// unary plus operator_x000D_
number = +numString;_x000D_
console.log(number);_x000D_
_x000D_
// conversion using mathematical function (subtraction)_x000D_
number = numString - 0;_x000D_
console.log(number);
_x000D_
_x000D_
_x000D_


Update(based on comments): Why doesn't this work on "large numbers"?

For the primitive type Number, the safest max value is 253-1(Number.MAX_SAFE_INTEGER).

_x000D_
_x000D_
console.log(Number.MAX_SAFE_INTEGER);
_x000D_
_x000D_
_x000D_

Now, lets consider the number string '099999999999999999999' and try to convert it using the above methods

_x000D_
_x000D_
const numString = '099999999999999999999';_x000D_
_x000D_
let parsedNumber = parseInt(numString, 10);_x000D_
console.log(`parseInt(radix=10) result: ${parsedNumber}`);_x000D_
_x000D_
parsedNumber = Number(numString);_x000D_
console.log(`Number conversion result: ${parsedNumber}`);_x000D_
_x000D_
parsedNumber = +numString;_x000D_
console.log(`Appending Unary plus operator result: ${parsedNumber}`);_x000D_
_x000D_
parsedNumber = numString - 0;_x000D_
console.log(`Subtracting zero conversion result: ${parsedNumber}`);
_x000D_
_x000D_
_x000D_

All results will be incorrect.

That's because, when converted, the numString value is greater than Number.MAX_SAFE_INTEGER. i.e.,

99999999999999999999 > 9007199254740991

This means all operation performed with the assumption that the stringcan be converted to number type fails.

For numbers greater than 253, primitive BigInt has been added recently. Check browser compatibility of BigInthere.

The conversion code will be like this.

const numString = '099999999999999999999';
const number = BigInt(numString);

P.S: Why radix is important for parseInt?

If radix is undefined or 0 (or absent), JavaScript assumes the following:

  • If the input string begins with "0x" or "0X", radix is 16 (hexadecimal) and the remainder of the string is parsed
  • If the input string begins with "0", radix is eight (octal) or 10 (decimal)
  • If the input string begins with any other value, the radix is 10 (decimal)

Exactly which radix is chosen is implementation-dependent. ECMAScript 5 specifies that 10 (decimal) is used, but not all browsers support this yet.

For this reason, always specify a radix when using parseInt

builder for HashMap

There's ImmutableMap.builder() in Guava.

Creating a Facebook share button with customized url, title and image

Crude, but it works on our system:

<div class="block-share spread-share p-t-md">
  <a href="http://www.facebook.com/share.php?u=http://www.voteleavetakecontrol.org/our_affiliates&title=Farmers+for+Britain+have+made+the+sensible+decision+to+Vote+Leave.+Be+part+of+a+better+future+for+us+all.+Please+share!" 
     target="_blank">
    <button class="btn btn-social btn-facebook">
      <span class="icon icon-facebook">
      </span> 
      Share on Facebook
    </button>
  </a>

  <a href="https://www.facebook.com/FarmersForBritain" target="_blank">
    <button class="btn btn-social btn-facebook">
      <span class="icon icon-facebook">
      </span>
      Like  on Facebook
    </button>
  </a>
</div>

How to get some values from a JSON string in C#?

Your strings are JSON formatted, so you will need to parse it into a object. For that you can use JSON.NET.

Here is an example on how to parse a JSON string into a dynamic object:

string source = "{\r\n   \"id\": \"100000280905615\", \r\n \"name\": \"Jerard Jones\",  \r\n   \"first_name\": \"Jerard\", \r\n   \"last_name\": \"Jones\", \r\n   \"link\": \"https://www.facebook.com/Jerard.Jones\", \r\n   \"username\": \"Jerard.Jones\", \r\n   \"gender\": \"female\", \r\n   \"locale\": \"en_US\"\r\n}";
dynamic data = JObject.Parse(source);
Console.WriteLine(data.id);
Console.WriteLine(data.first_name);
Console.WriteLine(data.last_name);
Console.WriteLine(data.gender);
Console.WriteLine(data.locale);

Happy coding!

What is INSTALL_PARSE_FAILED_NO_CERTIFICATES error?

I was getting this error because I did release that my ant release was failing because I ran out of disk space.

Valid characters of a hostname?

A "name" (Net, Host, Gateway, or Domain name) is a text string up to 24 characters drawn from the alphabet (A-Z), digits (0-9), minus sign (-), and period (.). Note that periods are only allowed when they serve to delimit components of "domain style names". (See RFC-921, "Domain Name System Implementation Schedule", for background). No blank or space characters are permitted as part of a name. No distinction is made between upper and lower case. The first character must be an alpha character. The last character must not be a minus sign or period. A host which serves as a GATEWAY should have "-GATEWAY" or "-GW" as part of its name. Hosts which do not serve as Internet gateways should not use "-GATEWAY" and "-GW" as part of their names. A host which is a TAC should have "-TAC" as the last part of its host name, if it is a DoD host. Single character names or nicknames are not allowed.

This is provided in http://support.microsoft.com/kb/149044

How to check if curl is enabled or disabled

you can check by putting these code in php file.

<?php
if(in_array  ('curl', get_loaded_extensions())) {
    echo "CURL is available on your web server";
}
else{
    echo "CURL is not available on your web server";
}

OR

var_dump(extension_loaded('curl'));

SQLiteDatabase.query method

if your SQL query is like this

SELECT col-1, col-2 FROM tableName WHERE col-1=apple,col-2=mango
GROUPBY col-3 HAVING Count(col-4) > 5  ORDERBY col-2 DESC LIMIT 15;

Then for query() method, we can do as:-

String table = "tableName";
String[] columns = {"col-1", "col-2"};
String selection = "col-1 =? AND col-2=?";       
String[] selectionArgs = {"apple","mango"};
String groupBy =col-3;
String having =" COUNT(col-4) > 5";
String orderBy = "col-2 DESC";
String limit = "15";

query(tableName, columns, selection, selectionArgs, groupBy, having, orderBy, limit);

Crystal Reports - Adding a parameter to a 'Command' query

Try this:

Select Project_Name, ReleaseDate, TaskName
From DB_Table
Where Project_Name like '{?Pm-?Proj_Name}'
  And ReleaseDate >= currentdate

currentdate should be a valid database function or field to work. If you are using MS SQL Server, use GETDATE() instead.

If all you want is to filter records in a subreport based on a parameter from the main report, it might be easier to simply add the table to the subreport, and then create a Project_Name link between the main report and subreport. You can then use the Select Expert to filter the ReleaseDate as well.

Insert multiple values using INSERT INTO (SQL Server 2005)

You can also use the following syntax:-

INSERT INTO MyTable (FirstCol, SecondCol)
SELECT 'First' ,1
UNION ALL
SELECT 'Second' ,2
UNION ALL
SELECT 'Third' ,3
UNION ALL
SELECT 'Fourth' ,4
UNION ALL
SELECT 'Fifth' ,5
GO

From here

Android - How to get application name? (Not package name)

If you need only the application name, not the package name, then just write this code.

 String app_name = packageInfo.applicationInfo.loadLabel(getPackageManager()).toString();

Remove part of a string

Here the strsplit solution for a dataframe using dplyr package

col1 = c("TGAS_1121", "MGAS_1432", "ATGAS_1121") 
col2 = c("T", "M", "A") 
df = data.frame(col1, col2)
df
        col1 col2
1  TGAS_1121    T
2  MGAS_1432    M
3 ATGAS_1121    A

df<-mutate(df,col1=as.character(col1))
df2<-mutate(df,col1=sapply(strsplit(df$col1, split='_', fixed=TRUE),function(x) (x[2])))
df2

  col1 col2
1 1121    T
2 1432    M
3 1121    A

display HTML page after loading complete

try using javascript for this! Seems like its the best and easiest way to do this. You'll get inbuilt funcn to execute a html code only after HTML page loads completely.

or else you may use state based programming where an event occurs at a particular state of the browser..

Change fill color on vector asset in Android Studio

Update: AppCompat support

Other answers suspecting if android:tint will work on only 21+ devices only, AppCompat(v23.2.0 and above) now provides a backward compatible handling of tint attribute.

So, the course of action would be to use AppCompatImageView and app:srcCompat(in AppCompat namespace) instead of android:src(Android namespace).

Here is an example(AndroidX: This is androidx.appcompat.widget.AppCompatImageView ;)):

<android.support.v7.widget.AppCompatImageView
        android:id="@+id/credits_material_icon"
        android:layout_width="20dp"
        android:layout_height="20dp"
        android:layout_marginBottom="8dp"
        android:layout_marginLeft="16dp"
        android:layout_marginStart="16dp"
        android:scaleType="fitCenter"
        android:tint="#ffd2ee"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:srcCompat="@drawable/ic_dollar_coin_stack" />

And don't forget to enable vector drawable support in gradle:

vectorDrawables.useSupportLibrary = true 

Connecting to Postgresql in a docker container from outside

I managed to get it run on linux

  1. run the docker postgres - make sure the port is published, I use alpine because it's lightweight.

    docker run --rm -P -p 127.0.0.1:5432:5432 -e POSTGRES_PASSWORD="1234" --name pg postgres:alpine
    
  2. using another terminal, access the database from the host using the postgres uri

    psql postgresql://postgres:1234@localhost:5432/postgres
    

for mac users, replace psql with pgcli

Check if not nil and not empty in Rails shortcut?

You can use .present? which comes included with ActiveSupport.

@city = @user.city.present?
# etc ...

You could even write it like this

def show
  %w(city state bio contact twitter mail).each do |attr|
    instance_variable_set "@#{attr}", @user[attr].present?
  end
end

It's worth noting that if you want to test if something is blank, you can use .blank? (this is the opposite of .present?)

Also, don't use foo == nil. Use foo.nil? instead.

m2e error in MavenArchiver.getManifest()

I encountered the same issue after updating the maven-jar-plugin to its latest version (at the time of writing), 3.0.2.
Eclipse 4.5.2 started flagging the pom.xml file with the org.apache.maven.archiver.MavenArchiver.getManifest error and a Maven > Update Project.. would not fix it.

Easy solution: downgrade to 2.6 version
Indeed a possible solution is to get back to version 2.6, a further update of the project would then remove any error. However, that's not the ideal scenario and a better solution is possible: update the m2e extensions (Eclipse Maven integration).

Better solution: update Eclipse m2e extensions
From Help > Install New Software.., add a new repository (via the Add.. option), pointing to the following URL:

  • https://repo1.maven.org/maven2/.m2e/connectors/m2eclipse-mavenarchiver/0.17.2/N/LATEST/

Then follow the update wizard as usual. Eclipse would then require a restart. Afterwards, a further Update Project.. on the concerned Maven project would remove any error and your Maven build could then enjoy the benefit of the latest maven-jar-plugin version.


Additonal notes
The reason for this issue is that from version 3.0.0 on, the concerned component, the maven-archiver and the related plexus-archiver has been upgraded to newer versions, breaking internal usages (via reflections) of the m2e integration in Eclipse. The only solution is then to properly update Eclipse, as described above.
Also note: while Eclipse would initially report errors, the Maven build (e.g. from command line) would keep on working perfectly, this issue is only related to the Eclipse-Maven integration, that is, to the IDE.

Angular pass callback function to child component as @Input similar to AngularJS way

An alternative to the answer Max Fahl gave.

You can define callback function as an arrow function in the parent component so that you won't need to bind that.

_x000D_
_x000D_
@Component({_x000D_
  ..._x000D_
  // unlike this, template: '<child [myCallback]="theCallback.bind(this)"></child>',_x000D_
  template: '<child [myCallback]="theCallback"></child>',_x000D_
  directives: [ChildComponent]_x000D_
})_x000D_
export class ParentComponent {_x000D_
_x000D_
   // unlike this, public theCallback(){_x000D_
   public theCallback = () => {_x000D_
    ..._x000D_
  }_x000D_
}_x000D_
_x000D_
@Component({...})_x000D_
export class ChildComponent{_x000D_
  //This will be bound to the ParentComponent.theCallback_x000D_
  @Input()_x000D_
  public myCallback: Function; _x000D_
  ..._x000D_
}
_x000D_
_x000D_
_x000D_

Modifying CSS class property values on the fly with JavaScript / jQuery

Okay.. had the same problem and fixed it, but the solution may not be for everyone.

If you know the indexes of the style sheet and rule you want to delete, try something like document.styleSheets[1].deleteRule(0); .

From the start, I had my main.css (index 0) file. Then, I created a new file, js_edit.css (index 1), that only contained one rule with the properties I wanted to remove when the page had finished loading (after a bunch of other JS functions too).

Now, since js_edit.css loads after main.css, you can just insert/delete rules in js_edit.css as you please and they will override the ones in main.css.

var x = document.styleSheets[1];
x.insertRule("p { font-size: 2rem; }", x.cssRules.length);

x.cssRules.length returns the number of rules in the second (index 1) style sheet thus inserting the new rule at the end.

I'm sure you can use a bunch of for-loops to search for the rule/property you want to modify and then rewrite the whole rule within the same sheet, but I found this way simpler for my needs.

http://www.quirksmode.org/dom/w3c_css.html helped me a lot.

jQuery counter to count up to a target number

I've created the tiniest code to do exactly that. It's not only for counting but for any task that needs to run in a given time. (let's say, do something for 5 seconds):

Demo:

var step = function(t, elapsed){
    // easing 
    t = t*t*t;

    // calculate new value
    var value = 300 * t; // will count from 0 to 300

    // limit value ("t" might be higher than "1")
    if( t > 0.999 )
        value = 300;

    // print value (converts it to an integer)
    someElement.innerHTML = value|0;
};

var done = function(){
    console.log('done counting!');
};


// Do-in settings object
var settings = {
    step     : step,
    duration : 3,
    done     : done,
    fps      : 24 // optional. Default is requestAnimationFrame
};

// initialize "Do-in" instance 
var doin = new Doin(settings);

Hidden property of a button in HTML

<html>
<head>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.4/jquery.min.js"></script>
<script>

function showButtons () { $('#b1, #b2, #b3').show(); }

</script>
<style type="text/css">
#b1, #b2, #b3 {
display: none;
}

</style>
</head>
<body>

<a href="#" onclick="showButtons();">Show me the money!</a>

<input type="submit" id="b1" value="B1" />
<input type="submit" id="b2" value="B2"/>
<input type="submit" id="b3" value="B3" />

</body>
</html>

TSQL select into Temp table from dynamic sql

declare @sql varchar(100);

declare @tablename as varchar(100);

select @tablename = 'your_table_name';

create table #tmp 
    (col1 int, col2 int, col3 int);

set @sql = 'select aa, bb, cc from ' + @tablename;

insert into #tmp(col1, col2, col3) exec( @sql );

select * from #tmp;

How to send FormData objects with Ajax-requests in jQuery?

JavaScript:

function submitForm() {
    var data1 = new FormData($('input[name^="file"]'));
    $.each($('input[name^="file"]')[0].files, function(i, file) {
        data1.append(i, file);
    });

    $.ajax({
        url: "<?php echo base_url() ?>employee/dashboard2/test2",
        type: "POST",
        data: data1,
        enctype: 'multipart/form-data',
        processData: false, // tell jQuery not to process the data
        contentType: false // tell jQuery not to set contentType
    }).done(function(data) {
        console.log("PHP Output:");
        console.log(data);
    });
    return false;
}

PHP:

public function upload_file() {
    foreach($_FILES as $key) {
        $name = time().$key['name'];
        $path = 'upload/'.$name;
        @move_uploaded_file($key['tmp_name'], $path);
    }
}

gitx How do I get my 'Detached HEAD' commits back into master

If checkout master was the last thing you did, then the reflog entry HEAD@{1} will contain your commits (otherwise use git reflog or git log -p to find them). Use git merge HEAD@{1} to fast forward them into master.

EDIT:

As noted in the comments, Git Ready has a great article on this.

git reflog and git reflog --all will give you the commit hashes of the mis-placed commits.

Git Ready: Reflog, Your Safety Net

Source: http://gitready.com/intermediate/2009/02/09/reflog-your-safety-net.html

CSS background image alt attribute

The general belief is that you shouldn't be using background images for things with meaningful semantic value so there isn't really a proper way to store alt data with those images. The important question is what are you going to be doing with that alt data? Do you want it to display if the images don't load? Do you need it for some programmatic function on the page? You could store the data arbitrarily using made up css properties that have no meaning (might cause errors?) OR by adding in hidden images that have the image and the alt tag, and then when you need a background images alt you can compare the image paths and then handle the data however you want using some custom script to simulate what you need. There's no way I know of to make the browser automatically handle some sort of alt attribute for background images though.

What is the size limit of a post request?

It is up to the http server to decide if there is a limit. The product I work on allows the admin to configure the limit.

Scanner vs. BufferedReader

I prefer Scanner because it doesn't throw checked exceptions and therefore it's usage results in a more streamlined code.

how to install gcc on windows 7 machine?

  1. Extract the package to C:\ from here and install it

  2. Copy the path C:\MinGW\bin which contains gcc.exe.

  3. go to Control Panel->System->Advanced>Environment variables, and add or modify PATH. (just concatenate with ';')

  4. Then, open a cmd.exe command prompt (Windows + R and type cmd, if already opened, please close and open a new one, to get the path change)

  5. change the folder to your file path by cd D:\c code Path

  6. type gcc main.c -o helloworld.o. It will compile the code. for C++ use g++

7 type ./helloworld to run the program.

If zlib1.dll is missing, download from here

How do I pass options to the Selenium Chrome driver using Python?

from selenium import webdriver

options = webdriver.ChromeOptions()
options.add_argument('--disable-logging')

# Update your desired_capabilities dict withe extra options.
desired_capabilities.update(options.to_capabilities())
driver = webdriver.Remote(desired_capabilities=options.to_capabilities())

Both the desired_capabilities and options.to_capabilities() are dictionaries. You can use the dict.update() method to add the options to the main set.

WAMP won't turn green. And the VCRUNTIME140.dll error

I had the same problem, and I solved it by installing :

NB : 64 bit installation was enough, I had to uninstall / reinstall Wamp after that

How do I execute a program using Maven?

In order to execute multiple programs, I also needed a profiles section:

<profiles>
  <profile>
    <id>traverse</id>
    <activation>
      <property>
        <name>traverse</name>
      </property>
    </activation>
    <build>
      <plugins>
        <plugin>
          <groupId>org.codehaus.mojo</groupId>
          <artifactId>exec-maven-plugin</artifactId>
          <configuration>
            <executable>java</executable>
            <arguments>
              <argument>-classpath</argument>
              <argument>org.dhappy.test.NeoTraverse</argument>
            </arguments>
          </configuration>
        </plugin>
      </plugins>
    </build>
  </profile>
</profiles>

This is then executable as:

mvn exec:exec -Ptraverse

How to find all the subclasses of a class given its name?

If you just want direct subclasses then .__subclasses__() works fine. If you want all subclasses, subclasses of subclasses, and so on, you'll need a function to do that for you.

Here's a simple, readable function that recursively finds all subclasses of a given class:

def get_all_subclasses(cls):
    all_subclasses = []

    for subclass in cls.__subclasses__():
        all_subclasses.append(subclass)
        all_subclasses.extend(get_all_subclasses(subclass))

    return all_subclasses

Python lookup hostname from IP with 1 second timeout

>>> import socket
>>> socket.gethostbyaddr("69.59.196.211")
('stackoverflow.com', ['211.196.59.69.in-addr.arpa'], ['69.59.196.211'])

For implementing the timeout on the function, this stackoverflow thread has answers on that.

npm ERR! Error: EPERM: operation not permitted, rename

These steps solved for me

Go to the package.json file in the file explorer Right click & select Properties. Deselect Read-only. Click Apply

NOTE: (In case if it is already deselected , check and uncheck the read-only once and click Apply)

Defined Edges With CSS3 Filter Blur

You can try adding the border on an other element:

DOM:

<div><img src="#" /></div>

CSS:

div {
   border: 1px solid black;
}
img {
    filter: blur(5px);
}

make: Nothing to be done for `all'

Sometimes "Nothing to be done for all" error can be caused by spaces before command in makefile rule instead of tab. Please ensure that you use tabs instead of spaces inside of your rules.

all:
<\t>$(CC) $(CFLAGS) ...

instead of

all:
    $(CC) $(CFLAGS) ...

Please see the GNU make manual for the rule syntax description: https://www.gnu.org/software/make/manual/make.html#Rule-Syntax

Bootstrap 4 File Input

You can try below given snippet to display the selected file name from the file input type.

document.querySelectorAll('input[type=file]').forEach( input => {
    input.addEventListener('change', e => {
        e.target.nextElementSibling.innerText = input.files[0].name;
    });
});

How to set calculation mode to manual when opening an excel file?

The best way around this would be to create an Excel called 'launcher.xlsm' in the same folder as the file you wish to open. In the 'launcher' file put the following code in the 'Workbook' object, but set the constant TargetWBName to be the name of the file you wish to open.

Private Const TargetWBName As String = "myworkbook.xlsx"

'// First, a function to tell us if the workbook is already open...
Function WorkbookOpen(WorkBookName As String) As Boolean
' returns TRUE if the workbook is open
    WorkbookOpen = False
    On Error GoTo WorkBookNotOpen
    If Len(Application.Workbooks(WorkBookName).Name) > 0 Then
        WorkbookOpen = True
        Exit Function
    End If
WorkBookNotOpen:
End Function

Private Sub Workbook_Open()
    'Check if our target workbook is open
    If WorkbookOpen(TargetWBName) = False Then
        'set calculation to manual
        Application.Calculation = xlCalculationManual
        Workbooks.Open ThisWorkbook.Path & "\" & TargetWBName
        DoEvents
        Me.Close False
    End If
End Sub

Set the constant 'TargetWBName' to be the name of the workbook that you wish to open. This code will simply switch calculation to manual, then open the file. The launcher file will then automatically close itself. *NOTE: If you do not wish to be prompted to 'Enable Content' every time you open this file (depending on your security settings) you should temporarily remove the 'me.close' to prevent it from closing itself, save the file and set it to be trusted, and then re-enable the 'me.close' call before saving again. Alternatively, you could just set the False to True after Me.Close

How to send an email with Gmail as provider using Python?

great answer from @David, here is for Python 3 without the generic try-except:

def send_email(user, password, recipient, subject, body):

    gmail_user = user
    gmail_pwd = password
    FROM = user
    TO = recipient if type(recipient) is list else [recipient]
    SUBJECT = subject
    TEXT = body

    # Prepare actual message
    message = """From: %s\nTo: %s\nSubject: %s\n\n%s
    """ % (FROM, ", ".join(TO), SUBJECT, TEXT)

    server = smtplib.SMTP("smtp.gmail.com", 587)
    server.ehlo()
    server.starttls()
    server.login(gmail_user, gmail_pwd)
    server.sendmail(FROM, TO, message)
    server.close()

Clear the value of bootstrap-datepicker

you have to do it in that way:

$('#datepicker').datepicker('clearDates');

Get exit code of a background process

As I see almost all answers use external utilities (mostly ps) to poll the state of the background process. There is a more unixesh solution, catching the SIGCHLD signal. In the signal handler it has to be checked which child process was stopped. It can be done by kill -0 <PID> built-in (universal) or checking the existence of /proc/<PID> directory (Linux specific) or using the jobs built-in ( specific. jobs -l also reports the pid. In this case the 3rd field of the output can be Stopped|Running|Done|Exit . ).

Here is my example.

The launched process is called loop.sh. It accepts -x or a number as an argument. For -x is exits with exit code 1. For a number it waits num*5 seconds. In every 5 seconds it prints its PID.

The launcher process is called launch.sh:

#!/bin/bash

handle_chld() {
    local tmp=()
    for((i=0;i<${#pids[@]};++i)); do
        if [ ! -d /proc/${pids[i]} ]; then
            wait ${pids[i]}
            echo "Stopped ${pids[i]}; exit code: $?"
        else tmp+=(${pids[i]})
        fi
    done
    pids=(${tmp[@]})
}

set -o monitor
trap "handle_chld" CHLD

# Start background processes
./loop.sh 3 &
pids+=($!)
./loop.sh 2 &
pids+=($!)
./loop.sh -x &
pids+=($!)

# Wait until all background processes are stopped
while [ ${#pids[@]} -gt 0 ]; do echo "WAITING FOR: ${pids[@]}"; sleep 2; done
echo STOPPED

For more explanation see: Starting a process from bash script failed

Free c# QR-Code generator

You can look at Open Source QR Code Library or messagingtoolkit-qrcode. I have not used either of them so I can not speak of their ease to use.

Use CASE statement to check if column exists in table - SQL Server

Final answer was a combination of two of the above (I've upvoted both to show my appreciation!):

select case 
   when exists (
      SELECT 1 
      FROM Sys.columns c 
      WHERE c.[object_id] = OBJECT_ID('dbo.Tags') 
         AND c.name = 'ModifiedByUserId'
   ) 
   then 1 
   else 0 
end

How to generate entire DDL of an Oracle schema (scriptable)?

You can spool the schema out to a file via SQL*Plus and dbms_metadata package. Then replace the schema name with another one via sed. This works for Oracle 10 and higher.

sqlplus<<EOF
set long 100000
set head off
set echo off
set pagesize 0
set verify off
set feedback off
spool schema.out

select dbms_metadata.get_ddl(object_type, object_name, owner)
from
(
    --Convert DBA_OBJECTS.OBJECT_TYPE to DBMS_METADATA object type:
    select
        owner,
        --Java object names may need to be converted with DBMS_JAVA.LONGNAME.
        --That code is not included since many database don't have Java installed.
        object_name,
        decode(object_type,
            'DATABASE LINK',      'DB_LINK',
            'JOB',                'PROCOBJ',
            'RULE SET',           'PROCOBJ',
            'RULE',               'PROCOBJ',
            'EVALUATION CONTEXT', 'PROCOBJ',
            'CREDENTIAL',         'PROCOBJ',
            'CHAIN',              'PROCOBJ',
            'PROGRAM',            'PROCOBJ',
            'PACKAGE',            'PACKAGE_SPEC',
            'PACKAGE BODY',       'PACKAGE_BODY',
            'TYPE',               'TYPE_SPEC',
            'TYPE BODY',          'TYPE_BODY',
            'MATERIALIZED VIEW',  'MATERIALIZED_VIEW',
            'QUEUE',              'AQ_QUEUE',
            'JAVA CLASS',         'JAVA_CLASS',
            'JAVA TYPE',          'JAVA_TYPE',
            'JAVA SOURCE',        'JAVA_SOURCE',
            'JAVA RESOURCE',      'JAVA_RESOURCE',
            'XML SCHEMA',         'XMLSCHEMA',
            object_type
        ) object_type
    from dba_objects 
    where owner in ('OWNER1')
        --These objects are included with other object types.
        and object_type not in ('INDEX PARTITION','INDEX SUBPARTITION',
           'LOB','LOB PARTITION','TABLE PARTITION','TABLE SUBPARTITION')
        --Ignore system-generated types that support collection processing.
        and not (object_type = 'TYPE' and object_name like 'SYS_PLSQL_%')
        --Exclude nested tables, their DDL is part of their parent table.
        and (owner, object_name) not in (select owner, table_name from dba_nested_tables)
        --Exclude overflow segments, their DDL is part of their parent table.
        and (owner, object_name) not in (select owner, table_name from dba_tables where iot_type = 'IOT_OVERFLOW')
)
order by owner, object_type, object_name;

spool off
quit
EOF

cat schema.out|sed 's/OWNER1/MYOWNER/g'>schema.out.change.sql

Put everything in a script and run it via cron (scheduler). Exporting objects can be tricky when advanced features are used. Don't be surprised if you need to add some more exceptions to the above code.

"Python version 2.7 required, which was not found in the registry" error when attempting to install netCDF4 on Windows 8

Check for the 32/64 bit you trying to install. both python interpreter and your app which trying to use python might be of different bit.

How to convert DataTable to class Object?

You may want to have a look at the code here. Although it doesn't answer your question directly you could adapt the generic class types that are used to map between data classes and business objects.

Also by using generic you run the conversion process as quickly as possible.

How to use comparison and ' if not' in python?

Operator precedence in python
You can see that not X has higher precedence than and. Which means that the not only apply to the first part (u0 <= u). Write:

if not (u0 <= u and u < u0+step):  

or even

if not (u0 <= u < u0+step):  

Sorting Directory.GetFiles()

Here's the VB.Net solution that I've used.

First make a class to compare dates:

Private Class DateComparer
    Implements System.Collections.IComparer

    Public Function Compare(ByVal info1 As Object, ByVal info2 As Object) As Integer Implements System.Collections.IComparer.Compare
        Dim FileInfo1 As System.IO.FileInfo = DirectCast(info1, System.IO.FileInfo)
        Dim FileInfo2 As System.IO.FileInfo = DirectCast(info2, System.IO.FileInfo)

        Dim Date1 As DateTime = FileInfo1.CreationTime
        Dim Date2 As DateTime = FileInfo2.CreationTime

        If Date1 > Date2 Then Return 1
        If Date1 < Date2 Then Return -1
        Return 0
    End Function
End Class

Then use the comparer while sorting the array:

Dim DirectoryInfo As New System.IO.DirectoryInfo("C:\")
Dim Files() As System.IO.FileInfo = DirectoryInfo.GetFiles()
Dim comparer As IComparer = New DateComparer()
Array.Sort(Files, comparer)

shift a std_logic_vector of n bit to right or left

There are two ways that you can achieve this. Concatenation, and shift/rotate functions.

  • Concatenation is the "manual" way of doing things. You specify what part of the original signal that you want to "keep" and then concatenate on data to one end or the other. For example: tmp <= tmp(14 downto 0) & '0';

  • Shift functions (logical, arithmetic): These are generic functions that allow you to shift or rotate a vector in many ways. The functions are: sll (shift left logical), srl (shift right logical). A logical shift inserts zeros. Arithmetric shifts (sra/sla) insert the left most or right most bit, but work in the same way as logical shift. Note that for all of these operations you specify what you want to shift (tmp), and how many times you want to perform the shift (n bits)

  • Rotate functions: rol (rotate left), ror (rotate right). Rotating does just that, the MSB ends up in the LSB and everything shifts left (rol) or the other way around for ror.

Here is a handy reference I found (see the first page).

What does %s and %d mean in printf in the C language?

%s%d%s%d\n is a format string. It is used to specify how the information is formatted on an output. here the format string is supposed to print string followed by a digit followed by a string and then again a digit. The last symbol \n represents carriage return which marks the end of a line. In C, strings cannot be concatenated by + or , although you can combine different outputs on a single line by using the appropriate format strings (the use of format strings is to format output info.).

Access to the path denied error in C#

tl;dr version: Make sure you are not trying to open a file marked in the file system as Read-Only in Read/Write mode.

I have come across this error in my travels trying to read in an XML file. I have found that in some circumstances (detailed below) this error would be generated for a file even though the path and file name are correct.

File details:

  • The path and file name are valid, the file exists
  • Both the service account and the logged in user have Full Control permissions to the file and the full path
  • The file is marked as Read-Only
  • It is running on Windows Server 2008 R2
  • The path to the file was using local drive letters, not UNC path

When trying to read the file programmatically, the following behavior was observed while running the exact same code:

  • When running as the logged in user, the file is read with no error
  • When running as the service account, trying to read the file generates the Access Is Denied error with no details

In order to fix this, I had to change the method call from the default (Opening as RW) to opening the file as RO. Once I made that one change, it stopped throwing an error.

ASP.net using a form to insert data into an sql server table

Simple, make a simple asp page with the designer (just for the beginning) Lets say the body is something like this:

<body>
    <form id="form1" runat="server">
    <div>
        <asp:TextBox ID="TextBox2" runat="server"></asp:TextBox>
        <br />
        <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
    </div>
    <p>
        <asp:Button ID="Button1" runat="server" Text="Button" />
    </p>
    </form>
</body>

Great, now every asp object IS an object. So you can access it in the asp's CS code. The asp's CS code is triggered by events (mostly). The class will probably inherit from System.Web.UI.Page

If you go to the cs file of the asp page, you'll see a protected void Page_Load(object sender, EventArgs e) ... That's the load event, you can use that to populate data into your objects when the page loads.

Now, go to the button in your designer (Button1) and look at its properties, you can design it, or add events from there. Just change to the events view, and create a method for the event.

The button is a web control Button Add a Click event to the button call it Button1Click:

void Button1Click(Object sender,EventArgs e) { }

Now when you click the button, this method will be called. Because ASP is object oriented, you can think of the page as the actual class, and the objects will hold the actual current data.

So if for example you want to access the text in TextBox1 you just need to call that object in the C# code:

String firstBox = TextBox1.Text;

In the same way you can populate the objects when event occur.

Now that you have the data the user posted in the textboxes , you can use regular C# SQL connections to add the data to your database.

Laravel stylesheets and javascript don't load for non-base routes

If you do hard code it, you should probably use the full path (href="http://example.com/public/css/app.css"). However, this means you'll have to manually adjust the URLs for development and production.

An Alternative to the above solutions would be to use <link rel="stylesheet" href="URL::to_asset('css/app.css')" /> in Laravel 3 or <link rel="stylesheet" href="URL::asset('css/app.css')" /> in Laravel 4. This will allow you to write your HTML the way you want it, but also let Laravel generate the proper path for you in any environment.

JSON to TypeScript class instance?

The best solution I found when dealing with Typescript classes and json objects: add a constructor in your Typescript class that takes the json data as parameter. In that constructor you extend your json object with jQuery, like this: $.extend( this, jsonData). $.extend allows keeping the javascript prototypes while adding the json object's properties.

export class Foo
{
    Name: string;
    getName(): string { return this.Name };

    constructor( jsonFoo: any )
    {
        $.extend( this, jsonFoo);
    }
}

In your ajax callback, translate your jsons in a your typescript object like this:

onNewFoo( jsonFoos : any[] )
{
  let receviedFoos = $.map( jsonFoos, (json) => { return new Foo( json ); } );

  // then call a method:
  let firstFooName = receviedFoos[0].GetName();
}

If you don't add the constructor, juste call in your ajax callback:

let newFoo = new Foo();
$.extend( newFoo, jsonData);
let name = newFoo.GetName()

...but the constructor will be useful if you want to convert the children json object too. See my detailed answer here.

.NET Excel Library that can read/write .xls files

You may consider 3rd party tool that called Excel Jetcell .NET component for read/write excel files:

C# sample

// Create New Excel Workbook
ExcelWorkbook Wbook = new ExcelWorkbook();
ExcelCellCollection Cells = Wbook.Worksheets.Add("Sheet1").Cells;

Cells["A1"].Value = "Excel writer example (C#)";
Cells["A1"].Style.Font.Bold = true;
Cells["B1"].Value = "=550 + 5";

// Write Excel XLS file
Wbook.WriteXLS("excel_net.xls");

VB.NET sample

' Create New Excel Workbook
Dim Wbook As ExcelWorkbook = New ExcelWorkbook()
Dim Cells As ExcelCellCollection = Wbook.Worksheets.Add("Sheet1").Cells

Cells("A1").Value = "Excel writer example (C#)"
Cells("A1").Style.Font.Bold = True
Cells("B1").Value = "=550 + 5"

' Write Excel XLS file
Wbook.WriteXLS("excel_net.xls")

What is object slicing?

If You have a base class A and a derived class B, then You can do the following.

void wantAnA(A myA)
{
   // work with myA
}

B derived;
// work with the object "derived"
wantAnA(derived);

Now the method wantAnA needs a copy of derived. However, the object derived cannot be copied completely, as the class B could invent additional member variables which are not in its base class A.

Therefore, to call wantAnA, the compiler will "slice off" all additional members of the derived class. The result might be an object you did not want to create, because

  • it may be incomplete,
  • it behaves like an A-object (all special behaviour of the class B is lost).

Excel - programm cells to change colour based on another cell

Select ColumnB and as two CF formula rules apply:

Green: =AND(B1048576="X",B1="Y")

Red: =AND(B1048576="X",B1="W")

enter image description here

How is the AND/OR operator represented as in Regular Expressions?

use
if in vim:

:s/{\|}/"/g

will replace { and } on " so {lol} becomes "lol"

Accessing a property in a parent Component

I had the same problem but I solved it differently. I don't know if it's a good way of doing it, but it works great for what I need.

I used @Inject on the constructor of the child component, like this:

import { Component, OnInit, Inject } from '@angular/core';
import { ParentComponent } from '../views/parent/parent.component';

export class ChildComponent{
    constructor(@Inject(ParentComponent) private parent: ParentComponent){

    }

    someMethod(){
        this.parent.aPublicProperty = 2;
    }
}

This worked for me, you only need to declare the method or property you want to call as public.

In my case, the AppComponent handles the routing, and I'm using badges in the menu items to alert the user that new unread messages are available. So everytime a user reads a message, I want that counter to refresh, so I call the refresh method so that the number at the menu nav gets updated with the new value. This is probably not the best way but I like it for its simplicity.

MySQL: How to add one day to datetime field in query

It`s possible to use MySQL specific syntax sugar:

SELECT ... date_field + INTERVAL 1 DAY

Looks much more pretty instead of DATE_ADD function

Swift programmatically navigate to another view controller/scene

You should push the new viewcontroller by using current navigation controller, not present.

self.navigationController.pushViewController(nextViewController, animated: true)

Angular 2 router.navigate

_x000D_
_x000D_
import { ActivatedRoute } from '@angular/router';_x000D_
_x000D_
export class ClassName {_x000D_
  _x000D_
  private router = ActivatedRoute;_x000D_
_x000D_
    constructor(r: ActivatedRoute) {_x000D_
        this.router =r;_x000D_
    }_x000D_
_x000D_
onSuccess() {_x000D_
     this.router.navigate(['/user_invitation'],_x000D_
         {queryParams: {email: loginEmail, code: userCode}});_x000D_
}_x000D_
_x000D_
}_x000D_
_x000D_
_x000D_
Get this values:_x000D_
---------------_x000D_
_x000D_
ngOnInit() {_x000D_
    this.route_x000D_
        .queryParams_x000D_
        .subscribe(params => {_x000D_
            let code = params['code'];_x000D_
            let userEmail = params['email'];_x000D_
        });_x000D_
}
_x000D_
_x000D_
_x000D_

Ref: https://angular.io/docs/ts/latest/api/router/index/NavigationExtras-interface.html

Checking whether a variable is an integer or not

You can do this.

if type(x) is int:

Microsoft Excel mangles Diacritics in .csv files?

Writing a BOM to the output CSV file actually did work for me in Django:

def handlePersoonListExport(request):
    # Retrieve a query_set
    ...

    template = loader.get_template("export.csv")
    context = Context({
        'data': query_set,
    })

    response = HttpResponse()
    response['Content-Disposition'] = 'attachment; filename=export.csv'
    response['Content-Type'] = 'text/csv; charset=utf-8'
    response.write("\xEF\xBB\xBF")
    response.write(template.render(context))

    return response

For more info http://crashcoursing.blogspot.com/2011/05/exporting-csv-with-special-characters.html Thanks guys!

Count the number of commits on a Git branch

To see total no of commits you can do as Peter suggested above

git rev-list --count HEAD

And if you want to see number of commits made by each person try this line

git shortlog -s -n

will generate output like this

135  Tom Preston-Werner
15  Jack Danger Canty
10  Chris Van Pelt
7  Mark Reid
6  remi

Running command line silently with VbScript and getting output?

Dim path As String = GetFolderPath(SpecialFolder.ApplicationData)
 Dim filepath As String = path + "\" + "your.bat"
    ' Create the file if it does not exist. 
    If File.Exists(filepath) = False Then
        File.Create(filepath)
    Else
    End If
    Dim attributes As FileAttributes
    attributes = File.GetAttributes(filepath)
    If (attributes And FileAttributes.ReadOnly) = FileAttributes.ReadOnly Then
        ' Remove from Readonly the file.
        attributes = RemoveAttribute(attributes, FileAttributes.ReadOnly)
        File.SetAttributes(filepath, attributes)
        Console.WriteLine("The {0} file is no longer RO.", filepath)
    Else
    End If
    If (attributes And FileAttributes.Hidden) = FileAttributes.Hidden Then
        ' Show the file.
        attributes = RemoveAttribute(attributes, FileAttributes.Hidden)
        File.SetAttributes(filepath, attributes)
        Console.WriteLine("The {0} file is no longer Hidden.", filepath)
    Else
    End If
    Dim sr As New StreamReader(filepath)
    Dim input As String = sr.ReadToEnd()
    sr.Close()
    Dim output As String = "@echo off"
    Dim output1 As String = vbNewLine + "your 1st cmd code"
    Dim output2 As String = vbNewLine + "your 2nd cmd code "
    Dim output3 As String = vbNewLine + "exit"
    Dim sw As New StreamWriter(filepath)
    sw.Write(output)
    sw.Write(output1)
    sw.Write(output2)
    sw.Write(output3)
    sw.Close()
    If (attributes And FileAttributes.Hidden) = FileAttributes.Hidden Then
    Else
        ' Hide the file.
        File.SetAttributes(filepath, File.GetAttributes(filepath) Or FileAttributes.Hidden)
        Console.WriteLine("The {0} file is now hidden.", filepath)
    End If
    Dim procInfo As New ProcessStartInfo(path + "\" + "your.bat")
    procInfo.WindowStyle = ProcessWindowStyle.Minimized
    procInfo.WindowStyle = ProcessWindowStyle.Hidden
    procInfo.CreateNoWindow = True
    procInfo.FileName = path + "\" + "your.bat"
    procInfo.Verb = "runas"
    Process.Start(procInfo)

it saves your .bat file to "Appdata of current user" ,if it does not exist and remove the attributes and after that set the "hidden" attributes to file after writing your cmd code and run it silently and capture all output saves it to file so if u wanna save all output of cmd to file just add your like this

code > C:\Users\Lenovo\Desktop\output.txt

just replace word "code" with your .bat file code or command and after that the directory of output file I found one code recently after searching alot if u wanna run .bat file in vb or c# or simply just add this in the same manner in which i have written

iOS9 Untrusted Enterprise Developer with no option to trust

For iOS 9 beta 3,4 users. Since the option to view profiles is not viewable do the following from Xcode.

  1. Open Xcode 7.
  2. Go to window, devices.
  3. Select your device.
  4. Delete all of the profiles loaded on the device.
  5. Delete the old app on your device.
  6. Clean and rebuild the app to your device.

On iOS 9.1+ n iOS 9.2+ go to Settings -> General -> Device Management -> press the Profile -> Press Trust.

Less than or equal to

You can use:

EQU - equal

NEQ - not equal

LSS - less than

LEQ - less than or equal

GTR - greater than

GEQ - greater than or equal

AVOID USING:

() ! ~ - * / % + - << >> & | = *= /= %= += -= &= ^= |= <<= >>=

Load and execution sequence of a web page?

If you're asking this because you want to speed up your web site, check out Yahoo's page on Best Practices for Speeding Up Your Web Site. It has a lot of best practices for speeding up your web site.

How can you float: right in React Native?

you can use following these component to float right

alignItems aligns children in the cross direction. For example, if children are flowing vertically, alignItems controls how they align horizontally.

alignItems: 'flex-end'

justifyContent aligns children in the main direction. For example, if children are flowing vertically, justifyContent controls how they align vertically.

justifyContent: 'flex-end'

alignSelf controls how a child aligns in the cross direction,

alignSelf : 'flex-end'

python numpy vector math

You can just use numpy arrays. Look at the numpy for matlab users page for a detailed overview of the pros and cons of arrays w.r.t. matrices.

As I mentioned in the comment, having to use the dot() function or method for mutiplication of vectors is the biggest pitfall. But then again, numpy arrays are consistent. All operations are element-wise. So adding or subtracting arrays and multiplication with a scalar all work as expected of vectors.

Edit2: Starting with Python 3.5 and numpy 1.10 you can use the @ infix-operator for matrix multiplication, thanks to pep 465.

Edit: Regarding your comment:

  1. Yes. The whole of numpy is based on arrays.

  2. Yes. linalg.norm(v) is a good way to get the length of a vector. But what you get depends on the possible second argument to norm! Read the docs.

  3. To normalize a vector, just divide it by the length you calculated in (2). Division of arrays by a scalar is also element-wise.

    An example in ipython:

    In [1]: import math
    
    In [2]: import numpy as np
    
    In [3]: a = np.array([4,2,7])
    
    In [4]: np.linalg.norm(a)
    Out[4]: 8.3066238629180749
    
    In [5]: math.sqrt(sum([n**2 for n in a]))
    Out[5]: 8.306623862918075
    
    In [6]: b = a/np.linalg.norm(a)
    
    In [7]: np.linalg.norm(b)
    Out[7]: 1.0
    

    Note that In [5] is an alternative way to calculate the length. In [6] shows normalizing the vector.

Copy table to a different database on a different SQL Server

Yes. add a linked server entry, and use select into using the four part db object naming convention.

Example:

SELECT * INTO targetTable 
FROM [sourceserver].[sourcedatabase].[dbo].[sourceTable]

How to declare a variable in SQL Server and use it in the same Stored Procedure

CREATE PROCEDURE AddBrand
@BrandName nvarchar(50) = null,
@CategoryID int = null
AS    
BEGIN

DECLARE @BrandID int = null
SELECT @BrandID = BrandID FROM tblBrand 
WHERE BrandName = @BrandName

INSERT INTO tblBrandinCategory (CategoryID, BrandID) 
       VALUES (@CategoryID, @BrandID)

END

EXEC AddBrand @BrandName = 'BMW', @CategoryId = 1

Angular2 : Can't bind to 'formGroup' since it isn't a known property of 'form'

try with

<form formGroup="userForm">

instead of

<form [formGroup]="userForm">

How to disable "prevent this page from creating additional dialogs"?

This is what I ended up doing, since we have a web app that has multiple users that are not under our control...(@DannyBeckett I know this isn't an exact answer to your question, but the people that are looking at your question might be helped by this.) You can at least detect if they are not seeing the dialogs. There are few things you most likely want to change like the time to display, or what you are actually displaying. Remember this will only notify the user that they are have managed to click that little checkbox.

window.nativeAlert = window.alert;
window.alert = function (message) {
    var timeBefore = new Date();
    var confirmBool = nativeAlert(message);
    var timeAfter = new Date();
    if ((timeAfter - timeBefore) < 350) {
        MySpecialDialog("You have alerts turned off");
    }
}

window.nativeConfirm = window.confirm;
window.confirm = function (message) {
    var timeBefore = new Date();
    var confirmBool = nativeConfirm(message);
    var timeAfter = new Date();
    if ((timeAfter - timeBefore) < 350) {
        MySpecialDialog("You have confirms turned off");
    }
    return confirmBool;
}

Obviously I have set the time to 3.5 milliseconds. But after some testing we were only able to click or close the dialogs in about 5 milliseconds plus.

When to use RabbitMQ over Kafka?

The most voted answer covers most part but I would like to high light use case point of view. Can kafka do that rabbit mq can do, answer is yes but can rabbit mq do everything that kafka does, the answer is no.

The thing that rabbit mq cannot do that makes kafka apart, is distributed message processing. With this now read back the most voted answer and it will make more sense.

To elaborate, take a use case where you need to create a messaging system that has super high throughput for example "likes" in facebook and You have chosen rabbit mq for that. You created an exchange and queue and a consumer where all publishers (in this case FB users) can publish 'likes' messages. Since your throughput is high, you will create multiple threads in consumer to process messages in parallel but you still bounded by the hardware capacity of the machine where consumer is running. Assuming that one consumer is not sufficient to process all messages - what would you do?

  • Can you add one more consumer to queue - no you cant do that.
  • Can you create a new queue and bind that queue to exchange that publishes 'likes' message, answer is no cause you will have messages processed twice.

That is the core problem that kafka solves. It lets you create distributed partitions (Queue in rabbit mq) and distributed consumer that talk to each other. That ensures your messages in a topic get processed by consumers distributed in various nodes (Machines).

Kafka brokers ensure that messages get load balanced across all partitions of that topic. Consumer group make sure that all consumer talk to each other and message does not get processed twice.

But in real life you will not face this problem unless your throughput is seriously high because rabbit mq can also process data very fast even with one consumer.

Angular, content type is not being sent with $http

$http({
    url: 'http://localhost:8080/example/teste',
    dataType: 'json',
    method: 'POST',
    data: '',
    headers: {
        "Content-Type": "application/json"
    }

}).success(function(response){
    $scope.response = response;
}).error(function(error){
    $scope.error = error;
});

Try like this.

How do you properly determine the current script directory?

Would

import os
cwd = os.getcwd()

do what you want? I'm not sure what exactly you mean by the "current script directory". What would the expected output be for the use cases you gave?

Why use a ReentrantLock if one can use synchronized(this)?

A ReentrantLock is unstructured, unlike synchronized constructs -- i.e. you don't need to use a block structure for locking and can even hold a lock across methods. An example:

private ReentrantLock lock;

public void foo() {
  ...
  lock.lock();
  ...
}

public void bar() {
  ...
  lock.unlock();
  ...
}

Such flow is impossible to represent via a single monitor in a synchronized construct.


Aside from that, ReentrantLock supports lock polling and interruptible lock waits that support time-out. ReentrantLock also has support for configurable fairness policy, allowing more flexible thread scheduling.

The constructor for this class accepts an optional fairness parameter. When set true, under contention, locks favor granting access to the longest-waiting thread. Otherwise this lock does not guarantee any particular access order. Programs using fair locks accessed by many threads may display lower overall throughput (i.e., are slower; often much slower) than those using the default setting, but have smaller variances in times to obtain locks and guarantee lack of starvation. Note however, that fairness of locks does not guarantee fairness of thread scheduling. Thus, one of many threads using a fair lock may obtain it multiple times in succession while other active threads are not progressing and not currently holding the lock. Also note that the untimed tryLock method does not honor the fairness setting. It will succeed if the lock is available even if other threads are waiting.


ReentrantLock may also be more scalable, performing much better under higher contention. You can read more about this here.

This claim has been contested, however; see the following comment:

In the reentrant lock test, a new lock is created each time, thus there is no exclusive locking and the resulting data is invalid. Also, the IBM link offers no source code for the underlying benchmark so its impossible to characterize whether the test was even conducted correctly.


When should you use ReentrantLocks? According to that developerWorks article...

The answer is pretty simple -- use it when you actually need something it provides that synchronized doesn't, like timed lock waits, interruptible lock waits, non-block-structured locks, multiple condition variables, or lock polling. ReentrantLock also has scalability benefits, and you should use it if you actually have a situation that exhibits high contention, but remember that the vast majority of synchronized blocks hardly ever exhibit any contention, let alone high contention. I would advise developing with synchronization until synchronization has proven to be inadequate, rather than simply assuming "the performance will be better" if you use ReentrantLock. Remember, these are advanced tools for advanced users. (And truly advanced users tend to prefer the simplest tools they can find until they're convinced the simple tools are inadequate.) As always, make it right first, and then worry about whether or not you have to make it faster.


One final aspect that's gonna become more relevant in the near future has to do with Java 15 and Project Loom. In the (new) world of virtual threads, the underlying scheduler would be able to work much better with ReentrantLock than it's able to do with synchronized, that's true at least in the initial Java 15 release but may be optimized later.

In the current Loom implementation, a virtual thread can be pinned in two situations: when there is a native frame on the stack — when Java code calls into native code (JNI) that then calls back into Java — and when inside a synchronized block or method. In those cases, blocking the virtual thread will block the physical thread that carries it. Once the native call completes or the monitor released (the synchronized block/method is exited) the thread is unpinned.

If you have a common I/O operation guarded by a synchronized, replace the monitor with a ReentrantLock to let your application benefit fully from Loom’s scalability boost even before we fix pinning by monitors (or, better yet, use the higher-performance StampedLock if you can).

Using CSS in Laravel views?

put your css File in public folder . (public/css/bootstrap-responsive.css) and <link href="./css/bootstrap-responsive.css" rel="stylesheet">

MySQL date format DD/MM/YYYY select query?

You can use STR_TO_DATE() to convert your strings to MySQL date values and ORDER BY the result:

ORDER BY STR_TO_DATE(datestring, '%d/%m/%Y')

However, you would be wise to convert the column to the DATE data type instead of using strings.

Sort a list of lists with a custom compare function

You need to slightly modify your compare function and use functools.cmp_to_key to pass it to sorted. Example code:

import functools

lst = [list(range(i, i+5)) for i in range(5, 1, -1)]

def fitness(item):
    return item[0]+item[1]+item[2]+item[3]+item[4]
def compare(item1, item2):
    return fitness(item1) - fitness(item2)

sorted(lst, key=functools.cmp_to_key(compare))

Output:

[[2, 3, 4, 5, 6], [3, 4, 5, 6, 7], [4, 5, 6, 7, 8], [5, 6, 7, 8, 9]]

Works :)

How do I get the last character of a string?

Here is a method using String.charAt():

String str = "India";
System.out.println("last char = " + str.charAt(str.length() - 1));

The resulting output is last char = a.

How to compare the contents of two string objects in PowerShell

You want to do $arrayOfString[0].Title -eq $myPbiject.item(0).Title

-match is for regex matching ( the second argument is a regex )

Java - Change int to ascii

There are many ways to convert an int to ASCII (depending on your needs) but here is a way to convert each integer byte to an ASCII character:

private static String toASCII(int value) {
    int length = 4;
    StringBuilder builder = new StringBuilder(length);
    for (int i = length - 1; i >= 0; i--) {
        builder.append((char) ((value >> (8 * i)) & 0xFF));
    }
    return builder.toString();
}

For example, the ASCII text for "TEST" can be represented as the byte array:

byte[] test = new byte[] { (byte) 0x54, (byte) 0x45, (byte) 0x53, (byte) 0x54 };

Then you could do the following:

int value = ByteBuffer.wrap(test).getInt(); // 1413829460
System.out.println(toASCII(value)); // outputs "TEST"

...so this essentially converts the 4 bytes in a 32-bit integer to 4 separate ASCII characters (one character per byte).

What's the difference between `raw_input()` and `input()` in Python 3?

Python 2:

  • raw_input() takes exactly what the user typed and passes it back as a string.

  • input() first takes the raw_input() and then performs an eval() on it as well.

The main difference is that input() expects a syntactically correct python statement where raw_input() does not.

Python 3:

  • raw_input() was renamed to input() so now input() returns the exact string.
  • Old input() was removed.

If you want to use the old input(), meaning you need to evaluate a user input as a python statement, you have to do it manually by using eval(input()).

HttpContext.Current.Request.Url.Host what it returns?

Yes, as long as the url you type into the browser www.someshopping.com and you aren't using url rewriting then

string currentURL = HttpContext.Current.Request.Url.Host;

will return www.someshopping.com

Note the difference between a local debugging environment and a production environment

How much data can a List can hold at the maximum?

The interface however defines the size() method, which returns an int.

Returns the number of elements in this list. If this list contains more than Integer.MAX_VALUE elements, returns Integer.MAX_VALUE.

So, no limit, but after you reach Integer.MAX_VALUE, the behaviour of the list changes a bit

ArrayList (which is tagged) is backed by an array, and is limited to the size of the array - i.e. Integer.MAX_VALUE

Truncate (not round off) decimal numbers in javascript

Here is an ES6 code which does what you want

_x000D_
_x000D_
const truncateTo = (unRouned, nrOfDecimals = 2) => {_x000D_
      const parts = String(unRouned).split(".");_x000D_
_x000D_
      if (parts.length !== 2) {_x000D_
          // without any decimal part_x000D_
        return unRouned;_x000D_
      }_x000D_
_x000D_
      const newDecimals = parts[1].slice(0, nrOfDecimals),_x000D_
        newString = `${parts[0]}.${newDecimals}`;_x000D_
_x000D_
      return Number(newString);_x000D_
    };_x000D_
_x000D_
// your examples _x000D_
_x000D_
 console.log(truncateTo(5.467)); // ---> 5.46_x000D_
_x000D_
 console.log(truncateTo(985.943)); // ---> 985.94_x000D_
_x000D_
// other examples _x000D_
_x000D_
 console.log(truncateTo(5)); // ---> 5_x000D_
_x000D_
 console.log(truncateTo(-5)); // ---> -5_x000D_
_x000D_
 console.log(truncateTo(-985.943)); // ---> -985.94
_x000D_
_x000D_
_x000D_

I want to delete all bin and obj folders to force all projects to rebuild everything

Is 'clean' not good enough? Note that you can call msbuild with /t:clean from the command-line.

How to print a string multiple times?

For example if you want to repeat a word called "HELP" for 1000 times the following is the best way.

word = ['HELP']
repeat = 1000 * word

Then you will get the list of 1000 words and make that into a data frame if you want by using following command

word_data =pd.DataFrame(repeat)
word_data.columns = ['list_of_words'] #To change the column name 

How can I export Excel files using JavaScript?

To answer your question with a working example:

<script type="text/javascript">
function DownloadJSON2CSV(objArray)
{
    var array = typeof objArray != 'object' ? JSON.parse(objArray) : objArray;

    var str = '';

    for (var i = 0; i < array.length; i++) {
        var line = new Array();

        for (var index in array[i]) {
           line.push('"' + array[i][index] + '"');
        }

        str += line.join(';');
        str += '\r\n';
    }
    window.open( "data:text/csv;charset=utf-8," + encodeURIComponent(str));
}
</script>

How to get the PYTHONPATH in shell?

Just write:

just write which python in your terminal and you will see the python path you are using.

ImportError: No module named six

If pip "says" six is installed but you're still getting:

ImportError: No module named six.moves

try re-installing six (worked for me):

pip uninstall six
pip install six

Android: How to handle right to left swipe gestures

I know its a bit late since 2012 but I hope it will help someone since I think it's a shorter and cleaner code than most of the answers:

view.setOnTouchListener((v, event) -> {
        
int action = MotionEventCompat.getActionMasked(event);

switch(action) {
    case (MotionEvent.ACTION_DOWN) :
        Log.d(DEBUG_TAG,"Action was DOWN");
        return true;

    case (MotionEvent.ACTION_MOVE) :
        Log.d(DEBUG_TAG,"Action was MOVE");
        return true;

    case (MotionEvent.ACTION_UP) :
        Log.d(DEBUG_TAG,"Action was UP");
        return true;

    case (MotionEvent.ACTION_CANCEL) :
        Log.d(DEBUG_TAG,"Action was CANCEL");
        return true;

    case (MotionEvent.ACTION_OUTSIDE) :
        Log.d(DEBUG_TAG,"Movement occurred outside bounds " +
                "of current screen element");
        return true;

    default :
        return super.onTouchEvent(event);
}
    });

of course you can leave only the relevant gestures to you.

src: https://developer.android.com/training/gestures/detector

C# windows application Event: CLR20r3 on application start

Have been fighting this all morning and now have it solved and why it happened. Posting with the hope it helps others

I installed the Krypton.Toolkit which added the tools to the Visual studio toolbox automatically. I then added the tools to the designer, which automatically added the dll to the projrect references, however the toolkit was marked as CopyLocal=false

I built an installer, using all dlls in the release build folder (of course the above dll wasn't there).

Setting copylocal=true, then rebuilding the installer, everything worked fine.

How to convert existing non-empty directory into a Git working directory and push files to a remote repository

This is how I do. I have added explanation to understand what the heck is going on.

Initialize Local Repository

  • first initialize Git with

    git init

  • Add all Files for version control with

    git add .

  • Create a commit with message of your choice

    git commit -m 'AddingBaseCode'

Initialize Remote Repository

  • Create a project on GitHub and copy the URL of your project . as shown below:

    enter image description here

Link Remote repo with Local repo

  • Now use copied URL to link your local repo with remote GitHub repo. When you clone a repository with git clone, it automatically creates a remote connection called origin pointing back to the cloned repository. The command remote is used to manage set of tracked repositories.

    git remote add origin https://github.com/hiteshsahu/Hassium-Word.git

Synchronize

  • Now we need to merge local code with remote code. This step is critical otherwise we won't be able to push code on GitHub. You must call 'git pull' before pushing your code.

    git pull origin master --allow-unrelated-histories

Commit your code

  • Finally push all changes on GitHub

    git push -u origin master

In Python, how do I read the exif data for an image?

You can use the _getexif() protected method of a PIL Image.

import PIL.Image
img = PIL.Image.open('img.jpg')
exif_data = img._getexif()

This should give you a dictionary indexed by EXIF numeric tags. If you want the dictionary indexed by the actual EXIF tag name strings, try something like:

import PIL.ExifTags
exif = {
    PIL.ExifTags.TAGS[k]: v
    for k, v in img._getexif().items()
    if k in PIL.ExifTags.TAGS
}

The type or namespace name does not exist in the namespace 'System.Web.Mvc'

View and check the reference paths in your csproj.

I had removed references to System.Web.Mvc (and others) and readded them to a custom path. C:\Project\OurWebReferences

However, after doing this, the reference path in the still csproj did not change. WAS

<Reference Include="System.Web.Mvc, Version=4.0.0.1, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">
  <SpecificVersion>False</SpecificVersion>
  <HintPath>..\..\..\..\OurWebProject\bin\Debug\System.Web.Mvc.dll</HintPath>
</Reference>

Changed to manually

<Reference Include="System.Web.Mvc, Version=4.0.0.1, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">
  <SpecificVersion>False</SpecificVersion>
        <HintPath>..\..\..\..\OurWebReferences\System.Web.Mvc.dll</HintPath>
</Reference>

Paths are an example only.

Is there an arraylist in Javascript?

Arrays are pretty flexible in JS, you can do:

var myArray = new Array();
myArray.push("string 1");
myArray.push("string 2");

How to set custom header in Volley Request

You can see this solution. It shows how to get/set cookies, but cookies are just one of the headers in a request/response. You have to override one of the Volley's *Request classes and set the required headers in getHeaders()


Here is the linked source:

public class StringRequest extends com.android.volley.toolbox.StringRequest {

private final Map<String, String> _params;

/**
 * @param method
 * @param url
 * @param params
 *            A {@link HashMap} to post with the request. Null is allowed
 *            and indicates no parameters will be posted along with request.
 * @param listener
 * @param errorListener
 */
public StringRequest(int method, String url, Map<String, String> params, Listener<String> listener,
        ErrorListener errorListener) {
    super(method, url, listener, errorListener);

    _params = params;
}

@Override
protected Map<String, String> getParams() {
    return _params;
}

/* (non-Javadoc)
 * @see com.android.volley.toolbox.StringRequest#parseNetworkResponse(com.android.volley.NetworkResponse)
 */
@Override
protected Response<String> parseNetworkResponse(NetworkResponse response) {
    // since we don't know which of the two underlying network vehicles
    // will Volley use, we have to handle and store session cookies manually
    MyApp.get().checkSessionCookie(response.headers);

    return super.parseNetworkResponse(response);
}

/* (non-Javadoc)
 * @see com.android.volley.Request#getHeaders()
 */
@Override
public Map<String, String> getHeaders() throws AuthFailureError {
    Map<String, String> headers = super.getHeaders();

    if (headers == null
            || headers.equals(Collections.emptyMap())) {
        headers = new HashMap<String, String>();
    }

    MyApp.get().addSessionCookie(headers);

    return headers;
}

}

And MyApp class:

public class MyApp extends Application {
    private static final String SET_COOKIE_KEY = "Set-Cookie";
    private static final String COOKIE_KEY = "Cookie";
    private static final String SESSION_COOKIE = "sessionid";

    private static MyApp _instance;
    private RequestQueue _requestQueue;
    private SharedPreferences _preferences;

    public static MyApp get() {
        return _instance;
    }

    @Override
    public void onCreate() {
        super.onCreate();
        _instance = this;
            _preferences = PreferenceManager.getDefaultSharedPreferences(this);
        _requestQueue = Volley.newRequestQueue(this);
    }

    public RequestQueue getRequestQueue() {
        return _requestQueue;
    }


    /**
     * Checks the response headers for session cookie and saves it
     * if it finds it.
     * @param headers Response Headers.
     */
    public final void checkSessionCookie(Map<String, String> headers) {
        if (headers.containsKey(SET_COOKIE_KEY)
                && headers.get(SET_COOKIE_KEY).startsWith(SESSION_COOKIE)) {
                String cookie = headers.get(SET_COOKIE_KEY);
                if (cookie.length() > 0) {
                    String[] splitCookie = cookie.split(";");
                    String[] splitSessionId = splitCookie[0].split("=");
                    cookie = splitSessionId[1];
                    Editor prefEditor = _preferences.edit();
                    prefEditor.putString(SESSION_COOKIE, cookie);
                    prefEditor.commit();
                }
            }
    }

    /**
     * Adds session cookie to headers if exists.
     * @param headers
     */
    public final void addSessionCookie(Map<String, String> headers) {
        String sessionId = _preferences.getString(SESSION_COOKIE, "");
        if (sessionId.length() > 0) {
            StringBuilder builder = new StringBuilder();
            builder.append(SESSION_COOKIE);
            builder.append("=");
            builder.append(sessionId);
            if (headers.containsKey(COOKIE_KEY)) {
                builder.append("; ");
                builder.append(headers.get(COOKIE_KEY));
            }
            headers.put(COOKIE_KEY, builder.toString());
        }
    }

}

Drop primary key using script in SQL Server database

You can look up the constraint name in the sys.key_constraints table:

SELECT name
FROM   sys.key_constraints
WHERE  [type] = 'PK'
       AND [parent_object_id] = Object_id('dbo.Student');

If you don't care about the name, but simply want to drop it, you can use a combination of this and dynamic sql:

DECLARE @table NVARCHAR(512), @sql NVARCHAR(MAX);

SELECT @table = N'dbo.Student';

SELECT @sql = 'ALTER TABLE ' + @table 
    + ' DROP CONSTRAINT ' + name + ';'
    FROM sys.key_constraints
    WHERE [type] = 'PK'
    AND [parent_object_id] = OBJECT_ID(@table);

EXEC sp_executeSQL @sql;

This code is from Aaron Bertrand (source).

What is the iPhone 4 user-agent?

This site seems to keep a complete list that's still maintained

iPhone, iPod Touch, and iPad from iOS 2.0 - 5.1.1 (to date).

You do need to assemble the full user-agent string out of the information listed in the page's columns.

Check if a Bash array contains a value

Borrowing from Dennis Williamson's answer, the following solution combines arrays, shell-safe quoting, and regular expressions to avoid the need for: iterating over loops; using pipes or other sub-processes; or using non-bash utilities.

declare -a array=('hello, stack' one 'two words' words last)
printf -v array_str -- ',,%q' "${array[@]}"

if [[ "${array_str},," =~ ,,words,, ]]
then
   echo 'Matches'
else
   echo "Doesn't match"
fi

The above code works by using Bash regular expressions to match against a stringified version of the array contents. There are six important steps to ensure that the regular expression match can't be fooled by clever combinations of values within the array:

  1. Construct the comparison string by using Bash's built-in printf shell-quoting, %q. Shell-quoting will ensure that special characters become "shell-safe" by being escaped with backslash \.
  2. Choose a special character to serve as a value delimiter. The delimiter HAS to be one of the special characters that will become escaped when using %q; that's the only way to guarantee that values within the array can't be constructed in clever ways to fool the regular expression match. I choose comma , because that character is the safest when eval'd or misused in an otherwise unexpected way.
  3. Combine all array elements into a single string, using two instances of the special character to serve as delimiter. Using comma as an example, I used ,,%q as the argument to printf. This is important because two instances of the special character can only appear next to each other when they appear as the delimiter; all other instances of the special character will be escaped.
  4. Append two trailing instances of the delimiter to the string, to allow matches against the last element of the array. Thus, instead of comparing against ${array_str}, compare against ${array_str},,.
  5. If the target string you're searching for is supplied by a user variable, you must escape all instances of the special character with a backslash. Otherwise, the regular expression match becomes vulnerable to being fooled by cleverly-crafted array elements.
  6. Perform a Bash regular expression match against the string.

what is the most efficient way of counting occurrences in pandas?

When you want to count the frequency of categorical data in a column in pandas dataFrame use: df['Column_Name'].value_counts()

-Source.

JUnit: how to avoid "no runnable methods" in test utils classes

What about adding an empty test method to these classes?

public void avoidAnnoyingErrorMessageWhenRunningTestsInAnt() {
    assertTrue(true); // do nothing;
}

How different is Objective-C from C++?

As others have said, Objective-C is much more dynamic in terms of how it thinks of objects vs. C++'s fairly static realm.

Objective-C, being in the Smalltalk lineage of object-oriented languages, has a concept of objects that is very similar to that of Java, Python, and other "standard", non-C++ object-oriented languages. Lots of dynamic dispatch, no operator overloading, send messages around.

C++ is its own weird animal; it mostly skipped the Smalltalk portion of the family tree. In some ways, it has a good module system with support for inheritance that happens to be able to be used for object-oriented programming. Things are much more static (overridable methods are not the default, for example).

VS 2017 Metadata file '.dll could not be found

In my case I run the tests and got error CS0006. It turned out that I run tests in Release mode. Switch to Debug mode fixed this error.

Textfield with only bottom border

Probably a duplicate of this post: A customized input text box in html/html5

_x000D_
_x000D_
input {_x000D_
  border: 0;_x000D_
  outline: 0;_x000D_
  background: transparent;_x000D_
  border-bottom: 1px solid black;_x000D_
}
_x000D_
<input></input>
_x000D_
_x000D_
_x000D_

How to search for a string in cell array in MATLAB?

I see that everybody missed the most important flaw in your code:

strs = {'HA' 'KU' 'LA' 'MA' 'TATA'}

should be:

strs = {'HA' 'KU' 'NA' 'MA' 'TATA'} 

or

strs = {'HAKUNA' 'MATATA'}

Now if you stick to using

ind=find(ismember(strs,'KU'))

You'll have no worries :).

How to create an Array, ArrayList, Stack and Queue in Java?

Without more details as to what the question is exactly asking, I am going to answer the title of the question,

Create an Array:

String[] myArray = new String[2];
int[] intArray = new int[2];

// or can be declared as follows
String[] myArray = {"this", "is", "my", "array"};
int[] intArray = {1,2,3,4};

Create an ArrayList:

ArrayList<String> myList = new ArrayList<String>();
myList.add("Hello");
myList.add("World");

ArrayList<Integer> myNum = new ArrayList<Integer>();
myNum.add(1);
myNum.add(2);

This means, create an ArrayList of String and Integer objects. You cannot use int because thats a primitive data types, see the link for a list of primitive data types.

Create a Stack:

Stack myStack = new Stack();
// add any type of elements (String, int, etc..)
myStack.push("Hello");
myStack.push(1);

Create an Queue: (using LinkedList)

Queue<String> myQueue = new LinkedList<String>();
Queue<Integer> myNumbers = new LinkedList<Integer>();
myQueue.add("Hello");
myQueue.add("World");
myNumbers.add(1);
myNumbers.add(2);

Same thing as an ArrayList, this declaration means create an Queue of String and Integer objects.


Update:

In response to your comment from the other given answer,

i am pretty confused now, why are using string. and what does <String> means

We are using String only as a pure example, but you can add any other object, but the main point is that you use an object not a primitive type. Each primitive data type has their own primitive wrapper class, see link for list of primitive data type's wrapper class.

I have posted some links to explain the difference between the two, but here are a list of primitive types

  • byte
  • short
  • char
  • int
  • long
  • boolean
  • double
  • float

Which means, you are not allowed to make an ArrayList of integer's like so:

ArrayList<int> numbers = new ArrayList<int>(); 
           ^ should be an object, int is not an object, but Integer is!
ArrayList<Integer> numbers = new ArrayList<Integer>();
            ^ perfectly valid

Also, you can use your own objects, here is my Monster object I created,

public class Monster {
   String name = null;
   String location = null;
   int age = 0;

public Monster(String name, String loc, int age) { 
   this.name = name;
   this.loc = location;
   this.age = age;
 }

public void printDetails() {
   System.out.println(name + " is from " + location +
                                     " and is " + age + " old.");
 }
} 

Here we have a Monster object, but now in our Main.java class we want to keep a record of all our Monster's that we create, so let's add them to an ArrayList

public class Main {
    ArrayList<Monster> myMonsters = new ArrayList<Monster>();

public Main() {
    Monster yetti = new Monster("Yetti", "The Mountains", 77);
    Monster lochness = new Monster("Lochness Monster", "Scotland", 20);

    myMonsters.add(yetti); // <-- added Yetti to our list
    myMonsters.add(lochness); // <--added Lochness to our list
  
    for (Monster m : myMonsters) {
        m.printDetails();
     }
   }

public static void main(String[] args) {
    new Main();
 }
}

(I helped my girlfriend's brother with a Java game, and he had to do something along those lines as well, but I hope the example was well demonstrated)

Close application and launch home screen on Android

You are wrong. There is one way to kill an application. In a class with super class Application, we use some field, for example, killApp. When we start the splash screen (first activity) in onResume(), we set a parameter for false for field killApp. In every activity which we have when onResume() is called in the end, we call something like that:

if(AppClass.killApp())
    finish();

Every activity which is getting to the screen have to call onResume(). When it is called, we have to check if our field killApp is true. If it is true, current activities call finish(). To invoke the full action, we use the next construction. For example, in the action for a button:

AppClass.setkillApplication(true);
   finish();
   return;

How to loop through an associative array and get the key?

 foreach($arr as $key=>$value){
    echo($key);    // key
 }

Google Drive as FTP Server

What about running the google-drive-ftp-adapter application in your local pc and then connect your filezilla client to that application? The google-drive-ftp-adapter application is not an online service, but its an alternative solution to connect to google drive through ftp.

The google-drive-ftp-adapter is an open source application hosted in github and it is a kind of standalone ftp-server java application that connects to your google drive in behalf of you, acting as a bridge (or adapter) between your ftp client and the google drive service. Once you have running the google-drive-ftp adapter, you can connect your preferred FTP client to the google-drive-ftp-adapter ftp server in your localhost (or wherever the app is running, like in a remote machine) to manage your files.

I use it in conjunction with beyond compare to synchronize my local files against the ones I have in the google drive and it serves well for the purpose.

This is the current github link hosting the google-drive-ftp-adapter repository: https://github.com/andresoviedo/google-drive-ftp-adapter

How to access array elements in a Django template?

when you render a request tou coctext some information: for exampel:

return render(request, 'path to template',{'username' :username , 'email'.email})

you can acces to it on template like this : for variabels :

{% if username %}{{ username }}{% endif %}

for array :

{% if username %}{{ username.1 }}{% endif %}
{% if username %}{{ username.2 }}{% endif %}

you can also name array objects in views.py and ten use it like:

{% if username %}{{ username.first }}{% endif %}

if there is other problem i wish to help you

Joining three tables using MySQL

Just adding a point to previous answers that in MySQL we can either use

table_factor syntax 

OR

joined_table syntax

mysql documentation

Table_factor example

SELECT prd.name, b.name 
FROM products prd, buyers b

Joined Table example

SELECT prd.name, b.name 
FROM products prd
 left join buyers b on b.bid = prd.bid;

FYI: Please ignore the fact the the left join on the joined table example doesnot make much sense (in reality we would use some sort of join table to link buyer to the product table instead of saving buyerID in product table).

How do you add a JToken to an JObject?

Just adding .First to your bananaToken should do it:
foodJsonObj["food"]["fruit"]["orange"].Parent.AddAfterSelf(bananaToken .First);
.First basically moves past the { to make it a JProperty instead of a JToken.

@Brian Rogers, Thanks I forgot the .Parent. Edited

How to install Python packages from the tar.gz file without using pip install

Thanks to the answers below combined I've got it working.

  • First needed to unpack the tar.gz file into a folder.
  • Then before running python setup.py install had to point cmd towards the correct folder. I did this by pushd C:\Users\absolutefilepathtotarunpackedfolder
  • Then run python setup.py install

Thanks Tales Padua & Hugo Honorem

How to force div to appear below not next to another?

Float the #list and #similar the right and add clear: right; to #similar

Like so:

#map { float:left; width:700px; height:500px; }
#list { float:right; width:200px; background:#eee; list-style:none; padding:0; }
#similar { float:right; width:200px; background:#000; clear:right; } 


<div id="map"></div>        
<ul id="list"></ul>
<div id="similar">this text should be below, not next to ul.</div>

You might need a wrapper(div) around all of them though that's the same width of the left and right element.

Convert double to string

Try c.ToString("F6");

(For a full explanation of numeric formatting, see MSDN)

What does the question mark in Java generics' type parameter mean?

Perhaps a contrived "real world" example would help.

At my place of work we have rubbish bins that come in different flavours. All bins contain rubbish, but some bins are specialist and do not take all types of rubbish. So we have Bin<CupRubbish> and Bin<RecylcableRubbish>. The type system needs to make sure I can't put my HalfEatenSandwichRubbish into either of these types, but it can go into a general rubbish bin Bin<Rubbish>. If I wanted to talk about a Bin of Rubbish which may be specialised so I can't put in incompatible rubbish, then that would be Bin<? extends Rubbish>.

(Note: ? extends does not mean read-only. For instance, I can with proper precautions take out a piece of rubbish from a bin of unknown speciality and later put it back in a different place.)

Not sure how much that helps. Pointer-to-pointer in presence of polymorphism isn't entirely obvious.

MySQL query to select events between start/end date

In PHP and phpMyAdmin

$tb = tableDataName; //Table name
$now = date('Y-m-d'); //Current date

//start and end is the fields of tabla with date format value (yyyy-m-d)

$query = "SELECT * FROM $tb WHERE start <= '".$now."' AND end >= '".$now."'";

How to check if ZooKeeper is running or up from command prompt?

I did some test:

When it's running:

$ /usr/lib/zookeeper/bin/zkServer.sh status
JMX enabled by default
Using config: /usr/lib/zookeeper/bin/../conf/zoo.cfg
Mode: follower

When it's stopped:

$ zkServer status                                                                                                                                
JMX enabled by default
Using config: /usr/local/etc/zookeeper/zoo.cfg
Error contacting service. It is probably not running.

I'm not running on the same machine, but you get the idea.

Entity Framework - Code First - Can't Store List<String>

This answer is based on the ones provided by @Sasan and @CAD bloke.

If you wish to use this in .NET Standard 2 or don't want Newtonsoft, see Xaniff's answer below

Works only with EF Core 2.1+ (not .NET Standard compatible)(Newtonsoft JsonConvert)

builder.Entity<YourEntity>().Property(p => p.Strings)
    .HasConversion(
        v => JsonConvert.SerializeObject(v),
        v => JsonConvert.DeserializeObject<List<string>>(v));

Using the EF Core fluent configuration we serialize/deserialize the List to/from JSON.

Why this code is the perfect mix of everything you could strive for:

  • The problem with Sasn's original answer is that it will turn into a big mess if the strings in the list contains commas (or any character chosen as the delimiter) because it will turn a single entry into multiple entries but it is the easiest to read and most concise.
  • The problem with CAD bloke's answer is that it is ugly and requires the model to be altered which is a bad design practice (see Marcell Toth's comment on Sasan's answer). But it is the only answer that is data-safe.

Converting String array to java.util.List

import java.util.Collections;

List myList = new ArrayList();
String[] myArray = new String[] {"Java", "Util", "List"};

Collections.addAll(myList, myArray);

How to pass a view's onClick event to its parent on Android?

If your TextView create click issues, than remove android:inputType="" from your xml file.

How can I remove file extension from a website address?

Actually, the simplest way to manipulate this is to

  1. Open a new folder on your server, e.g. "Data"
  2. Put index.php (or index.html) in it

And then the URL www.yoursite.com/data will read that index.php file. If you want to take it further, open a subfolder (e.g. "List") in it, put another index.php in that folder and you can have www.yoursite.com/data/list run that PHP file.

This way you can have full control over this, very useful for SEO.

Explode string by one or more spaces or tabs

@OP it doesn't matter, you can just split on a space with explode. Until you want to use those values, iterate over the exploded values and discard blanks.

$str = "A      B      C      D";
$s = explode(" ",$str);
foreach ($s as $a=>$b){    
    if ( trim($b) ) {
     print "using $b\n";
    }
}

Change DIV content using ajax, php and jQuery

You could achieve this quite easily with jQuery by registering for the click event of the anchors (with class="movie") and using the .load() method to send an AJAX request and replace the contents of the summary div:

$(function() {
    $('.movie').click(function() {
        $('#summary').load(this.href);

        // it's important to return false from the click
        // handler in order to cancel the default action
        // of the link which is to redirect to the url and
        // execute the AJAX request
        return false;
    });
});

Is it possible to change the location of packages for NuGet?

One more little tidbit that I just discovered. (This may be so basic that some haven't mentioned it, but it was important for my solution.) The "packages" folder ends up in the same folder as your .sln file.

We moved our .sln file and then fixed all of the paths inside to find the various projects and voila! Our packages folder ended up where we wanted it.

How to undo "git commit --amend" done instead of "git commit"

None of these answers with the use of HEAD@{1} worked out for me, so here's my solution:

git reflog

d0c9f22 HEAD@{0}: commit (amend): [Feature] - ABC Commit Description 
c296452 HEAD@{1}: commit: [Feature] - ABC Commit Description 

git reset --soft c296452

Your staging environment will now contain all of the changes that you accidentally merged with the c296452 commit.

SQL Server Insert Example

I hope this will help you

Create table :

create table users (id int,first_name varchar(10),last_name varchar(10));

Insert values into the table :

insert into users (id,first_name,last_name) values(1,'Abhishek','Anand');

null check in jsf expression language

Use empty (it checks both nullness and emptiness) and group the nested ternary expression by parentheses (EL is in certain implementations/versions namely somewhat problematic with nested ternary expressions). Thus, so:

styleClass="#{empty obj.validationErrorMap ? ' ' :  
 (obj.validationErrorMap.contains('key') ? 'highlight_field' : 'highlight_row')}"

If still in vain (I would then check JBoss EL configs), use the "normal" EL approach:

styleClass="#{empty obj.validationErrorMap ? ' ' :  
 (obj.validationErrorMap['key'] ne null ? 'highlight_field' : 'highlight_row')}"

Update: as per the comments, the Map turns out to actually be a List (please work on your naming conventions). To check if a List contains an item the "normal" EL way, use JSTL fn:contains (although not explicitly documented, it works for List as well).

styleClass="#{empty obj.validationErrorMap ? ' ' :  
 (fn:contains(obj.validationErrorMap, 'key') ? 'highlight_field' : 'highlight_row')}"

Post a json object to mvc controller with jquery and ajax

instead of receiving the json string a model binding is better. For example:

[HttpPost]       
public ActionResult AddUser(UserAddModel model)
{
    if (ModelState.IsValid) {
        return Json(new { Response = "Success" });
    }
    return Json(new { Response = "Error" });
}

<script>
function submitForm() {    
    $.ajax({
        type: 'POST',
        url: "@Url.Action("AddUser")",
        contentType: "application/json; charset=utf-8",
        dataType: 'json',
        data: $("form[name=UserAddForm]").serialize(),
        success: function (data) {
            console.log(data);
        }
    });
}
</script>

Multiple separate IF conditions in SQL Server

IF you are checking one variable against multiple condition then you would use something like this Here the block of code where the condition is true will be executed and other blocks will be ignored.

IF(@Var1 Condition1)
     BEGIN
      /*Your Code Goes here*/
     END

ELSE IF(@Var1 Condition2)
      BEGIN
        /*Your Code Goes here*/ 
      END 

    ELSE      --<--- Default Task if none of the above is true
     BEGIN
       /*Your Code Goes here*/
     END

If you are checking conditions against multiple variables then you would have to go for multiple IF Statements, Each block of code will be executed independently from other blocks.

IF(@Var1 Condition1)
 BEGIN
   /*Your Code Goes here*/
 END


IF(@Var2 Condition1)
 BEGIN
   /*Your Code Goes here*/
 END


IF(@Var3 Condition1)
 BEGIN
   /*Your Code Goes here*/
 END

After every IF statement if there are more than one statement being executed you MUST put them in BEGIN..END Block. Anyway it is always best practice to use BEGIN..END blocks

Update

Found something in your code some BEGIN END you are missing

ELSE IF(@ID IS NOT NULL AND @ID in (SELECT ID FROM Places))   -- Outer Most Block ELSE IF
BEGIN   
     SELECT @MyName = Name ...  
    ...Some stuff....                       
    IF(SOMETHNG_1)         -- IF
                 --BEGIN
        BEGIN TRY               
            UPDATE ....                                                                 
        END TRY

        BEGIN CATCH
            SELECT ERROR_MESSAGE() AS 'Message' 
            RETURN -1
        END CATCH
                -- END
    ELSE IF(SOMETHNG_2)    -- ELSE IF
                 -- BEGIN
        BEGIN TRY
            UPDATE ...                                                      
        END TRY
        BEGIN CATCH
            SELECT ERROR_MESSAGE() AS 'Message' 
            RETURN -1
        END CATCH   
               -- END
    ELSE                  -- ELSE
        BEGIN
            BEGIN TRY
                UPDATE ...                                                              
            END TRY
            BEGIN CATCH
                SELECT ERROR_MESSAGE() AS 'Message' 
                RETURN -1
            END CATCH   
         END             
      --The above works I then insert this below and these if statement become nested----
          IF(@A!= @SA)
            BEGIN
             exec Store procedure 
                    @FIELD = 15,
                    ... more params...
            END                 
        IF(@S!= @SS)
          BEGIN
             exec Store procedure 
                    @FIELD = 10,
                    ... more params...

C# DLL config file

I've found what seems like a good solution to this issue. I am using VS 2008 C#. My solution involves the use of distinct namespaces between multiple configuration files. I've posted the solution on my blog: http://tommiecarter.blogspot.com/2011/02/how-to-access-multiple-config-files-in.html.

For example:

This namespace read/writes dll settings:

var x = company.dlllibrary.Properties.Settings.Default.SettingName;
company.dlllibrary.Properties.Settings.Default.SettingName = value;

This namespace read/writes the exe settings:

company.exeservice.Properties.Settings.Default.SettingName = value;
var x = company.exeservice.Properties.Settings.Default.SettingName;

There are some caveats mentioned in the article. HTH

fastest way to export blobs from table into individual files

I tried using a CLR function and it was more than twice as fast as BCP. Here's my code.

Original Method:

SET @bcpCommand = 'bcp "SELECT blobcolumn FROM blobtable WHERE ID = ' + CAST(@FileID AS VARCHAR(20)) + '" queryout "' + @FileName + '" -T -c'
EXEC master..xp_cmdshell @bcpCommand

CLR Method:

declare @file varbinary(max) = (select blobcolumn from blobtable WHERE ID = @fileid)
declare @filepath nvarchar(4000) = N'c:\temp\' + @FileName
SELECT Master.dbo.WriteToFile(@file, @filepath, 0)

C# Code for the CLR function

using System;
using System.Data;
using System.Data.SqlTypes;
using System.IO;
using Microsoft.SqlServer.Server;

namespace BlobExport
{
    public class Functions
    {
      [SqlFunction]
      public static SqlString WriteToFile(SqlBytes binary, SqlString path, SqlBoolean append)
      {        
        try
        {
          if (!binary.IsNull && !path.IsNull && !append.IsNull)
          {         
            var dir = Path.GetDirectoryName(path.Value);           
            if (!Directory.Exists(dir))              
              Directory.CreateDirectory(dir);            
              using (var fs = new FileStream(path.Value, append ? FileMode.Append : FileMode.OpenOrCreate))
            {
                byte[] byteArr = binary.Value;
                for (int i = 0; i < byteArr.Length; i++)
                {
                    fs.WriteByte(byteArr[i]);
                };
            }
            return "SUCCESS";
          }
          else
             "NULL INPUT";
        }
        catch (Exception ex)
        {          
          return ex.Message;
        }
      }
    }
}

How to add a bot to a Telegram Group?

You have to use @BotFather, send it command: /setjoingroups There will be dialog like this:

YOU: /setjoingroups

BotFather: Choose a bot to change group membership settings.

YOU: @YourBot

BotFather: 'Enable' - bot can be added to groups. 'Disable' - block group invitations, the bot can't be added to groups. Current status is: DISABLED

YOU: Enable

BotFather: Success! The new status is: ENABLED.

After this you will see button "Add to Group" in your bot's profile.

How to undo a git pull?

This worked for me.

git reset --hard ORIG_HEAD 

Undo a merge or pull:

$ git pull                         (1)
Auto-merging nitfol
CONFLICT (content): Merge conflict in nitfol
Automatic merge failed; fix conflicts and then commit the result.
$ git reset --hard                 (2)
$ git pull . topic/branch          (3)
Updating from 41223... to 13134...
Fast-forward
$ git reset --hard ORIG_HEAD       (4)

Checkout this: HEAD and ORIG_HEAD in Git for more.

Double precision floating values in Python?

Decimal datatype

  • Unlike hardware based binary floating point, the decimal module has a user alterable precision (defaulting to 28 places) which can be as large as needed for a given problem.

If you are pressed by performance issuses, have a look at GMPY

password-check directive in angularjs

Something like this works for me:

js:

.directive('sameAs', function() { return {
    require : 'ngModel',
    link : function(scope, elm, attrs, ngModelCtrl) {

        ngModelCtrl.$validators.sameAs = function(modelValue, viewValue) {
            var checkedVal = attrs.sameAs;
            var thisInputVal = viewValue;

            if (thisInputVal == checkedVal) {
                return true; // valid
            } else {
                return false;
            }
        };
    }
}; });

html:

<input type="password" name="password" id="password" ng-model="password" />

<input type="password" name="passwordRepeat" id="passwordRepeat" 
    ng-model="passwordRepeat" same-as="{{password}}" />

Fixing a systemd service 203/EXEC failure (no such file or directory)

If that is a copy/paste from your script, you've permuted this line:

#!/usr/env/bin bash

There's no #!/usr/env/bin, you meant #!/usr/bin/env.

Convert a string to integer with decimal in Python

"Convert" only makes sense when you change from one data type to another without loss of fidelity. The number represented by the string is a float and will lose precision upon being forced into an int.

You want to round instead, probably (I hope that the numbers don't represent currency because then rounding gets a whole lot more complicated).

round(float('23.45678'))

What order are the Junit @Before/@After called?

I think based on the documentation of the @Before and @After the right conclusion is to give the methods unique names. I use the following pattern in my tests:

public abstract class AbstractBaseTest {

  @Before
  public final void baseSetUp() { // or any other meaningful name
    System.out.println("AbstractBaseTest.setUp");
  }

  @After
  public final void baseTearDown() { // or any other meaningful name
    System.out.println("AbstractBaseTest.tearDown");
  }
}

and

public class Test extends AbstractBaseTest {

  @Before
  public void setUp() {
    System.out.println("Test.setUp");
  }

  @After
  public void tearDown() {
    System.out.println("Test.tearDown");
  }

  @Test
  public void test1() throws Exception {
    System.out.println("test1");
  }

  @Test
  public void test2() throws Exception {
    System.out.println("test2");
  }
}

give as a result

AbstractBaseTest.setUp
Test.setUp
test1
Test.tearDown
AbstractBaseTest.tearDown
AbstractBaseTest.setUp
Test.setUp
test2
Test.tearDown
AbstractBaseTest.tearDown

Advantage of this approach: Users of the AbstractBaseTest class cannot override the setUp/tearDown methods by accident. If they want to, they need to know the exact name and can do it.

(Minor) disadvantage of this approach: Users cannot see that there are things happening before or after their setUp/tearDown. They need to know that these things are provided by the abstract class. But I assume that's the reason why they use the abstract class

How to get the system uptime in Windows?

I use this little PowerShell snippet:

function Get-SystemUptime {
    $operatingSystem = Get-WmiObject Win32_OperatingSystem
    "$((Get-Date) - ([Management.ManagementDateTimeConverter]::ToDateTime($operatingSystem.LastBootUpTime)))"
}

which then yields something like the following:

PS> Get-SystemUptime
6.20:40:40.2625526

Passing a string array as a parameter to a function java

How about:

public class test {
    public static void someFunction(String[] strArray) { 
        // do something 
    }

    public static void main(String[] args) {
        String[] strArray = new String[]{"Foo","Bar","Baz"};
        someFunction(strArray);
    }
}

Create a <ul> and fill it based on a passed array

First of all, don't create HTML elements by string concatenation. Use DOM manipulation. It's faster, cleaner, and less error-prone. This alone solves one of your problems. Then, just let it accept any array as an argument:

var options = [
        set0 = ['Option 1','Option 2'],
        set1 = ['First Option','Second Option','Third Option']
    ];

function makeUL(array) {
    // Create the list element:
    var list = document.createElement('ul');

    for (var i = 0; i < array.length; i++) {
        // Create the list item:
        var item = document.createElement('li');

        // Set its contents:
        item.appendChild(document.createTextNode(array[i]));

        // Add it to the list:
        list.appendChild(item);
    }

    // Finally, return the constructed list:
    return list;
}

// Add the contents of options[0] to #foo:
document.getElementById('foo').appendChild(makeUL(options[0]));

Here's a demo. You might also want to note that set0 and set1 are leaking into the global scope; if you meant to create a sort of associative array, you should use an object:

var options = {
    set0: ['Option 1', 'Option 2'],
    set1: ['First Option', 'Second Option', 'Third Option']
};

And access them like so:

makeUL(options.set0);

Browser: Identifier X has already been declared

Remember that window is the global namespace. These two lines attempt to declare the same variable:

window.APP = { ... }
const APP = window.APP

The second definition is not allowed in strict mode (enabled with 'use strict' at the top of your file).

To fix the problem, simply remove the const APP = declaration. The variable will still be accessible, as it belongs to the global namespace.

How to load a xib file in a UIView

Create a XIB file :

File -> new File ->ios->cocoa touch class -> next

enter image description here

make sure check mark "also create XIB file"

I would like to perform with tableview so I choosed subclass UITableViewCell

you can choose as your requerment

enter image description here

XIB file desing as your wish (RestaurantTableViewCell.xib)

enter image description here

we need to grab the row height to set table each row hegiht

enter image description here

Now! need to huck them swift file . i am hucked the restaurantPhoto and restaurantName you can huck all of you .

enter image description here

Now adding a UITableView

enter image description here

name
The name of the nib file, which need not include the .nib extension.

owner
The object to assign as the nib’s File's Owner object.

options
A dictionary containing the options to use when opening the nib file.

first if you do not define first then grabing all view .. so you need to grab one view inside that set frist .

Bundle.main.loadNibNamed("yourUIView", owner: self, options: nil)?.first as! yourUIView

here is table view controller Full code

import UIKit

class RestaurantTableViewController: UIViewController ,UITableViewDataSource,UITableViewDelegate{

    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
    func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return 5
    }
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let restaurantTableviewCell = Bundle.main.loadNibNamed("RestaurantTableViewCell", owner: self, options: nil)?.first as! RestaurantTableViewCell

        restaurantTableviewCell.restaurantPhoto.image = UIImage(named: "image1")
        restaurantTableviewCell.restaurantName.text = "KFC Chicken"

        return restaurantTableviewCell
    }
   // set row height
    func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
        return 150
    }

}

you done :)

enter image description here

MVC 4 Razor adding input type date

If you want to use @Html.EditorFor() you have to use jQuery ui and update your Asp.net Mvc to 5.2.6.0 with NuGet Package Manager.

@Html.EditorFor(m => m.EntryDate, new { htmlAttributes = new { @class = "datepicker" } })

@section Scripts {

@Scripts.Render("~/bundles/jqueryval")

<script>

    $(document).ready(function(){

      $('.datepicker').datepicker();

     });

</script>

}

How to get Text BOLD in Alert or Confirm box?

The alert() dialog is not rendered in HTML, and thus the HTML you have embedded is meaningless.

You'd need to use a custom modal to achieve that.

Getting a count of objects in a queryset in django

Use related name to count votes for a specific contest

class Item(models.Model):
    name = models.CharField()

class Contest(models.Model);
    name = models.CharField()

class Votes(models.Model):
    user = models.ForeignKey(User)
    item = models.ForeignKey(Item)
    contest = models.ForeignKey(Contest, related_name="contest_votes")
    comment = models.TextField()

>>> comments = Contest.objects.get(id=contest_id).contest_votes.count()

Calling @Html.Partial to display a partial view belonging to a different controller

As GvS said, but I also find it useful to use strongly typed views so that I can write something like

@Html.Partial(MVC.Student.Index(), model)

without magic strings.

Angular ng-if="" with multiple arguments

For people looking to do if statements with multiple 'or' values.

<div ng-if="::(a || b || c || d || e || f)"><div>

Why am I getting "(304) Not Modified" error on some links when using HttpWebRequest?

I think you have not installed these features. see below in picture.

enter image description here

I also suffered from this problem some days ago. After installing this feature then I solved it. If you have not installed this feature then installed it.

Install Process:

  1. go to android studio
  2. Tools
  3. Android
  4. SDK Manager
  5. Appearance & Behavior
  6. Android SDK

Abstract methods in Java

The error message tells the exact reason: "abstract methods cannot have a body".

They can only be defined in abstract classes and interfaces (interface methods are implicitly abstract!) and the idea is, that the subclass implements the method.

Example:

 public abstract class AbstractGreeter {
   public abstract String getHelloMessage();

   public void sayHello() {
     System.out.println(getHelloMessage());
   }
 }

 public class FrenchGreeter extends AbstractGreeter{

   // we must implement the abstract method
   @Override
   public String getHelloMessage() {
     return "bonjour";
   }
 }

How to enable authentication on MongoDB through Docker?

If you take a look at:

you will notice that there are two variables used in the docker-entrypoint.sh:

  • MONGO_INITDB_ROOT_USERNAME
  • MONGO_INITDB_ROOT_PASSWORD

You can use them to setup root user. For example you can use following docker-compose.yml file:

mongo-container:
  image: mongo:3.4.2
  environment:
      # provide your credentials here
      - MONGO_INITDB_ROOT_USERNAME=root
      - MONGO_INITDB_ROOT_PASSWORD=rootPassXXX
  ports:
    - "27017:27017"
  volumes:
      # if you wish to setup additional user accounts specific per DB or with different roles you can use following entry point
    - "$PWD/mongo-entrypoint/:/docker-entrypoint-initdb.d/"
  # no --auth is needed here as presence of username and password add this option automatically
  command: mongod

Now when starting the container by docker-compose up you should notice following entries:

...
I CONTROL  [initandlisten] options: { net: { bindIp: "127.0.0.1" }, processManagement: { fork: true }, security: { authorization: "enabled" }, systemLog: { destination: "file", path: "/proc/1/fd/1" } }
...
I ACCESS   [conn1] note: no users configured in admin.system.users, allowing localhost access
...
Successfully added user: {
    "user" : "root",
    "roles" : [
        {
            "role" : "root",
            "db" : "admin"
        }
    ]
}

To add custom users apart of root use the entrypoint exectuable script (placed under $PWD/mongo-entrypoint dir as it is mounted in docker-compose to entrypoint):

#!/usr/bin/env bash
echo "Creating mongo users..."
mongo admin --host localhost -u USER_PREVIOUSLY_DEFINED -p PASS_YOU_PREVIOUSLY_DEFINED --eval "db.createUser({user: 'ANOTHER_USER', pwd: 'PASS', roles: [{role: 'readWrite', db: 'xxx'}]}); db.createUser({user: 'admin', pwd: 'PASS', roles: [{role: 'userAdminAnyDatabase', db: 'admin'}]});"
echo "Mongo users created."

Entrypoint script will be executed and additional users will be created.

How to Rotate a UIImage 90 degrees?

I like the simple elegance of Peter Sarnowski's answer, but it can cause problems when you can't rely on EXIF metadata and the like. In situations where you need to rotate the actual image data I would recommend something like this:

- (UIImage *)rotateImage:(UIImage *) img
{
    CGSize imgSize = [img size];
    UIGraphicsBeginImageContext(imgSize);
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextRotateCTM(context, M_PI_2);
    CGContextTranslateCTM(context, 0, -640);
    [img drawInRect:CGRectMake(0, 0, imgSize.height, imgSize.width)];
    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return newImage;
}

The above code takes an image whose orientation is Landscape (can't remember if it's Landscape Left or Landscape Right) and rotates it into Portrait. It is an example which can be modified for your needs.

The key arguments you would have to play with are CGContextRotateCTM(context, M_PI_2) where you decide how much you want to rotate by, but then you have to make sure the picture still draws on the screen using CGContextTranslateCTM(context, 0, -640). This last part is quite important to make sure you see the image and not a blank screen.

For more info check out the source.

powerpoint loop a series of animation

Unfortunately you're probably done with the animation and presentation already. In the hopes this answer can help future questioners, however, this blog post has a walkthrough of steps that can loop a single slide as a sort of sub-presentation.

First, click Slide Show > Set Up Show.

Put a checkmark to Loop continuously until 'Esc'.

Click Ok. Now, Click Slide Show > Custom Shows. Click New.

Select the slide you are looping, click Add. Click Ok and Close.

Click on the slide you are looping. Click Slide Show > Slide Transition. Under Advance slide, put a checkmark to Automatically After. This will allow the slide to loop automatically. Do NOT Apply to all slides.

Right click on the thumbnail of the current slide, select Hide Slide.

Now, you will need to insert a new slide just before the slide you are looping. On the new slide, insert an action button. Set the hyperlink to the custom show you have created. Put a checkmark on "Show and Return"

This has worked for me.

How does the Spring @ResponseBody annotation work?

@RequestBody annotation binds the HTTPRequest body to the domain object. Spring automatically deserializes incoming HTTP Request to object using HttpMessageConverters. HttpMessageConverter converts body of request to resolve the method argument depending on the content type of the request. Many examples how to use converters https://upcodein.com/search/jc/mg/ResponseBody/page/0

What is "Advanced" SQL?

I suppose subqueries and PIVOT would qualify, as well as multiple joins, unions and the like.

Round to at most 2 decimal places (only if necessary)

You should use:

Math.round( num * 100 + Number.EPSILON ) / 100

No one seems to be aware of Number.EPSILON.

Also it's worth noting that this is not a JavaScript weirdness like some people stated.

That is simply the way floating point numbers works in a computer. Like 99% of programming languages, JavaScript doesn't have home made floating point numbers; it relies on the CPU/FPU for that. A computer uses binary, and in binary, there isn't any numbers like 0.1, but a mere binary approximation for that. Why? For the same reason than 1/3 cannot be written in decimal: its value is 0.33333333... with an infinity of threes.

Here come Number.EPSILON. That number is the difference between 1 and the next number existing in the double precision floating point numbers. That's it: There is no number between 1 and 1 + Number.EPSILON.

EDIT:

As asked in the comments, let's clarify one thing: adding Number.EPSILON is relevant only when the value to round is the result of an arithmetic operation, as it can swallow some floating point error delta.

It's not useful when the value comes from a direct source (e.g.: literal, user input or sensor).

EDIT (2019):

Like @maganap and some peoples have pointed out, it's best to add Number.EPSILON before multiplying:

Math.round( ( num + Number.EPSILON ) * 100 ) / 100

EDIT (december 2019):

Lately, I use a function similar to this one for comparing numbers epsilon-aware:

const ESPILON_RATE = 1 + Number.EPSILON ;
const ESPILON_ZERO = Number.MIN_VALUE ;

function epsilonEquals( a , b ) {
  if ( Number.isNaN( a ) || Number.isNaN( b ) ) {
    return false ;
  }
  if ( a === 0 || b === 0 ) {
    return a <= b + EPSILON_ZERO && b <= a + EPSILON_ZERO ;
  }
  return a <= b * EPSILON_RATE && b <= a * EPSILON_RATE ;
}

My use-case is an assertion + data validation lib I'm developing for many years.

In fact, in the code I'm using ESPILON_RATE = 1 + 4 * Number.EPSILON and EPSILON_ZERO = 4 * Number.MIN_VALUE (four times the epsilon), because I want an equality checker loose enough for cumulating floating point error.

So far, it looks perfect for me. I hope it will help.

How to use the pass statement?

pass in Python basically does nothing, but unlike a comment it is not ignored by interpreter. So you can take advantage of it in a lot of places by making it a place holder:

1: Can be used in class

class TestClass: 
    pass

2: Can be use in loop and conditional statements:

if (something == true):  # used in conditional statement
    pass
   
while (some condition is true):  # user is not sure about the body of the loop
    pass

3: Can be used in function :

def testFunction(args): # programmer wants to implement the body of the function later
    pass

pass is mostly used when programmer does not want to give implementation at the moment but still wants to create a certain class/function/conditional statement which can be used later on. Since the Python interpreter does not allow for blank or unimplemented class/function/conditional statement it gives an error:

IndentationError: expected an indented block

pass can be used in such scenarios.

Convert character to Date in R

library(lubridate) if your date format is like this '04/24/2017 05:35:00'then change it like below prods.all$Date2<-gsub("/","-",prods.all$Date2) then change the date format parse_date_time(prods.all$Date2, orders="mdy hms")

UIImageView - How to get the file name of the image assigned?

if ([imageForCheckMark.image isEqual:[UIImage imageNamed:@"crossCheckMark.png"]]||[imageForCheckMark.image isEqual:[UIImage imageNamed:@"checkMark.png"]])
{

}

format a number with commas and decimals in C# (asp.net MVC3)

CultureInfo us = new CultureInfo("en-US");
TotalAmount.ToString("N", us)

Adding a new value to an existing ENUM Type

PostgreSQL 9.1 introduces ability to ALTER Enum types:

ALTER TYPE enum_type ADD VALUE 'new_value'; -- appends to list
ALTER TYPE enum_type ADD VALUE 'new_value' BEFORE 'old_value';
ALTER TYPE enum_type ADD VALUE 'new_value' AFTER 'old_value';

Swift: declare an empty dictionary

var parking = [Dictionary < String, Double >()]

^ this adds a dictionary for a [string:double] input

How do I install cURL on Windows?

I agree with Erroid, you must add PHP directory into PATH environment.

PATH=%PATH%;<Your_PHP_Path>

Example

PATH=%PATH%;C:\php

It worked for me. Thank you.

Java double.MAX_VALUE?

this states that Account.deposit(Double.MAX_VALUE); it is setting deposit value to MAX value of Double dataType.to procced for running tests.

Checking out Git tag leads to "detached HEAD state"

Okay, first a few terms slightly oversimplified.

In git, a tag (like many other things) is what's called a treeish. It's a way of referring to a point in in the history of the project. Treeishes can be a tag, a commit, a date specifier, an ordinal specifier or many other things.

Now a branch is just like a tag but is movable. When you are "on" a branch and make a commit, the branch is moved to the new commit you made indicating it's current position.

Your HEAD is pointer to a branch which is considered "current". Usually when you clone a repository, HEAD will point to master which in turn will point to a commit. When you then do something like git checkout experimental, you switch the HEAD to point to the experimental branch which might point to a different commit.

Now the explanation.

When you do a git checkout v2.0, you are switching to a commit that is not pointed to by a branch. The HEAD is now "detached" and not pointing to a branch. If you decide to make a commit now (as you may), there's no branch pointer to update to track this commit. Switching back to another commit will make you lose this new commit you've made. That's what the message is telling you.

Usually, what you can do is to say git checkout -b v2.0-fixes v2.0. This will create a new branch pointer at the commit pointed to by the treeish v2.0 (a tag in this case) and then shift your HEAD to point to that. Now, if you make commits, it will be possible to track them (using the v2.0-fixes branch) and you can work like you usually would. There's nothing "wrong" with what you've done especially if you just want to take a look at the v2.0 code. If however, you want to make any alterations there which you want to track, you'll need a branch.

You should spend some time understanding the whole DAG model of git. It's surprisingly simple and makes all the commands quite clear.

What's the most appropriate HTTP status code for an "item not found" error page

A 404 return code actually means 'resource not found', and applies to any entity for which a request was made but not satisfied. So it works equally-well for pages, subsections of pages, and any item that exists on the page which has a specific request to be rendered.

So 404 is the right code to use in this scenario. Note that it doesn't apply to 'server not found', which is a different situation in which a request was issued but not answered at all, as opposed to answered but without the resource requested.

I just assigned a variable, but echo $variable shows something else

The answer from ks1322 helped me to identify the issue while using docker-compose exec:

If you omit the -T flag, docker-compose exec add a special character that break output, we see b instead of 1b:

$ test=$(/usr/local/bin/docker-compose exec db bash -c "echo 1")
$ echo "${test}b"
b
echo "${test}" | cat -vte
1^M$

With -T flag, docker-compose exec works as expected:

$ test=$(/usr/local/bin/docker-compose exec -T db bash -c "echo 1")
$ echo "${test}b"
1b

How to query MongoDB with "like"?

>> db.car.distinct('name')
[ "honda", "tat", "tata", "tata3" ]

>> db.car.find({"name":/. *ta.* /})

NuGet Package Restore Not Working

There is a shortcut to make Nuget restore work.

  1. Make sure internet connection or Nuget urls are proper in VS Tools options menu

  2. Look at .nuget or nuget folder in the solution, else - copy from any to get nuget.exe

  3. DELETE packages folders, if exists

  4. Open the Package manager console execute this command

  • paste full path of nuget.exe RESTORE full path of .sln file!
  1. use Install-pacakge command, if build did not get through for any missing references.