Programs & Examples On #Word completion

How to enable scrolling of content inside a modal?

If I recall correctly, setting overflow:hidden on the body didn't work on all the browsers I was testing for a modal library I built for a mobile site. Specifically, I had trouble with preventing the body from scrolling in addition to the modal scrolling even when I put overflow:hidden on the body.

For my current site, I ended up doing something like this. It basically just stores your current scroll position in addition to setting "overflow" to "hidden" on the page body, then restores the scroll position after the modal closes. There's a condition in there for when another bootstrap modal opens while one is already active. Otherwise, the rest of the code should be self explanatory. Note that if the overflow:hidden on the body doesn't prevent the window from scrolling for a given browser, this at least sets the original scroll location back upon exit.

function bindBootstrapModalEvents() {
    var $body = $('body'),
        curPos = 0,
        isOpened = false,
        isOpenedTwice = false;
    $body.off('shown.bs.modal hidden.bs.modal', '.modal');
    $body.on('shown.bs.modal', '.modal', function () {
        if (isOpened) {
            isOpenedTwice = true;
        } else {
            isOpened = true;
            curPos = $(window).scrollTop();
            $body.css('overflow', 'hidden');
        }
    });
    $body.on('hidden.bs.modal', '.modal', function () {
        if (!isOpenedTwice) {
            $(window).scrollTop(curPos);
            $body.css('overflow', 'visible');
            isOpened = false;
        }
        isOpenedTwice = false;
    });
}

If you don't like this, the other option would be to assign a max-height and overflow:auto to .modal-body like so:

.modal-body {
  max-height:300px;
  overflow:auto;
}

For this case, you could configure the max-height for different screen sizes and leave the overflow:auto for different screen sizes. You would have to make sure that the modal header, footer, and body don't add up to more than the screen size, though, so I would include that part in your calculations.

how do I get a new line, after using float:left?

Also such way

<br clear="all" />

Docker: Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock

sudo setfacl --modify user:(user name or ID):rw /var/run/docker.sock

Several times I tried to execute the command

sudo chmod 777 /var/run/docker.sock

but unfortunately, I have to do this every time when I'm logging in to ubuntu system. It doesn't require a restart and is more secure than usermod or chown. user ID is required when the user name only exists inside the container, but not on the host.

I hope that it will help you solve the problem.

How to write a function that takes a positive integer N and returns a list of the first N natural numbers

Here are a few ways to create a list with N of continuous natural numbers starting from 1.

1 range:

def numbers(n): 
    return range(1, n+1);

2 List Comprehensions:

def numbers(n):
    return [i for i in range(1, n+1)]

You may want to look into the method xrange and the concepts of generators, those are fun in python. Good luck with your Learning!

Get escaped URL parameter

Just in case you guys have the url like localhost/index.xsp?a=1#something and you need to get the param not the hash.

var vars = [], hash, anchor;
var q = document.URL.split('?')[1];
if(q != undefined){
    q = q.split('&');
    for(var i = 0; i < q.length; i++){
        hash = q[i].split('=');
        anchor = hash[1].split('#');
        vars.push(anchor[0]);
        vars[hash[0]] = anchor[0];
    }
}

Removing App ID from Developer Connection

As @AlexanderN pointed out, you can now delete App IDs.

  1. In your Member Center go to the Certificates, Identifiers & Profiles section.
  2. Go to Identifiers folder.
  3. Select the App ID you want to delete and click Settings
  4. Scroll down and click Delete.

INSERT VALUES WHERE NOT EXISTS

There is a great solution for this problem ,You can use the Merge Keyword of Sql

Merge MyTargetTable hba
USING (SELECT Id = 8, Name = 'Product Listing Message') temp 
ON temp.Id = hba.Id
WHEN NOT matched THEN 
INSERT (Id, Name) VALUES (temp.Id, temp.Name);

You can check this before following, below is the sample

IF OBJECT_ID ('dbo.TargetTable') IS NOT NULL
    DROP TABLE dbo.TargetTable
GO

CREATE TABLE dbo.TargetTable
    (
    Id   INT NOT NULL,
    Name VARCHAR (255) NOT NULL,
    CONSTRAINT PK_TargetTable PRIMARY KEY (Id)
    )
GO



INSERT INTO dbo.TargetTable (Name)
VALUES ('Unknown')
GO

INSERT INTO dbo.TargetTable (Name)
VALUES ('Mapping')
GO

INSERT INTO dbo.TargetTable (Name)
VALUES ('Update')
GO

INSERT INTO dbo.TargetTable (Name)
VALUES ('Message')
GO

INSERT INTO dbo.TargetTable (Name)
VALUES ('Switch')
GO

INSERT INTO dbo.TargetTable (Name)
VALUES ('Unmatched')
GO

INSERT INTO dbo.TargetTable (Name)
VALUES ('ProductMessage')
GO


Merge MyTargetTable hba
USING (SELECT Id = 8, Name = 'Listing Message') temp 
ON temp.Id = hba.Id
WHEN NOT matched THEN 
INSERT (Id, Name) VALUES (temp.Id, temp.Name);

Best data type to store money values in MySQL

I prefer to use BIGINT, and store the values in by multiply with 100, so that it will become integer.

For e.g., to represent a currency value of 93.49, the value shall be stored as 9349, while displaying the value we can divide by 100 and display. This will occupy less storage space.

Caution:
Mostly we don't perform currency * currency multiplication, in case if we are doing it then divide the result with 100 and store, so that it returns to proper precision.

add onclick function to a submit button

  1. Create a hidden button with id="hiddenBtn" and type="submit" that do the submit
  2. Change current button to type="button"
  3. set onclick of the current button call a function look like below:

    function foo() { // do something before submit ... // trigger click event of the hidden button $('#hinddenBtn').trigger("click"); }

How to extract week number in sql

Use 'dd-mon-yyyy' if you are using the 2nd date format specified in your answer. Ex:

to_date(<column name>,'dd-mon-yyyy')

Finding blocking/locking queries in MS SQL (mssql)

You may find this query useful:

SELECT * 
FROM sys.dm_exec_requests
WHERE DB_NAME(database_id) = 'YourDBName' 
AND blocking_session_id <> 0

Check whether a table contains rows or not sql server 2005

Also, you can use exists

select case when exists (select 1 from table) 
          then 'contains rows' 
          else 'doesnt contain rows' 
       end

or to check if there are child rows for a particular record :

select * from Table t1
where exists(
select 1 from ChildTable t2
where t1.id = t2.parentid)

or in a procedure

if exists(select 1 from table)
begin
 -- do stuff
end

How to see what privileges are granted to schema of another user

Login into the database. then run the below query

select * from dba_role_privs where grantee = 'SCHEMA_NAME';

All the role granted to the schema will be listed.

Thanks Szilagyi Donat for the answer. This one is taken from same and just where clause added.

Perform .join on value in array of objects

I've also come across using the reduce method, this is what it looks like:

[
  {name: "Joe", age: 22},
  {name: "Kevin", age: 24},
  {name: "Peter", age: 21}
].reduce(function (a, b) {return (a.name || a) + ", " + b.name})

The (a.name || a) is so the first element is treated correctly, but the rest (where a is a string, and so a.name is undefined) isn't treated as an object.

Edit: I've now refactored it further to this:

x.reduce(function(a, b) {return a + ["", ", "][+!!a.length] + b.name;}, "");

which I believe is cleaner as a is always a string, b is always an object (due to the use of the optional initialValue parameter in reduce)

Edit 6 months later: Oh what was I thinking. "cleaner". I've angered the code Gods.

What is the `zero` value for time.Time in Go?

Invoking an empty time.Time struct literal will return Go's zero date. Thus, for the following print statement:

fmt.Println(time.Time{})

The output is:

0001-01-01 00:00:00 +0000 UTC

For the sake of completeness, the official documentation explicitly states:

The zero value of type Time is January 1, year 1, 00:00:00.000000000 UTC.

joining two select statements

You should use UNION if you want to combine different resultsets. Try the following:

(SELECT * 
 FROM ( SELECT * 
        FROM orders_products 
        INNER JOIN orders ON orders_products.orders_id = orders.orders_id  
        WHERE products_id = 181) AS A)
UNION 

(SELECT * 
 FROM ( SELECT * 
        FROM orders_products 
        INNER JOIN orders ON orders_products.orders_id = orders.orders_id 
        WHERE products_id = 180) AS B
ON A.orders_id=B.orders_id)

Split code over multiple lines in an R script

I know this post is old, but I had a Situation like this and just want to share my solution. All the answers above work fine. But if you have a Code such as those in data.table chaining Syntax it becomes abit challenging. e.g. I had a Problem like this.

mass <- files[, Veg:=tstrsplit(files$file, "/")[1:4][[1]]][, Rain:=tstrsplit(files$file, "/")[1:4][[2]]][, Roughness:=tstrsplit(files$file, "/")[1:4][[3]]][, Geom:=tstrsplit(files$file, "/")[1:4][[4]]][time_[s]<=12000]

I tried most of the suggestions above and they didn´t work. but I figured out that they can be split after the comma within []. Splitting at ][ doesn´t work.

mass <- files[, Veg:=tstrsplit(files$file, "/")[1:4][[1]]][, 
    Rain:=tstrsplit(files$file, "/")[1:4][[2]]][, 
    Roughness:=tstrsplit(files$file, "/")[1:4][[3]]][, 
    Geom:=tstrsplit(files$file, "/")[1:4][[4]]][`time_[s]`<=12000]

What do the python file extensions, .pyc .pyd .pyo stand for?

  • .py - Regular script
  • .py3 - (rarely used) Python3 script. Python3 scripts usually end with ".py" not ".py3", but I have seen that a few times
  • .pyc - compiled script (Bytecode)
  • .pyo - optimized pyc file (As of Python3.5, Python will only use pyc rather than pyo and pyc)
  • .pyw - Python script to run in Windowed mode, without a console; executed with pythonw.exe
  • .pyx - Cython src to be converted to C/C++
  • .pyd - Python script made as a Windows DLL
  • .pxd - Cython script which is equivalent to a C/C++ header
  • .pxi - MyPy stub
  • .pyi - Stub file (PEP 484)
  • .pyz - Python script archive (PEP 441); this is a script containing compressed Python scripts (ZIP) in binary form after the standard Python script header
  • .pywz - Python script archive for MS-Windows (PEP 441); this is a script containing compressed Python scripts (ZIP) in binary form after the standard Python script header
  • .py[cod] - wildcard notation in ".gitignore" that means the file may be ".pyc", ".pyo", or ".pyd".
  • .pth - a path configuration file; its contents are additional items (one per line) to be added to sys.path. See site module.

A larger list of additional Python file-extensions (mostly rare and unofficial) can be found at http://dcjtech.info/topic/python-file-extensions/

how do I print an unsigned char as hex in c++ using ostream?

In C++20 you'll be able to use std::format to do this:

std::cout << std::format("a is {:x}; b is {:x}\n", a, b);

Output:

a is 0; b is ff

In the meantime you can use the {fmt} library, std::format is based on. {fmt} also provides the print function that makes this even easier and more efficient (godbolt):

fmt::print("a is {:x}; b is {:x}\n", a, b);

Disclaimer: I'm the author of {fmt} and C++20 std::format.

How to access static resources when mapping a global front controller servlet on /*

Map the controller servlet on a more specific url-pattern like /pages/*, put the static content in a specific folder like /static and create a Filter listening on /* which transparently continues the chain for any static content and dispatches requests to the controller servlet for other content.

In a nutshell:

<filter>
    <filter-name>filter</filter-name>
    <filter-class>com.example.Filter</filter-class>
</filter>
<filter-mapping>
    <filter-name>filter</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

<servlet>
    <servlet-name>controller</servlet-name>
    <servlet-class>com.example.Controller</servlet-class>
</servlet>
<servlet-mapping>
    <servlet-name>controller</servlet-name>
    <url-pattern>/pages/*</url-pattern>
</servlet-mapping>

with the following in filter's doFilter():

HttpServletRequest req = (HttpServletRequest) request;
String path = req.getRequestURI().substring(req.getContextPath().length());

if (path.startsWith("/static")) {
    chain.doFilter(request, response); // Goes to default servlet.
} else {
    request.getRequestDispatcher("/pages" + path).forward(request, response);
}

No, this does not end up with /pages in browser address bar. It's fully transparent. You can if necessary make "/static" and/or "/pages" an init-param of the filter.

Set Culture in an ASP.Net MVC app

I know this is an old question, but if you really would like to have this working with your ModelBinder (in respect to DefaultModelBinder.ResourceClassKey = "MyResource"; as well as the resources indicated in the data annotations of the viewmodel classes), the controller or even an ActionFilter is too late to set the culture.

The culture could be set in Application_AcquireRequestState, for example:

protected void Application_AcquireRequestState(object sender, EventArgs e)
    {
        // For example a cookie, but better extract it from the url
        string culture = HttpContext.Current.Request.Cookies["culture"].Value;

        Thread.CurrentThread.CurrentCulture = CultureInfo.GetCultureInfo(culture);
        Thread.CurrentThread.CurrentUICulture = CultureInfo.GetCultureInfo(culture);
    }

EDIT

Actually there is a better way using a custom routehandler which sets the culture according to the url, perfectly described by Alex Adamyan on his blog.

All there is to do is to override the GetHttpHandler method and set the culture there.

public class MultiCultureMvcRouteHandler : MvcRouteHandler
{
    protected override IHttpHandler GetHttpHandler(RequestContext requestContext)
    {
        // get culture from route data
        var culture = requestContext.RouteData.Values["culture"].ToString();
        var ci = new CultureInfo(culture);
        Thread.CurrentThread.CurrentUICulture = ci;
        Thread.CurrentThread.CurrentCulture = CultureInfo.CreateSpecificCulture(ci.Name);
        return base.GetHttpHandler(requestContext);
    }
}

Find empty or NaN entry in Pandas Dataframe

Check if the columns contain Nan using .isnull() and check for empty strings using .eq(''), then join the two together using the bitwise OR operator |.

Sum along axis 0 to find columns with missing data, then sum along axis 1 to the index locations for rows with missing data.

missing_cols, missing_rows = (
    (df2.isnull().sum(x) | df2.eq('').sum(x))
    .loc[lambda x: x.gt(0)].index
    for x in (0, 1)
)

>>> df2.loc[missing_rows, missing_cols]
         A2       A3
2            1.10035
5 -0.508501         
6       NaN      NaN
7       NaN      NaN

Character Limit on Instagram Usernames

Limit - 30 symbols. Username must contains only letters, numbers, periods and underscores.

How to find the length of an array list?

System.out.println(myList.size());

Since no elements are in the list

output => 0

myList.add("newString");  // use myList.add() to insert elements to the arraylist
System.out.println(myList.size());

Since one element is added to the list

output => 1

how to check the version of jar file?

Each jar version has a unique checksum. You can calculate the checksum for you jar (that had no version info) and compare it with the different versions of the jar. We can also search a jar using checksum.

Refer this Question to calculate checksum: What is the best way to calculate a checksum for a file that is on my machine?

jQuery Datepicker localization

Datepicker in german (Deutsch):

$.datepicker.regional['de'] = {
    monthNames: ['Januar','Februar','März','April','Mai','Juni',
    'Juli','August','September','Oktober','November','Dezember'],
    monthNamesShort: ['Jan','Feb','Mär','Apr','Mai','Jun',
    'Jul','Aug','Sep','Okt','Nov','Dez'],
    dayNames: ['Sonntag','Montag','Dienstag','Mittwoch','Donnerstag','Freitag','Samstag'],
    dayNamesShort: ['Son','Mon','Die','Mit','Don','Fre','Sam'],
    dayNamesMin: ['So','Mo','Di','Mi','Do','Fr','Sa'],
    firstDay: 1};
 $.datepicker.setDefaults($.datepicker.regional['de']);

Update a local branch with the changes from a tracked remote branch

You don't use the : syntax - pull always modifies the currently checked-out branch. Thus:

git pull origin my_remote_branch

while you have my_local_branch checked out will do what you want.

Since you already have the tracking branch set, you don't even need to specify - you could just do...

git pull

while you have my_local_branch checked out, and it will update from the tracked branch.

How to select the first element in the dropdown using jquery?

Your selector is wrong, you were probably looking for

$('select option:nth-child(1)')

This will work also:

$('select option:first-child')

What is use of c_str function In c++

It's used to make std::string interoperable with C code that requires a null terminated char*.

Java project in Eclipse: The type java.lang.Object cannot be resolved. It is indirectly referenced from required .class files

Right click on project -->Show in Navigator In navigator view you can see .classpath file, do delete this file and build the project. This worked for me. PS. If you have integrated you eclipse project with some version control like perfoce/svn , then unlinking the project before you delete the .classpath will be helpful.

How to bind bootstrap popover on dynamic elements

This is how I made the code so it can handle dynamically created elements using popover feature. Using this code, you can trigger the popover to show by default.

HTML:

<div rel="this-should-be-the-target">
</div>

JQuery:

$(function() {
    var targetElement = 'rel="this-should-be-the-target"';
    initPopover(targetElement, "Test Popover Content");

    // use this line if you want it to show by default
    $(targetElement).popover('show');
    
    function initPopover(target, popOverContent) {
        $(target).each(function(i, obj) {
            $(this).popover({
                placement : 'auto',
                trigger : 'hover',
                "html": true,
                content: popOverContent
            });
         });
     }
});

How to set the JSTL variable value in javascript?

You have to use the normal string concatenation but you have to make sure the value is a Valid XML string, you will find a good practice to write XML in this source http://oreilly.com/pub/h/2127, or if you like you can use an API in javascript to write XML as helma for example.

Dropdown using javascript onchange

easy

<script>
jQuery.noConflict()(document).ready(function() {
    $('#hide').css('display','none');
    $('#plano').change(function(){

        if(document.getElementById('plano').value == 1){
            $('#hide').show('slow');    

        }else 
            if(document.getElementById('plano').value == 0){

             $('#hide').hide('slow'); 
        }else
            if(document.getElementById('plano').value == 0){
             $('#hide').css('display','none');  

            }

    });
    $('#plano').change();
});
</script>

this example shows and hides the div if selected in combobox some specific value

TypeError: Can't convert 'int' object to str implicitly

You cannot concatenate a string with an int. You would need to convert your int to a string using the str function, or use formatting to format your output.

Change: -

print("Ok. Your balance is now at " + balanceAfterStrength + " skill points.")

to: -

print("Ok. Your balance is now at {} skill points.".format(balanceAfterStrength))

or: -

print("Ok. Your balance is now at " + str(balanceAfterStrength) + " skill points.")

or as per the comment, use , to pass different strings to your print function, rather than concatenating using +: -

print("Ok. Your balance is now at ", balanceAfterStrength, " skill points.")

C# - Making a Process.Start wait until the process has start-up

Do you mean wait until it's done? Then use Process.WaitForExit:

var process = new Process {
    StartInfo = new ProcessStartInfo {
        FileName = "popup.exe"
    }
};
process.Start();
process.WaitForExit();

Alternatively, if it's an application with a UI that you are waiting to enter into a message loop, you can say:

process.Start();
process.WaitForInputIdle();

Lastly, if neither of these apply, just Thread.Sleep for some reasonable amount of time:

process.Start();
Thread.Sleep(1000); // sleep for one second

NGinx Default public www location?

Just to note that the default index page for the nginx server will also display the root location as well. From the nginx (1.4.3) on Amazon Linux AMI, you get the following:

This is the default index.html page that is distributed with nginx on the Amazon Linux AMI. It is located in /usr/share/nginx/html.

You should now put your content in a location of your choice and edit the root configuration directive in the nginx configuration file /etc/nginx/nginx.conf

How to hide collapsible Bootstrap 4 navbar on click

You can use a simply bind on click and close, like this: (click)="drawer.close()

<a class="nav-link" [routerLink]="navItem.link" routerLinkActive="selected" (click)="drawer.close()">

PHP Try and Catch for SQL Insert

You can implement throwing exceptions on mysql query fail on your own. What you need is to write a wrapper for mysql_query function, e.g.:

// user defined. corresponding MySQL errno for duplicate key entry
const MYSQL_DUPLICATE_KEY_ENTRY = 1022;

// user defined MySQL exceptions
class MySQLException extends Exception {}
class MySQLDuplicateKeyException extends MySQLException {}

function my_mysql_query($query, $conn=false) {
    $res = mysql_query($query, $conn);
    if (!$res) {
        $errno = mysql_errno($conn);
        $error = mysql_error($conn);
        switch ($errno) {
        case MYSQL_DUPLICATE_KEY_ENTRY:
            throw new MySQLDuplicateKeyException($error, $errno);
            break;
        default:
            throw MySQLException($error, $errno);
            break;
        }
    }
    // ...
    // doing something
    // ...
    if ($something_is_wrong) {
        throw new Exception("Logic exception while performing query result processing");
    }

}

try {
    mysql_query("INSERT INTO redirects SET ua_string = '$ua_string'")
}
catch (MySQLDuplicateKeyException $e) {
    // duplicate entry exception
    $e->getMessage();
}
catch (MySQLException $e) {
    // other mysql exception (not duplicate key entry)
    $e->getMessage();
}
catch (Exception $e) {
    // not a MySQL exception
    $e->getMessage();
}

How do I associate file types with an iPhone application?

BIG WARNING: Make ONE HUNDRED PERCENT sure that your extension is not already tied to some mime type.

We used the extension '.icz' for our custom files for, basically, ever, and Safari just never would let you open them saying "Safari cannot open this file." no matter what we did or tried with the UT stuff above.

Eventually I realized that there are some UT* C functions you can use to explore various things, and while .icz gives the right answer (our app):

In app did load at top, just do this...

NSString * UTI = (NSString *)UTTypeCreatePreferredIdentifierForTag(kUTTagClassFilenameExtension, 
                                                                   (CFStringRef)@"icz", 
                                                                   NULL);
CFURLRef ur =UTTypeCopyDeclaringBundleURL(UTI);

and put break after that line and see what UTI and ur are -- in our case, it was our identifier as we wanted), and the bundle url (ur) was pointing to our app's folder.

But the MIME type that Dropbox gives us back for our link, which you can check by doing e.g.

$ curl -D headers THEURLGOESHERE > /dev/null
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 27393  100 27393    0     0  24983      0  0:00:01  0:00:01 --:--:-- 28926
$ cat headers
HTTP/1.1 200 OK
accept-ranges: bytes
cache-control: max-age=0
content-disposition: attachment; filename="123.icz"
Content-Type: text/calendar
Date: Fri, 24 May 2013 17:41:28 GMT
etag: 872926d
pragma: public
Server: nginx
x-dropbox-request-id: 13bd327248d90fde
X-RequestId: bf9adc56934eff0bfb68a01d526eba1f
x-server-response-time: 379
Content-Length: 27393
Connection: keep-alive

The Content-Type is what we want. Dropbox claims this is a text/calendar entry. Great. But in my case, I've ALREADY TRIED PUTTING text/calendar into my app's mime types, and it still doesn't work. Instead, when I try to get the UTI and bundle url for the text/calendar mimetype,

NSString * UTI = (NSString *)UTTypeCreatePreferredIdentifierForTag(kUTTagClassMIMEType,
                                                                   (CFStringRef)@"text/calendar", 
                                                                   NULL);

CFURLRef ur =UTTypeCopyDeclaringBundleURL(UTI);

I see "com.apple.ical.ics" as the UTI and ".../MobileCoreTypes.bundle/" as the bundle URL. Not our app, but Apple. So I try putting com.apple.ical.ics into the LSItemContentTypes alongside my own, and into UTConformsTo in the export, but no go.

So basically, if Apple thinks they want to at some point handle some form of file type (that could be created 10 years after your app is live, mind you), you will have to change extension cause they'll simply not let you handle the file type.

How do I use dataReceived event of the SerialPort Port Object in C#?

Might very well be the Console.ReadLine blocking your callback's Console.Writeline, in fact. The sample on MSDN looks ALMOST identical, except they use ReadKey (which doesn't lock the console).

Difference between socket and websocket?

WebSocket is just another application level protocol over TCP protocol, just like HTTP.

Some snippets < Spring in Action 4> quoted below, hope it can help you understand WebSocket better.

In its simplest form, a WebSocket is just a communication channel between two applications (not necessarily a browser is involved)...WebSocket communication can be used between any kinds of applications, but the most common use of WebSocket is to facilitate communication between a server application and a browser-based application.

Set a cookie to never expire

You shouldn't do that and that's not possible anyway, If you want you can set a greater value such as 10 years ahead.

By the way, I have never seen a cookie with such requirement :)

Generating random whole numbers in JavaScript in a specific range?

Use this function to get random numbers between given range

function rnd(min,max){
    return Math.floor(Math.random()*(max-min+1)+min );
}

How to store Configuration file and read it using React

You can use the dotenv package no matter what setup you use. It allows you to create a .env in your project root and specify your keys like so

REACT_APP_SERVER_PORT=8000

In your applications entry file your just call dotenv(); before accessing the keys like so

process.env.REACT_APP_SERVER_PORT

Include another HTML file in a HTML file

html5rocks.com has a very good tutorial on this stuff, and this might be a little late, but I myself didn't know this existed. w3schools also has a way to do this using their new library called w3.js. The thing is, this requires the use of a web server and and HTTPRequest object. You can't actually load these locally and test them on your machine. What you can do though, is use polyfills provided on the html5rocks link at the top, or follow their tutorial. With a little JS magic, you can do something like this:

 var link = document.createElement('link');
 if('import' in link){
     //Run import code
     link.setAttribute('rel','import');
     link.setAttribute('href',importPath);
     document.getElementsByTagName('head')[0].appendChild(link);
     //Create a phantom element to append the import document text to
     link = document.querySelector('link[rel="import"]');
     var docText = document.createElement('div');
     docText.innerHTML = link.import;
     element.appendChild(docText.cloneNode(true));
 } else {
     //Imports aren't supported, so call polyfill
     importPolyfill(importPath);
 }

This will make the link (Can change to be the wanted link element if already set), set the import (unless you already have it), and then append it. It will then from there take that and parse the file in HTML, and then append it to the desired element under a div. This can all be changed to fit your needs from the appending element to the link you are using. I hope this helped, it may irrelevant now if newer, faster ways have come out without using libraries and frameworks such as jQuery or W3.js.

UPDATE: This will throw an error saying that the local import has been blocked by CORS policy. Might need access to the deep web to be able to use this because of the properties of the deep web. (Meaning no practical use)

How to limit the number of dropzone.js files uploaded?

Nowell pointed it out that this has been addressed as of August 6th, 2013. A working example using this form might be:

<form class="dropzone" id="my-awesome-dropzone"></form>

You could use this JavaScript:

Dropzone.options.myAwesomeDropzone = {
  maxFiles: 1,
  accept: function(file, done) {
    console.log("uploaded");
    done();
  },
  init: function() {
    this.on("maxfilesexceeded", function(file){
        alert("No more files please!");
    });
  }
};

The dropzone element even gets a special style, so you can do things like:

<style>
  .dz-max-files-reached {background-color: red};
</style>

SQL Server : Arithmetic overflow error converting expression to data type int

Is the problem with SUM(billableDuration)? To find out, try commenting out that line and see if it works.

It could be that the sum is exceeding the maximum int. If so, try replacing it with SUM(CAST(billableDuration AS BIGINT)).

How to remove gaps between subplots in matplotlib?

Have you tried plt.tight_layout()?

with plt.tight_layout() enter image description here without it: enter image description here

Or: something like this (use add_axes)

left=[0.1,0.3,0.5,0.7]
width=[0.2,0.2, 0.2, 0.2]
rectLS=[]
for x in left:
   for y in left:
       rectLS.append([x, y, 0.2, 0.2])
axLS=[]
fig=plt.figure()
axLS.append(fig.add_axes(rectLS[0]))
for i in [1,2,3]:
     axLS.append(fig.add_axes(rectLS[i],sharey=axLS[-1]))    
axLS.append(fig.add_axes(rectLS[4]))
for i in [1,2,3]:
     axLS.append(fig.add_axes(rectLS[i+4],sharex=axLS[i],sharey=axLS[-1]))
axLS.append(fig.add_axes(rectLS[8]))
for i in [5,6,7]:
     axLS.append(fig.add_axes(rectLS[i+4],sharex=axLS[i],sharey=axLS[-1]))     
axLS.append(fig.add_axes(rectLS[12]))
for i in [9,10,11]:
     axLS.append(fig.add_axes(rectLS[i+4],sharex=axLS[i],sharey=axLS[-1]))

If you don't need to share axes, then simply axLS=map(fig.add_axes, rectLS) enter image description here

Cross-browser window resize event - JavaScript / jQuery

Besides the window resize functions mentioned it is important to understand that the resize events fire a lot if used without a deboucing the events.

Paul Irish has an excellent function that debounces the resize calls a great deal. Very recommended to use. Works cross-browser. Tested it in IE8 the other day and all was fine.

http://www.paulirish.com/2009/throttled-smartresize-jquery-event-handler/

Make sure to check out the demo to see the difference.

Here is the function for completeness.

(function($,sr){

  // debouncing function from John Hann
  // http://unscriptable.com/index.php/2009/03/20/debouncing-javascript-methods/
  var debounce = function (func, threshold, execAsap) {
      var timeout;

      return function debounced () {
          var obj = this, args = arguments;
          function delayed () {
              if (!execAsap)
                  func.apply(obj, args);
              timeout = null;
          };

          if (timeout)
              clearTimeout(timeout);
          else if (execAsap)
              func.apply(obj, args);

          timeout = setTimeout(delayed, threshold || 100);
      };
  }
  // smartresize 
  jQuery.fn[sr] = function(fn){  return fn ? this.bind('resize', debounce(fn)) : this.trigger(sr); };

})(jQuery,'smartresize');


// usage:
$(window).smartresize(function(){
  // code that takes it easy...
});

Simplest way to merge ES6 Maps/Sets?

You can use the spread syntax to merge them together:

const map1 = {a: 1, b: 2}
const map2 = {b: 1, c: 2, a: 5}

const mergedMap = {...a, ...b}

=> {a: 5, b: 1, c: 2}

jquery get all form elements: input, textarea & select

Try something like this:

<form action="/" id="searchForm">
<input type="text" name="s" placeholder="Search...">
<input type="submit" value="Search">
</form>
<!-- the result of the search will be rendered inside this div -->
<div id="result"></div>

<script>
// Attach a submit handler to the form
$( "#searchForm" ).submit(function( event ) {

  // Stop form from submitting normally
event.preventDefault();

// Get some values from elements on the page:
var $form = $( this ),
term = $form.find( "input[name='s']" ).val(),
url = $form.attr( "action" );

// Send the data using post
var posting = $.post( url, { s: term } );

// Put the results in a div
posting.done(function( data ) {
  var content = $( data ).find( "#content" );
  $( "#result" ).empty().append( content );
    });
  });
</script>

Note the use of input[]

LINQ to Entities does not recognize the method 'System.String ToString()' method, and this method cannot be translated into a store expression

The problem is that you are calling ToString in a LINQ to Entities query. That means the parser is trying to convert the ToString call into its equivalent SQL (which isn't possible...hence the exception).

All you have to do is move the ToString call to a separate line:

var keyString = item.Key.ToString();

var pages = from p in context.entities
            where p.Serial == keyString
            select p;

What does the line "#!/bin/sh" mean in a UNIX shell script?

The first line tells the shell that if you execute the script directly (./run.sh; as opposed to /bin/sh run.sh), it should use that program (/bin/sh in this case) to interpret it.

You can also use it to pass arguments, commonly -e (exit on error), or use other programs (/bin/awk, /usr/bin/perl, etc).

How can I find non-ASCII characters in MySQL?

In Oracle we can use below.

SELECT * FROM TABLE_A WHERE ASCIISTR(COLUMN_A) <> COLUMN_A;

Deserializing JSON to .NET object using Newtonsoft (or LINQ to JSON maybe?)

If you just need to get a few items from the JSON object, I would use Json.NET's LINQ to JSON JObject class. For example:

JToken token = JObject.Parse(stringFullOfJson);

int page = (int)token.SelectToken("page");
int totalPages = (int)token.SelectToken("total_pages");

I like this approach because you don't need to fully deserialize the JSON object. This comes in handy with APIs that can sometimes surprise you with missing object properties, like Twitter.

Documentation: Serializing and Deserializing JSON with Json.NET and LINQ to JSON with Json.NET

missing FROM-clause entry for table

SELECT 
   AcId, AcName, PldepPer, RepId, CustCatg, HardCode, BlockCust, CrPeriod, CrLimit, 
   BillLimit, Mode, PNotes, gtab82.memno 
FROM
   VCustomer AS v1
INNER JOIN   
   gtab82 ON gtab82.memacid = v1.AcId 
WHERE (AcGrCode = '204' OR CreDebt = 'True') 
AND Masked = 'false'
ORDER BY AcName

You typically only use an alias for a table name when you need to prefix a column with the table name due to duplicate column names in the joined tables and the table name is long or when the table is joined to itself. In your case you use an alias for VCustomer but only use it in the ON clause for uncertain reasons. You may want to review that aspect of your code.

Splitting on first occurrence

For me the better approach is that:

s.split('mango', 1)[-1]

...because if happens that occurrence is not in the string you'll get "IndexError: list index out of range".

Therefore -1 will not get any harm cause number of occurrences is already set to one.

Group by multiple field names in java 8

You have a few options here. The simplest is to chain your collectors:

Map<String, Map<Integer, List<Person>>> map = people
    .collect(Collectors.groupingBy(Person::getName,
        Collectors.groupingBy(Person::getAge));

Then to get a list of 18 year old people called Fred you would use:

map.get("Fred").get(18);

A second option is to define a class that represents the grouping. This can be inside Person. This code uses a record but it could just as easily be a class (with equals and hashCode defined) in versions of Java before JEP 359 was added:

class Person {
    record NameAge(String name, int age) { }

    public NameAge getNameAge() {
        return new NameAge(name, age);
    }
}

Then you can use:

Map<NameAge, List<Person>> map = people.collect(Collectors.groupingBy(Person::getNameAge));

and search with

map.get(new NameAge("Fred", 18));

Finally if you don't want to implement your own group record then many of the Java frameworks around have a pair class designed for this type of thing. For example: apache commons pair If you use one of these libraries then you can make the key to the map a pair of the name and age:

Map<Pair<String, Integer>, List<Person>> map =
    people.collect(Collectors.groupingBy(p -> Pair.of(p.getName(), p.getAge())));

and retrieve with:

map.get(Pair.of("Fred", 18));

Personally I don't really see much value in generic tuples now that records are available in the language as records display intent better and require very little code.

.net Core 2.0 - Package was restored using .NetFramework 4.6.1 instead of target framework .netCore 2.0. The package may not be fully compatible

The package is not fully compatible with dotnetcore 2.0 for now.

eg, for 'Microsoft.AspNet.WebApi.Client' it maybe supported in version (5.2.4). See Consume new Microsoft.AspNet.WebApi.Client.5.2.4 package for details.

You could try the standard Client package as Federico mentioned.

If that still not work, then as a workaround you can only create a Console App (.Net Framework) instead of the .net core 2.0 console app.

Reference this thread: Microsoft.AspNet.WebApi.Client supported in .NET Core or not?

Taskkill /f doesn't kill a process

I could solve my issue rearding this problem by killing explorer.exe which in turn was addicted to the process I wanted to kill. I guess this may also happen if processes open interfaces via hook which may be locked.

Python subprocess/Popen with a modified environment

To temporarily set an environment variable without having to copy the os.envrion object etc, I do this:

process = subprocess.Popen(['env', 'RSYNC_PASSWORD=foobar', 'rsync', \
'rsync://[email protected]::'], stdout=subprocess.PIPE)

Using CRON jobs to visit url?

you can use this for url with parameters:

lynx -dump "http://vps-managed.com/tasks.php?code=23456"

lynx is available on all systems by default.

Print values for multiple variables on the same line from within a for-loop

As an additional note, there is no need for the for loop because of R's vectorization.

This:

P <- 243.51
t <- 31 / 365
n <- 365

for (r in seq(0.15, 0.22, by = 0.01))    
     A <- P * ((1 + (r/ n))^ (n * t))
     interest <- A - P
}

is equivalent to:

P <- 243.51
t <- 31 / 365
n <- 365
r <- seq(0.15, 0.22, by = 0.01)
A <- P * ((1 + (r/ n))^ (n * t))
interest <- A - P

Because r is a vector, the expression above containing it is performed for all values of the vector.

Date format in dd/MM/yyyy hh:mm:ss

This will be varchar but should format as you need.

RIGHT('0' + LTRIM(DAY(d)), 2) + '/'
+ RIGHT('0' + LTRIM(MONTH(d)), 2) + '/'
+ LTRIM(YEAR(d)) + ' '
+ RIGHT('0' + LTRIM(DATEPART(HOUR, d)), 2) + ':'
+ RIGHT('0' + LTRIM(DATEPART(MINUTE, d)), 2) + ':'
+ RIGHT('0' + LTRIM(DATEPART(SECOND, d)), 2)

Where d is your datetime field or variable.

Get second child using jQuery

Try this:

$("td:eq(1)", $(t))

or

$("td", $(t)).eq(1)

Servlet returns "HTTP Status 404 The requested resource (/servlet) is not available"

My issue was that my method was missing the @RequestBody annotation. After adding the annotation I no longer received the 404 exception.

SQL conditional SELECT

Sounds like they want the ability to return only allowed fields, which means the number of fields returned also has to be dynamic. This will work with 2 variables. Anything more than that will be getting confusing.

IF (selectField1 = true AND selectField2 = true)
BEGIN
   SELECT Field1, Field2
   FROM Table
END
ELSE IF (selectField1 = true)
BEGIN
   SELECT Field1
   FROM Table
END
ELSE IF (selectField2 = true)
BEGIN
   SELECT Field2
   FROM Table
END

Dynamic SQL will help with multiples. This examples is assuming atleast 1 column is true.

DECLARE @sql varchar(MAX)
SET @sql = 'SELECT '
IF (selectField1 = true)
BEGIN
   SET @sql = @sql + 'Field1, '
END
IF (selectField2 = true)
BEGIN
   SET @sql = @sql + 'Field2, '
END
...
-- DROP ', '
@sql = SUBSTRING(@sql, 1, LEN(@sql)-2)

SET @sql = @sql + ' FROM Table'

EXEC(@sql)

Troubleshooting BadImageFormatException

When I faced this issue the following solved it for me:

I was calling a OpenCV dll from inside another exe, my dll did not contained the already needed opencv dlls like highgui, features2d, and etc available in the folder of my exe file. I copied all these to the directory of my exe project and it suddenly worked.

AngularJs ReferenceError: angular is not defined

If you've downloaded the angular.js file from Google, you need to make sure that Everyone has Read access to it, or it will not be loaded by your HTML file. By default, it seems to download with No access permissions, so you'll also be getting a message such as:

GET http://localhost/myApp/js/angular.js

This maddened me for about half an hour!

Taking the record with the max date

SELECT mu_file, mudate
  FROM flightdata t_ext
 WHERE mudate = (SELECT MAX (mudate)
                     FROM flightdata where mudate < sysdate)

How to escape double quotes in a title attribute

The escape code &#34; can also be used instead of &quot;.

Alter user defined type in SQL Server

1.Rename the old UDT,
2.Execute query , 3.Drop the old UDT.

Hidden features of Python

While debugging complex data structures pprint module comes handy.

Quoting from the docs..

>>> import pprint    
>>> stuff = sys.path[:]
>>> stuff.insert(0, stuff)
>>> pprint.pprint(stuff)
[<Recursion on list with id=869440>,
 '',
 '/usr/local/lib/python1.5',
 '/usr/local/lib/python1.5/test',
 '/usr/local/lib/python1.5/sunos5',
 '/usr/local/lib/python1.5/sharedmodules',
 '/usr/local/lib/python1.5/tkinter']

How do I prevent an Android device from going to sleep programmatically?

One option is to use a wake lock. Example from the docs:

PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
PowerManager.WakeLock wl = pm.newWakeLock(PowerManager.SCREEN_DIM_WAKE_LOCK, "My Tag");
wl.acquire();

// screen and CPU will stay awake during this section

wl.release();

There's also a table on this page that describes the different kinds of wakelocks.

Be aware that some caution needs to be taken when using wake locks. Ensure that you always release() the lock when you're done with it (or not in the foreground). Otherwise your app can potentially cause some serious battery drain and CPU usage.

The documentation also contains a useful page that describes different approaches to keeping a device awake, and when you might choose to use one. If "prevent device from going to sleep" only refers to the screen (and not keeping the CPU active) then a wake lock is probably more than you need.

You also need to be sure you have the WAKE_LOCK permission set in your manifest in order to use this method.

cout is not a member of std

Also remember that it must be:

#include "stdafx.h"
#include <iostream>

and not the other way around

#include <iostream>
#include "stdafx.h"

how to take user input in Array using java?

It vastly depends on how you intend to take this input, i.e. how your program is intending to interact with the user.

The simplest example is if you're bundling an executable - in this case the user can just provide the array elements on the command-line and the corresponding array will be accessible from your application's main method.

Alternatively, if you're writing some kind of webapp, you'd want to accept values in the doGet/doPost method of your application, either by manually parsing query parameters, or by serving the user with an HTML form that submits to your parsing page.

If it's a Swing application you would probably want to pop up a text box for the user to enter input. And in other contexts you may read the values from a database/file, where they have previously been deposited by the user.

Basically, reading input as arrays is quite easy, once you have worked out a way to get input. You need to think about the context in which your application will run, and how your users would likely expect to interact with this type of application, then decide on an I/O architecture that makes sense.

Reactjs: Unexpected token '<' Error

Use the following code. I have added reference to React and React DOM. Use ES6/Babel to transform you JS code into vanilla JavaScript. Note that Render method comes from ReactDOM and make sure that render method has a target specified in the DOM. Sometimes you might face an issue that the render() method can't find the target element. This happens because the react code is executed before the DOM renders. To counter this use jQuery ready() to call the render() method of React. This way you will be sure about DOM being rendered first. You can also use defer attribute on your app script.

HTML code:

<!DOCTYPE html>
<html>
<head>
<meta charset=utf-8 />
<title>JS Bin</title>
</head>
<body>
  <div id='main-content'></div>
<script src="CDN link to/react-15.1.0.js"></script>
<script src="CDN link to/react-dom-15.1.0.js"></script>

</body>
</html>

JS code:

var LikeOrNot = React.createClass({
    render: function () {
      return (
        <li>Like</li>
      );
    }
});

ReactDOM.render(<LikeOrNot />,
                document.getElementById('main-content'));

Hope this solves your issue. :-)

How to replace list item in best way

Why not use the extension methods?

Consider the following code:

        var intArray = new int[] { 0, 1, 1, 2, 3, 4 };
        // Replaces the first occurance and returns the index
        var index = intArray.Replace(1, 0);
        // {0, 0, 1, 2, 3, 4}; index=1

        var stringList = new List<string> { "a", "a", "c", "d"};
        stringList.ReplaceAll("a", "b");
        // {"b", "b", "c", "d"};

        var intEnum = intArray.Select(x => x);
        intEnum = intEnum.Replace(0, 1);
        // {0, 0, 1, 2, 3, 4} => {1, 1, 1, 2, 3, 4}
  • No code duplication
  • There is no need to type long linq expressions
  • There is no need for additional usings

The source code:

namespace System.Collections.Generic
{
    public static class Extensions
    {
        public static int Replace<T>(this IList<T> source, T oldValue, T newValue)
        {
            if (source == null)
                throw new ArgumentNullException(nameof(source));

            var index = source.IndexOf(oldValue);
            if (index != -1)
                source[index] = newValue;
            return index;
        }

        public static void ReplaceAll<T>(this IList<T> source, T oldValue, T newValue)
        {
            if (source == null)
                throw new ArgumentNullException(nameof(source));

            int index = -1;
            do
            {
                index = source.IndexOf(oldValue);
                if (index != -1)
                    source[index] = newValue;
            } while (index != -1);
        }


        public static IEnumerable<T> Replace<T>(this IEnumerable<T> source, T oldValue, T newValue)
        {
            if (source == null)
                throw new ArgumentNullException(nameof(source));

            return source.Select(x => EqualityComparer<T>.Default.Equals(x, oldValue) ? newValue : x);
        }
    }
}

The first two methods have been added to change the objects of reference types in place. Of course, you can use just the third method for all types.

P.S. Thanks to mike's observation, I've added the ReplaceAll method.

Refused to display in a frame because it set 'X-Frame-Options' to 'SAMEORIGIN'

I did the below changes and works fine for me.

Just add the attribute <iframe src="URL" target="_parent" />

_parent: this would open embedded page in same window.

_blank: In different tab

How to control size of list-style-type disc in CSS?

I have always had good luck with using background images instead of trusting all browsers to interpret the bullet in exactly the same way. This would also give you tight control over the size of the bullet.

.moreLinks li {
    background: url("bullet.gif") no-repeat left 5px;
    padding-left: 1em;
}

Also, you may want to move your DIV outside of the UL. It's invalid markup as you have it now. You can use a list header LH if you must have it inside the list.

batch script - read line by line

The "call" solution has some problems.

It fails with many different contents, as the parameters of a CALL are parsed twice by the parser.
These lines will produce more or less strange problems

one
two%222
three & 333
four=444
five"555"555"
six"&666
seven!777^!
the next line is empty

the end

Therefore you shouldn't use the value of %%a with a call, better move it to a variable and then call a function with only the name of the variable.

@echo off
SETLOCAL DisableDelayedExpansion
FOR /F "usebackq delims=" %%a in (`"findstr /n ^^ t.txt"`) do (
    set "myVar=%%a"
    call :processLine myVar
)
goto :eof

:processLine
SETLOCAL EnableDelayedExpansion
set "line=!%1!"
set "line=!line:*:=!"
echo(!line!
ENDLOCAL
goto :eof

Get the index of a certain value in an array in PHP

array_search is the way to do it.

array_search ( mixed $needle , array $haystack [, bool $strict = FALSE ] ) : mixed

From the docs:

$array = array(0 => 'blue', 1 => 'red', 2 => 'green', 3 => 'red');

$key = array_search('green', $array); // $key = 2;
$key = array_search('red', $array);   // $key = 1;

You could loop over the array manually and find the index but why do it when there's a function for that. This function always returns a key and it will work well with associative and normal arrays.

How to use JavaScript to change div backgroundColor

This one might be a bit weird because I am really not a serious programmer and I am discovering things in programming the way penicillin was invented - sheer accident. So how to change an element on mouseover? Use the :hover attribute just like with a elements.

Example:

div.classname:hover
{
    background-color: black;
}

This changes any div with the class classname to have a black background on mousover. You can basically change any attribute. Tested in IE and Firefox

Happy programming!

CSS Div stretch 100% page height

Here is the solution I finally came up with when using a div as a container for a dynamic background.

  • Remove the z-index for non-background uses.
  • Remove left or right for a full height column.
  • Remove top or bottom for a full width row.

EDIT 1: CSS below has been edited because it did not show correctly in FF and Chrome. moved position:relative to be on the HTML and set the body to height:100% instead of min-height:100%.

EDIT 2: Added extra comments to CSS. Added some more instructions above.

The CSS:

html{
    min-height:100%;/* make sure it is at least as tall as the viewport */
    position:relative;
}
body{
    height:100%; /* force the BODY element to match the height of the HTML element */
}
#cloud-container{
    position:absolute;
    top:0;
    bottom:0;
    left:0;
    right:0;
    overflow:hidden;
    z-index:-1; /* Remove this line if it's not going to be a background! */
}

The html:

<!doctype html>
<html>
<body>
    <div id="cloud-container"></div>
</body>
</html>

Why?

html{min-height:100%;position:relative;}

Without this the cloud-container DIV is removed from the HTML's layout context. position: relative ensures that the DIV remains inside the HTML box when it is drawn so that bottom:0 refers to the bottom of the HTML box. You can also use height:100% on the cloud-container as it now refers to the height of the HTML tag and not the viewport.

How can I override the OnBeforeUnload dialog and replace it with my own?

While there isn't anything you can do about the box in some circumstances, you can intercept someone clicking on a link. For me, this was worth the effort for most scenarios and as a fallback, I've left the unload event.

I've used Boxy instead of the standard jQuery Dialog, it is available here: http://onehackoranother.com/projects/jquery/boxy/

$(':input').change(function() {
    if(!is_dirty){
        // When the user changes a field on this page, set our is_dirty flag.
        is_dirty = true;
    }
});

$('a').mousedown(function(e) {
    if(is_dirty) {
        // if the user navigates away from this page via an anchor link, 
        //    popup a new boxy confirmation.
        answer = Boxy.confirm("You have made some changes which you might want to save.");
    }
});

window.onbeforeunload = function() {
if((is_dirty)&&(!answer)){
            // call this if the box wasn't shown.
    return 'You have made some changes which you might want to save.';
    }
};

You could attach to another event, and filter more on what kind of anchor was clicked, but this works for me and what I want to do and serves as an example for others to use or improve. Thought I would share this for those wanting this solution.

I have cut out code, so this may not work as is.

C++ static virtual members?

No, this is not possible, because static member functions lack a this pointer. And static members (both functions and variables) are not really class members per-se. They just happen to be invoked by ClassName::member, and adhere to the class access specifiers. Their storage is defined somewhere outside the class; storage is not created each time you instantiated an object of the class. Pointers to class members are special in semantics and syntax. A pointer to a static member is a normal pointer in all regards.

virtual functions in a class needs the this pointer, and is very coupled to the class, hence they can't be static.

ImportError: No module named 'django.core.urlresolvers'

For those who might be trying to create a Travis Build, the default path from which Django is installed from the requirements.txt file points to a repo whose django_extensions module has not been updated. The only workaround, for now, is to install from the master branch using pip. That is where the patch is made. But for now, we'll have to wait.

You can try this in the meantime, it might help

- pip install git+https://github.com/chibisov/drf-extensions.git@master

- pip install git+https://github.com/django-extensions/django-extensions.git@master

How to check heap usage of a running JVM from the command line?

For Java 8 you can use the following command line to get the heap space utilization in kB:

jstat -gc <PID> | tail -n 1 | awk '{split($0,a," "); sum=a[3]+a[4]+a[6]+a[8]; print sum}'

The command basically sums up:

  • S0U: Survivor space 0 utilization (kB).
  • S1U: Survivor space 1 utilization (kB).
  • EU: Eden space utilization (kB).
  • OU: Old space utilization (kB).

You may also want to include the metaspace and the compressed class space utilization. In this case you have to add a[10] and a[12] to the awk sum.

Inner join with count() on three tables

As Frank pointed out, you need to use DISTINCT. Also, since you are using composite primary keys (which is perfectly fine, BTW) you need to make sure that you use the whole key in your joins:

SELECT
    P.pe_name,
    COUNT(DISTINCT O.ord_id) AS num_orders,
    COUNT(I.item_id) AS num_items
FROM
    People P
INNER JOIN Orders O ON
    O.pe_id = P.pe_id
INNER JOIN Items I ON
    I.ord_id = O.ord_id AND
    I.pe_id = O.pe_id
GROUP BY
    P.pe_name

Without I.ord_id = O.ord_id it was joining each item row to every order row for a person.

Fastest way to convert a dict's keys & values from `unicode` to `str`?

DATA = { u'spam': u'eggs', u'foo': frozenset([u'Gah!']), u'bar': { u'baz': 97 },
         u'list': [u'list', (True, u'Maybe'), set([u'and', u'a', u'set', 1])]}

def convert(data):
    if isinstance(data, basestring):
        return str(data)
    elif isinstance(data, collections.Mapping):
        return dict(map(convert, data.iteritems()))
    elif isinstance(data, collections.Iterable):
        return type(data)(map(convert, data))
    else:
        return data

print DATA
print convert(DATA)
# Prints:
# {u'list': [u'list', (True, u'Maybe'), set([u'and', u'a', u'set', 1])], u'foo': frozenset([u'Gah!']), u'bar': {u'baz': 97}, u'spam': u'eggs'}
# {'bar': {'baz': 97}, 'foo': frozenset(['Gah!']), 'list': ['list', (True, 'Maybe'), set(['and', 'a', 'set', 1])], 'spam': 'eggs'}

Assumptions:

  • You've imported the collections module and can make use of the abstract base classes it provides
  • You're happy to convert using the default encoding (use data.encode('utf-8') rather than str(data) if you need an explicit encoding).

If you need to support other container types, hopefully it's obvious how to follow the pattern and add cases for them.

How to allow only numbers in textbox in mvc4 razor

Please use DataType attribue but this will except negative values so the regular expression below will avoid this

   [DataType(DataType.PhoneNumber,ErrorMessage="Not a number")]
   [Display(Name = "Oxygen")]
   [RegularExpression( @"^\d+$")]
   [Required(ErrorMessage="{0} is required")]
   [Range(0,30,ErrorMessage="Please use values between 0 to 30")]
    public int Oxygen { get; set; }

Convert generator object to list for debugging

Simply call list on the generator.

lst = list(gen)
lst

Be aware that this affects the generator which will not return any further items.

You also cannot directly call list in IPython, as it conflicts with a command for listing lines of code.

Tested on this file:

def gen():
    yield 1
    yield 2
    yield 3
    yield 4
    yield 5
import ipdb
ipdb.set_trace()

g1 = gen()

text = "aha" + "bebe"

mylst = range(10, 20)

which when run:

$ python code.py 
> /home/javl/sandbox/so/debug/code.py(10)<module>()
      9 
---> 10 g1 = gen()
     11 

ipdb> n
> /home/javl/sandbox/so/debug/code.py(12)<module>()
     11 
---> 12 text = "aha" + "bebe"
     13 

ipdb> lst = list(g1)
ipdb> lst
[1, 2, 3, 4, 5]
ipdb> q
Exiting Debugger.

General method for escaping function/variable/debugger name conflicts

There are debugger commands p and pp that will print and prettyprint any expression following them.

So you could use it as follows:

$ python code.py 
> /home/javl/sandbox/so/debug/code.py(10)<module>()
      9 
---> 10 g1 = gen()
     11 

ipdb> n
> /home/javl/sandbox/so/debug/code.py(12)<module>()
     11 
---> 12 text = "aha" + "bebe"
     13 

ipdb> p list(g1)
[1, 2, 3, 4, 5]
ipdb> c

There is also an exec command, called by prefixing your expression with !, which forces debugger to take your expression as Python one.

ipdb> !list(g1)
[]

For more details see help p, help pp and help exec when in debugger.

ipdb> help exec
(!) statement
Execute the (one-line) statement in the context of
the current stack frame.
The exclamation point can be omitted unless the first word
of the statement resembles a debugger command.
To assign to a global variable you must always prefix the
command with a 'global' command, e.g.:
(Pdb) global list_options; list_options = ['-l']

How can you strip non-ASCII characters from a string? (in C#)

Here is a pure .NET solution that doesn't use regular expressions:

string inputString = "Räksmörgås";
string asAscii = Encoding.ASCII.GetString(
    Encoding.Convert(
        Encoding.UTF8,
        Encoding.GetEncoding(
            Encoding.ASCII.EncodingName,
            new EncoderReplacementFallback(string.Empty),
            new DecoderExceptionFallback()
            ),
        Encoding.UTF8.GetBytes(inputString)
    )
);

It may look cumbersome, but it should be intuitive. It uses the .NET ASCII encoding to convert a string. UTF8 is used during the conversion because it can represent any of the original characters. It uses an EncoderReplacementFallback to to convert any non-ASCII character to an empty string.

Consider defining a bean of type 'package' in your configuration [Spring-Boot]

To fix errors like:

It happened to me that the LocalContainerEntityManagerFactoryBean class did not have the setPackagesToScan method. Then I proceeded to use the @EntityScan annotation which doesn't work correctly.

Later I could find the method setPackagesToScan() but in another module, so the problem came from the dependency which did not have this method because it was an old version.

This method can be found in the spring-data-jpa or spring-orm dependency of updated versions:

From:

implementation("org.springframework", "spring-orm", "2.5.1") 

To:

implementation("org.springframework", "spring-orm", "5.2.9.RELEASE")

Or to:

implementation("org.springframework.data", "spring-data-jpa", "2.3.4.RELEASE")

In addition, it was not necessary to add other annotations other than that of @SprintBootApplication.

@SpringBootApplication
open class MoebiusApplication : SpringBootServletInitializer()

@Bean
open fun entityManagerFactory() : LocalContainerEntityManagerFactoryBean {
    val em = LocalContainerEntityManagerFactoryBean()
    em.dataSource = dataSource()
    em.setPackagesToScan("app.mobius.domain.entity")
    ... 
}

GL

Source

warning: incompatible implicit declaration of built-in function ‘xyz’

In C, using a previously undeclared function constitutes an implicit declaration of the function. In an implicit declaration, the return type is int if I recall correctly. Now, GCC has built-in definitions for some standard functions. If an implicit declaration does not match the built-in definition, you get this warning.

To fix the problem, you have to declare the functions before using them; normally you do this by including the appropriate header. I recommend not to use the -fno-builtin-* flags if possible.

Instead of stdlib.h, you should try:

#include <string.h>

That's where strcpy and strncpy are defined, at least according to the strcpy(2) man page.

The exit function is defined in stdlib.h, though, so I don't know what's going on there.

Why docker container exits immediately

There are many possible ways to cause a docker to exit immediately. For me, it was the problem with my Dockerfile. There was a bug in that file. I had ENTRYPOINT ["dotnet", "M4Movie_Api.dll] instead of ENTRYPOINT ["dotnet", "M4Movie_Api.dll"]. As you can see I had missed one quotation(") at the end.

To analyze the problem I started my container and quickly attached my container so that I could see what was the exact problem.

C:\SVenu\M4Movie\Api\Api>docker start 4ea373efa21b


C:\SVenu\M4Movie\Api\Api>docker attach 4ea373efa21b

Where 4ea373efa21b is my container id. This drives me to the actual issue.

enter image description here

After finding the issue, I had to build, restore, publish my container again.

How to disable postback on an asp Button (System.Web.UI.WebControls.Button)

You can use JQuery for this

<asp:Button runat="server" ID="btnID" />

than in JQuery

$("#btnID").click(function(e){e.preventDefault();})

How do I create a multiline Python string with inline variables?

If anyone came here from python-graphql client looking for a solution to pass an object as variable here's what I used:

query = """
{{
  pairs(block: {block} first: 200, orderBy: trackedReserveETH, orderDirection: desc) {{
    id
    txCount
    reserveUSD
    trackedReserveETH
    volumeUSD
  }}
}}
""".format(block=''.join(['{number: ', str(block), '}']))

 query = gql(query)

Make sure to escape all curly braces like I did: "{{", "}}"

How do I cast a JSON Object to a TypeScript class?

https://jvilk.com/MakeTypes/

you can use this site to generate a proxy for you. it generates a class and can parse and validate your input JSON object.

What happened to the .pull-left and .pull-right classes in Bootstrap 4?

Thay are removed.

Use float-left instead of pull-left. And float-right instead of pull-right.

Check bootstrap Documentation here:

Added .float-{sm,md,lg,xl}-{left,right,none} classes for responsive floats and removed .pull-left and .pull-right since they’re redundant to .float-left and .float-right.

Microsoft.Jet.OLEDB.4.0' provider is not registered on the local machine

I'm using VS2013 for Winforms, the below solution worked for me.

JVM heap parameters

The JVM will start with memory useage at the initial heap level. If the maxheap is higher, it will grow to the maxheap size as memory requirements exceed it's current memory.

So,

  • -Xms512m -Xmx512m

JVM starts with 512 M, never resizes.

  • -Xms64m -Xmx512m

JVM starts with 64M, grows (up to max ceiling of 512) if mem. requirements exceed 64.

Change background color for selected ListBox item

You need to use ListBox.ItemContainerStyle.

ListBox.ItemTemplate specifies how the content of an item should be displayed. But WPF still wraps each item in a ListBoxItem control, which by default gets its Background set to the system highlight colour if it is selected. You can't stop WPF creating the ListBoxItem controls, but you can style them -- in your case, to set the Background to always be Transparent or Black or whatever -- and to do so, you use ItemContainerStyle.

juFo's answer shows one possible implementation, by "hijacking" the system background brush resource within the context of the item style; another, perhaps more idiomatic technique is to use a Setter for the Background property.

Styling of Select2 dropdown select boxes

This is how i changed placeholder arrow color, the 2 classes are for dropdown open and dropdown closed, you need to change the #fff to the color you want:

.select2-container--default.select2-container--open .select2-selection--single .select2-selection__arrow b {
    border-color: transparent transparent #fff transparent !important;
  }
  .select2-container--default .select2-selection--single .select2-selection__arrow b {
    border-color: #fff transparent transparent transparent !important;
  }

Render partial from different folder (not shared)

The VirtualPathProviderViewEngine, on which the WebFormsViewEngine is based, is supposed to support the "~" and "/" characters at the front of the path so your examples above should work.

I noticed your examples use the path "~/Account/myPartial.ascx", but you mentioned that your user control is in the Views/Account folder. Have you tried

<%Html.RenderPartial("~/Views/Account/myPartial.ascx");%>

or is that just a typo in your question?

How to Get a Sublist in C#

You want List::GetRange(firstIndex, count). See http://msdn.microsoft.com/en-us/library/21k0e39c.aspx

// I have a List called list
List sublist = list.GetRange(5, 5); // (gets elements 5,6,7,8,9)
List anotherSublist = list.GetRange(0, 4); // gets elements 0,1,2,3)

Is that what you're after?

If you're looking to delete the sublist items from the original list, you can then do:

// list is our original list
// sublist is our (newly created) sublist built from GetRange()
foreach (Type t in sublist)
{
    list.Remove(t);
}

How to include clean target in Makefile?

The best thing is probably to create a variable that holds your binaries:

binaries=code1 code2

Then use that in the all-target, to avoid repeating:

all: clean $(binaries)

Now, you can use this with the clean-target, too, and just add some globs to catch object files and stuff:

.PHONY: clean

clean:
    rm -f $(binaries) *.o

Note use of the .PHONY to make clean a pseudo-target. This is a GNU make feature, so if you need to be portable to other make implementations, don't use it.

How to select specified node within Xpath node sets by index with Selenium?

There is no i in xpath is not entirely true. You can still use the count() to find the index.

Consider the following page

_x000D_
_x000D_
<html>_x000D_
_x000D_
 <head>_x000D_
  <title>HTML Sample table</title>_x000D_
 </head>_x000D_
_x000D_
 <style>_x000D_
 table, td, th {_x000D_
  border: 1px solid black;_x000D_
  font-size: 15px;_x000D_
  font-family: Trebuchet MS, sans-serif;_x000D_
 }_x000D_
 table {_x000D_
  border-collapse: collapse;_x000D_
  width: 100%;_x000D_
 }_x000D_
_x000D_
 th, td {_x000D_
  text-align: left;_x000D_
  padding: 8px;_x000D_
 }_x000D_
_x000D_
 tr:nth-child(even){background-color: #f2f2f2}_x000D_
_x000D_
 th {_x000D_
  background-color: #4CAF50;_x000D_
  color: white;_x000D_
 }_x000D_
 </style>_x000D_
_x000D_
 <body>_x000D_
 <table>_x000D_
  <thead>_x000D_
   <tr>_x000D_
    <th>Heading 1</th>_x000D_
    <th>Heading 2</th>_x000D_
    <th>Heading 3</th>_x000D_
    <th>Heading 4</th>_x000D_
    <th>Heading 5</th>_x000D_
    <th>Heading 6</th>_x000D_
   </tr>_x000D_
  </thead>_x000D_
  <tbody>_x000D_
   <tr>_x000D_
    <td>Data row 1 col 1</td>_x000D_
    <td>Data row 1 col 2</td>_x000D_
    <td>Data row 1 col 3</td>_x000D_
    <td>Data row 1 col 4</td>_x000D_
    <td>Data row 1 col 5</td>_x000D_
    <td>Data row 1 col 6</td>_x000D_
   </tr>_x000D_
   <tr>_x000D_
    <td>Data row 2 col 1</td>_x000D_
    <td>Data row 2 col 2</td>_x000D_
    <td>Data row 2 col 3</td>_x000D_
    <td>Data row 2 col 4</td>_x000D_
    <td>Data row 2 col 5</td>_x000D_
    <td>Data row 2 col 6</td>_x000D_
   </tr>_x000D_
   <tr>_x000D_
    <td>Data row 3 col 1</td>_x000D_
    <td>Data row 3 col 2</td>_x000D_
    <td>Data row 3 col 3</td>_x000D_
    <td>Data row 3 col 4</td>_x000D_
    <td>Data row 3 col 5</td>_x000D_
    <td>Data row 3 col 6</td>_x000D_
   </tr>_x000D_
   <tr>_x000D_
    <td>Data row 4 col 1</td>_x000D_
    <td>Data row 4 col 2</td>_x000D_
    <td>Data row 4 col 3</td>_x000D_
    <td>Data row 4 col 4</td>_x000D_
    <td>Data row 4 col 5</td>_x000D_
    <td>Data row 4 col 6</td>_x000D_
   </tr>_x000D_
   <tr>_x000D_
    <td>Data row 5 col 1</td>_x000D_
    <td>Data row 5 col 2</td>_x000D_
    <td>Data row 5 col 3</td>_x000D_
    <td>Data row 5 col 4</td>_x000D_
    <td>Data row 5 col 5</td>_x000D_
    <td>Data row 5 col 6</td>_x000D_
   </tr>_x000D_
   <tr>_x000D_
    <td><button>Modify</button></td>_x000D_
    <td><button>Modify</button></td>_x000D_
    <td><button>Modify</button></td>_x000D_
    <td><button>Modify</button></td>_x000D_
    <td><button>Modify</button></td>_x000D_
    <td><button>Modify</button></td>_x000D_
   </tr>_x000D_
  </tbody>_x000D_
 </table>_x000D_
_x000D_
 </br>_x000D_
_x000D_
 <table>_x000D_
  <thead>_x000D_
   <tr>_x000D_
    <th>Heading 7</th>_x000D_
    <th>Heading 8</th>_x000D_
    <th>Heading 9</th>_x000D_
    <th>Heading 10</th>_x000D_
    <th>Heading 11</th>_x000D_
    <th>Heading 12</th>_x000D_
   </tr>_x000D_
  </thead>_x000D_
  <tbody>_x000D_
   <tr>_x000D_
    <td>Data row 1 col 1</td>_x000D_
    <td>Data row 1 col 2</td>_x000D_
    <td>Data row 1 col 3</td>_x000D_
    <td>Data row 1 col 4</td>_x000D_
    <td>Data row 1 col 5</td>_x000D_
    <td>Data row 1 col 6</td>_x000D_
   </tr>_x000D_
   <tr>_x000D_
    <td>Data row 2 col 1</td>_x000D_
    <td>Data row 2 col 2</td>_x000D_
    <td>Data row 2 col 3</td>_x000D_
    <td>Data row 2 col 4</td>_x000D_
    <td>Data row 2 col 5</td>_x000D_
    <td>Data row 2 col 6</td>_x000D_
   </tr>_x000D_
   <tr>_x000D_
    <td>Data row 3 col 1</td>_x000D_
    <td>Data row 3 col 2</td>_x000D_
    <td>Data row 3 col 3</td>_x000D_
    <td>Data row 3 col 4</td>_x000D_
    <td>Data row 3 col 5</td>_x000D_
    <td>Data row 3 col 6</td>_x000D_
   </tr>_x000D_
   <tr>_x000D_
    <td>Data row 4 col 1</td>_x000D_
    <td>Data row 4 col 2</td>_x000D_
    <td>Data row 4 col 3</td>_x000D_
    <td>Data row 4 col 4</td>_x000D_
    <td>Data row 4 col 5</td>_x000D_
    <td>Data row 4 col 6</td>_x000D_
   </tr>_x000D_
   <tr>_x000D_
    <td>Data row 5 col 1</td>_x000D_
    <td>Data row 5 col 2</td>_x000D_
    <td>Data row 5 col 3</td>_x000D_
    <td>Data row 5 col 4</td>_x000D_
    <td>Data row 5 col 5</td>_x000D_
    <td>Data row 5 col 6</td>_x000D_
   </tr>_x000D_
   <tr>_x000D_
    <td><button>Modify</button></td>_x000D_
    <td><button>Modify</button></td>_x000D_
    <td><button>Modify</button></td>_x000D_
    <td><button>Modify</button></td>_x000D_
    <td><button>Modify</button></td>_x000D_
    <td><button>Modify</button></td>_x000D_
   </tr>_x000D_
  </tbody>_x000D_
 </table>_x000D_
_x000D_
 </body>_x000D_
</html>
_x000D_
_x000D_
_x000D_

The page has 2 tables and has 6 columns each with unique column names and 6 rows with variable data. The last row has the Modify button in both the tables.

Assuming that the user has to select the 4th Modify button from the first table based on the heading

Use the xpath //th[.='Heading 4']/ancestor::thead/following-sibling::tbody/tr/td[count(//tr/th[.='Heading 4']/preceding-sibling::th)+1]/button

The count() operator comes in handy in situations like these.

Logic:

  1. Find the header for the Modify button using //th[.='Heading 4']
  2. Find the index of the header column using count(//tr/th[.='Heading 4']/preceding-sibling::th)+1

Note: Index starts at 0

  1. Get the rows for the corresponding header using //th[.='Heading 4']/ancestor::thead/following-sibling::tbody/tr/td[count(//tr/th[.='Heading 4']/preceding-sibling::th)+1]

  2. Get the Modify button from the extracted node list using //th[.='Heading 4']/ancestor::thead/following-sibling::tbody/tr/td[count(//tr/th[.='Heading 4']/preceding-sibling::th)+1]/button

How can I remove the decimal part from JavaScript number?

Here is the compressive in detailed explanation with the help of above posts:

1. Math.trunc() : It is used to remove those digits which are followed by dot. It converts implicitly. But, not supported in IE.

Example:

Math.trunc(10.5) // 10

Math.trunc(-10.5) // -10

Other Alternative way: Use of bitwise not operator:

Example:

x= 5.5

~~x // 5

2. Math.floor() : It is used to give the minimum integer value posiible. It is supported in all browsers.

Example:

Math.floor(10.5) // 10

Math.floor( -10.5) // -11

3. Math.ceil() : It is used to give the highest integer value possible. It is supported in all browsers.

Example:

Math.ceil(10.5) // 11

Math.ceil(-10.5) // -10

4. Math.round() : It is rounded to the nearest integer. It is supported in all browsers.

Example:

Math.round(10.5) // 11

Math.round(-10.5)// -10

Math.round(10.49) // 10

Math.round(-10.51) // -11

assign headers based on existing row in dataframe in R

The cleanest way is use a function of janitor package that is built for exactly this purpose.

janitor::row_to_names(DF,1)

If you want to use any other row than the first one, pass it in the second parameter.

Python Prime number checker

def isprime(n):
    '''check if integer n is a prime'''

    # make sure n is a positive integer
    n = abs(int(n))

    # 0 and 1 are not primes
    if n < 2:
        return False

    # 2 is the only even prime number
    if n == 2: 
        return True    

    # all other even numbers are not primes
    if not n & 1: 
        return False

    # range starts with 3 and only needs to go up 
    # the square root of n for all odd numbers
    for x in range(3, int(n**0.5) + 1, 2):
        if n % x == 0:
            return False

    return True

Taken from:

http://www.daniweb.com/software-development/python/code/216880/check-if-a-number-is-a-prime-number-python

Delete certain lines in a txt file via a batch file

If you have sed:

sed -e '/REFERENCE/d' -e '/ERROR/d' [FILENAME]

Where FILENAME is the name of the text file with the good & bad lines

session not created: This version of ChromeDriver only supports Chrome version 74 error with ChromeDriver Chrome using Selenium

Make sure You have the latest version of webdriver-manager. You can install the same using npm i webdriver-manager@latest --save

Then run the following

command.webdriver-manager update

fix java.net.SocketTimeoutException: Read timed out

I don't think it's enough merely to get the response. I think you need to read it (get the entity and read it via EntityUtils.consume()).

e.g. (from the doc)

     System.out.println("<< Response: " + response.getStatusLine());
     System.out.println(EntityUtils.toString(response.getEntity()));

Java Can't connect to X11 window server using 'localhost:10.0' as the value of the DISPLAY variable

Michael-O gave useful approach to solve the problem. Another way to solve this is by starting the server with Putty Console.

How can I get the current user's username in Bash?

On most Linux systems, simply typing whoami on the command line provides the user ID.

However, on Solaris, you may have to determine the user ID, by determining the UID of the user logged-in through the command below.

echo $UID

Once the UID is known, find the user by matching the UID against the /etc/passwd file.

cat /etc/passwd | cut -d":" -f1,3

How do I read a specified line in a text file?

Tried and tested. It's as simple as follows:

string line = File.ReadLines(filePath).ElementAt(actualLineNumber - 1);

As long as you have a text file, this should work. Later, depending upon what data you expect to read, you can cast the string accordingly and use it.

What is the correct XPath for choosing attributes that contain "foo"?

Have you tried something like:

//a[contains(@prop, "Foo")]

I've never used the contains function before but suspect that it should work as advertised...

MySql with JAVA error. The last packet sent successfully to the server was 0 milliseconds ago

Search the file my.cnf and comment the line

skip-networking

to

#skip-networking

Restart mysql

Can I convert long to int?

Sometimes you're not actually interested in the actual value, but in its usage as checksum/hashcode. In this case, the built-in method GetHashCode() is a good choice:

int checkSumAsInt32 = checkSumAsIn64.GetHashCode();

ArrayList vs List<> in C#

ArrayList is the collections of different types data whereas List<> is the collection of similar type of its own depedencties.

Support for the experimental syntax 'classProperties' isn't currently enabled

I am using the babel parser explicitly. None of the above solutions worked for me. This worked.

const ast = parser.parse(inputCode, {
      sourceType: 'module',
      plugins: [
        'jsx',
        'classProperties', // '@babel/plugin-proposal-class-properties',
      ],
    });

JavaScript pattern for multiple constructors

This is the example given for multiple constructors in Programming in HTML5 with JavaScript and CSS3 - Exam Ref.

function Book() {
    //just creates an empty book.
}


function Book(title, length, author) {
    this.title = title;
    this.Length = length;
    this.author = author;
}

Book.prototype = {
    ISBN: "",
    Length: -1,
    genre: "",
    covering: "",
    author: "",
    currentPage: 0,
    title: "",

    flipTo: function FlipToAPage(pNum) {
        this.currentPage = pNum;
    },

    turnPageForward: function turnForward() {
        this.flipTo(this.currentPage++);
    },

    turnPageBackward: function turnBackward() {
        this.flipTo(this.currentPage--);
    }
};

var books = new Array(new Book(), new Book("First Edition", 350, "Random"));

How to detect when an @Input() value changes in Angular?

I just want to add that there is another Lifecycle hook called DoCheck that is useful if the @Input value is not a primitive value.

I have an Array as an Input so this does not fire the OnChanges event when the content changes (because the checking that Angular does is 'simple' and not deep so the Array is still an Array, even though the content on the Array has changed).

I then implement some custom checking code to decide if I want to update my view with the changed Array.

How to insert pandas dataframe via mysqldb into database?

This should do the trick:

import pandas as pd
import pymysql
pymysql.install_as_MySQLdb()
from sqlalchemy import create_engine

# Create engine
engine = create_engine('mysql://USER_NAME_HERE:PASS_HERE@HOST_ADRESS_HERE/DB_NAME_HERE')

# Create the connection and close it(whether successed of failed)
with engine.begin() as connection:
  df.to_sql(name='INSERT_TABLE_NAME_HERE/INSERT_NEW_TABLE_NAME', con=connection, if_exists='append', index=False)

What generates the "text file busy" message in Unix?

If you are running the .sh from a ssh connection with a tool like MobaXTerm, and if said tool has an autosave utility to edit remote file from local machine, that will lock the file.

Closing and reopening the SSH session solves it.

Send array with Ajax to PHP script

Encode your data string into JSON.

dataString = ??? ; // array?
var jsonString = JSON.stringify(dataString);
   $.ajax({
        type: "POST",
        url: "script.php",
        data: {data : jsonString}, 
        cache: false,

        success: function(){
            alert("OK");
        }
    });

In your PHP

$data = json_decode(stripslashes($_POST['data']));

  // here i would like use foreach:

  foreach($data as $d){
     echo $d;
  }

Note

When you send data via POST, it needs to be as a keyvalue pair.

Thus

data: dataString

is wrong. Instead do:

data: {data:dataString}

ConvergenceWarning: Liblinear failed to converge, increase the number of iterations

Normally when an optimization algorithm does not converge, it is usually because the problem is not well-conditioned, perhaps due to a poor scaling of the decision variables. There are a few things you can try.

  1. Normalize your training data so that the problem hopefully becomes more well conditioned, which in turn can speed up convergence. One possibility is to scale your data to 0 mean, unit standard deviation using Scikit-Learn's StandardScaler for an example. Note that you have to apply the StandardScaler fitted on the training data to the test data.
  2. Related to 1), make sure the other arguments such as regularization weight, C, is set appropriately.
  3. Set max_iter to a larger value. The default is 1000.
  4. Set dual = True if number of features > number of examples and vice versa. This solves the SVM optimization problem using the dual formulation. Thanks @Nino van Hooff for pointing this out, and @JamesKo for spotting my mistake.
  5. Use a different solver, for e.g., the L-BFGS solver if you are using Logistic Regression. See @5ervant's answer.

Note: One should not ignore this warning.

This warning came about because

  1. Solving the linear SVM is just solving a quadratic optimization problem. The solver is typically an iterative algorithm that keeps a running estimate of the solution (i.e., the weight and bias for the SVM). It stops running when the solution corresponds to an objective value that is optimal for this convex optimization problem, or when it hits the maximum number of iterations set.

  2. If the algorithm does not converge, then the current estimate of the SVM's parameters are not guaranteed to be any good, hence the predictions can also be complete garbage.

Edit

In addition, consider the comment by @Nino van Hooff and @5ervant to use the dual formulation of the SVM. This is especially important if the number of features you have, D, is more than the number of training examples N. This is what the dual formulation of the SVM is particular designed for and helps with the conditioning of the optimization problem. Credit to @5ervant for noticing and pointing this out.

Furthermore, @5ervant also pointed out the possibility of changing the solver, in particular the use of the L-BFGS solver. Credit to him (i.e., upvote his answer, not mine).

I would like to provide a quick rough explanation for those who are interested (I am :)) why this matters in this case. Second-order methods, and in particular approximate second-order method like the L-BFGS solver, will help with ill-conditioned problems because it is approximating the Hessian at each iteration and using it to scale the gradient direction. This allows it to get better convergence rate but possibly at a higher compute cost per iteration. That is, it takes fewer iterations to finish but each iteration will be slower than a typical first-order method like gradient-descent or its variants.

For e.g., a typical first-order method might update the solution at each iteration like

x(k + 1) = x(k) - alpha(k) * gradient(f(x(k)))

where alpha(k), the step size at iteration k, depends on the particular choice of algorithm or learning rate schedule.

A second order method, for e.g., Newton, will have an update equation

x(k + 1) = x(k) - alpha(k) * Hessian(x(k))^(-1) * gradient(f(x(k)))

That is, it uses the information of the local curvature encoded in the Hessian to scale the gradient accordingly. If the problem is ill-conditioned, the gradient will be pointing in less than ideal directions and the inverse Hessian scaling will help correct this.

In particular, L-BFGS mentioned in @5ervant's answer is a way to approximate the inverse of the Hessian as computing it can be an expensive operation.

However, second-order methods might converge much faster (i.e., requires fewer iterations) than first-order methods like the usual gradient-descent based solvers, which as you guys know by now sometimes fail to even converge. This can compensate for the time spent at each iteration.

In summary, if you have a well-conditioned problem, or if you can make it well-conditioned through other means such as using regularization and/or feature scaling and/or making sure you have more examples than features, you probably don't have to use a second-order method. But these days with many models optimizing non-convex problems (e.g., those in DL models), second order methods such as L-BFGS methods plays a different role there and there are evidence to suggest they can sometimes find better solutions compared to first-order methods. But that is another story.

UILabel font size?

Check that your labels aren't set to automatically resize. In IB, it's called "Autoshrink" and is right beside the font setting. Programmatically, it's called adjustsFontSizeToFitWidth.

How to change color of Toolbar back button in Android?

You can add a style to your styles.xml,

<style name="ToolbarTheme" parent="@style/ThemeOverlay.AppCompat.ActionBar">
  <!-- Customize color of navigation drawer icon and back arrow --> 
  <item name="colorControlNormal">@color/toolbar_color_control_normal</item>
</style>

and add this as theme to your toolbar in toolbar layout.xml using app:theme, check below

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.Toolbar 
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:minHeight="?attr/actionBarSize"
    android:background="?attr/colorPrimary"
    app:theme="@style/ToolbarTheme" >
</android.support.v7.widget.Toolbar>

Content Security Policy: The page's settings blocked the loading of a resource

You can disable them in your browser.

Firefox

Type about:config in the Firefox address bar and find security.csp.enable and set it to false.

Chrome

You can install the extension called Disable Content-Security-Policy to disable CSP.

Reload chart data via JSON with Highcharts

The other answers didn't work for me. I found the answer in their documentation:

http://api.highcharts.com/highcharts#Series

Using this method (see JSFiddle example):

var chart = new Highcharts.Chart({
    chart: {
        renderTo: 'container'
    },

    series: [{
        data: [29.9, 71.5, 106.4, 129.2, 144.0, 176.0, 135.6, 148.5, 216.4, 194.1, 95.6, 54.4]        
    }]
});

// the button action
$('#button').click(function() {
    chart.series[0].setData([129.2, 144.0, 176.0, 135.6, 148.5, 216.4, 194.1, 95.6, 54.4, 29.9, 71.5, 106.4] );
});

How to set the text/value/content of an `Entry` widget using a button in tkinter

e= StringVar()
def fileDialog():
    filename = filedialog.askopenfilename(initialdir = "/",title = "Select A 
    File",filetype = (("jpeg","*.jpg"),("png","*.png"),("All Files","*.*")))
    e.set(filename)
la = Entry(self,textvariable = e,width = 30).place(x=230,y=330)
butt=Button(self,text="Browse",width=7,command=fileDialog).place(x=430,y=328)

PHP PDO with foreach and fetch

$users = $dbh->query($sql);
foreach ($users as $row) {
    print $row["name"] . "-" . $row["sex"] ."<br/>";
}
foreach ($users as $row) {
    print $row["name"] . "-" . $row["sex"] ."<br/>";
}

Here $users is a PDOStatement object over which you can iterate. The first iteration outputs all results, the second does nothing since you can only iterate over the result once. That's because the data is being streamed from the database and iterating over the result with foreach is essentially shorthand for:

while ($row = $users->fetch()) ...

Once you've completed that loop, you need to reset the cursor on the database side before you can loop over it again.

$users = $dbh->query($sql);
foreach ($users as $row) {
    print $row["name"] . "-" . $row["sex"] ."<br/>";
}
echo "<br/>";
$result = $users->fetch(PDO::FETCH_ASSOC);
foreach($result as $key => $value) {
    echo $key . "-" . $value . "<br/>";
}

Here all results are being output by the first loop. The call to fetch will return false, since you have already exhausted the result set (see above), so you get an error trying to loop over false.

In the last example you are simply fetching the first result row and are looping over it.

How do you create a dropdownlist from an enum in ASP.NET MVC?

I bumped into the same problem, found this question, and thought that the solution provided by Ash wasn't what I was looking for; Having to create the HTML myself means less flexibility compared to the built-in Html.DropDownList() function.

Turns out C#3 etc. makes this pretty easy. I have an enum called TaskStatus:

var statuses = from TaskStatus s in Enum.GetValues(typeof(TaskStatus))
               select new { ID = s, Name = s.ToString() };
ViewData["taskStatus"] = new SelectList(statuses, "ID", "Name", task.Status);

This creates a good ol' SelectList that can be used like you're used to in the view:

<td><b>Status:</b></td><td><%=Html.DropDownList("taskStatus")%></td></tr>

The anonymous type and LINQ makes this so much more elegant IMHO. No offence intended, Ash. :)

Semi-transparent color layer over background-image?

I simply used background-image css property on the target background div.
Note background-image only accepts gradient color functions.
So I used linear-gradient adding the same desired overlay color twice (use last rgba value to control color opacity).

Also, found these two useful resources to:

  1. Add text (or div with any other content) over the background image: Hero Image
  2. Blur background image only, without blurring the div on top: Blurred Background Image

HTML

<div class="header_div">
</div>

<div class="header_text">
  <h1>Header Text</h1>
</div>

CSS

.header_div {
  position: relative;
  text-align: cover;
  min-height: 90vh;
  margin-top: 5vh;
  background-position: center;
  background-repeat: no-repeat;
  background-size: cover;
  width: 100vw;
  background-image: linear-gradient(rgba(38, 32, 96, 0.2), rgba(38, 32, 96, 0.4)), url("images\\header img2.jpg");
  filter: blur(2px);
}

.header_text {
  position: absolute;
  top: 50%;
  right: 50%;
  transform: translate(50%, -50%);
}

java.util.NoSuchElementException - Scanner reading user input

the reason of the exception has been explained already, however the suggested solution isn't really the best.

You should create a class that keeps a Scanner as private using Singleton Pattern, that makes that scanner unique on your code.

Then you can implement the methods you need or you can create a getScanner ( not recommended ) and you can control it with a private boolean, something like alreadyClosed.

If you are not aware how to use Singleton Pattern, here's a example:

public class Reader {
    
    
    private Scanner reader;
    private static Reader singleton = null;
    private boolean alreadyClosed;
    
    private Reader() {
        alreadyClosed = false;
        reader = new Scanner(System.in);
    }
    
    public static Reader getInstance() {
        if(singleton == null) {
            singleton = new Reader();
        }
        return singleton;
    }
    
    public int nextInt() throws AlreadyClosedException {
        if(!alreadyClosed) {
            return reader.nextInt();
        }
        throw new AlreadyClosedException(); //Custom exception
    }
    
    public double nextDouble() throws AlreadyClosedException {
        if(!alreadyClosed) {
            return reader.nextDouble();
        }
        throw new AlreadyClosedException();
    }
    
    public String nextLine() throws AlreadyClosedException {
        if(!alreadyClosed) {
            return reader.nextLine();
        }
        throw new AlreadyClosedException();
    }
    
    public void close() {
        alreadyClosed = true;
        reader.close();
    }   
}

How to create and handle composite primary key in JPA

The MyKey class (@Embeddable) should not have any relationships like @ManyToOne

What does "int 0x80" mean in assembly code?

int 0x80 is the assembly language instruction that is used to invoke system calls in Linux on x86 (i.e., Intel-compatible) processors.

http://www.linfo.org/int_0x80.html

How to minify php page html output?

You can use a well tested Java minifier like HTMLCompressor by invoking it using passthru (exec).
Remember to redirect console using 2>&1

This however may not be useful, if speed is a concern. I use it for static php output

Why is setState in reactjs Async instead of Sync?

You can use the following wrap to make sync call

_x000D_
_x000D_
this.setState((state =>{_x000D_
  return{_x000D_
    something_x000D_
  }_x000D_
})
_x000D_
_x000D_
_x000D_

Merging two CSV files using Python

When I'm working with csv files, I often use the pandas library. It makes things like this very easy. For example:

import pandas as pd

a = pd.read_csv("filea.csv")
b = pd.read_csv("fileb.csv")
b = b.dropna(axis=1)
merged = a.merge(b, on='title')
merged.to_csv("output.csv", index=False)

Some explanation follows. First, we read in the csv files:

>>> a = pd.read_csv("filea.csv")
>>> b = pd.read_csv("fileb.csv")
>>> a
   title  stage    jan    feb
0   darn  3.001  0.421  0.532
1     ok  2.829  1.036  0.751
2  three  1.115  1.146  2.921
>>> b
   title    mar    apr    may       jun  Unnamed: 5
0   darn  0.631  1.321  0.951    1.7510         NaN
1     ok  1.001  0.247  2.456    0.3216         NaN
2  three  0.285  1.283  0.924  956.0000         NaN

and we see there's an extra column of data (note that the first line of fileb.csv -- title,mar,apr,may,jun, -- has an extra comma at the end). We can get rid of that easily enough:

>>> b = b.dropna(axis=1)
>>> b
   title    mar    apr    may       jun
0   darn  0.631  1.321  0.951    1.7510
1     ok  1.001  0.247  2.456    0.3216
2  three  0.285  1.283  0.924  956.0000

Now we can merge a and b on the title column:

>>> merged = a.merge(b, on='title')
>>> merged
   title  stage    jan    feb    mar    apr    may       jun
0   darn  3.001  0.421  0.532  0.631  1.321  0.951    1.7510
1     ok  2.829  1.036  0.751  1.001  0.247  2.456    0.3216
2  three  1.115  1.146  2.921  0.285  1.283  0.924  956.0000

and finally write this out:

>>> merged.to_csv("output.csv", index=False)

producing:

title,stage,jan,feb,mar,apr,may,jun
darn,3.001,0.421,0.532,0.631,1.321,0.951,1.751
ok,2.829,1.036,0.751,1.001,0.247,2.456,0.3216
three,1.115,1.146,2.921,0.285,1.283,0.924,956.0

Calculating difference between two timestamps in Oracle in milliseconds

Easier solution:

SELECT numtodsinterval(date1-date2,'day') time_difference from dates;

For timestamps:

SELECT (extract(DAY FROM time2-time1)*24*60*60)+ 
(extract(HOUR FROM time2-time1)*60*60)+
(extract(MINUTE FROM time2-time1)*60)+
extract(SECOND FROM time2-time1)
into diff FROM dual;

RETURN diff;

How to format number of decimal places in wpf using style/template?

The accepted answer does not show 0 in integer place on giving input like 0.299. It shows .3 in WPF UI. So my suggestion to use following string format

<TextBox Text="{Binding Value,  StringFormat={}{0:#,0.0}}" 

How to align an indented line in a span that wraps into multiple lines?

Also you can try to use

display:inline-block;

if you would like the span element to align horizontally.

Incase you would like to align span elements vertically, just use

 display:block;

How to make for loops in Java increase by increments other than 1

It's just a syntax error. You just have to replace j+3 by j=j+3 or j+=3.

How can I display a list view in an Android Alert Dialog?

This is too simple

final CharSequence[] items = {"Take Photo", "Choose from Library", "Cancel"};

AlertDialog.Builder builder = new AlertDialog.Builder(MyProfile.this);

builder.setTitle("Add Photo!");
builder.setItems(items, new DialogInterface.OnClickListener() {
    @Override
    public void onClick(DialogInterface dialog, int item) {
        if (items[item].equals("Take Photo")) {
            getCapturesProfilePicFromCamera();
        } else if (items[item].equals("Choose from Library")) {
            getProfilePicFromGallery();
        } else if (items[item].equals("Cancel")) {
            dialog.dismiss();
        }
    }
});
builder.show();

What is the difference between venv, pyvenv, pyenv, virtualenv, virtualenvwrapper, pipenv, etc?

UPDATE 20200825:

Added below "Conclusion" paragraph

I've went down the pipenv rabbit hole (it's a deep and dark hole indeed...) and since the last answer is over 2 years ago, felt it was useful to update the discussion with the latest developments on the Python virtual envelopes topic I've found.

DISCLAIMER:

This answer is NOT about continuing the raging debate about the merits of pipenv versus venv as envelope solutions- I make no endorsement of either. It's about PyPA endorsing conflicting standards and how future development of virtualenv promises to negate making an either/or choice between them at all. I focused on these two tools precisely because they are the anointed ones by PyPA.

venv

As the OP notes, venv is a tool for virtualizing environments. NOT a third party solution, but native tool. PyPA endorses venv for creating VIRTUAL ENVELOPES: "Changed in version 3.5: The use of venv is now recommended for creating virtual environments".

pipenv

pipenv- like venv - can be used to create virtual envelopes but additionally rolls-in package management and vulnerability checking functionality. Instead of using requirements.txt, pipenv delivers package management via Pipfile. As PyPA endorses pipenv for PACKAGE MANAGEMENT, that would seem to imply pipfile is to supplant requirements.txt.

HOWEVER: pipenv uses virtualenv as its tool for creating virtual envelopes, NOT venv which is endorsed by PyPA as the go-to tool for creating virtual envelopes.

Conflicting Standards:

So if settling on a virtual envelope solution wasn't difficult enough, we now have PyPA endorsing two different tools which use different virtual envelope solutions. The raging Github debate on venv vs virtualenv which highlights this conflict can be found here.

Conflict Resolution:

The Github debate referenced in above link has steered virtualenv development in the direction of accommodating venv in future releases:

prefer built-in venv: if the target python has venv we'll create the environment using that (and then perform subsequent operations on that to facilitate other guarantees we offer)

Conclusion:

So it looks like there will be some future convergence between the two rival virtual envelope solutions, but as of now pipenv- which uses virtualenv - varies materially from venv.

Given the problems pipenv solves and the fact that PyPA has given its blessing, it appears to have a bright future. And if virtualenv delivers on its proposed development objectives, choosing a virtual envelope solution should no longer be a case of either pipenv OR venv.

Update 20200825:

An oft repeated criticism of Pipenv I saw when producing this analysis was that it was not actively maintained. Indeed, what's the point of using a solution whose future could be seen questionable due to lack of continuous development? After a dry spell of about 18 months, Pipenv is once again being actively developed. Indeed, large and material updates have since been released.

How to smooth a curve in the right way?

For a project of mine, I needed to create intervals for time-series modeling, and to make the procedure more efficient I created tsmoothie: A python library for time-series smoothing and outlier detection in a vectorized way.

It provides different smoothing algorithms together with the possibility to computes intervals.

Here I use a ConvolutionSmoother but you can also test it others.

import numpy as np
import matplotlib.pyplot as plt
from tsmoothie.smoother import *

x = np.linspace(0,2*np.pi,100)
y = np.sin(x) + np.random.random(100) * 0.2

# operate smoothing
smoother = ConvolutionSmoother(window_len=5, window_type='ones')
smoother.smooth(y)

# generate intervals
low, up = smoother.get_intervals('sigma_interval', n_sigma=2)

# plot the smoothed timeseries with intervals
plt.figure(figsize=(11,6))
plt.plot(smoother.smooth_data[0], linewidth=3, color='blue')
plt.plot(smoother.data[0], '.k')
plt.fill_between(range(len(smoother.data[0])), low[0], up[0], alpha=0.3)

enter image description here

I point out also that tsmoothie can carry out the smoothing of multiple timeseries in a vectorized way

Webdriver Screenshot

Here they asked a similar question, and the answer seems more complete, I leave the source:

How to take partial screenshot with Selenium WebDriver in python?

from selenium import webdriver
from PIL import Image
from io import BytesIO

fox = webdriver.Firefox()
fox.get('http://stackoverflow.com/')

# now that we have the preliminary stuff out of the way time to get that image :D
element = fox.find_element_by_id('hlogo') # find part of the page you want image of
location = element.location
size = element.size
png = fox.get_screenshot_as_png() # saves screenshot of entire page
fox.quit()

im = Image.open(BytesIO(png)) # uses PIL library to open image in memory

left = location['x']
top = location['y']
right = location['x'] + size['width']
bottom = location['y'] + size['height']


im = im.crop((left, top, right, bottom)) # defines crop points
im.save('screenshot.png') # saves new cropped image

How to get a string after a specific substring?

Try this general approach:

import re
my_string="hello python world , i'm a beginner "
p = re.compile("world(.*)")
print (p.findall(my_string))

#[" , i'm a beginner "]

Android Studio emulator does not come with Play Store for API 23

Go to http://opengapps.org/ and download the pico version of your platform and android version. Unzip the downloaded folder to get
1. GmsCore.apk
2. GoogleServicesFramework.apk
3. GoogleLoginService.apk
4. Phonesky.apk

Then, locate your emulator.exe. You will probably find it in
C:\Users\<YOUR_USER_NAME>\AppData\Local\Android\sdk\tools

Run the command:
emulator -avd <YOUR_EMULATOR'S_NAME> -netdelay none -netspeed full -no-boot-anim -writable-system

Note: Use -writable-system to start your emulator with writable system image.

Then,
adb root
adb remount
adb push <PATH_TO GmsCore.apk> /system/priv-app
adb push <PATH_TO GoogleServicesFramework.apk> /system/priv-app
adb push <PATH_TO GoogleLoginService.apk> /system/priv-app
adb push <PATH_TO Phonesky.apk> /system/priv-app

Then, reboot the emulator
adb shell stop
adb shell start

To verify run,
adb shell pm list packages and you will find com.google.android.gms package for google

Installing a plain plugin jar in Eclipse 3.5

Simplest way - just put in the Eclipse plugins folder. You can start Eclipse with the -clean option to make sure Eclipse cleans its' plugins cache and sees the new plugin.

In general, it is far more recommended to install plugins using proper update sites.

What is a Python equivalent of PHP's var_dump()?

The closest thing to PHP's var_dump() is pprint() with the getmembers() function in the built-in inspect module:

from inspect import getmembers
from pprint import pprint
pprint(getmembers(yourObj))

Bundler: Command not found

Make sure you do rbenv rehash when installing different rubies

Find ALL tweets from a user (not just the first 3,200)

http://greptweet.com/ is an attempt to surpass the 3200 limit by backing up tweets, and besides that is useful for simple searches.

enabling cross-origin resource sharing on IIS7

It is likely a case of IIS 7 'handling' the HTTP OPTIONS response instead of your application specifying it. To determine this, in IIS7,

  1. Go to your site's Handler Mappings.

  2. Scroll down to 'OPTIONSVerbHandler'.

  3. Change the 'ProtocolSupportModule' to 'IsapiHandler'

  4. Set the executable: %windir%\Microsoft.NET\Framework\v4.0.30319\aspnet_isapi.dll

Now, your config entries above should kick in when an HTTP OPTIONS verb is sent.

Alternatively you can respond to the HTTP OPTIONS verb in your BeginRequest method.

    protected void Application_BeginRequest(object sender,EventArgs e)
    {
        HttpContext.Current.Response.AddHeader("Access-Control-Allow-Origin", "*");

        if(HttpContext.Current.Request.HttpMethod == "OPTIONS")
        {
            //These headers are handling the "pre-flight" OPTIONS call sent by the browser
            HttpContext.Current.Response.AddHeader("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE");
            HttpContext.Current.Response.AddHeader("Access-Control-Allow-Headers", "Content-Type, Accept");
            HttpContext.Current.Response.AddHeader("Access-Control-Max-Age", "1728000" );
            HttpContext.Current.Response.End();
        }

    }

Converting a date string to a DateTime object using Joda Time library

From comments I picked an answer like and also adding TimeZone:

String dateTime = "2015-07-18T13:32:56.971-0400";

DateTimeFormatter formatter = DateTimeFormat.forPattern("yyyy-MM-dd'T'HH:mm:ss.SSSZZ")
        .withLocale(Locale.ROOT)
        .withChronology(ISOChronology.getInstanceUTC());

DateTime dt = formatter.parseDateTime(dateTime);

Simple state machine example in C#?

I would recommend state.cs. I personally used state.js (the JavaScript version) and am very happy with it. That C# version works in a similar way.

You instantiate states:

        // create the state machine
        var player = new StateMachine<State>( "player" );

        // create some states
        var initial = player.CreatePseudoState( "initial", PseudoStateKind.Initial );
        var operational = player.CreateCompositeState( "operational" );
        ...

You instantiate some transitions:

        var t0 = player.CreateTransition( initial, operational );
        player.CreateTransition( history, stopped );
        player.CreateTransition<String>( stopped, running, ( state, command ) => command.Equals( "play" ) );
        player.CreateTransition<String>( active, stopped, ( state, command ) => command.Equals( "stop" ) );

You define actions on states and transitions:

    t0.Effect += DisengageHead;
    t0.Effect += StopMotor;

And that's (pretty much) it. Look at the website for more information.

I want to execute shell commands from Maven's pom.xml

This worked for me too. Later, I ended-up switching to the maven-antrun-plugin to avoid warnings in Eclipse. And I prefer using default plugins when possible. Example:

<plugin>
    <artifactId>maven-antrun-plugin</artifactId>
    <version>3.0.0</version>
    <executions>
        <execution>
            <id>get-the-hostname</id>
            <phase>package</phase>
            <configuration>
                <target>
                    <exec executable="bash">
                        <arg value="-c"/>
                        <arg value="hostname"/>
                    </exec>
                </target>
            </configuration>
            <goals>
                <goal>run</goal>
            </goals>
        </execution>
    </executions>
</plugin>

How to prevent scanf causing a buffer overflow in C?

Directly using scanf(3) and its variants poses a number of problems. Typically, users and non-interactive use cases are defined in terms of lines of input. It's rare to see a case where, if enough objects are not found, more lines will solve the problem, yet that's the default mode for scanf. (If a user didn't know to enter a number on the first line, a second and third line will probably not help.)

At least if you fgets(3) you know how many input lines your program will need, and you won't have any buffer overflows...

How do I check if a file exists in Java?

Simple example with good coding practices and covering all cases :

 private static void fetchIndexSafely(String url) throws FileAlreadyExistsException {
        File f = new File(Constants.RFC_INDEX_LOCAL_NAME);
        if (f.exists()) {
            throw new FileAlreadyExistsException(f.getAbsolutePath());
        } else {
            try {
                URL u = new URL(url);
                FileUtils.copyURLToFile(u, f);
            } catch (MalformedURLException ex) {
                Logger.getLogger(RfcFetcher.class.getName()).log(Level.SEVERE, null, ex);
            } catch (IOException ex) {
                Logger.getLogger(RfcFetcher.class.getName()).log(Level.SEVERE, null, ex);
            }
        }
    }

Reference and more examples at

https://zgrepcode.com/examples/java/java/nio/file/filealreadyexistsexception-implementations

Find elements inside forms and iframe using Java and Selenium WebDriver

Before you try searching for the elements within the iframe you will have to switch Selenium focus to the iframe.

Try this before searching for the elements within the iframe:

driver.switchTo().frame(driver.findElement(By.name("iFrameTitle")));

jQuery - simple input validation - "empty" and "not empty"

You could do this

$("#input").blur(function(){
    if($(this).val() == ''){
        alert('empty'); 
    }
});

http://jsfiddle.net/jasongennaro/Y5P9k/1/

When the input has lost focus that is .blur(), then check the value of the #input.

If it is empty == '' then trigger the alert.

PHP passing $_GET in linux command prompt

I don't have a php-cgi binary on Ubuntu, so I did this:

% alias php-cgi="php -r '"'parse_str(implode("&", array_slice($argv, 2)), $_GET); include($argv[1]);'"' --"
% php-cgi test1.php foo=123
<html>
You set foo to 123.
</html>

%cat test1.php
<html>You set foo to <?php print $_GET['foo']?>.</html>

How do I make a file:// hyperlink that works in both IE and Firefox?

At least with Chrome, (I don't know about Firefox) You can drag the icon to the left of the URL in the browser to a folder location on your desktop and it will create a file that behaves as an internet shortcut.

I don't know if the file format is universal yet, however Chrome seems to know what to do with it.

The file produced is a .url file and contains the following:

[InternetShortcut] URL=http://www.accordingtothescriptures.org/prophecy/353prophecies.html

You can replace the URL with anything you'd like.

angularjs: allows only numbers to be typed into a text box

 <input
    onkeypress="return (event.charCode >= 48 && event.charCode <= 57) ||                         
    event.charCode == 0 || event.charCode == 46">

javax.persistence.PersistenceException: No Persistence provider for EntityManager named customerManager

I had the same problem today. My persistence.xml was in the wrong location. I had to put it in the following path:

project/src/main/resources/META-INF/persistence.xml

Rank function in MySQL

While the most upvoted answer ranks, it doesn't partition, You can do a self Join to get the whole thing partitioned also:

SELECT    a.first_name,
      a.age,
      a.gender,
        count(b.age)+1 as rank
FROM  person a left join person b on a.age>b.age and a.gender=b.gender 
group by  a.first_name,
      a.age,
      a.gender

Use Case

CREATE TABLE person (id int, first_name varchar(20), age int, gender char(1));

INSERT INTO person VALUES (1, 'Bob', 25, 'M');
INSERT INTO person VALUES (2, 'Jane', 20, 'F');
INSERT INTO person VALUES (3, 'Jack', 30, 'M');
INSERT INTO person VALUES (4, 'Bill', 32, 'M');
INSERT INTO person VALUES (5, 'Nick', 22, 'M');
INSERT INTO person VALUES (6, 'Kathy', 18, 'F');
INSERT INTO person VALUES (7, 'Steve', 36, 'M');
INSERT INTO person VALUES (8, 'Anne', 25, 'F');

Answer:

Bill    32  M   4
Bob     25  M   2
Jack    30  M   3
Nick    22  M   1
Steve   36  M   5
Anne    25  F   3
Jane    20  F   2
Kathy   18  F   1

How to see the changes between two commits without commits in-between?

$git log

commit-1(new/latest/recent commit)
commit-2
commit-3
commit-4
*
*
commit-n(first commit)

$git diff commit-2 commit-1

display's all changes between commit-2 to commit-1 (patch of commit-1 alone & equivalent to git diff HEAD~1 HEAD)

similarly $git diff commit-4 commit-1

display's all changes between commit-4 to commit-1 (patch of commit-1, commit-2 & commit-3 together. Equivalent to git diff HEAD~3 HEAD)

$git diff commit-1 commit-2

By changing order commit ID's it is possible to get revert patch . ("$git diff commit-1 commit-2 > revert_patch_of_commit-1.diff")

How to check that Request.QueryString has a specific value or not in ASP.NET?

To check for an empty QueryString you should use Request.QueryString.HasKeys property.

To check if the key is present: Request.QueryString.AllKeys.Contains()

Then you can get ist's Value and do any other check you want, such as isNullOrEmpty, etc.

Why doesn't Dijkstra's algorithm work for negative weight edges?

Dijkstra's Algorithm assumes that all edges are positive weighted and this assumption helps the algorithm run faster ( O(V^2) ) than others which take into account the possibility of negative edges (e.g bellman ford's algorithm with complexity of O(V^3)).

This algorithm wont give the correct result in the following case where A is the source vertex:

enter image description here

Also, Dijkstra's Algorithm may sometimes give correct solution even if there are negative edges. Following is an example of such a case:

enter image description here

It will never detect a negative cycle and always produce a result which will always be incorrect if a negative weight cycle is reachable from the source, as in such a case there exists no shortest path in the graph from the source vertex.

Making Maven run all tests, even when some fail

I just found the "-fae" parameter, which causes Maven to run all tests and not stop on failure.

Cookie blocked/not saved in IFRAME in Internet Explorer

A better solution would be to make an Ajax call inside the iframe to the page that would get/set cookies...

Angular routerLink does not navigate to the corresponding component

I was using routerlink instead of routerLink.

Unable to open project... cannot be opened because the project file cannot be parsed

I got this exact same error because Cordova will allow you to create a project with spaces in it, and Xcode doesn't know how to deal.

Is there a decent wait function in C++?

getchar() provides a simplistic answer (waits for keyboard input). Call Sleep(milliseconds) to sleep before exit. Sleep function (MSDN)

How to determine the last Row used in VBA including blank spaces in between

You're really close. Try using a large row number with End(xlUp)

Function ultimaFilaBlanco(col As String) As Long

        Dim lastRow As Long
        With ActiveSheet
            lastRow = ActiveSheet.Cells(1048576, col).End(xlUp).row
        End With

        ultimaFilaBlanco = lastRow

End Function

Access-Control-Allow-Origin and Angular.js $http

I've had success with express and editing the res.header. Mine matches yours pretty closely but I have a different Allow-Headers as noted below:

res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");

I'm also using Angular and Node/Express, but I don't have the headers called out in the Angular code only the node/express

How to read XML response from a URL in java?

Ok I think I have solves the problem below is a working code

//
package xmlhttp;

import org.jdesktop.http.Response;

import org.jdesktop.http.Session;

import org.jdesktop.http.State;



public class GetXmlHttp{


    public static void main(String[] args) {

        getResponse();

    }

    public static void getResponse()
    {

        final Session session = new Session();

        try {
            String url="http://192.172.2.23:8080/geoserver/wfs?request=GetFeature&version=1.1.0&outputFormat=GML2&typeName=topp:networkcoverage,topp:tehsil&bbox=73.07846689124875,33.67929015631999,73.07946689124876,33.68029015632,EPSG:4326";
            final Response res=session.get(url);
            boolean notDone=true;
            do
            {
                System.out.print(session.getState().toString());

                if(session.getState()==State.DONE)
                {
                    String xml=res.toString();
                    System.out.println(xml);
                    notDone=false;


                }

            }while(notDone);

        } catch (Exception e1) {

            e1.printStackTrace();
        }


    }

}

Unable to connect PostgreSQL to remote database using pgAdmin

In linux terminal try this:

  • sudo service postgresql start : to start the server
  • sudo service postgresql stop : to stop thee server
  • sudo service postgresql status : to check server status

Get the value for a listbox item by index

Here I can't see even a single correct answer for this question (in WinForms tag) and it's strange for such frequent question.

Items of a ListBox control may be DataRowView, Complex Objects, Anonymous types, primary types and other types. Underlying value of an item should be calculated base on ValueMember.

ListBox control has a GetItemText which helps you to get the item text regardless of the type of object you added as item. It really needs such GetItemValue method.

GetItemValue Extension Method

We can create GetItemValue Extension Method to get item value which works like GetItemText:

using System;
using System.Windows.Forms;
using System.ComponentModel;
public static class ListControlExtensions
{
    public static object GetItemValue(this ListControl list, object item)
    {
        if (item == null)
            throw new ArgumentNullException("item");

        if (string.IsNullOrEmpty(list.ValueMember))
            return item;

        var property = TypeDescriptor.GetProperties(item)[list.ValueMember];
        if (property == null)
            throw new ArgumentException(
                string.Format("item doesn't contain '{0}' property or column.",
                list.ValueMember));
        return property.GetValue(item);
    }
}

Using above method you don't need to worry about settings of ListBox and it will return expected Value for an item. It works with List<T>, Array, ArrayList, DataTable, List of Anonymous Types, list of primary types and all other lists which you can use as data source. Here is an example of usage:

//Gets underlying value at index 2 based on settings
this.listBox1.GetItemValue(this.listBox1.Items[2]);

Since we created the GetItemValue method as an extension method, when you want to use the method, don't forget to include the namespace which you put the class in.

This method is applicable on ComboBox and CheckedListBox too.

Brew doctor says: "Warning: /usr/local/include isn't writable."

The only one that worked for me on El Capitan was:

sudo chown -R $(whoami) /usr/local

Get the content of a sharepoint folder with Excel VBA

In addition to:

myFilePath = replace(myFilePath, "/", "\")
myFilePath = replace(myFilePath, "http:", "")

also replace space:

myFilePath = replace(myFilePath, " ", "%20")

Select method of Range class failed via VBA

The correct answer to this particular questions is "don't select". Sometimes you have to select or activate, but 99% of the time you don't. If your code looks like

Select something
Do something to the selection
Select something else
Do something to the selection

You probably need to refactor and consider not selecting.

The error, Method 'Range' of object '_Worksheet' failed, error 1004, that you're getting is because the sheet with the button on it doesn't have a range named "Result". Most (maybe all) properties that return an object have a default Parent object. In this case, you're using the Range property to return a Range object. Because you don't qualify the Range property, Excel uses the default.

The default Parent object can be different based on the circumstances. If your code were in a standard module, then the ActiveSheet would be the default Parent and Excel would try to resolve ActiveSheet.Range("Result"). Your code is in a sheet's class module (the sheet with the button on it). When the unqualified reference is used there, the default Parent is the sheet that's attached to that module. In this case they're the same because the sheet has to be active to click the button, but that isn't always the case.

When Excel gives the error that includes text like '_Object' (yours said '_Worksheet') it's always referring to the default Parent object - the underscore gives that away. Generally the way to fix that is to qualify the reference by being explicit about the parent. But in the case of selecting and activating when you don't need to, it's better to just refactor the code.

Here's one way to write your code without any selecting or activating.

Private Sub cmdRecord_Click()

    Dim shSource As Worksheet
    Dim shDest As Worksheet
    Dim rNext As Range

    'Me refers to the sheet whose class module you're in
    'Me.Parent refers to the workbook
    Set shSource = Me.Parent.Worksheets("BxWsn Simulation")
    Set shDest = Me.Parent.Worksheets("Reslt Record")

    Set rNext = shDest.Cells(shDest.Rows.Count, 1).End(xlUp).Offset(1, 0)

    shSource.Range("Result").Copy
    rNext.PasteSpecial xlPasteFormulasAndNumberFormats

    Application.CutCopyMode = False

End Sub

When I'm in a class module, like the sheet's class module that you're working in, I always try to do things in terms of that class. So I use Me.Parent instead of ActiveWorkbook. It makes the code more portable and prevents unexpected problems when things change.

I'm sure the code you have now runs in milliseconds, so you may not care, but avoiding selecting will definitely speed up your code and you don't have to set ScreenUpdating. That may become important as your code grows or in a different situation.

How to overlay image with color in CSS?

Use mutple backgorund on the element, and use a linear-gradient as your color overlay by declaring both start and end color-stops as the same value.

Note that layers in a multi-background declaration are read much like they are rendered, top-to-bottom, so put your overlay first, then your bg image:

#header {
  background: 
    linear-gradient(to bottom, rgba(100, 100, 0, 0.5), rgba(100, 100, 0, 0.5)) cover,
    url(../img/bg.jpg) 0 0 no-repeat fixed;
  height: 100%;
  overflow: hidden;
  color: #FFFFFF
}

How do I deploy Node.js applications as a single executable file?

There are a number of steps you have to go through to create an installer and it varies for each Operating System. For Example:

C# Syntax - Split String into Array by Comma, Convert To Generic List, and Reverse Order

What your missing here is that .Reverse() is a void method. It's not possible to assign the result of .Reverse() to a variable. You can however alter the order to use Enumerable.Reverse() and get your result

var x = "Tom,Scott,Bob".Split(',').Reverse().ToList<string>()

The difference is that Enumerable.Reverse() returns an IEnumerable<T> instead of being void return

fill an array in C#

Say you want to fill with number 13.

int[] myarr = Enumerable.Range(0, 10).Select(n => 13).ToArray();

or

List<int> myarr = Enumerable.Range(0,10).Select(n => 13).ToList();

if you prefer a list.

Setting max width for body using Bootstrap

Edit

A better way to do this is:

  1. Create your own less file as a main less file ( like bootstrap.less ).

  2. Import all bootstrap less files you need. (in this case, you just need to Import all responsive less files but responsive-1200px-min.less)

  3. If you need to modify anything in original bootstrap less file, you just need to write your own less to overwrite bootstrap's less code. (Just remember to put your less code/file after @import { /* bootstrap's less file */ };).

Original

I have the same problem. This is how I fixed it.

Find the media query:

@media (max-width:1200px) ...

Remove it. (I mean the whole thing , not just @media (max-width:1200px))

Since the default width of Bootstrap is 940px, you don't need to do anything.

If you want to have your own max-width, just modify the css rule in the media query that matches your desired width.

Check if string matches pattern

import re
import sys

prog = re.compile('([A-Z]\d+)+')

while True:
  line = sys.stdin.readline()
  if not line: break

  if prog.match(line):
    print 'matched'
  else:
    print 'not matched'

How to fully clean bin and obj folders within Visual Studio?

Clean will remove all intermediate and final files created by the build process, such as .obj files and .exe or .dll files.

It does not, however, remove the directories where those files get built. I don't see a compelling reason why you need the directories to be removed. Can you explain further?

If you look inside these directories before and after a "Clean", you should see your compiled output get cleaned up.

Using await outside of an async function

As of Node.js 14.3.0 the top-level await is supported.

Required flag: --experimental-top-level-await.

Further details: https://v8.dev/features/top-level-await

How to install sshpass on mac?

Please follow the steps below to install sshpass in mac.

curl -O -L https://fossies.org/linux/privat/sshpass-1.06.tar.gz && tar xvzf sshpass-1.06.tar.gz

cd sshpass-1.06

./configure

sudo make install

Differences between strong and weak in Objective-C

Strong: Basically Used With Properties we used to get or send data from/into another classes. Weak: Usually all outlets, connections are of Weak type from Interface.

Nonatomic: Such type of properties are used in conditions when we don't want to share our outlet or object into different simultaneous Threads. In other words, Nonatomic instance make our properties to deal with one thread at a time. Hopefully it helpful for you.

Pipe to/from the clipboard in Bash script

On Windows (with Cygwin) try cat /dev/clipboard or echo "foo" > /dev/clipboard as mentioned in this article.