Programs & Examples On #Pulpcore

Does a valid XML file require an XML declaration?

Xml declaration is optional so your xml is well-formed without it. But it is recommended to use it so that wrong assumptions are not made by the parsers, specifically about the encoding used.

OnclientClick and OnClick is not working at the same time?

function UpdateClick(btn) {

    for (i = 0; i < Page_Validators.length; i++) {

        ValidatorValidate(Page_Validators[i]);

        if (Page_Validators[i].isvalid == false)

            return false;
    }

    btn.disabled = 'false';

    btn.value = 'Please Wait...';

    return true;
}

React - How to force a function component to render?

You can now, using React hooks

Using react hooks, you can now call useState() in your function component.

useState() will return an array of 2 things:

  1. A value, representing the current state.
  2. Its setter. Use it to update the value.

Updating the value by its setter will force your function component to re-render,
just like forceUpdate does:

import React, { useState } from 'react';

//create your forceUpdate hook
function useForceUpdate(){
    const [value, setValue] = useState(0); // integer state
    return () => setValue(value => value + 1); // update the state to force render
}

function MyComponent() {
    // call your hook here
    const forceUpdate = useForceUpdate();
    
    return (
        <div>
            {/*Clicking on the button will force to re-render like force update does */}
            <button onClick={forceUpdate}>
                Click to re-render
            </button>
        </div>
    );
}

You can find a demo here.

The component above uses a custom hook function (useForceUpdate) which uses the react state hook useState. It increments the component's state's value and thus tells React to re-render the component.

EDIT

In an old version of this answer, the snippet used a boolean value, and toggled it in forceUpdate(). Now that I've edited my answer, the snippet use a number rather than a boolean.

Why ? (you would ask me)

Because once it happened to me that my forceUpdate() was called twice subsequently from 2 different events, and thus it was reseting the boolean value at its original state, and the component never rendered.

This is because in the useState's setter (setValue here), React compare the previous state with the new one, and render only if the state is different.

For div to extend full height

This might be of some help: http://www.webmasterworld.com/forum83/200.htm

A relevant quote:

Most attempts to accomplish this were made by assigning the property and value: div{height:100%} - this alone will not work. The reason is that without a parent defined height, the div{height:100%;} has nothing to factor 100% percent of, and will default to a value of div{height:auto;} - auto is an "as needed value" which is governed by the actual content, so that the div{height:100%} will a=only extend as far as the content demands.

The solution to the problem is found by assigning a height value to the parent container, in this case, the body element. Writing your body stlye to include height 100% supplies the needed value.

html, body { 
  margin:0; 
  padding:0; 
  height:100%; 
}

Rearrange columns using cut

You can use Perl for that:

perl -ane 'print "$F[1] $F[0]\n"' < file.txt
  • -e option means execute the command after it
  • -n means read line by line (open the file, in this case STDOUT, and loop over lines)
  • -a means split such lines to a vector called @F ("F" - like Field). Perl indexes vectors starting from 0 unlike cut which indexes fields starting form 1.
  • You can add -F pattern (with no space between -F and pattern) to use pattern as a field separator when reading the file instead of the default whitespace

The advantage of running perl is that (if you know Perl) you can do much more computation on F than rearranging columns.

How to check for an undefined or null variable in JavaScript?

Best way to compare undefined or null or 0 with ES5 and ES6 standards

 if ((Boolean(some_variable_1) && Boolean(some_variable_2)) === false) {
    // do something
    }

automatically execute an Excel macro on a cell change

Handle the Worksheet_Change event or the Workbook_SheetChange event.

The event handlers take an argument "Target As Range", so you can check if the range that's changing includes the cell you're interested in.

How does "make" app know default target to build if no target is specified?

GNU Make also allows you to specify the default make target using a special variable called .DEFAULT_GOAL. You can even unset this variable in the middle of the Makefile, causing the next target in the file to become the default target.

Ref: The Gnu Make manual - Special Variables

Can I write into the console in a unit test? If yes, why doesn't the console window open?

I have an easier solution (that I used myself recently, for a host of lazy reasons). Add this method to the class you are working in:

public static void DumbDebug(string message)
{
    File.WriteAllText(@"C:\AdHocConsole\" + message + ".txt", "this is really dumb. I wish Microsoft had more obvious solutions to its solutions problems.");
}

Then...open up the directory AdHocConsole, and order by created time. Make sure when you add your 'print statements'. They are distinct though, else there will be juggling.

How to list all `env` properties within jenkins pipeline job?

another way to get exactly the output mentioned in the question:

envtext= "printenv".execute().text
envtext.split('\n').each
{   envvar=it.split("=")
    println envvar[0]+" is "+envvar[1]
}

This can easily be extended to build a map with a subset of env vars matching a criteria:

envdict=[:]
envtext= "printenv".execute().text
envtext.split('\n').each
{   envvar=it.split("=")
    if (envvar[0].startsWith("GERRIT_"))
        envdict.put(envvar[0],envvar[1])
}    
envdict.each{println it.key+" is "+it.value}

Using momentjs to convert date to epoch then back to date

http://momentjs.com/docs/#/displaying/unix-timestamp/

You get the number of unix seconds, not milliseconds!

You you need to multiply it with 1000 or using valueOf() and don't forget to use a formatter, since you are using a non ISO 8601 format. And if you forget to pass the formatter, the date will be parsed in the UTC timezone or as an invalid date.

moment("10/15/2014 9:00", "MM/DD/YYYY HH:mm").valueOf()

React ignores 'for' attribute of the label element

The for attribute is called htmlFor for consistency with the DOM property API. If you're using the development build of React, you should have seen a warning in your console about this.

VBA Subscript out of range - error 9

Suggest the following simplification: capture return value from Workbooks.Add instead of subscripting Windows() afterward, as follows:

Set wkb = Workbooks.Add
wkb.SaveAs ...

wkb.Activate ' instead of Windows(expression).Activate


General Philosophy Advice:

Avoid use Excel's built-ins: ActiveWorkbook, ActiveSheet, and Selection: capture return values, and, favor qualified expressions instead.

Use the built-ins only once and only in outermost macros(subs) and capture at macro start, e.g.

Set wkb = ActiveWorkbook
Set wks = ActiveSheet
Set sel = Selection

During and within macros do not rely on these built-in names, instead capture return values, e.g.

Set wkb = Workbooks.Add 'instead of Workbooks.Add without return value capture
wkb.Activate 'instead of Activeworkbook.Activate

Also, try to use qualified expressions, e.g.

wkb.Sheets("Sheet3").Name = "foo" ' instead of Sheets("Sheet3").Name = "foo"

or

Set newWks = wkb.Sheets.Add
newWks.Name = "bar" 'instead of ActiveSheet.Name = "bar"

Use qualified expressions, e.g.

newWks.Name = "bar" 'instead of `xyz.Select` followed by Selection.Name = "bar" 

These methods will work better in general, give less confusing results, will be more robust when refactoring (e.g. moving lines of code around within and between methods) and, will work better across versions of Excel. Selection, for example, changes differently during macro execution from one version of Excel to another.

Also please note that you'll likely find that you don't need to .Activate nearly as much when using more qualified expressions. (This can mean the for the user the screen will flicker less.) Thus the whole line Windows(expression).Activate could simply be eliminated instead of even being replaced by wkb.Activate.

(Also note: I think the .Select statements you show are not contributing and can be omitted.)

(I think that Excel's macro recorder is responsible for promoting this more fragile style of programming using ActiveSheet, ActiveWorkbook, Selection, and Select so much; this style leaves a lot of room for improvement.)

How can I check if a scrollbar is visible?

You can do this using a combination of the Element.scrollHeight and Element.clientHeight attributes.

According to MDN:

The Element.scrollHeight read-only attribute is a measurement of the height of an element's content, including content not visible on the screen due to overflow. The scrollHeight value is equal to the minimum clientHeight the element would require in order to fit all the content in the viewpoint without using a vertical scrollbar. It includes the element padding but not its margin.

And:

The Element.clientHeight read-only property returns the inner height of an element in pixels, including padding but not the horizontal scrollbar height, border, or margin.

clientHeight can be calculated as CSS height + CSS padding - height of horizontal scrollbar (if present).

Therefore, the element will display a scrollbar if the scroll height is greater than the client height, so the answer to your question is:

function scrollbarVisible(element) {
  return element.scrollHeight > element.clientHeight;
}

How do I read the first line of a file using cat?

Adding one more obnoxious alternative to the list:

perl -pe'$.<=1||last' file
# or 
perl -pe'$.<=1||last' < file
# or
cat file | perl -pe'$.<=1||last'

How to get the changes on a branch in Git

Similar to several answers like Alex V's and NDavis, but none of them are quite the same.

When already in the branch in question

Using:

git diff master...

Which combines several features:

  • it's super short
  • shows the actual changes

Update:

This should probably be git diff master, but also this shows the diff, not the commits as the question specified.

Iframe transparent background

Set the background color of the src to none and allow transparencey.

[WITHIN SCR PAGE STYLE]
<style type="text/css">
    body
    {
        background:none transparent;
    }
</style>

[IFRAME]
<iframe src="#" allowtransparency="true">Error, iFrame failed to load.</iframe>

NOTE: I code my CSS a little different to how everyone else does.

Differences between INDEX, PRIMARY, UNIQUE, FULLTEXT in MySQL?

Differences

  • KEY or INDEX refers to a normal non-unique index. Non-distinct values for the index are allowed, so the index may contain rows with identical values in all columns of the index. These indexes don't enforce any restraints on your data so they are used only for access - for quickly reaching certain ranges of records without scanning all records.

  • UNIQUE refers to an index where all rows of the index must be unique. That is, the same row may not have identical non-NULL values for all columns in this index as another row. As well as being used to quickly reach certain record ranges, UNIQUE indexes can be used to enforce restraints on data, because the database system does not allow the distinct values rule to be broken when inserting or updating data.

    Your database system may allow a UNIQUE index to be applied to columns which allow NULL values, in which case two rows are allowed to be identical if they both contain a NULL value (the rationale here is that NULL is considered not equal to itself). Depending on your application, however, you may find this undesirable: if you wish to prevent this, you should disallow NULL values in the relevant columns.

  • PRIMARY acts exactly like a UNIQUE index, except that it is always named 'PRIMARY', and there may be only one on a table (and there should always be one; though some database systems don't enforce this). A PRIMARY index is intended as a primary means to uniquely identify any row in the table, so unlike UNIQUE it should not be used on any columns which allow NULL values. Your PRIMARY index should be on the smallest number of columns that are sufficient to uniquely identify a row. Often, this is just one column containing a unique auto-incremented number, but if there is anything else that can uniquely identify a row, such as "countrycode" in a list of countries, you can use that instead.

    Some database systems (such as MySQL's InnoDB) will store a table's records on disk in the order in which they appear in the PRIMARY index.

  • FULLTEXT indexes are different from all of the above, and their behaviour differs significantly between database systems. FULLTEXT indexes are only useful for full text searches done with the MATCH() / AGAINST() clause, unlike the above three - which are typically implemented internally using b-trees (allowing for selecting, sorting or ranges starting from left most column) or hash tables (allowing for selection starting from left most column).

    Where the other index types are general-purpose, a FULLTEXT index is specialised, in that it serves a narrow purpose: it's only used for a "full text search" feature.

Similarities

  • All of these indexes may have more than one column in them.

  • With the exception of FULLTEXT, the column order is significant: for the index to be useful in a query, the query must use columns from the index starting from the left - it can't use just the second, third or fourth part of an index, unless it is also using the previous columns in the index to match static values. (For a FULLTEXT index to be useful to a query, the query must use all columns of the index.)

How to disassemble a memory range with GDB?

Do you only want to disassemble your actual main? If so try this:

(gdb) info line main 
(gdb) disas STARTADDRESS ENDADDRESS

Like so:

USER@MACHINE /cygdrive/c/prog/dsa
$ gcc-3.exe -g main.c

USER@MACHINE /cygdrive/c/prog/dsa
$ gdb a.exe
GNU gdb 6.8.0.20080328-cvs (cygwin-special)
...
(gdb) info line main
Line 3 of "main.c" starts at address 0x401050 <main> and ends at 0x401075 <main+
(gdb) disas 0x401050 0x401075
Dump of assembler code from 0x401050 to 0x401075:
0x00401050 <main+0>:    push   %ebp
0x00401051 <main+1>:    mov    %esp,%ebp
0x00401053 <main+3>:    sub    $0x18,%esp
0x00401056 <main+6>:    and    $0xfffffff0,%esp
0x00401059 <main+9>:    mov    $0x0,%eax
0x0040105e <main+14>:   add    $0xf,%eax
0x00401061 <main+17>:   add    $0xf,%eax
0x00401064 <main+20>:   shr    $0x4,%eax
0x00401067 <main+23>:   shl    $0x4,%eax
0x0040106a <main+26>:   mov    %eax,-0xc(%ebp)
0x0040106d <main+29>:   mov    -0xc(%ebp),%eax
0x00401070 <main+32>:   call   0x4010c4 <_alloca>
End of assembler dump.

I don't see your system interrupt call however. (its been a while since I last tried to make a system call in assembly. INT 21h though, last I recall

How do I add a newline to a TextView in Android?

Make sure your \n is in "\n" for it to work.

How to change the playing speed of videos in HTML5?

(Tested in Chrome while playing videos on YouTube, but should work anywhere--especially useful for speeding up online training videos).

For anyone wanting to add these as "bookmarklets" (bookmarks) to your browser, use these browser bookmark names and URLs, and add each of the following bookmarks to the top of your browser:

enter image description here

Name: 0.5x
URL:

javascript:

document.querySelector('video').playbackRate = 0.5;

Name: 1.0x
URL:

javascript:

document.querySelector('video').playbackRate = 1.0;

Name: 1.5x
URL:

javascript:

document.querySelector('video').playbackRate = 1.5;

Name: 2.0x
URL:

javascript:

document.querySelector('video').playbackRate = 2.0;

References:

  1. The main answer by Jeremy Visser
  2. Copied from my GitHub gist here: https://gist.github.com/ElectricRCAircraftGuy/0a788876da1386ca0daecbe78b4feb44#other-bookmarklets
    1. Get other bookmarklets here too, such as for aiding you on GitHub.

How to access cookies in AngularJS?

AngularJS provides ngCookies module and $cookieStore service to use Browser Cookies.

We need to add angular-cookies.min.js file to use cookie feature.

Here is some method of AngularJS Cookie.

  • get(key); // This method returns the value of given cookie key.

  • getObject(key); //This method returns the deserialized value of given cookie key.

  • getAll(); //This method returns a key value object with all the cookies.

  • put(key, value, [options]); //This method sets a value for given cookie key.

  • remove(key, [options]); //This method remove given cookie.

Example

Html

<!DOCTYPE html>
<html ng-app="myApp">
<head>
<script src="//ajax.googleapis.com/ajax/libs/angularjs/1.3.0-beta.1/angular.min.js"></script>
<script src="//ajax.googleapis.com/ajax/libs/angularjs/1.3.0-beta.1/angular-cookies.min.js"></script>
</head>
<body ng-controller="MyController">
{{cookiesUserName}} loves {{cookietechnology}}.
</body>
</html>

JavaScript

var myApp = angular.module('myApp', ['ngCookies']);
myApp.controller('MyController', ['$scope', '$cookies', '$cookieStore', '$window', function($scope, $cookies, $cookieStore, $window) {
$cookies.userName = 'Max Joe';
$scope.cookiesUserName = $cookies.userName;
$cookieStore.put('technology', 'Web');
$scope.cookietechnology = $cookieStore.get('technology'); }]);

I have Taken reference from http://www.tutsway.com/simple-example-of-cookie-in-angular-js.php.

open the file upload dialogue box onclick the image

  <label for="profileImage"> 
  <a style="cursor: pointer;"><em class="fa fa-upload"></em> Change Profile 
  Image</a></label> 
  <input type="file" name="profileImage" id="profileImage" style="display: none;">

jQuery selector to get form by name

    // this will give all the forms on the page.

    $('form')

   // If you know the name of form then.

    $('form[name="myFormName"]')

  //  If you don't know know the name but the position (starts with 0)

    $('form:eq(1)')  // 2nd form will be fetched.

Add marker to Google Map on Click

Currently the method to add the listener to the map would be

map.addListener('click', function(e) {
    placeMarker(e.latLng, map);
});

And not

google.maps.event.addListener(map, 'click', function(e) {
    placeMarker(e.latLng, map);
});

Reference

How to change the height of a <br>?

Interestingly, if the break tag is written in full-form as follows:

<br></br>

then the CSS line-height:145% works. If the break tag is written as:

<br> or 
<br/> 

then it doesn't work, at least in Chrome, IE and firefox. Weird!

How to get textLabel of selected row in swift?

In swift 4 : by overriding method

override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        let storyboard = UIStoryboard(name : "Main", bundle: nil)
        let next vc = storyboard.instantiateViewController(withIdentifier: "nextvcIdentifier") as! NextViewController

       self.navigationController?.pushViewController(prayerVC, animated: true)
}

How to search for a string in text files?

As Jeffrey Said, you are not checking the value of check(). In addition, your check() function is not returning anything. Note the difference:

def check():
    with open('example.txt') as f:
        datafile = f.readlines()
    found = False  # This isn't really necessary
    for line in datafile:
        if blabla in line:
            # found = True # Not necessary
            return True
    return False  # Because you finished the search without finding

Then you can test the output of check():

if check():
    print('True')
else:
    print('False')

How to get file size in Java

Did a quick google. Seems that to find the file size you do this,

long size = f.length();

The differences between the three methods you posted can be found here

getFreeSpace() and getTotalSpace() are pretty self explanatory, getUsableSpace() seems to be the space that the JVM can use, which in most cases will be the same as the amount of free space.

How to pass parameters to a modal?

You should really use Angular UI for that needs. Check it out: Angular UI Dialog

In a nutshell, with Angular UI dialog, you can pass variable from a controller to the dialog controller using resolve. Here's your "from" controller:

var d = $dialog.dialog({
  backdrop: true,
  keyboard: true,
  backdropClick: true,
  templateUrl:  '<url_of_your_template>',
  controller: 'MyDialogCtrl',
  // Interesting stuff here.
  resolve: {
    username: 'foo'
  }
});

d.open();

And in your dialog controller:

angular.module('mymodule')
  .controller('MyDialogCtrl', function ($scope, username) {
  // Here, username is 'foo'
  $scope.username = username;
}

EDIT: Since the new version of the ui-dialog, the resolve entry becomes:

resolve: { username: function () { return 'foo'; } }

Difference between two dates in MySQL

SELECT TIMESTAMPDIFF(HOUR,NOW(),'2013-05-15 10:23:23')
   calculates difference in hour.(for days--> you have to define day replacing hour
SELECT DATEDIFF('2012-2-2','2012-2-1')

SELECT TO_DAYS ('2012-2-2')-TO_DAYS('2012-2-1')

How to create major and minor gridlines with different linestyles in Python

Actually, it is as simple as setting major and minor separately:

In [9]: plot([23, 456, 676, 89, 906, 34, 2345])
Out[9]: [<matplotlib.lines.Line2D at 0x6112f90>]

In [10]: yscale('log')

In [11]: grid(b=True, which='major', color='b', linestyle='-')

In [12]: grid(b=True, which='minor', color='r', linestyle='--')

The gotcha with minor grids is that you have to have minor tick marks turned on too. In the above code this is done by yscale('log'), but it can also be done with plt.minorticks_on().

enter image description here

What is a race condition?

What is a race condition?

The situation when the process is critically dependent on the sequence or timing of other events.

For example, Processor A and processor B both needs identical resource for their execution.

How do you detect them?

There are tools to detect race condition automatically:

How do you handle them?

Race condition can be handled by Mutex or Semaphores. They act as a lock allows a process to acquire a resource based on certain requirements to prevent race condition.

How do you prevent them from occurring?

There are various ways to prevent race condition, such as Critical Section Avoidance.

  1. No two processes simultaneously inside their critical regions. (Mutual Exclusion)
  2. No assumptions are made about speeds or the number of CPUs.
  3. No process running outside its critical region which blocks other processes.
  4. No process has to wait forever to enter its critical region. (A waits for B resources, B waits for C resources, C waits for A resources)

Could not create SSL/TLS secure channel, despite setting ServerCertificateValidationCallback

If you are using a new domain name, and you have done all the above and you are still getting the same error, check to see if you clear the DNS cache on your PC. Clear your DNS for more details.

Windows® 8

To clear your DNS cache if you use Windows 8, perform the following steps:

On your keyboard, press Win+X to open the WinX Menu.

Right-click Command Prompt and select Run as Administrator.

Run the following command:

ipconfig /flushdns

If the command succeeds, the system returns the following message:

Windows IP configuration successfully flushed the DNS Resolver Cache.

Windows® 7

To clear your DNS cache if you use Windows 7, perform the following steps:

Click Start.

Enter cmd in the Start menu search text box.

Right-click Command Prompt and select Run as Administrator.

Run the following command:

ipconfig /flushdns

If the command succeeds, the system returns the following message: Windows IP configuration successfully flushed the DNS Resolver Cache.

How to set bot's status

Simple way to initiate the message on startup:

bot.on('ready', () => {
    bot.user.setStatus('available')
    bot.user.setPresence({
        game: {
            name: 'with depression',
            type: "STREAMING",
            url: "https://www.twitch.tv/monstercat"
        }
    });
});

You can also just declare it elsewhere after startup, to change the message as needed:

bot.user.setPresence({ game: { name: 'with depression', type: "streaming", url: "https://www.twitch.tv/monstercat"}}); 

Why does JavaScript only work after opening developer tools in IE once?

HTML5 Boilerplate has a nice pre-made code for console problems fixing:

// Avoid `console` errors in browsers that lack a console.
(function() {
    var method;
    var noop = function () {};
    var methods = [
        'assert', 'clear', 'count', 'debug', 'dir', 'dirxml', 'error',
        'exception', 'group', 'groupCollapsed', 'groupEnd', 'info', 'log',
        'markTimeline', 'profile', 'profileEnd', 'table', 'time', 'timeEnd',
        'timeStamp', 'trace', 'warn'
    ];
    var length = methods.length;
    var console = (window.console = window.console || {});

    while (length--) {
        method = methods[length];

        // Only stub undefined methods.
        if (!console[method]) {
            console[method] = noop;
        }
    }
}());

As @plus- pointed in comments, latest version is available on their GitHub page

Execute jQuery function after another function completes

You can use below code

$.when( Typer() ).done(function() {
       playBGM();
});

Typescript: How to extend two classes?

Unfortunately typescript does not support multiple inheritance. Therefore there is no completely trivial answer, you will probably have to restructure your program

Here are a few suggestions:

  • If this additional class contains behaviour that many of your subclasses share, it makes sense to insert it into the class hierarchy, somewhere at the top. Maybe you could derive the common superclass of Sprite, Texture, Layer, ... from this class ? This would be a good choice, if you can find a good spot in the type hirarchy. But I would not recommend to just insert this class at a random point. Inheritance expresses an "Is a - relationship" e.g. a dog is an animal, a texture is an instance of this class. You would have to ask yourself, if this really models the relationship between the objects in your code. A logical inheritance tree is very valuable

  • If the additional class does not fit logically into the type hierarchy, you could use aggregation. That means that you add an instance variable of the type of this class to a common superclass of Sprite, Texture, Layer, ... Then you can access the variable with its getter/setter in all subclasses. This models a "Has a - relationship".

  • You could also convert your class into an interface. Then you could extend the interface with all your classes but would have to implement the methods correctly in each class. This means some code redundancy but in this case not much.

You have to decide for yourself which approach you like best. Personally I would recommend to convert the class to an interface.

One tip: Typescript offers properties, which are syntactic sugar for getters and setters. You might want to take a look at this: http://blogs.microsoft.co.il/gilf/2013/01/22/creating-properties-in-typescript/

SQL - using alias in Group By

SQL is implemented as if a query was executed in the following order:

  1. FROM clause
  2. WHERE clause
  3. GROUP BY clause
  4. HAVING clause
  5. SELECT clause
  6. ORDER BY clause

For most relational database systems, this order explains which names (columns or aliases) are valid because they must have been introduced in a previous step.

So in Oracle and SQL Server, you cannot use a term in the GROUP BY clause that you define in the SELECT clause because the GROUP BY is executed before the SELECT clause.

There are exceptions though: MySQL and Postgres seem to have additional smartness that allows it.

Disabling the button after once click

Use modern Js events, with "once"!

const button = document.getElementById(btnId);
button.addEventListener("click", function() {
    // Submit form
}, {once : true});

// Disabling works too, but this is a more standard approach for general one-time events

Documentation, CanIUse

How to capture Curl output to a file?

There are several options to make curl output to a file

 # saves it to myfile.txt
curl http://www.example.com/data.txt -o myfile.txt

# The #1 will get substituted with the url, so the filename contains the url
curl http://www.example.com/data.txt -o "file_#1.txt" 

# saves to data.txt, the filename extracted from the URL
curl http://www.example.com/data.txt -O 

# saves to filename determined by the Content-Disposition header sent by the server.
curl http://www.example.com/data.txt -O -J 

Rails params explained?

Basically, parameters are user specified data to rails application.

When you post a form, you do it generally with POST request as opposed to GET request. You can think normal rails requests as GET requests, when you browse the site, if it helps.

When you submit a form, the control is thrown back to the application. How do you get the values you have submitted to the form? params is how.

About your code. @vote = Vote.new params[:vote] creates new Vote to database using data of params[:vote]. Given your form user submitted was named under name :vote, all data of it is in this :vote field of the hash.

Next two lines are used to get item and uid user has submitted to the form.

@extant = Vote.find(:last, :conditions => ["item_id = ? AND user_id = ?", item, uid])

finds newest, or last inserted, vote from database with conditions item_id = item and user_id = uid.

Next lines takes last vote time and current time.

How to prevent ENTER keypress to submit a web form?

put into javascript external file

   (function ($) {
 $(window).keydown(function (event) {  

    if (event.keyCode == 13) {

        return false;
    }
});

 })(jQuery);

or somewhere inside body tag

<script>


$(document).ready(function() {
    $(window).keydown(function(event) {
        alert(1);

        if(event.keyCode == 13) {

            return false;
        }
    });
});

</script>

Convert Java String to sql.Timestamp

Here's the intended way to convert a String to a Date:

String timestamp = "2011-10-02-18.48.05.123";
DateFormat df = new SimpleDateFormat("yyyy-MM-dd-kk.mm.ss.SSS");
Date parsedDate = df.parse(timestamp);

Admittedly, it only has millisecond resolution, but in all services slower than Twitter, that's all you'll need, especially since most machines don't even track down to the actual nanoseconds.

Can't connect to HTTPS site using cURL. Returns 0 length content instead. What can I do?

You should also try checking the error messages in curl_error(). You might need to do this once after each curl_* function.

http://www.php.net/curl_error

How do I connect C# with Postgres?

Here is a walkthrough, Using PostgreSQL in your C# (.NET) application (An introduction):

In this article, I would like to show you the basics of using a PostgreSQL database in your .NET application. The reason why I'm doing this is the lack of PostgreSQL articles on CodeProject despite the fact that it is a very good RDBMS. I have used PostgreSQL back in the days when PHP was my main programming language, and I thought.... well, why not use it in my C# application.

Other than that you will need to give us some specific problems that you are having so that we can help diagnose the problem.

How do I use method overloading in Python?

In Python, overloading is not an applied concept. However, if you are trying to create a case where, for instance, you want one initializer to be performed if passed an argument of type foo and another initializer for an argument of type bar then, since everything in Python is handled as object, you can check the name of the passed object's class type and write conditional handling based on that.

class A:
   def __init__(self, arg)
      # Get the Argument's class type as a String
      argClass = arg.__class__.__name__

      if argClass == 'foo':
         print 'Arg is of type "foo"'
         ...
      elif argClass == 'bar':
         print 'Arg is of type "bar"'
         ...
      else
         print 'Arg is of a different type'
         ...

This concept can be applied to multiple different scenarios through different methods as needed.

Could you explain STA and MTA?

I find the existing explanations too gobbledygook. Here's my explanation in plain English:

STA: If a thread creates a COM object that's set to STA (when calling CoCreateXXX you can pass a flag that sets the COM object to STA mode), then only this thread can access this COM object (that's what STA means - Single Threaded Apartment), other thread trying to call methods on this COM object is under the hood silently turned into delivering messages to the thread that creates(owns) the COM object. This is very much like the fact that only the thread that created a UI control can access it directly. And this mechanism is meant to prevent complicated lock/unlock operations.

MTA: If a thread creates a COM object that's set to MTA, then pretty much every thread can directly call methods on it.

That's pretty much the gist of it. Although technically there're some details I didn't mention, such as in the 'STA' paragraph, the creator thread must itself be STA. But this is pretty much all you have to know to understand STA/MTA/NA.

Best way to overlay an ESRI shapefile on google maps?

as of 12.03.2019 FusionTables is no more...

Import the Shapefile into Google FusionTables ( http://www.google.com/fusiontables ) using http://www.shpescape.com/ and from there you can use the data in a number of ways, eg. display it using GoogleMaps.

Error:(9, 5) error: resource android:attr/dialogCornerRadius not found

I had the exact same issue. The following thread helped me solve it. Just set your Compile SDK version to Android P.

https://stackoverflow.com/a/49172361/1542720

I fixed this issue by selecting:

API 27+: Android API 27, P preview (Preview)

in the project structure settings. the following image shows my settings. The 13 errors that were coming while building the app, have disappeared.

Gradle settings

Execute write on doc: It isn't possible to write into a document from an asynchronously-loaded external script unless it is explicitly opened.

In case this is useful to anyone I had this same issue. I was bringing in a footer into a web page via jQuery. Inside that footer were some Google scripts for ads and retargeting. I had to move those scripts from the footer and place them directly in the page and that eliminated the notice.

Java: How to convert String[] to List or Set

Collections.addAll provides the shortest (one-line) receipt

Having

String[] array = {"foo", "bar", "baz"}; 
Set<String> set = new HashSet<>();

You can do as below

Collections.addAll(set, array); 

Column/Vertical selection with Keyboard in SublimeText 3

The SublimeText 3 Column-Select plugin should be all you need. Install that, then make sure you have something like the following in your 'Default (OSX).sublime-keymap' file:

    // Column mode
    { "keys": ["ctrl+alt+up"], "command": "column_select", "args": {"by": "lines", "forward": false}},
    { "keys": ["ctrl+alt+down"], "command": "column_select", "args": {"by": "lines", "forward": true}},
    { "keys": ["ctrl+alt+pageup"], "command": "column_select", "args": {"by": "pages", "forward": false}},
    { "keys": ["ctrl+alt+pagedown"], "command": "column_select", "args": {"by": "pages", "forward": true}},
    { "keys": ["ctrl+alt+home"], "command": "column_select", "args": {"by": "all", "forward": false}},
    { "keys": ["ctrl+alt+end"], "command": "column_select", "args": {"by": "all", "forward": true}}

What exactly about it did not work for you?

Why does Node.js' fs.readFile() return a buffer instead of string?

Async:

fs.readFile('test.txt', 'utf8', callback);

Sync:

var content = fs.readFileSync('test.txt', 'utf8');

Add event handler for body.onload by javascript within <body> part

body.addEventListener("load", init(), false);

That init() is saying run this function now and assign whatever it returns to the load event.

What you want is to assign the reference to the function, not the result. So you need to drop the ().

body.addEventListener("load", init, false);

Also you should be using window.onload and not body.onload

addEventListener is supported in most browsers except IE 8.

How to open, read, and write from serial port in C?

I wrote this a long time ago (from years 1985-1992, with just a few tweaks since then), and just copy and paste the bits needed into each project.

You must call cfmakeraw on a tty obtained from tcgetattr. You cannot zero-out a struct termios, configure it, and then set the tty with tcsetattr. If you use the zero-out method, then you will experience unexplained intermittent failures, especially on the BSDs and OS X. "Unexplained intermittent failures" include hanging in read(3).

#include <errno.h>
#include <fcntl.h> 
#include <string.h>
#include <termios.h>
#include <unistd.h>

int
set_interface_attribs (int fd, int speed, int parity)
{
        struct termios tty;
        if (tcgetattr (fd, &tty) != 0)
        {
                error_message ("error %d from tcgetattr", errno);
                return -1;
        }

        cfsetospeed (&tty, speed);
        cfsetispeed (&tty, speed);

        tty.c_cflag = (tty.c_cflag & ~CSIZE) | CS8;     // 8-bit chars
        // disable IGNBRK for mismatched speed tests; otherwise receive break
        // as \000 chars
        tty.c_iflag &= ~IGNBRK;         // disable break processing
        tty.c_lflag = 0;                // no signaling chars, no echo,
                                        // no canonical processing
        tty.c_oflag = 0;                // no remapping, no delays
        tty.c_cc[VMIN]  = 0;            // read doesn't block
        tty.c_cc[VTIME] = 5;            // 0.5 seconds read timeout

        tty.c_iflag &= ~(IXON | IXOFF | IXANY); // shut off xon/xoff ctrl

        tty.c_cflag |= (CLOCAL | CREAD);// ignore modem controls,
                                        // enable reading
        tty.c_cflag &= ~(PARENB | PARODD);      // shut off parity
        tty.c_cflag |= parity;
        tty.c_cflag &= ~CSTOPB;
        tty.c_cflag &= ~CRTSCTS;

        if (tcsetattr (fd, TCSANOW, &tty) != 0)
        {
                error_message ("error %d from tcsetattr", errno);
                return -1;
        }
        return 0;
}

void
set_blocking (int fd, int should_block)
{
        struct termios tty;
        memset (&tty, 0, sizeof tty);
        if (tcgetattr (fd, &tty) != 0)
        {
                error_message ("error %d from tggetattr", errno);
                return;
        }

        tty.c_cc[VMIN]  = should_block ? 1 : 0;
        tty.c_cc[VTIME] = 5;            // 0.5 seconds read timeout

        if (tcsetattr (fd, TCSANOW, &tty) != 0)
                error_message ("error %d setting term attributes", errno);
}


...
char *portname = "/dev/ttyUSB1"
 ...
int fd = open (portname, O_RDWR | O_NOCTTY | O_SYNC);
if (fd < 0)
{
        error_message ("error %d opening %s: %s", errno, portname, strerror (errno));
        return;
}

set_interface_attribs (fd, B115200, 0);  // set speed to 115,200 bps, 8n1 (no parity)
set_blocking (fd, 0);                // set no blocking

write (fd, "hello!\n", 7);           // send 7 character greeting

usleep ((7 + 25) * 100);             // sleep enough to transmit the 7 plus
                                     // receive 25:  approx 100 uS per char transmit
char buf [100];
int n = read (fd, buf, sizeof buf);  // read up to 100 characters if ready to read

The values for speed are B115200, B230400, B9600, B19200, B38400, B57600, B1200, B2400, B4800, etc. The values for parity are 0 (meaning no parity), PARENB|PARODD (enable parity and use odd), PARENB (enable parity and use even), PARENB|PARODD|CMSPAR (mark parity), and PARENB|CMSPAR (space parity).

"Blocking" sets whether a read() on the port waits for the specified number of characters to arrive. Setting no blocking means that a read() returns however many characters are available without waiting for more, up to the buffer limit.


Addendum:

CMSPAR is needed only for choosing mark and space parity, which is uncommon. For most applications, it can be omitted. My header file /usr/include/bits/termios.h enables definition of CMSPAR only if the preprocessor symbol __USE_MISC is defined. That definition occurs (in features.h) with

#if defined _BSD_SOURCE || defined _SVID_SOURCE
 #define __USE_MISC     1
#endif

The introductory comments of <features.h> says:

/* These are defined by the user (or the compiler)
   to specify the desired environment:

...
   _BSD_SOURCE          ISO C, POSIX, and 4.3BSD things.
   _SVID_SOURCE         ISO C, POSIX, and SVID things.
...
 */

How can I style a PHP echo text?

Store your results in variables, and use them in your HTML and add the necessary styling.

$usercity = $ip['cityName'];
$usercountry = $ip['countryName'];

And in the HTML, you could do:

<div id="userdetails">
<p> User's IP: <?php echo $usercity; ?> </p>
<p> Country: <?php echo $usercountry; ?> </p>
</div>

Now, you can simply add the styles for country class in your CSS, like so:

#userdetails {

/* styles go here */

}

Alternatively, you could also use this in your HTML:

<p style="font-size:15px; font-color: green;"><?php echo $userip; ?> </p>
<p style="font-size:15px; font-color: green;"><?php echo $usercountry; ?> </p>

Hope this helps!

How to change the DataTable Column Name?

Rename the Column by doing the following:

dataTable.Columns["ColumnName"].ColumnName = "newColumnName";

matplotlib has no attribute 'pyplot'

pyplot is a sub-module of matplotlib which doesn't get imported with a simple import matplotlib.

>>> import matplotlib
>>> print matplotlib.pyplot
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'module' object has no attribute 'pyplot'
>>> import matplotlib.pyplot
>>> 

It seems customary to do: import matplotlib.pyplot as plt at which time you can use the various functions and classes it contains:

p = plt.plot(...)

Browser Caching of CSS files

That depends on what headers you are sending along with your CSS files. Check your server configuration as you are probably not sending them manually. Do a google search for "http caching" to learn about different caching options you can set. You can force the browser to download a fresh copy of the file everytime it loads it for instance, or you can cache the file for one week...

Erase whole array Python

Well yes arrays do exist, and no they're not different to lists when it comes to things like del and append:

>>> from array import array
>>> foo = array('i', range(5))
>>> foo
array('i', [0, 1, 2, 3, 4])
>>> del foo[:]
>>> foo
array('i')
>>> foo.append(42)
>>> foo
array('i', [42])
>>>

Differences worth noting: you need to specify the type when creating the array, and you save storage at the expense of extra time converting between the C type and the Python type when you do arr[i] = expression or arr.append(expression), and lvalue = arr[i]

Does Notepad++ show all hidden characters?

Yes, it does. The way to enable this depends on your version of Notepad++. On newer versions you can use:

Menu View ? Show Symbol ? *Show All Characters`

or

Menu View ? Show Symbol ? Show White Space and TAB

(Thanks to bers' comment and bkaid's answers below for these updated locations.)


On older versions you can look for:

Menu View ? Show all characters

or

Menu View ? Show White Space and TAB

How do synchronized static methods work in Java and can I use it for loading Hibernate entities?

How the synchronized Java keyword works

When you add the synchronized keyword to a static method, the method can only be called by a single thread at a time.

In your case, every method call will:

  • create a new SessionFactory
  • create a new Session
  • fetch the entity
  • return the entity back to the caller

However, these were your requirements:

  • I want this to prevent access to info to the same DB instance.
  • preventing getObjectById being called for all classes when it is called by a particular class

So, even if the getObjectById method is thread-safe, the implementation is wrong.

SessionFactory best practices

The SessionFactory is thread-safe, and it's a very expensive object to create as it needs to parse the entity classes and build the internal entity metamodel representation.

So, you shouldn't create the SessionFactory on every getObjectById method call.

Instead, you should create a singleton instance for it.

private static final SessionFactory sessionFactory = new Configuration()
    .configure()
    .buildSessionFactory();

The Session should always be closed

You didn't close the Session in a finally block, and this can leak database resources if an exception is thrown when loading the entity.

According to the Session.load method JavaDoc might throw a HibernateException if the entity cannot be found in the database.

You should not use this method to determine if an instance exists (use get() instead). Use this only to retrieve an instance that you assume exists, where non-existence would be an actual error.

That's why you need to use a finally block to close the Session, like this:

public static synchronized Object getObjectById (Class objclass, Long id) {    
     Session session = null;
     try {
         session = sessionFactory.openSession();
         return session.load(objclass, id);
     } finally {
         if(session != null) {
             session.close(); 
         }
     }
 }

Preventing multi-thread access

In your case, you wanted to make sure only one thread gets access to that particular entity.

But the synchronized keyword only prevents two threads from calling the getObjectById concurrently. If the two threads call this method one after the other, you will still have two threads using this entity.

So, if you want to lock a given database object so no other thread can modify it, then you need to use database locks.

The synchronized keyword only works in a single JVM. If you have multiple web nodes, this will not prevent multi-thread access across multiple JVMs.

What you need to do is use LockModeType.PESSIMISTIC_READ or LockModeType.PESSIMISTIC_WRITE while applying the changes to the DB, like this:

Session session = null;
EntityTransaction tx = null;

try {
    session = sessionFactory.openSession();
    
    tx = session.getTransaction();
    tx.begin();

    Post post = session.find(
        Post.class, 
        id, 
        LockModeType.LockModeType.PESSIMISTIC_READ
    );

    post.setTitle("High-Performance Java Perisstence");

    tx.commit();
} catch(Exception e) {
    LOGGER.error("Post entity could not be changed", e);
    if(tx != null) {
        tx.rollback(); 
    }
} finally {
    if(session != null) {
        session.close(); 
    }
}

So, this is what I did:

  • I created a new EntityTransaction and started a new database transaction
  • I loaded the Post entity while holding a lock on the associated database record
  • I changed the Post entity and committed the transaction
  • In the case of an Exception being thrown, I rolled back the transaction

How do I keep Python print from adding newlines or spaces?

print('''first line \
second line''')

it will produce

first line second line

How to split an integer into an array of digits?

Maybe join+split:

>>> a=12345
>>> list(map(int,' '.join(str(a)).split()))
[1, 2, 3, 4, 5]
>>> [int(i) for i in ' '.join(str(a)).split()]
[1, 2, 3, 4, 5]
>>> 

str.join + str.split is your friend, also we use map or list comprehension to get a list, (split what we join :-)).

How to find out "The most popular repositories" on Github?

Ranking by stars or forks is not working. Each promoted or created by a famous company repository is popular at the beginning. Also it is possible to have a number of them which are in trend right now (publications, marketing, events). It doesn't mean that those repositories are useful/popular.

The gitmostwanted.com project (repo at github) analyses GH Archive data in order to highlight the most interesting repositories and exclude others. Just compare the results with mentioned resources.

How to create an empty file with Ansible?

Changed if file not exists. Create empty file.

- name: create fake 'nologin' shell
  file:
    path: /etc/nologin
    state: touch
  register: p
  changed_when: p.diff.before.state == "absent"

How can one run multiple versions of PHP 5.x on a development LAMP server?

Note: The following method will work on windows.

An alternative method (if it is ok to run a single version of PHP at a time) is to define multiple Apache services, each of which will use a different PHP version.

First of all use conditions in the Apache configuration file:

 <ifdefine php54>
    SetEnv PHPRC C:/apache/php54/
    ScriptAlias /php/ "C:/apache/php54/"
    AddType application/x-httpd-php .php
    Action application/x-httpd-php "/php/php-cgi.exe"
</ifdefine>

<ifdefine php55>
    SetEnv PHPRC C:/apache/php55/
    ScriptAlias /php/ "C:/apache/php55/"
    AddType application/x-httpd-php .php
    Action application/x-httpd-php "/php/php-cgi.exe"
</ifdefine>

Now using the httpd.exe create two separate services from command line (elevated to administrator):

httpd.exe -k install -n Apache224_php54 -D php54

httpd.exe -k install -n Apache224_php55 -D php55

Now you can start one of the above services at a time (should shutdown one before starting the other).

If you have previously installed Apache as service you can remove that using below command (replace the service name with the one you have used):

apache -k uninstall -n Apache224

One further note is that I personally use a "notification area icon program" called "Seobiseu" to start and stop services as needed. I have added the two above services to it.

Java: recommended solution for deep cloning/copying an instance

For deep cloning (clones the entire object hierarchy):

  • commons-lang SerializationUtils - using serialization - if all classes are in your control and you can force implementing Serializable.

  • Java Deep Cloning Library - using reflection - in cases when the classes or the objects you want to clone are out of your control (a 3rd party library) and you can't make them implement Serializable, or in cases you don't want to implement Serializable.

For shallow cloning (clones only the first level properties):

I deliberately omitted the "do-it-yourself" option - the API's above provide a good control over what to and what not to clone (for example using transient, or String[] ignoreProperties), so reinventing the wheel isn't preferred.

At runtime, find all classes in a Java application that extend a base class

use this

public static Set<Class> getExtendedClasses(Class superClass)
{
    try
    {
        ResolverUtil resolver = new ResolverUtil();
        resolver.findImplementations(superClass, superClass.getPackage().getName());
        return resolver.getClasses();  
    }
    catch(Exception e)
    {Log.d("Log:", " Err: getExtendedClasses() ");}

    return null;
}

getExtendedClasses(Animals.class);

Edit:

  • library for (ResolverUtil) : Stripes

How to check if DST (Daylight Saving Time) is in effect, and if so, the offset?

The getTimezoneOffset() method in JavaScript, in a browser, returns the number of minutes offset from the 00:00 time zone. For example, America/New_York time zone in Daylight Savings (DST) returns the number 300. 300 minutes is 5 hours difference from zero. 300 minutes divided by 60 minutes is 5 hours. Every time zone is compared to the zero time zone, +00:00 / Etc/GMT / Greenwich time.

MDN Web Docs

The next thing that you must know, is that the offset has the opposite sign of the actual time zone.

Information about time zones is maintained by the Internet Assigned Numbers Authority (iana)

iana time zones

A nicely formatted table of Time Zones is supplied by joda.org

joda-time Time Zones

+00:00 or Etc/GMT is Greenwich time

All time zones are offset from +00:00 / "Etc/GMT" / Greenwich time

Daylight Savings Time is always an earlier time than the "regular" time in the summer. You set your clocks back in the fall season. ("Fall Back" slogan to remember what to do)

So, America/New_York time in Daylight Savings (winter) is one hour before the regular time. So, for example, what was normally 5 p.m. in the afternoon in New York city in the summer, is now 4 p.m. America/New_York time in Daylight Savings. The name "America/New_York" time is a "Long Format" time zone name. The east coast of the U.S typically calls their time zone Eastern Standard Time (EST)

If you want to compare today's time zone offset to the time zone offset of some other date, you need to know that mathematical sign (+/- "Positive / Negative") of the time zone offset is the opposite of the time zone.

Look at the time zone table at joda.org and find the time zone for "America/New_York" It will have a negative sign in front of the Standard Offset.

The earth rotates counter-clockwise on it's axis. A person watch the sunrise in Greenwich sees the sunrise 5 hours before someone in New York City will see the sunrise. And someone on the West Coast of the U.S. will see the sunrise after someone on the East Coast of the U.S. sees the sunrise.

There's a reason why you need to know all of this. So that you'll be able to logically determine whether some JavaScript code is getting the DST status correctly or not, without needing to test every time zone at different times of the year.

Imagine that it's November in New York City, and the clocks have been set back an hour. In the summer in New York City, the offset is 240 minutes or 4 hours.

You can test this by creating a date that is in July and then getting the offset.

var July_Date = new Date(2017, 6, 1);
var july_Timezone_OffSet = July_Date.getTimezoneOffset();

console.log('july_Timezone_OffSet: ' + july_Timezone_OffSet)

What will print to the browser's developer tools console log?

Answer is: 240

So, now you can create a date in January and see what your browser returns for a time zone offset for the winter season.

var Jan_Date = new Date(2017, 0, 1);//Month is zero indexed - Jan is zero
var jan_Timezone_OffSet = Jan_Date.getTimezoneOffset();

console.log('jan_Timezone_OffSet: ' + jan_Timezone_OffSet)

Answer is: 300

Obviously 300 is bigger than 240. So, what does this mean? Should you write code that tests for the winter offset being bigger than the summer offset? Or the summer offset less than the winter offset? If there is a difference between the summer and winter time zone offsets, then you can assume that DST is being used for this time zone. But that doesn't tell you if today is using DST for the browsers time zone. So, you'll need to get the time zone offset for today.

var today = new Date();
var todaysTimeZone = today.getTimezoneOffset();

console.log('todaysTimeZone : ' + todaysTimeZone)

Answer is: ? - Depends on the time of year

If today's time zone offset and the summer time zone offset is the same, AND the summer and winter time zone offsets are different, then by logical deduction, today must be NOT be in DST.

Can you omit comparing the summer and winter time zone offsets, (To know if DST is used for this time zone) and just compare today's time zone offset to the summer TZ offset, and always get the correct answer?

today's TZ Offset !== Summer TZ Offset

Well, is today in the winter or summer? If you knew that then you could apply the following logic:

if ( it_is_winter && ( todays_TZ_Offset !== summer_TZ_Offset) {
  var are_We_In_DST = true;
}

But the problem is, that you don't know if today's date is in winter or summer. Every time zone can have it's own rules for when DST starts and stops. You'd need to keep track of every time zone's rules for every time zone in the world. So, if there is a better and easier way then you might as well do it the better and easier way.

What we are left with, is that you need to know if this time zone uses DST, and then compare today's time zone offset with the summer time zone offset. That will always give you a reliable answer.

The final logic is:

if ( DST_Is_Used_In_This_Time_Zone && ( todays_TZ_Offset !== summer_TZ_Offset) {
  var are_We_In_DST = true;
}

Function to determine if the time zone in the browser uses DST:

function is_DST_Used_In_This_TimeZone() {
  var Jan_Date, jan_Timezone_OffSet, July_Date, july_Timezone_OffSet 
      offsetsNotEqual, thisYear, today;

  today = new Date();//Create a date object that is now
  thisYear = today.getFullYear();//Get the year as a number

  Jan_Date = new Date(thisYear, 0, 1);//Month is zero indexed - Jan is zero
  jan_Timezone_OffSet = Jan_Date.getTimezoneOffset();

  console.log('jan_Timezone_OffSet: ' + jan_Timezone_OffSet)

  July_Date = new Date(thisYear, 6, 1);
  july_Timezone_OffSet = July_Date.getTimezoneOffset();

  console.log('july_Timezone_OffSet: ' + july_Timezone_OffSet)

  offsetsNotEqual = july_Timezone_OffSet !== jan_Timezone_OffSet;//True if not equal

  console.log('offsetsNotEqual: ' + offsetsNotEqual);

  return offsetsNotEqual;//If the offsets are not equal for summer and
       //winter then the only possible reason is that DST is used for
       //this time zone
}

How many times a substring occurs

You can count the frequency using two ways:

  1. Using the count() in str:

    a.count(b)

  2. Or, you can use:

    len(a.split(b))-1

Where a is the string and b is the substring whose frequency is to be calculated.

How to create checkbox inside dropdown?

Simply use bootstrap-multiselect where you can populate dropdown with multiselect option and many more feaatures.

For doc and tutorials you may visit below link

https://www.npmjs.com/package/bootstrap-multiselect

http://davidstutz.de/bootstrap-multiselect/

What does LINQ return when the results are empty

.ToList returns an empty list. (same as new List() );

100% width table overflowing div container

Add display: block; and overflow: auto; to .my-table. This will simply cut off anything past the 280px limit you enforced. There's no way to make it "look pretty" with that requirement due to words like pélagosthrough which are wider than 280px.

while-else-loop

Java does not have this control structure.
It should be noted though, that other languages do.
Python for example, has the while-else construct.

In Java's case, you can mimic this behaviour as you have already shown:

if (rowIndex >= dataColLinker.size()) {
    do {
        dataColLinker.add(value);
    } while(rowIndex >= dataColLinker.size());
} else {
    dataColLinker.set(rowIndex, value);
}

Python dictionary replace values

via dict.update() function

In case you need a declarative solution, you can use dict.update() to change values in a dict.

Either like this:

my_dict.update({'key1': 'value1', 'key2': 'value2'})

or like this:

my_dict.update(key1='value1', key2='value2')

via dictionary unpacking

Since Python 3.5 you can also use dictionary unpacking for this:

my_dict = { **my_dict, 'key1': 'value1', 'key2': 'value2'}

Note: This creates a new dictionary.

via merge operator or update operator

Since Python 3.9 you can also use the merge operator on dictionaries:

my_dict = my_dict | {'key1': 'value1', 'key2': 'value2'}

Note: This creates a new dictionary.

Or you can use the update operator:

my_dict |= {'key1': 'value1', 'key2': 'value2'}

How can I change or remove HTML5 form validation default error messages?

I found a bug on Ankur answer and I've fixed it with this correction:

 <input type="text" pattern="[a-zA-Z]+"
    oninvalid="setCustomValidity('Plz enter on Alphabets ')"
    onchange="try{setCustomValidity('')}catch(e){}" />

The bug seen when you set an invalid input data, then correct the input and send the form. oops! you can't do this. I've tested it on firefox and chrome

How to retrieve data from sqlite database in android and display it in TextView

You may use this following code actually it is rough but plz check it out

db = openOrCreateDatabase("sms.db", SQLiteDatabase.CREATE_IF_NECESSARY, null);
Cursor cc = db.rawQuery("SELECT * FROM datatable", null);
final ArrayList<String> row1 = new ArrayList<String>();
final ArrayList<String> row2 = new ArrayList<String>();

if(cc!=null) {
    cc.moveToFirst();   
    startManagingCursor(cc);
    for (int i=0; i<cc.getCount(); i++) {

    String number  = cc.getString(0);
    String message = cc.getString(1);
    row1.add(number);
    row2.add(message);

    final EditText et3 = (EditText) findViewById(R.id.editText3);
    final EditText et4 = (EditText) findViewById(R.id.editText4);
    Button bt1 = (Button) findViewById(R.id.button1);
    bt1.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub

            switch (v.getId()) {
                case R.id.button1:
                    et3.setText(row1.get(count));
                    et4.setText(row2.get(count));
                    count++;
                    break;
                default:
                    break;
            }

        }
    });

cc.moveToNext();
}

Format certain floating dataframe columns into percentage in pandas

Often times we are interested in calculating the full significant digits, but for the visual aesthetics, we may want to see only few decimal point when we display the dataframe.

In jupyter-notebook, pandas can utilize the html formatting taking advantage of the method called style.

For the case of just seeing two significant digits of some columns, we can use this code snippet:

Given dataframe

import numpy as np
import pandas as pd

df = pd.DataFrame({'var1': [1.458315, 1.576704, 1.629253, 1.6693310000000001, 1.705139, 1.740447, 1.77598, 1.812037, 1.85313, 1.9439849999999999],
          'var2': [1.500092, 1.6084450000000001, 1.652577, 1.685456, 1.7120959999999998, 1.741961, 1.7708009999999998, 1.7993270000000001, 1.8229819999999999, 1.8684009999999998],
          'var3': [-0.0057090000000000005, -0.005122, -0.0047539999999999995, -0.003525, -0.003134, -0.0012230000000000001, -0.0017230000000000001, -0.002013, -0.001396, 0.005732]})

print(df)
       var1      var2      var3
0  1.458315  1.500092 -0.005709
1  1.576704  1.608445 -0.005122
2  1.629253  1.652577 -0.004754
3  1.669331  1.685456 -0.003525
4  1.705139  1.712096 -0.003134
5  1.740447  1.741961 -0.001223
6  1.775980  1.770801 -0.001723
7  1.812037  1.799327 -0.002013
8  1.853130  1.822982 -0.001396
9  1.943985  1.868401  0.005732

Style to get required format

    df.style.format({'var1': "{:.2f}",'var2': "{:.2f}",'var3': "{:.2%}"})

Gives:

var1    var2    var3
id          
0   1.46    1.50    -0.57%
1   1.58    1.61    -0.51%
2   1.63    1.65    -0.48%
3   1.67    1.69    -0.35%
4   1.71    1.71    -0.31%
5   1.74    1.74    -0.12%
6   1.78    1.77    -0.17%
7   1.81    1.80    -0.20%
8   1.85    1.82    -0.14%
9   1.94    1.87    0.57%

Update

If display command is not found try following:

from IPython.display import display

df_style = df.style.format({'var1': "{:.2f}",'var2': "{:.2f}",'var3': "{:.2%}"})

display(df_style)

Requirements

  • To use display command, you need to have installed Ipython in your machine.
  • The display command does not work in online python interpreter which do not have IPyton installed such as https://repl.it/languages/python3
  • The display command works in jupyter-notebook, jupyter-lab, Google-colab, kaggle-kernels, IBM-watson,Mode-Analytics and many other platforms out of the box, you do not even have to import display from IPython.display

Create HTML table using Javascript

The problem is that if you try to write a <table> or a <tr> or <td> tag using JS every time you insert a new tag the browser will try to close it as it will think that there is an error on the code.

Instead of writing your table line by line, concatenate your table into a variable and insert it once created:

<script language="javascript" type="text/javascript">
<!--

var myArray    = new Array();
    myArray[0] = 1;
    myArray[1] = 2.218;
    myArray[2] = 33;
    myArray[3] = 114.94;
    myArray[4] = 5;
    myArray[5] = 33;
    myArray[6] = 114.980;
    myArray[7] = 5;

    var myTable= "<table><tr><td style='width: 100px; color: red;'>Col Head 1</td>";
    myTable+= "<td style='width: 100px; color: red; text-align: right;'>Col Head 2</td>";
    myTable+="<td style='width: 100px; color: red; text-align: right;'>Col Head 3</td></tr>";

    myTable+="<tr><td style='width: 100px;                   '>---------------</td>";
    myTable+="<td     style='width: 100px; text-align: right;'>---------------</td>";
    myTable+="<td     style='width: 100px; text-align: right;'>---------------</td></tr>";

  for (var i=0; i<8; i++) {
    myTable+="<tr><td style='width: 100px;'>Number " + i + " is:</td>";
    myArray[i] = myArray[i].toFixed(3);
    myTable+="<td style='width: 100px; text-align: right;'>" + myArray[i] + "</td>";
    myTable+="<td style='width: 100px; text-align: right;'>" + myArray[i] + "</td></tr>";
  }  
   myTable+="</table>";

 document.write( myTable);

//-->
</script> 

If your code is in an external JS file, in HTML create an element with an ID where you want your table to appear:

<div id="tablePrint"> </div>

And in JS instead of document.write(myTable) use the following code:

document.getElementById('tablePrint').innerHTML = myTable;

How to apply a patch generated with git format-patch?

If you're using a JetBrains IDE (like IntelliJ IDEA, Android Studio, PyCharm), you can drag the patch file and drop it inside the IDE, and a dialog will appear, showing the patch's content. All you have to do now is to click "Apply patch", and a commit will be created.

How should I print types like off_t and size_t?

For Microsoft, the answer is different. VS2013 is largely C99 compliant but "[t]he hh, j, z, and t length prefixes are not supported." For size_t "that is, unsigned __int32 on 32-bit platforms, unsigned __int64 on 64-bit platforms" use prefix I (capital eye) with type specifier o, u, x, or X. See VS2013 Size specification

As for off_t, it is defined as long in VC\include\sys\types.h.

Fatal error: Call to undefined function mb_strlen()

For me the following command did the trick

sudo apt install php-mbstring

minimum double value in C/C++

Floating point numbers (IEEE 754) are symmetrical, so if you can represent the greatest value (DBL_MAX or numeric_limits<double>::max()), just prepend a minus sign.

And then is the cool way:

double f;
(*((long long*)&f))= ~(1LL<<52);

How do I get java logging output to appear on a single line?

As of Java 7, java.util.logging.SimpleFormatter supports getting its format from a system property, so adding something like this to the JVM command line will cause it to print on one line:

-Djava.util.logging.SimpleFormatter.format='%1$tY-%1$tm-%1$td %1$tH:%1$tM:%1$tS %4$s %2$s %5$s%6$s%n'

Alternatively, you can also add this to your logger.properties:

java.util.logging.SimpleFormatter.format='%1$tY-%1$tm-%1$td %1$tH:%1$tM:%1$tS %4$s %2$s %5$s%6$s%n'

PHP/regex: How to get the string value of HTML tag?

In your pattern, you simply want to match all text between the two tags. Thus, you could use for example a [\w\W] to match all characters.

function getTextBetweenTags($string, $tagname) {
    $pattern = "/<$tagname>([\w\W]*?)<\/$tagname>/";
    preg_match($pattern, $string, $matches);
    return $matches[1];
}

Convert a string to datetime in PowerShell

Hope below helps!

PS C:\Users\aameer>$invoice = $object.'Invoice Month'
$invoice = "01-" + $invoice
[datetime]$Format_date =$invoice

Now type is converted. You can use method or can access any property.

Example :$Format_date.AddDays(5)

Value Change Listener to JTextField

If we use runnable method SwingUtilities.invokeLater() while using Document listener application is getting stuck sometimes and taking time to update the result(As per my experiment). Instead of that we can also use KeyReleased event for text field change listener as mentioned here.

usernameTextField.addKeyListener(new KeyAdapter() {
    public void keyReleased(KeyEvent e) {
        JTextField textField = (JTextField) e.getSource();
        String text = textField.getText();
        textField.setText(text.toUpperCase());
    }
});

php return 500 error but no error log

SOLVED I struggled with this and later on, I realized that I was working on PHP 5.6, so I upgraded to PHP 7.0, then I released there were comments placed by git for conflicting codes. I found something like this in my code <<<<<<<< But solved it.

Why is datetime.strptime not working in this simple example?

You are importing the module datetime, which doesn't have a strptime function.

That module does have a datetime object with that method though:

import datetime
dtDate = datetime.datetime.strptime(sDate, "%m/%d/%Y")

Alternatively you can import the datetime object from the module:

from datetime import datetime
dtDate = datetime.strptime(sDate, "%m/%d/%Y")

Note that the strptime method was added in python 2.5; if you are using an older version use the following code instead:

import datetime, time
dtDate = datetime.datetime(*time.strptime(sDate, "%m/%d/%Y")[:6])

Get month and year from a datetime in SQL Server 2005

In SQL server 2012, below can be used

select FORMAT(getdate(), 'MMM yyyy')

This gives exact "Jun 2016"

ng-mouseover and leave to toggle item using mouse in angularjs

Angular solution

You can fix it like this:

$scope.hoverIn = function(){
    this.hoverEdit = true;
};

$scope.hoverOut = function(){
    this.hoverEdit = false;
};

Inside of ngMouseover (and similar) functions context is a current item scope, so this refers to the current child scope.

Also you need to put ngRepeat on li:

<ul>
    <li ng-repeat="task in tasks" ng-mouseover="hoverIn()" ng-mouseleave="hoverOut()">
        {{task.name}}
        <span ng-show="hoverEdit">
            <a>Edit</a>
        </span>
    </li>
</ul>

Demo

CSS solution

However, when possible try to do such things with CSS only, this would be the optimal solution and no JS required:

ul li span {display: none;}
ul li:hover span {display: inline;}

How to correctly use Html.ActionLink with ASP.NET MVC 4 Areas

I hate answering my own question, but @Matt Bodily put me on the right track.

The @Html.Action method actually invokes a controller and renders the view, so that wouldn't work to create a snippet of HTML in my case, as this was causing a recursive function call resulting in a StackOverflowException. The @Url.Action(action, controller, { area = "abc" }) does indeed return the URL, but I finally discovered an overload of Html.ActionLink that provided a better solution for my case:

@Html.ActionLink("Admin", "Index", "Home", new { area = "Admin" }, null)

Note: , null is significant in this case, to match the right signature.

Documentation: @Html.ActionLink (LinkExtensions.ActionLink)

Documentation for this particular overload:

LinkExtensions.ActionLink(Controller, Action, Text, RouteArgs, HtmlAttributes)

It's been difficult to find documentation for these helpers. I tend to search for "Html.ActionLink" when I probably should have searched for "LinkExtensions.ActionLink", if that helps anyone in the future.

Still marking Matt's response as the answer.

Edit: Found yet another HTML helper to solve this:

@Html.RouteLink("Admin", new { action = "Index", controller = "Home", area = "Admin" })

Retrieve version from maven pom.xml in code

    <build>
            <finalName>${project.artifactId}-${project.version}</finalName>
            <pluginManagement>
                <plugins>
                    <plugin>
                        <groupId>org.apache.maven.plugins</groupId>
                        <artifactId>maven-war-plugin</artifactId>
                        <version>3.2.2</version>
                        <configuration>
                            <failOnMissingWebXml>false</failOnMissingWebXml>
                            <archive>
                                <manifest>
                                    <addDefaultImplementationEntries>true</addDefaultImplementationEntries>
                                    <addDefaultSpecificationEntries>true</addDefaultSpecificationEntries>
                                </manifest>
                            </archive>
                        </configuration>
                    </plugin>
                 </plugins>
            </pluginManagement>
</build>

Get Version using this.getClass().getPackage().getImplementationVersion()

PS Don't forget to add:

<manifest>
    <addDefaultImplementationEntries>true</addDefaultImplementationEntries>
    <addDefaultSpecificationEntries>true</addDefaultSpecificationEntries>
</manifest>

How to timeout a thread

I was looking for an ExecutorService that can interrupt all timed out Runnables executed by it, but found none. After a few hours I created one as below. This class can be modified to enhance robustness.

public class TimedExecutorService extends ThreadPoolExecutor {
    long timeout;
    public TimedExecutorService(int numThreads, long timeout, TimeUnit unit) {
        super(numThreads, numThreads, 0L, TimeUnit.MILLISECONDS, new ArrayBlockingQueue<Runnable>(numThreads + 1));
        this.timeout = unit.toMillis(timeout);
    }

    @Override
    protected void beforeExecute(Thread thread, Runnable runnable) {
        Thread interruptionThread = new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    // Wait until timeout and interrupt this thread
                    Thread.sleep(timeout);
                    System.out.println("The runnable times out.");
                    thread.interrupt();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        });
        interruptionThread.start();
    }
}

Usage:

public static void main(String[] args) {

    Runnable abcdRunnable = new Runnable() {
        @Override
        public void run() {
            System.out.println("abcdRunnable started");
            try {
                Thread.sleep(20000);
            } catch (InterruptedException e) {
                // logger.info("The runnable times out.");
            }
            System.out.println("abcdRunnable ended");
        }
    };

    Runnable xyzwRunnable = new Runnable() {
        @Override
        public void run() {
            System.out.println("xyzwRunnable started");
            try {
                Thread.sleep(20000);
            } catch (InterruptedException e) {
                // logger.info("The runnable times out.");
            }
            System.out.println("xyzwRunnable ended");
        }
    };

    int numThreads = 2, timeout = 5;
    ExecutorService timedExecutor = new TimedExecutorService(numThreads, timeout, TimeUnit.SECONDS);
    timedExecutor.execute(abcdRunnable);
    timedExecutor.execute(xyzwRunnable);
    timedExecutor.shutdown();
}

Sort divs in jQuery based on attribute 'data-sort'?

Answered the same question here:

To repost:

After searching through many solutions I decided to blog about how to sort in jquery. In summary, steps to sort jquery "array-like" objects by data attribute...

  1. select all object via jquery selector
  2. convert to actual array (not array-like jquery object)
  3. sort the array of objects
  4. convert back to jquery object with the array of dom objects

Html

<div class="item" data-order="2">2</div>
<div class="item" data-order="1">1</div>
<div class="item" data-order="4">4</div>
<div class="item" data-order="3">3</div>

Plain jquery selector

$('.item');
[<div class="item" data-order="2">2</div>,
 <div class="item" data-order="1">1</div>,
 <div class="item" data-order="4">4</div>,
 <div class="item" data-order="3">3</div>
]

Lets sort this by data-order

function getSorted(selector, attrName) {
    return $($(selector).toArray().sort(function(a, b){
        var aVal = parseInt(a.getAttribute(attrName)),
            bVal = parseInt(b.getAttribute(attrName));
        return aVal - bVal;
    }));
}
> getSorted('.item', 'data-order')
[<div class="item" data-order="1">1</div>,
 <div class="item" data-order="2">2</div>,
 <div class="item" data-order="3">3</div>,
 <div class="item" data-order="4">4</div>
]

See how getSorted() works.

Hope this helps!

What is the opposite of evt.preventDefault();

I had to delay a form submission in jQuery in order to execute an asynchronous call. Here's the simplified code...

$("$theform").submit(function(e) {
    e.preventDefault();
    var $this = $(this);
    $.ajax('/path/to/script.php',
        {
        type: "POST",
        data: { value: $("#input_control").val() }
    }).done(function(response) {
        $this.unbind('submit').submit();
    });
});

How can I select the row with the highest ID in MySQL?

This is the only proposed method who actually selects the whole row, not only the max(id) field. It uses a subquery

SELECT * FROM permlog WHERE id = ( SELECT MAX( id ) FROM permlog )

Invoke JSF managed bean action on page load

@PostConstruct is run ONCE in first when Bean Created. the solution is create a Unused property and Do your Action in Getter method of this property and add this property to your .xhtml file like this :

<h:inputHidden  value="#{loginBean.loginStatus}"/>

and in your bean code:

public void setLoginStatus(String loginStatus) {
    this.loginStatus = loginStatus;
}

public String getLoginStatus()  {
    // Do your stuff here.
    return loginStatus;
}

addClass and removeClass in jQuery - not removing class

The issue is caused because of event bubbling. The first part of your code to add .grown works fine.

The second part "removing grown class" on clicking the link doesn't work as expected as both the handler for .close_button and .clickable are executed. So it removes and readd the grown class to the div.

You can avoid this by using e.stopPropagation() inside .close_button click handler to avoid the event from bubbling.

DEMO: http://jsfiddle.net/vL8DP/

Full Code

$(document).on('click', '.clickable', function () {
   $(this).addClass('grown').removeClass('spot');
}).on('click', '.close_button', function (e) {
   e.stopPropagation();
   $(this).closest('.clickable').removeClass('grown').addClass('spot');
});

How to fetch data from local JSON file on react native?

Since React Native 0.4.3 you can read your local JSON file like this:

const customData = require('./customData.json');

and then access customData like a normal JS object.

How to create Temp table with SELECT * INTO tempTable FROM CTE Query

Sample DDL

create table #Temp
(
    EventID int, 
    EventTitle Varchar(50), 
    EventStartDate DateTime, 
    EventEndDate DatetIme, 
    EventEnumDays int,
    EventStartTime Datetime,
    EventEndTime DateTime, 
    EventRecurring Bit, 
    EventType int
)

;WITH Calendar
AS (SELECT /*...*/)

Insert Into #Temp
Select EventID, EventStartDate, EventEndDate, PlannedDate as [EventDates], Cast(PlannedDate As datetime) AS DT, Cast(EventStartTime As time) AS ST,Cast(EventEndTime As time) AS ET, EventTitle
,EventType from Calendar
where (PlannedDate >= GETDATE()) AND ',' + EventEnumDays + ',' like '%,' + cast(datepart(dw, PlannedDate) as char(1)) + ',%'
    or EventEnumDays is null

Make sure that the table is deleted after use

If(OBJECT_ID('tempdb..#temp') Is Not Null)
Begin
    Drop Table #Temp
End

Encrypting & Decrypting a String in C#

If you need to store a password in memory and would like to have it encrypted you should use SecureString:

http://msdn.microsoft.com/en-us/library/system.security.securestring.aspx

For more general uses I would use a FIPS approved algorithm such as Advanced Encryption Standard, formerly known as Rijndael. See this page for an implementation example:

http://msdn.microsoft.com/en-us/library/system.security.cryptography.rijndael.aspx

generate a random number between 1 and 10 in c

You need a different seed at every execution.

You can start to call at the beginning of your program:

srand(time(NULL));

Note that % 10 yields a result from 0 to 9 and not from 1 to 10: just add 1 to your % expression to get 1 to 10.

HTML Entity Decode

Inspired by Robert K's solution, strips html tags and prevents executing scripts and eventhandlers like: <img src=fake onerror="prompt(1)"> Tested on latest Chrome, FF, IE (should work from IE9, but haven't tested).

var decodeEntities = (function () {
        //create a new html document (doesn't execute script tags in child elements)
        var doc = document.implementation.createHTMLDocument("");
        var element = doc.createElement('div');

        function getText(str) {
            element.innerHTML = str;
            str = element.textContent;
            element.textContent = '';
            return str;
        }

        function decodeHTMLEntities(str) {
            if (str && typeof str === 'string') {
                var x = getText(str);
                while (str !== x) {
                    str = x;
                    x = getText(x);
                }
                return x;
            }
        }
        return decodeHTMLEntities;
    })();

Simply call:

decodeEntities('<img src=fake onerror="prompt(1)">');
decodeEntities("<script>alert('aaa!')</script>");

Add quotation at the start and end of each line in Notepad++

  • Place your cursor at the end of the text.
  • Press SHIFT and ->. The cursor will move to the next line.
  • Press CTRL-F and type , in "Replace with:" and press ENTER.

You will need to put a quote at the beginning of your first text and the end of your last.

XSS filtering function in PHP

According to www.mcafeesecure.com General Solution for vulnerable to cross-site scripting (XSS) filter function can be:

function xss_cleaner($input_str) {
    $return_str = str_replace( array('<','>',"'",'"',')','('), array('&lt;','&gt;','&apos;','&#x22;','&#x29;','&#x28;'), $input_str );
    $return_str = str_ireplace( '%3Cscript', '', $return_str );
    return $return_str;
}

UIDevice uniqueIdentifier deprecated - What to do now?

It looks like for iOS 6, Apple is recommending you use the NSUUID class.

From the message now in the UIDevice docs for uniqueIdentifier property:

Deprecated in iOS 5.0. Use the identifierForVendor property of this class or the advertisingIdentifier property of the ASIdentifierManager class instead, as appropriate, or use the UUID method of the NSUUID class to create a UUID and write it to the user defaults database.

Checking if a key exists in a JS object

You can try this:

const data = {
  name : "Test",
  value: 12
}

if("name" in data){
  //Found
}
else {
  //Not found
}

How to find rows that have a value that contains a lowercase letter

I have to add BINARY to the ColumnX, to get result as case sensitive

SELECT * FROM MyTable WHERE BINARY(ColumnX) REGEXP '^[a-z]';

DropDownList's SelectedIndexChanged event not firing

try setting AutoPostBack="True" on the DropDownList.

How to make html table vertically scrollable

This is a work around.

http://jsfiddle.net/JJV59/2/

[EDIT]

<!DOCTYPE html>
<html>
<head>
<meta charset=utf-8 />
<title>JS Bin</title>
<!--[if IE]>
  <script src="http://html5shiv.googlecode.com/svn/trunk/html5.js"></script>
<![endif]-->

</head>
<body>

<table cellspacing="1" width="100%" bgcolor="#cccccc">
    <thead>
        <tr>
            <td bgcolor="#ffffff" width="70px">
            </td>
            <td class="csstablelisttd" width="70px">
                <b>Time Slot&nbsp;</b>
            </td>
            <td class="csstablelisttd">
                <b>&nbsp;Patient Name</b>
            </td>
        </tr>
    </thead>
</table>
<!-- THIS GIVES THE SCROLLER -->
<div style="height: 500px; overflow-y: auto">
    <table id="tableAppointment" cellspacing="1" width="100%" bgcolor="#cccccc">
         <tbody>
            <tr>
                <td class="csstablelisttd" valign="top" width="70px">
                    8:00AM
                </td>
                <td class="csstablelisttd" width="70px">
                    0
                </td>
                <td class="csstablelisttd">
                    <span>Name 1</span>
                </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        15
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        30
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        45
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd" valign="top" width="90px">
                        9:00AM
                    </td>
                    <td class="csstablelisttd">
                        0
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        15
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        30
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        45
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd" valign="top" width="90px">
                        10:00AM
                    </td>
                    <td class="csstablelisttd">
                        0
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        15
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        30
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        45
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd" valign="top" width="90px">
                        11:00AM
                    </td>
                    <td class="csstablelisttd">
                        0
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        15
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        30
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        45
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd" valign="top" width="90px">
                        12:00PM
                    </td>
                    <td class="csstablelisttd">
                        0
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        15
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        30
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        45
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd" valign="top" width="90px">
                        01:00PM
                    </td>
                    <td class="csstablelisttd">
                        0
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        15
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        30
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        45
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd" valign="top" width="90px">
                        02:00PM
                    </td>
                    <td class="csstablelisttd">
                        0
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        15
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        30
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        45
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd" valign="top" width="90px">
                        03:00PM
                    </td>
                    <td class="csstablelisttd">
                        0
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        15
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        30
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        45
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd" valign="top" width="90px">
                        04:00PM
                    </td>
                    <td class="csstablelisttd">
                        0
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        15
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        30
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        45
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd" valign="top" width="90px">
                        05:00PM
                    </td>
                    <td class="csstablelisttd">
                        0
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        15
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        30
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        45
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd" valign="top" width="90px">
                        06:00PM
                    </td>
                    <td class="csstablelisttd">
                        0
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        15
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        30
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        45
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd" valign="top" width="90px">
                        07:00PM
                    </td>
                    <td class="csstablelisttd">
                        0
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        15
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        30
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd">
                    </td>
                    <td class="csstablelisttd">
                        45
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
                <tr>
                    <td class="csstablelisttd" valign="top" width="90px">
                        08:00PM
                    </td>
                    <td class="csstablelisttd">
                        0
                    </td>
                    <td class="csstablelisttd">
                        <span></span>
                    </td>
                </tr>
            </tbody>
        </table>    
    </div>

</body>
</html>

How to remove new line characters from a string?

A LINQ approach:

string s = "This is a Test String.\n   This is a next line.\t This is a tab.\n'";

string s1 = String.Join("", s.Where(c => c != '\n' && c != '\r' && c != '\t'));

How to maintain page scroll position after a jquery event is carried out?

For all who came here from google and are using an anchor element for firing the event, please make sure to void the click likewise:

<a  
href='javascript:void(0)'  
onclick='javascript:whatever causing the page to scroll to the top'  
></a>

Getting "TypeError: failed to fetch" when the request hasn't actually failed

I know it's a relative old post but, I would like to share what worked for me: I've simply input "http://" before "localhost" in the url. Hope it helps somebody.

How to read files from resources folder in Scala?

For Scala >= 2.12, use Source.fromResource:

scala.io.Source.fromResource("located_in_resouces.any")

How do I center content in a div using CSS?

To align horizontally it's pretty straight forward:

    <style type="text/css"> 
body  {
    margin: 0; 
    padding: 0;
    text-align: center;
}
.bodyclass #container { 
    width: ???px; /*SET your width here*/
    margin: 0 auto;
    text-align: left;
} 
</style>
<body class="bodyclass ">
<div id="container">type your content here</div>
</body>

and for vertical align, it's a bit tricky: here's the source

    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html>
<head>
  <title>Universal vertical center with CSS</title>
  <style>
    .greenBorder {border: 1px solid green;} /* just borders to see it */
  </style>
</head>

<body>
  <div class="greenBorder" style="display: table; height: 400px; #position: relative; overflow: hidden;">
    <div style=" #position: absolute; #top: 50%;display: table-cell; vertical-align: middle;">
      <div class="greenBorder" style=" #position: relative; #top: -50%">
        any text<br>
        any height<br>
        any content, for example generated from DB<br>
        everything is vertically centered
      </div>
    </div>
  </div>
</body>
</html>

how to inherit Constructor from super class to sub class

You inherit class attributes, not class constructors .This is how it goes :

If no constructor is added in the super class, if no then the compiler adds a no argument contructor. This default constructor is invoked implicitly whenever a new instance of the sub class is created . Here the sub class may or may not have constructor, all is ok .

if a constructor is provided in the super class, the compiler will see if it is a no arg constructor or a constructor with parameters.

if no args, then the compiler will invoke it for any sub class instanciation . Here also the sub class may or may not have constructor, all is ok .

if 1 or more contructors in the parent class have parameters and no args constructor is absent, then the subclass has to have at least 1 constructor where an implicit call for the parent class construct is made via super (parent_contractor params) .

this way you are sure that the inherited class attributes are always instanciated .

How to set image to UIImage

First declare UIImageView and give it frame

UIImageView *imageView = [[UIImageView alloc] initWithFrame: CGRectMake( 10.0f, 15.0f, 40.0f,40.0f )];
        [imageView setBackgroundColor: [UIColor clearColor]];
        [imageView setImage:[UIImage imageNamed:@"comments_profile_image.png"]];
        [self.view addSubview: imageView];

getActionBar() returns null

This answer is late but might be helpful to anyone who arrives from Google: You might well need to declare

<item name="android:windowActionBar">true</item>

in your styles.xml. It seems false can be the default. You also need to be on API 11 or higher.

More details can be found in the documentation here. Specifically, quote:

Tip: If you have a custom activity theme in which you'd like to remove the action bar, set the android:windowActionBar style property to false. However, if you remove the action bar using a theme, then the window will not allow the action bar at all, so you cannot add it later—calling getActionBar() will return null.

What is a practical, real world example of the Linked List?

What is a practical, real world example of the Linked List?

The simplest and most straightforward is a train.

Train cars are linked in a specific order so that they may be loaded, unloaded, transferred, dropped off, and picked up in the most efficient manner possible.

For instance, the Jiffy Mix plant needs sugar, flour, cornmeal, etc. Just around the bend might be a paper processing plant that needs chlorine, sulfuric acid, and hydrogen.

Now, we can stop the train, unload each car of its contents, then let the train go on, but then everything else on the train has to sit while flour is sucked out of the caisson, then the sugar, etc.

Instead, the cars are loaded on the train in order so that a whole chunk of it can be detached, and the remainder of the train moves on.

The end of the train is easier to detach than a portion in the middle, and vastly easier than detaching a few cars in one spot, and a few cars in another spot.

If needed, however, you can insert and remove items at any point in the train.

Much like a linked list.

-Adam

jQuery Validation using the class instead of the name value

I know this is an old question. But I too needed the same one recently, and I got this question from stackoverflow + another answer from this blog. The answer which was in the blog was more straight forward as it focuses specially for this kind of a validation. Here is how to do it.

$.validator.addClassRules("price", {
     required: true,
     minlength: 2
});

This method does not require you to have validate method above this call.

Hope this will help someone in the future too. Source here.

How do I print the type or class of a variable in Swift?

In lldb as of beta 5, you can see the class of an object with the command:

fr v -d r shipDate

which outputs something like:

(DBSalesOrderShipDate_DBSalesOrderShipDate_ *) shipDate = 0x7f859940

The command expanded out means something like:

Frame Variable (print a frame variable) -d run_target (expand dynamic types)

Something useful to know is that using "Frame Variable" to output variable values guarantees no code is executed.

Set Label Text with JQuery

I would just query for the for attribute instead of repetitively recursing the DOM tree.

$("input:checkbox").on("change", function() {
    $("label[for='"+this.id+"']").text("TESTTTT");
});

How to make a button redirect to another page using jQuery or just Javascript

Without script:

<form action="where-you-want-to-go"><input type="submit"></form>

Better yet, since you are just going somewhere, present the user with the standard interface for "just going somewhere":

<a href="where-you-want-to-go">ta da</a>

Although, the context sounds like "Simulate a normal search where the user submits a form", in which case the first option is the way to go.

Find a file by name in Visual Studio Code

I believe the action name is "workbench.action.quickOpen".

Delete newline in Vim

If you are on the first line, pressing (upper case) J will join that line and the next line together, removing the newline. You can also combine this with a count, so pressing 3J will combine all 3 lines together.

How to implement my very own URI scheme on Android

Complementing the @DanielLew answer, to get the values of the parameteres you have to do this:

URI example: myapp://path/to/what/i/want?keyOne=valueOne&keyTwo=valueTwo

in your activity:

Intent intent = getIntent();
if (Intent.ACTION_VIEW.equals(intent.getAction())) {
  Uri uri = intent.getData();
  String valueOne = uri.getQueryParameter("keyOne");
  String valueTwo = uri.getQueryParameter("keyTwo");
}

System.loadLibrary(...) couldn't find native library in my case

This is an Android 8 update.

In earlier version of Android, to LoadLibrary native shared libraries (for access via JNI for example) I hard-wired my native code to iterate through a range of potential directory paths for the lib folder, based on the various apk installation/upgrade algorithms:

/data/data/<PackageName>/lib
/data/app-lib/<PackageName>-1/lib
/data/app-lib/<PackageName>-2/lib
/data/app/<PackageName>-1/lib
/data/app/<PackageName>-2/lib

This approach is hokey and will not work for Android 8; from https://developer.android.com/about/versions/oreo/android-8.0-changes.html you'll see that as part of their "Security" changes you now need to use sourceDir:

"You can no longer assume that APKs reside in directories whose names end in -1 or -2. Apps should use sourceDir to get the directory, and not rely on the directory format directly."

Correction, sourceDir is not the way to find your native shared libraries; use something like. Tested for Android 4.4.4 --> 8.0

// Return Full path to the directory where native JNI libraries are stored.
private static String getNativeLibraryDir(Context context) {
    ApplicationInfo appInfo = context.getApplicationInfo();
    return appInfo.nativeLibraryDir;
}

JSON and escaping characters

This is SUPER late and probably not relevant anymore, but if anyone stumbles upon this answer, I believe I know the cause.

So the JSON encoded string is perfectly valid with the degree symbol in it, as the other answer mentions. The problem is most likely in the character encoding that you are reading/writing with. Depending on how you are using Gson, you are probably passing it a java.io.Reader instance. Any time you are creating a Reader from an InputStream, you need to specify the character encoding, or java.nio.charset.Charset instance (it's usually best to use java.nio.charset.StandardCharsets.UTF_8). If you don't specify a Charset, Java will use your platform default encoding, which on Windows is usually CP-1252.

What does "Git push non-fast-forward updates were rejected" mean?

GitHub has a nice section called "Dealing with “non-fast-forward” errors"

This error can be a bit overwhelming at first, do not fear.
Simply put, git cannot make the change on the remote without losing commits, so it refuses the push.
Usually this is caused by another user pushing to the same branch. You can remedy this by fetching and merging the remote branch, or using pull to perform both at once.

In other cases this error is a result of destructive changes made locally by using commands like git commit --amend or git rebase.
While you can override the remote by adding --force to the push command, you should only do so if you are absolutely certain this is what you want to do.
Force-pushes can cause issues for other users that have fetched the remote branch, and is considered bad practice. When in doubt, don’t force-push.


Git cannot make changes on the remote like a fast-forward merge, which a Visual Git Reference illustrates like:

alt text

This is not exactly your case, but helps to see what "fast-forward" is (where the HEAD of a branch is simply moved to a new more recent commit).


The "branch master->master (non-fast-forward) Already-up-to-date" is usually for local branches which don't track their remote counter-part.
See for instance this SO question "git pull says up-to-date but git push rejects non-fast forward".
Or the two branches are connected, but in disagreement with their respective history:
See "Never-ending GIT story - what am I doing wrong here?"

This means that your subversion branch and your remote git master branch do not agree on something.
Some change was pushed/committed to one that is not in the other.
Fire up gitk --all, and it should give you a clue as to what went wrong - look for "forks" in the history.

Table variable error: Must declare the scalar variable "@temp"

If you bracket the @ you can use it directly

declare @TEMP table (ID int, Name varchar(max))
insert into @temp values (1,'one'), (2,'two')

SELECT * FROM @TEMP 
WHERE [@TEMP].[ID] = 1

Huge performance difference when using group by vs distinct

The two queries express the same question. Apparently the query optimizer chooses two different execution plans. My guess would be that the distinct approach is executed like:

  • Copy all business_key values to a temporary table
  • Sort the temporary table
  • Scan the temporary table, returning each item that is different from the one before it

The group by could be executed like:

  • Scan the full table, storing each value of business key in a hashtable
  • Return the keys of the hashtable

The first method optimizes for memory usage: it would still perform reasonably well when part of the temporary table has to be swapped out. The second method optimizes for speed, but potentially requires a large amount of memory if there are a lot of different keys.

Since you either have enough memory or few different keys, the second method outperforms the first. It's not unusual to see performance differences of 10x or even 100x between two execution plans.

Show which git tag you are on?

Edit: Jakub Narebski has more git-fu. The following much simpler command works perfectly:

git describe --tags

(Or without the --tags if you have checked out an annotated tag. My tag is lightweight, so I need the --tags.)

original answer follows:

git describe --exact-match --tags $(git log -n1 --pretty='%h')

Someone with more git-fu may have a more elegant solution...

This leverages the fact that git-log reports the log starting from what you've checked out. %h prints the abbreviated hash. Then git describe --exact-match --tags finds the tag (lightweight or annotated) that exactly matches that commit.

The $() syntax above assumes you're using bash or similar.

Can jQuery provide the tag name?

Consider the fast FILTER method:

$('.rnd').filter('h2,h4')

returns:

[<h2 id=?"foo" class=?"rnd">?Second?</h2>?, <h4 id=?"bar" class=?"rnd">?Fourth?</h4>?]

so:

$('.rnd').filter('h2,h4').each(function() { /*...$(this)...*/ });

Change <select>'s option and trigger events with JavaScript

Try this:

<select id="sel">
 <option value='1'>One</option>
  <option value='2'>Two</option> 
  <option value='3'>Three</option> 
  </select> 


  <input type="button" value="Change option to 2"  onclick="changeOpt()"/>

  <script>

  function changeOpt(){
  document.getElementById("sel").options[1].selected = true;

alert("changed")
  }

  </script>

Runnable with a parameter?

I would first want to know what you are trying to accomplish here to need an argument to be passed to new Runnable() or to run(). The usual way should be to have a Runnable object which passes data(str) to its threads by setting member variables before starting. The run() method then uses these member variable values to do execute someFunc()

How to quickly test some javascript code?

Following is a free list of tools you can use to check, test and verify your JS code:

  1. Google Code Playground
  2. JavaScript Sandbox
  3. jsbin
  4. jsfiddle
  5. pastebin
  6. jsdo.it
  7. firebug
  8. html5snippet.net

Hope this helps.

path.join vs path.resolve with __dirname

From the doc for path.resolve:

The resulting path is normalized and trailing slashes are removed unless the path is resolved to the root directory.

But path.join keeps trailing slashes

So

__dirname = '/';
path.resolve(__dirname, 'foo/'); // '/foo'
path.join(__dirname, 'foo/'); // '/foo/'

Is there a link to the "latest" jQuery library on Google APIs?

Not for nothing, but you shouldn't just automatically use the latest library. If they release the newest library tomorrow and it breaks some of your scripts, you are SOL, but if you use the library you used to develop the scripts, you will ensure they will work.

Is it good practice to use the xor operator for boolean checks?

I personally prefer the "boolean1 ^ boolean2" expression due to its succinctness.

If I was in your situation (working in a team), I would strike a compromise by encapsulating the "boolean1 ^ boolean2" logic in a function with a descriptive name such as "isDifferent(boolean1, boolean2)".

For example, instead of using "boolean1 ^ boolean2", you would call "isDifferent(boolean1, boolean2)" like so:

if (isDifferent(boolean1, boolean2))
{
  //do it
}

Your "isDifferent(boolean1, boolean2)" function would look like:

private boolean isDifferent(boolean1, boolean2)
{
    return boolean1 ^ boolean2;
}

Of course, this solution entails the use of an ostensibly extraneous function call, which in itself is subject to Best Practices scrutiny, but it avoids the verbose (and ugly) expression "(boolean1 && !boolean2) || (boolean2 && !boolean1)"!

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

This problem occurs due to missing import of FormsModule,ReactiveFormsModule .I also came with same problem. My case was diff. as i was working with modules.So i missed above imports in my parent modules though i had imported it into child modules,it wasn't working.

Then i imported it into my parent modules as below, and it worked!

import { ReactiveFormsModule,FormsModule  } from '@angular/forms';
import { AlertModule } from 'ngx-bootstrap';

         @NgModule({
          imports: [
            CommonModule,
            FormsModule,
            ReactiveFormsModule,
    ],
      declarations: [MyComponent]
    })

Sending data through POST request from a node.js server to a node.js server

Posting data is a matter of sending a query string (just like the way you would send it with an URL after the ?) as the request body.

This requires Content-Type and Content-Length headers, so the receiving server knows how to interpret the incoming data. (*)

var querystring = require('querystring');
var http = require('http');

var data = querystring.stringify({
      username: yourUsernameValue,
      password: yourPasswordValue
    });

var options = {
    host: 'my.url',
    port: 80,
    path: '/login',
    method: 'POST',
    headers: {
        'Content-Type': 'application/x-www-form-urlencoded',
        'Content-Length': Buffer.byteLength(data)
    }
};

var req = http.request(options, function(res) {
    res.setEncoding('utf8');
    res.on('data', function (chunk) {
        console.log("body: " + chunk);
    });
});

req.write(data);
req.end();

(*) Sending data requires the Content-Type header to be set correctly, i.e. application/x-www-form-urlencoded for the traditional format that a standard HTML form would use.

It's easy to send JSON (application/json) in exactly the same manner; just JSON.stringify() the data beforehand.

URL-encoded data supports one level of structure (i.e. key and value). JSON is useful when it comes to exchanging data that has a nested structure.

The bottom line is: The server must be able to interpret the content type in question. It could be text/plain or anything else; there is no need to convert data if the receiving server understands it as it is.

Add a charset parameter (e.g. application/json; charset=Windows-1252) if your data is in an unusual character set, i.e. not UTF-8. This can be necessary if you read it from a file, for example.

Getting user input

sys.argv[0] is not the first argument but the filename of the python program you are currently executing. I think you want sys.argv[1]

How do I set the default schema for a user in MySQL

There is no default database for user. There is default database for current session.

You can get it using DATABASE() function -

SELECT DATABASE();

And you can set it using USE statement -

USE database1;

You should set it manually - USE db_name, or in the connection string.

is there a post render callback for Angular JS directive?

I got this working with the following directive:

app.directive('datatableSetup', function () {
    return { link: function (scope, elm, attrs) { elm.dataTable(); } }
});

And in the HTML:

<table class="table table-hover dataTable dataTable-columnfilter " datatable-setup="">

trouble shooting if the above doesnt work for you.

1) note that 'datatableSetup' is the equivalent of 'datatable-setup'. Angular changes the format into camel case.

2) make sure that app is defined before the directive. e.g. simple app definition and directive.

var app = angular.module('app', []);
app.directive('datatableSetup', function () {
    return { link: function (scope, elm, attrs) { elm.dataTable(); } }
});

When do you use POST and when do you use GET?

My general rule of thumb is to use Get when you are making requests to the server that aren't going to alter state. Posts are reserved for requests to the server that alter state.

Google Maps API v3: InfoWindow not sizing correctly

I have tried all of these solutions and none worked. After some trial and error I figured it out.

<style type="text/css">
#map_canvas {
    line-height:normal;
}
</style>

Set line-height:normal for the map canvas div.

Encoding an image file with base64

The first answer will print a string with prefix b'. That means your string will be like this b'your_string' To solve this issue please add the following line of code.

encoded_string= base64.b64encode(img_file.read())
print(encoded_string.decode('utf-8'))

C# catch a stack overflow exception

The right way is to fix the overflow, but....

You can give yourself a bigger stack:-

using System.Threading;
Thread T = new Thread(threadDelegate, stackSizeInBytes);
T.Start();

You can use System.Diagnostics.StackTrace FrameCount property to count the frames you've used and throw your own exception when a frame limit is reached.

Or, you can calculate the size of the stack remaining and throw your own exception when it falls below a threshold:-

class Program
{
    static int n;
    static int topOfStack;
    const int stackSize = 1000000; // Default?

    // The func is 76 bytes, but we need space to unwind the exception.
    const int spaceRequired = 18*1024; 

    unsafe static void Main(string[] args)
    {
        int var;
        topOfStack = (int)&var;

        n=0;
        recurse();
    }

    unsafe static void recurse()
    {
        int remaining;
        remaining = stackSize - (topOfStack - (int)&remaining);
        if (remaining < spaceRequired)
            throw new Exception("Cheese");
        n++;
        recurse();
    }
}

Just catch the Cheese. ;)

How do I calculate power-of in C#?

See Math.Pow. The function takes a value and raises it to a specified power:

Math.Pow(100.00, 3.00); // 100.00 ^ 3.00

Run a shell script with an html button

This is really just an expansion of BBB's answer which lead to to get my experiment working.

This script will simply create a file /tmp/testfile when you click on the button that says "Open Script".

This requires 3 files.

  1. The actual HTML Website with a button.
  2. A php script which executes the script
  3. A Script

The File Tree:

root@test:/var/www/html# tree testscript/
testscript/
+-- index.html
+-- testexec.php
+-- test.sh

1. The main WebPage:

root@test:/var/www/html# cat testscript/index.html
<form action="/testscript/testexec.php">
    <input type="submit" value="Open Script">
</form>

2. The PHP Page that runs the script and redirects back to the main page:

root@test:/var/www/html# cat testscript/testexec.php
<?php
shell_exec("/var/www/html/testscript/test.sh");
header('Location: http://192.168.1.222/testscript/index.html?success=true');
?>

3. The Script :

root@test:/var/www/html# cat testscript/test.sh

#!/bin/bash

touch /tmp/testfile

MySQL dump by query

Combining much of above here is my real practical example, selecting records based on both meterid & timestamp. I have needed this command for years. Executes really quickly.

mysqldump -uuser -ppassword main_dbo trHourly --where="MeterID =5406 AND TIMESTAMP<'2014-10-13 05:00:00'" --no-create-info --skip-extended-insert | grep  '^INSERT' > 5406.sql

Use jQuery to change value of a label

I seem to have a blind spot as regards your html structure, but I think that this is what you're looking for. It should find the currently-selected option from the select input, assign its text to the newVal variable and then apply that variable to the value attribute of the #costLabel label:

jQuery

$(document).ready(
  function() {
    $('select[name=package]').change(
      function(){
        var newText = $('option:selected',this).text();
        $('#costLabel').text('Total price: ' + newText);
      }
      );
  }
  );

html:

  <form name="thisForm" id="thisForm" action="#" method="post">
  <fieldset>
    <select name="package" id="package">
        <option value="standard">Standard - &euro;55 Monthly</option>
        <option value="standardAnn">Standard - &euro;49 Monthly</option>            
        <option value="premium">Premium - &euro;99 Monthly</option>
        <option value="premiumAnn" selected="selected">Premium - &euro;89 Monthly</option>            
        <option value="platinum">Platinum - &euro;149 Monthly</option>
        <option value="platinumAnn">Platinum - &euro;134 Monthly</option>   
    </select>
  </fieldset>
    
    <fieldset>
      <label id="costLabel" name="costLabel">Total price: </label>
    </fieldset>
  </form>

Working demo of the above at: JS Bin

What strategies and tools are useful for finding memory leaks in .NET?

One of the best tools is using the Debugging Tools for Windows, and taking a memory dump of the process using adplus, then use windbg and the sos plugin to analyze the process memory, threads, and call stacks.

You can use this method for identifying problems on servers too, after installing the tools, share the directory, then connect to the share from the server using (net use) and either take a crash or hang dump of the process.

Then analyze offline.

laravel foreach loop in controller

Is sku just a property of the Product model? If so:

$products = Product::whereOwnerAndStatus($owner, 0)->take($count)->get();

foreach ($products as $product ) {
  // Access $product->sku here...
}

Or is sku a relationship to another model? If that is the case, then, as long as your relationship is setup properly, you code should work.

Visual Studio Code pylint: Unable to import 'protorpc'

I was still getting these errors even after confirming that the correct python and pylint were being used from my virtual env.

Eventually I figured out that in Visual Studio Code I was A) opening my project directory, which is B) where my Python virtual environment was, but I was C) running my main Python program from two levels deeper. Those three things need to be in sync for everything to work.

Here's what I would recommend:

  1. In Visual Studio Code, open the directory containing your main Python program. (This may or may not be the top level of the project directory.)

  2. Select Terminal menu > New Terminal, and create an virtual environment directly inside the same directory.

    python3 -m venv env
    
  3. Install pylint in the virtual environment. If you select any Python file in the sidebar, Visual Studio Code will offer to do this for you. Alternatively, source env/bin/activate then pip install pylint.

  4. In the blue bottom bar of the editor window, choose the Python interpreter env/bin/python. Alternatively, go to Settings and set "Python: Python Path." This sets python.pythonPath in Settings.json.

Android: how to draw a border to a LinearLayout

Extend LinearLayout/RelativeLayout and use it straight on the XML

package com.pkg_name ;
...imports...
public class LinearLayoutOutlined extends LinearLayout {
    Paint paint;    

    public LinearLayoutOutlined(Context context) {
        super(context);
        // TODO Auto-generated constructor stub
        setWillNotDraw(false) ;
        paint = new Paint();
    }
    public LinearLayoutOutlined(Context context, AttributeSet attrs) {
        super(context, attrs);
        // TODO Auto-generated constructor stub
        setWillNotDraw(false) ;
        paint = new Paint();
    }
    @Override
    protected void onDraw(Canvas canvas) {
        /*
        Paint fillPaint = paint;
        fillPaint.setARGB(255, 0, 255, 0);
        fillPaint.setStyle(Paint.Style.FILL);
        canvas.drawPaint(fillPaint) ;
        */

        Paint strokePaint = paint;
        strokePaint.setARGB(255, 255, 0, 0);
        strokePaint.setStyle(Paint.Style.STROKE);
        strokePaint.setStrokeWidth(2);  
        Rect r = canvas.getClipBounds() ;
        Rect outline = new Rect( 1,1,r.right-1, r.bottom-1) ;
        canvas.drawRect(outline, strokePaint) ;
    }

}

<?xml version="1.0" encoding="utf-8"?>

<com.pkg_name.LinearLayoutOutlined
   xmlns:android="http://schemas.android.com/apk/res/android"
   android:orientation="vertical"
    android:layout_width=...
    android:layout_height=...
   >
   ... your widgets here ...

</com.pkg_name.LinearLayoutOutlined>

How to clear the text of all textBoxes in the form?

Try this:

var t = this.Controls.OfType<TextBox>().AsEnumerable<TextBox>();
foreach (TextBox item in t)
{
    item.Text = "";
}

How do I center text horizontally and vertically in a TextView?

I have added xml snippet to make a textview center alligned in both Linear and Relative Layout.

In Linear Layout

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Text In Center"
android:layout_gravity="center"
android:gravity="center"/>

In Relative Layout

<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Text In Center"
android:layout_centerInParent= true/>

How to import a CSS file in a React Component

You need to use css-loader when creating bundle with webpack.

Install it:

npm install css-loader --save-dev

And add it to loaders in your webpack configs:

module.exports = {
  module: {
    loaders: [
      { test: /\.css$/, loader: "style-loader!css-loader" },
      // ...
    ]
  }
};

After this, you will be able to include css files in js.

how to display none through code behind

Try if this works:

Panel2.Style.Add("display", "none");

IOS: verify if a point is inside a rect

UIView's pointInside:withEvent: could be a good solution. Will return a boolean value indicating wether or not the given CGPoint is in the UIView instance you are using. Example:

UIView *aView = [UIView alloc]initWithFrame:CGRectMake(0,0,100,100);
CGPoint aPoint = CGPointMake(5,5);
BOOL isPointInsideView = [aView pointInside:aPoint withEvent:nil];

Android Crop Center of Bitmap

You can used following code that can solve your problem.

Matrix matrix = new Matrix();
matrix.postScale(0.5f, 0.5f);
Bitmap croppedBitmap = Bitmap.createBitmap(bitmapOriginal, 100, 100,100, 100, matrix, true);

Above method do postScalling of image before cropping, so you can get best result with cropped image without getting OOM error.

For more detail you can refer this blog

Overloading operators in typedef structs (c++)

Instead of typedef struct { ... } pos; you should be doing struct pos { ... };. The issue here is that you are using the pos type name before it is defined. By moving the name to the top of the struct definition, you are able to use that name within the struct definition itself.

Further, the typedef struct { ... } name; pattern is a C-ism, and doesn't have much place in C++.

To answer your question about inline, there is no difference in this case. When a method is defined within the struct/class definition, it is implicitly declared inline. When you explicitly specify inline, the compiler effectively ignores it because the method is already declared inline.

(inline methods will not trigger a linker error if the same method is defined in multiple object files; the linker will simply ignore all but one of them, assuming that they are all the same implementation. This is the only guaranteed change in behavior with inline methods. Nowadays, they do not affect the compiler's decision regarding whether or not to inline functions; they simply facilitate making the function implementation available in all translation units, which gives the compiler the option to inline the function, if it decides it would be beneficial to do so.)

How to globally replace a forward slash in a JavaScript string?

This has worked for me in turning "//" into just "/".

str.replace(/\/\//g, '/');

Read all contacts' phone numbers in android

In the same way just get their other numbers using the other "People" references

People.TYPE_HOME
People.TYPE_MOBILE
People.TYPE_OTHER
People.TYPE_WORK

How to remove all white spaces from a given text file

Much simpler to my opinion:

sed -r 's/\s+//g' filename

Passing parameters from jsp to Spring Controller method

Use the @RequestParam to pass a parameter to the controller handler method. In the jsp your form should have an input field with name = "id" like the following:

<input type="text" name="id" />
<input type="submit" />

Then in your controller, your handler method should be like the following:

@RequestMapping("listNotes")
public String listNotes(@RequestParam("id") int id) {
    Person person = personService.getCurrentlyAuthenticatedUser();
    model.addAttribute("person", new Person());
    model.addAttribute("listPersons", this.personService.listPersons());
    model.addAttribute("listNotes", this.notesService.listNotesBySectionId(id, person));
    return "note";
}

Please also refer to these answers and tutorial:

YAML Multi-Line Arrays

A YAML sequence is an array. So this is the right way to express it:

key:
  - string1
  - string2      
  - string3
  - string4
  - string5
  - string6

That's identical in meaning to:

key: ['string1', 'string2', 'string3', 'string4', 'string5', 'string6']

It's also legal to split a single-line array over several lines:

key: ['string1', 'string2', 'string3', 
  'string4', 'string5', 
  'string6']

and even have multi-line strings in single-line arrays:

key: ['string1', 'long
  string', 'string3', 'string4', 'string5', 'string6']

I ran into a merge conflict. How can I abort the merge?

git merge --abort

Abort the current conflict resolution process, and try to reconstruct the pre-merge state.

If there were uncommitted worktree changes present when the merge started, git merge --abort will in some cases be unable to reconstruct these changes. It is therefore recommended to always commit or stash your changes before running git merge.

git merge --abort is equivalent to git reset --merge when MERGE_HEAD is present.

http://www.git-scm.com/docs/git-merge

Python 'list indices must be integers, not tuple"

To create list of lists, you need to separate them with commas, like this

coin_args = [
    ["pennies", '2.5', '50.0', '.01'],
    ["nickles", '5.0', '40.0', '.05'],
    ["dimes", '2.268', '50.0', '.1'],
    ["quarters", '5.67', '40.0', '.25']
]

How to read/write arbitrary bits in C/C++

"How do I for example read a 3 bit integer value starting at the second bit?"

int number = // whatever;
uint8_t val; // uint8_t is the smallest data type capable of holding 3 bits
val = (number & (1 << 2 | 1 << 3 | 1 << 4)) >> 2;

(I assumed that "second bit" is bit #2, i. e. the third bit really.)

Spring-Security-Oauth2: Full authentication is required to access this resource

The client_id and client_secret, by default, should go in the Authorization header, not the form-urlencoded body.

  1. Concatenate your client_id and client_secret, with a colon between them: [email protected]:12345678.
  2. Base 64 encode the result: YWJjQGdtYWlsLmNvbToxMjM0NTY3OA==
  3. Set the Authorization header: Authorization: Basic YWJjQGdtYWlsLmNvbToxMjM0NTY3OA==

Can I dispatch an action in reducer?

Dispatching an action within a reducer is an anti-pattern. Your reducer should be without side effects, simply digesting the action payload and returning a new state object. Adding listeners and dispatching actions within the reducer can lead to chained actions and other side effects.

Sounds like your initialized AudioElement class and the event listener belong within a component rather than in state. Within the event listener you can dispatch an action, which will update progress in state.

You can either initialize the AudioElement class object in a new React component or just convert that class to a React component.

class MyAudioPlayer extends React.Component {
  constructor(props) {
    super(props);

    this.player = new AudioElement('test.mp3');

    this.player.audio.ontimeupdate = this.updateProgress;
  }

  updateProgress () {
    // Dispatch action to reducer with updated progress.
    // You might want to actually send the current time and do the
    // calculation from within the reducer.
    this.props.updateProgressAction();
  }

  render () {
    // Render the audio player controls, progress bar, whatever else
    return <p>Progress: {this.props.progress}</p>;
  }
}

class MyContainer extends React.Component {
   render() {
     return <MyAudioPlayer updateProgress={this.props.updateProgress} />
   }
}

function mapStateToProps (state) { return {}; }

return connect(mapStateToProps, {
  updateProgressAction
})(MyContainer);

Note that the updateProgressAction is automatically wrapped with dispatch so you don't need to call dispatch directly.

Enum Naming Convention - Plural

The situation never really applies to plural.

An enum shows an attribute of something or another. I'll give an example:

enum Humour
{
  Irony,
  Sarcasm,
  Slapstick,
  Nothing
}

You can have one type, but try think of it in the multiple, rather than plural:

Humour.Irony | Humour.Sarcasm

Rather than

Humours { Irony, Sarcasm }

You have a sense of humour, you don't have a sense of humours.

WPF: Setting the Width (and Height) as a Percentage Value

IValueConverter implementation can be used. Converter class which takes inheritance from IValueConverter takes some parameters like value (percentage) and parameter (parent's width) and returns desired width value. In XAML file, component's width is set with the desired value:

public class SizePercentageConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        if (parameter == null)
            return 0.7 * value.ToDouble();

        string[] split = parameter.ToString().Split('.');
        double parameterDouble = split[0].ToDouble() + split[1].ToDouble() / (Math.Pow(10, split[1].Length));
        return value.ToDouble() * parameterDouble;
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        // Don't need to implement this
        return null;
    }
}

XAML:

<UserControl.Resources>
    <m:SizePercentageConverter x:Key="PercentageConverter" />
</UserControl.Resources>

<ScrollViewer VerticalScrollBarVisibility="Auto"
          HorizontalScrollBarVisibility="Disabled"
          Width="{Binding Converter={StaticResource PercentageConverter}, RelativeSource={RelativeSource Mode=FindAncestor,AncestorType={x:Type Border}},Path=ActualWidth}"
          Height="{Binding Converter={StaticResource PercentageConverter}, ConverterParameter=0.6, RelativeSource={RelativeSource Mode=FindAncestor,AncestorType={x:Type Border}},Path=ActualHeight}">
....
</ScrollViewer>

php Replacing multiple spaces with a single space

Use preg_replace() and instead of [ \t\n\r] use \s:

$output = preg_replace('!\s+!', ' ', $input);

From Regular Expression Basic Syntax Reference:

\d, \w and \s

Shorthand character classes matching digits, word characters (letters, digits, and underscores), and whitespace (spaces, tabs, and line breaks). Can be used inside and outside character classes.

Spring default behavior for lazy-init

When we use lazy-init="default" as an attribute in element, the container picks up the value specified by default-lazy-init="true|false" attribute of element and uses it as lazy-init="true|false".

If default-lazy-init attribute is not present in element than lazy-init="default" in element will behave as if lazy-init-"false".

Unsupported operand type(s) for +: 'int' and 'str'

try,

str_list = " ".join([str(ele) for ele in numlist])

this statement will give you each element of your list in string format

print("The list now looks like [{0}]".format(str_list))

and,

change print(numlist.pop(2)+" has been removed") to

print("{0} has been removed".format(numlist.pop(2)))

as well.

How to execute a .bat file from a C# windows form app?

Here is what you are looking for:

Service hangs up at WaitForExit after calling batch file

It's about a question as to why a service can't execute a file, but it shows all the code necessary to do so.

Short form for Java if statement

The way to do it is with ternary operator:

name = city.getName() == null ? city.getName() : "N/A"

However, I believe you have a typo in your code above, and you mean to say:

if (city.getName() != null) ...

How to fix Subversion lock error

Subversion supports a command named "Cleanup"; it is used to release the locks on a projectenter image description here

Align Bootstrap Navigation to Center

Thank you all for your help, I added this code and it seems it fixed the issue:

.navbar .navbar-nav {
    display: inline-block;
    float: none;
}

.navbar .navbar-collapse {
    text-align: center;
}

Source

Center content in responsive bootstrap navbar

How to find the sum of an array of numbers

Vanilla JavaScript is all you need:

> a = [1,2,3,4]; a.foo = 5; a['bar'] = 6; sum = 0; a.forEach(function(e){sum += e}); sum
10
> a = [1,2,3,4]; a.foo = 5; a['bar'] = 6; sum = 0; a.forEach(e => sum += e); sum
10
> a = [1,2,3,4]; a.foo = 5; a['bar'] = 6; sum = 0; for(e in a) sum += e; sum
"00123foobar"
> a = [1,2,3,4]; a.foo = 5; a['bar'] = 6; sum = 0; for(e of a) sum += e; sum
10

Regex select all text between tags

preg_match_all(/<pre>([^>]*?)<\/pre>/,$content,$matches) this regex will select everyting between tag. no matter is it in new line(work with multiline.

Select columns in PySpark dataframe

Try something like this:

df.select([c for c in df.columns if c in ['_2','_4','_5']]).show()

How to copy java.util.list Collection

You may create a new list with an input of a previous list like so:

List one = new ArrayList()
//... add data, sort, etc
List two = new ArrayList(one);

This will allow you to modify the order or what elemtents are contained independent of the first list.

Keep in mind that the two lists will contain the same objects though, so if you modify an object in List two, the same object will be modified in list one.

example:

MyObject value1 = one.get(0);
MyObject value2 = two.get(0);
value1 == value2 //true
value1.setName("hello");
value2.getName(); //returns "hello"

Edit

To avoid this you need a deep copy of each element in the list like so:

List<Torero> one = new ArrayList<Torero>();
//add elements

List<Torero> two = new Arraylist<Torero>();
for(Torero t : one){
    Torero copy = deepCopy(t);
    two.add(copy);
}

with copy like the following:

public Torero deepCopy(Torero input){
    Torero copy = new Torero();
    copy.setValue(input.getValue());//.. copy primitives, deep copy objects again

    return copy;
}

Count Vowels in String Python

  1 #!/usr/bin/python
  2 
  3 a = raw_input('Enter the statement: ')
  4 
  5 ########### To count number of words in the statement ##########
  6 
  7 words = len(a.split(' '))
  8 print 'Number of words in the statement are: %r' %words 
  9 
 10 ########### To count vowels in the statement ##########
 11 
 12 print '\n' "Below is the vowel's count in the statement" '\n'
 13 vowels = 'aeiou'
 14 
 15 for key in vowels:
 16     print  key, '=', a.lower().count(key)
 17 

How to make the tab character 4 spaces instead of 8 spaces in nano?

If you use nano with a language like python (as in your example) it's also a good idea to convert tabs to spaces.

Edit your ~/.nanorc file (or create it) and add:

set tabsize 4
set tabstospaces

If you already got a file with tabs and want to convert them to spaces i recommend the expandcommand (shell):

expand -4 input.py > output.py

Change bootstrap navbar background color and font color

Most likely these classes are already defined by Bootstrap, make sure that your CSS file that you want to override the classes with is called AFTER the Bootstrap CSS.

<link rel="stylesheet" href="css/bootstrap.css" /> <!-- Call Bootstrap first -->
<link rel="stylesheet" href="css/bootstrap-override.css" /> <!-- Call override CSS second -->

Otherwise, you can put !important at the end of your CSS like this: color:#ffffff!important; but I would advise against using !important at all costs.