SyntaxFix

Programs & Examples On #Clucene

CLucene is a C++ search engine that is a port of Lucene.

SecurityError: The operation is insecure - window.history.pushState()

We experienced the SecurityError: The operation is insecure when a user disabled their cookies prior to visiting our site, any subsequent XHR requests trying to use the session would obviously fail and cause this error.

How to change dot size in gnuplot

Use the pointtype and pointsize options, e.g.

plot "./points.dat" using 1:2 pt 7 ps 10

where pt 7 gives you a filled circle and ps 10 is the size.

See: Plotting data.

How to get domain root url in Laravel 4?

UPDATE (2017-07-12)

A better solution is actually to use Request::getHost()

Previous answer:

I just checked and Request::root(); does return http://www.example.com in my case, no matter which route I'm on. You can then do the following to strip off the http:// part:

if (starts_with(Request::root(), 'http://'))
{
    $domain = substr (Request::root(), 7); // $domain is now 'www.example.com'
}

You may want to double check or post more code (routes.php, controller code, ...) if the problem persists.

Another solution is to simply use $_SERVER['SERVER_NAME'].

Python check if list items are integers?

Fast, simple, but maybe not always right:

>>> [x for x in mylist if x.isdigit()]
['1', '2', '3', '4']

More traditional if you need to get numbers:

new_list = []
for value in mylist:
    try:
        new_list.append(int(value))
    except ValueError:
        continue

Note: The result has integers. Convert them back to strings if needed, replacing the lines above with:

try:
    new_list.append(str(int(value)))

What is "with (nolock)" in SQL Server?

WITH (NOLOCK) is the equivalent of using READ UNCOMMITED as a transaction isolation level. So, you stand the risk of reading an uncommitted row that is subsequently rolled back, i.e. data that never made it into the database. So, while it can prevent reads being deadlocked by other operations, it comes with a risk. In a banking application with high transaction rates, it's probably not going to be the right solution to whatever problem you're trying to solve with it IMHO.

How to get a Fragment to remove itself, i.e. its equivalent of finish()?

If you are using the new Navigation Component, is simple as

findNavController().popBackStack()

It will do all the FragmentTransaction in behind for you.

Axios handling errors

call the request function from anywhere without having to use catch().

First, while handling most errors in one place is a good Idea, it's not that easy with requests. Some errors (e.g. 400 validation errors like: "username taken" or "invalid email") should be passed on.

So we now use a Promise based function:

const baseRequest = async (method: string, url: string, data: ?{}) =>
  new Promise<{ data: any }>((resolve, reject) => {
    const requestConfig: any = {
      method,
      data,
      timeout: 10000,
      url,
      headers: {},
    };

    try {
      const response = await axios(requestConfig);
      // Request Succeeded!
      resolve(response);
    } catch (error) {
      // Request Failed!

      if (error.response) {
        // Request made and server responded
        reject(response);
      } else if (error.request) {
        // The request was made but no response was received
        reject(response);
      } else {
        // Something happened in setting up the request that triggered an Error
        reject(response);
      }
    }
  };

you can then use the request like

try {
  response = await baseRequest('GET', 'https://myApi.com/path/to/endpoint')
} catch (error) {
  // either handle errors or don't
}

How can I schedule a daily backup with SQL Server Express?

We have used the combination of:

  1. Cobian Backup for scheduling/maintenance

  2. ExpressMaint for backup

Both of these are free. The process is to script ExpressMaint to take a backup as a Cobian "before Backup" event. I usually let this overwrite the previous backup file. Cobian then takes a zip/7zip out of this and archives these to the backup folder. In Cobian you can specify the number of full copies to keep, make multiple backup cycles etc.

ExpressMaint command syntax example:

expressmaint -S HOST\SQLEXPRESS -D ALL_USER -T DB -R logpath -RU WEEKS -RV 1 -B backuppath -BU HOURS -BV 3

Align HTML input fields by :

You could use a label (see JsFiddle)

CSS

label { display: inline-block; width: 210px; text-align: right; }

HTML

<html> 
    <label for="name">Name:</label><input id="name" type="text"><br />
    <label for="email">Email Address:</label><input id="email" type="text"><br /> 
    <label for="desc">Description of the input value:</label><input id="desc" type="text"><br /> 
 </html>

Or you could use those labels in a table (JsFiddle)

<html>
    <table>
        <tbody>
            <tr><td><label for="name">Name:</label></td><td><input id="name" type="text"></td></tr>
            <tr><td><label for="email">Email Address:</label></td><td><input id="email" type = "text"></td></tr>
            <tr><td><label for="desc">Description of the input value:</label></td><td><input id="desc" type="text"></td></tr>
        </tbody>
    </table>
 </html>

JS search in object values

Below shared for specific given property

searchContent:function(s, arr,propertyName){
            var matches = [];
            var propertyNameString=this.propertyNameToStr(propertyName);
            for (var i = arr.length; i--; ){
                if((""+Object.getOwnPropertyDescriptor(arr[i], propertyNameString).value).indexOf(s) > -1)
                    matches.push(arr[i]);
            }
            return matches;
        },
    propertyNameToStr: function (propertyFunction) {
            return /\.([^\.;]+);?\s*\}$/.exec(propertyFunction.toString())[1];
    }

//usage as below

result=$localStorage.searchContent(cabNo,appDataObj.getAll(),function() { dummy.cabDriverName; })

PHP - find entry by object property from an array of objects

 
$arr = [
  [
    'ID' => 1
  ]
];

echo array_search(1, array_column($arr, 'ID')); // prints 0 (!== false)

Above code echoes the index of the matching element, or false if none.

To get the corresponding element, do something like:

$i = array_search(1, array_column($arr, 'ID'));
$element = ($i !== false ? $arr[$i] : null);

array_column works both on an array of arrays, and on an array of objects.

Using Tempdata in ASP.NET MVC - Best practice

Please note that MVC 3 onwards the persistence behavior of TempData has changed, now the value in TempData is persisted until it is read, and not just for the next request.

The value of TempData persists until it is read or until the session times out. Persisting TempData in this way enables scenarios such as redirection, because the values in TempData are available beyond a single request. https://msdn.microsoft.com/en-in/library/dd394711%28v=vs.100%29.aspx

How do I import .sql files into SQLite 3?

From a sqlite prompt:

sqlite> .read db.sql

Or:

cat db.sql | sqlite3 database.db

Also, your SQL is invalid - you need ; on the end of your statements:

create table server(name varchar(50),ipaddress varchar(15),id init);
create table client(name varchar(50),ipaddress varchar(15),id init);

Why doesn't height: 100% work to expand divs to the screen height?

Try to play around also with the calc and overflow functions

.myClassName {
    overflow: auto;
    height: calc(100% - 1.5em);
}

How do I search for files in Visual Studio Code?

Win: CTRL+P or CTRL+E

Mac: CMD+P or CMD+E

Don't want to remember another shortcut?

Open the Command Palette:

  • Menu: View -> Command Palette
  • Windows Shortcut: Ctrl+Shift+P

and hit backspace to delete ">" character and then begin typing to search for files via filename. :)

How does a hash table work?

Lots of answers, but none of them are very visual, and hash tables can easily "click" when visualised.

Hash tables are often implemented as arrays of linked lists. If we imagine a table storing people's names, after a few insertions it might be laid out in memory as below, where ()-enclosed numbers are hash values of the text/name.

bucket#  bucket content / linked list

[0]      --> "sue"(780) --> null
[1]      null
[2]      --> "fred"(42) --> "bill"(9282) --> "jane"(42) --> null
[3]      --> "mary"(73) --> null
[4]      null
[5]      --> "masayuki"(75) --> "sarwar"(105) --> null
[6]      --> "margaret"(2626) --> null
[7]      null
[8]      --> "bob"(308) --> null
[9]      null

A few points:

  • each of the array entries (indices [0], [1]...) is known as a bucket, and starts a - possibly empty - linked list of values (aka elements, in this example - people's names)
  • each value (e.g. "fred" with hash 42) is linked from bucket [hash % number_of_buckets] e.g. 42 % 10 == [2]; % is the modulo operator - the remainder when divided by the number of buckets
  • multiple data values may collide at and be linked from the same bucket, most often because their hash values collide after the modulo operation (e.g. 42 % 10 == [2], and 9282 % 10 == [2]), but occasionally because the hash values are the same (e.g. "fred" and "jane" both shown with hash 42 above)
    • most hash tables handle collisions - with slightly reduced performance but no functional confusion - by comparing the full value (here text) of a value being sought or inserted to each value already in the linked list at the hashed-to bucket

Linked list lengths relate to load factor, not the number of values

If the table size grows, hash tables implemented as above tend to resize themselves (i.e. create a bigger array of buckets, create new/updated linked lists there-from, delete the old array) to keep the ratio of values to buckets (aka load factor) somewhere in the 0.5 to 1.0 range.

Hans gives the actual formula for other load factors in a comment below, but for indicative values: with load factor 1 and a cryptographic strength hash function, 1/e (~36.8%) of buckets will tend to be empty, another 1/e (~36.8%) have one element, 1/(2e) or ~18.4% two elements, 1/(3!e) about 6.1% three elements, 1/(4!e) or ~1.5% four elements, 1/(5!e) ~.3% have five etc.. - the average chain length from non-empty buckets is ~1.58 no matter how many elements are in the table (i.e. whether there are 100 elements and 100 buckets, or 100 million elements and 100 million buckets), which is why we say lookup/insert/erase are O(1) constant time operations.

How a hash table can associate keys with values

Given a hash table implementation as described above, we can imagine creating a value type such as `struct Value { string name; int age; };`, and equality comparison and hash functions that only look at the `name` field (ignoring age), and then something wonderful happens: we can store `Value` records like `{"sue", 63}` in the table, then later search for "sue" without knowing her age, find the stored value and recover or even update her age - happy birthday Sue - which interestingly doesn't change the hash value so doesn't require that we move Sue's record to another bucket.

When we do this, we're using the hash table as an associative container aka map, and the values it stores can be deemed to consist of a key (the name) and one or more other fields still termed - confusingly - the value (in my example, just the age). A hash table implementation used as a map is known as a hash map.

This contrasts with the example earlier in this answer where we stored discrete values like "sue", which you could think of as being its own key: that kind of usage is known as a hash set.

There are other ways to implement a hash table

Not all hash tables use linked lists (known as separate chaining), but most general purpose ones do, as the main alternative closed hashing (aka open addressing) - particularly with erase operations supported - has less stable performance properties with collision-prone keys/hash functions.

A few words on hash functions

Strong hashing...

A general purpose, worst-case collision-minimising hash function's job is to spray the keys around the hash table buckets effectively at random, while always generating the same hash value for the same key. Even one bit changing anywhere in the key would ideally - randomly - flip about half the bits in the resultant hash value.

This is normally orchestrated with maths too complicated for me to grok. I'll mention one easy-to-understand way - not the most scalable or cache friendly but inherently elegant (like encryption with a one-time pad!) - as I think it helps drive home the desirable qualities mentioned above. Say you were hashing 64-bit doubles - you could create 8 tables each of 256 random numbers (code below), then use each 8-bit/1-byte slice of the double's memory representation to index into a different table, XORing the random numbers you look up. With this approach, it's easy to see that a bit (in the binary digit sense) changing anywhere in the double results in a different random number being looked up in one of the tables, and a totally uncorrelated final value.

// note caveats above: cache unfriendly (SLOW) but strong hashing...
std::size_t random[8][256] = { ...random data... };
auto p = (const std::byte*)&my_double;
size_t hash = random[0][p[0]] ^
              random[1][p[1]] ^
              ... ^
              random[7][p[7]];

Weak but oft-fast hashing...

Many libraries' hashing functions pass integers through unchanged (known as a trivial or identity hash function); it's the other extreme from the strong hashing described above. An identity hash is extremely collision prone in the worst cases, but the hope is that in the fairly common case of integer keys that tend to be incrementing (perhaps with some gaps), they'll map into successive buckets leaving fewer empty than random hashing leaves (our ~36.8% at load factor 1 mentioned earlier), thereby having fewer collisions and fewer longer linked lists of colliding elements than is achieved by random mappings. It's also great to save the time it takes to generate a strong hash, and if keys are looked up in order they'll be found in buckets nearby in memory, improving cache hits. When the keys don't increment nicely, the hope is they'll be random enough they won't need a strong hash function to totally randomise their placement into buckets.

Stuck while installing Visual Studio 2015 (Update for Microsoft Windows (KB2999226))

Same thing happened to me and I got it working doing this:

  • Do not cancel the installation (using the cancel button), instead force showdown your computer so the process is killed and you get a reboot.
  • After the reboot, just start the install process again.

This worked for me.

How to open remote files in sublime text 3

On macOS, one option is to install FUSE for macOS and use sshfs to mount a remote directory:

mkdir local_dir
sshfs remote_user@remote_host:remote_dir/ local_dir

Some caveats apply with mounting network volumes, so YMMV.

What does this symbol mean in JavaScript?

See the documentation on MDN about expressions and operators and statements.

Basic keywords and general expressions

this keyword:

var x = function() vs. function x() — Function declaration syntax

(function(){…})() — IIFE (Immediately Invoked Function Expression)

someFunction()() — Functions which return other functions

=> — Equal sign, greater than: arrow function expression syntax

|> — Pipe, greater than: Pipeline operator

function*, yield, yield* — Star after function or yield: generator functions

[], Array() — Square brackets: array notation

If the square brackets appear on the left side of an assignment ([a] = ...), or inside a function's parameters, it's a destructuring assignment.

{key: value} — Curly brackets: object literal syntax (not to be confused with blocks)

If the curly brackets appear on the left side of an assignment ({ a } = ...) or inside a function's parameters, it's a destructuring assignment.

`…${…}…` — Backticks, dollar sign with curly brackets: template literals

/…/ — Slashes: regular expression literals

$ — Dollar sign in regex replace patterns: $$, $&, $`, $', $n

() — Parentheses: grouping operator

Property-related expressions

obj.prop, obj[prop], obj["prop"] — Square brackets or dot: property accessors

?., ?.[], ?.() — Question mark, dot: optional chaining operator

:: — Double colon: bind operator

new operator

...iter — Three dots: spread syntax; rest parameters

Increment and decrement

++, -- — Double plus or minus: pre- / post-increment / -decrement operators

Unary and binary (arithmetic, logical, bitwise) operators

delete operator

void operator

+, - — Plus and minus: addition or concatenation, and subtraction operators; unary sign operators

|, &, ^, ~ — Single pipe, ampersand, circumflex, tilde: bitwise OR, AND, XOR, & NOT operators

% — Percent sign: remainder operator

&&, ||, ! — Double ampersand, double pipe, exclamation point: logical operators

?? — Double question mark: nullish-coalescing operator

** — Double star: power operator (exponentiation)

Equality operators

==, === — Equal signs: equality operators

!=, !== — Exclamation point and equal signs: inequality operators

Bit shift operators

<<, >>, >>> — Two or three angle brackets: bit shift operators

Conditional operator

…?…:… — Question mark and colon: conditional (ternary) operator

Assignment operators

= — Equal sign: assignment operator

%= — Percent equals: remainder assignment

+= — Plus equals: addition assignment operator

&&=, ||=, ??= — Double ampersand, pipe, or question mark, followed by equal sign: logical assignments

Destructuring

Comma operator

, — Comma operator

Control flow

{…} — Curly brackets: blocks (not to be confused with object literal syntax)

Declarations

var, let, const — Declaring variables

Label

label: — Colon: labels

# — Hash (number sign): Private methods or private fields

Annotation-specified bean name conflicts with existing, non-compatible bean def

Sometimes the problem occurs if you have moved your classes around and it refers to old classes, even if they don't exist.

In this case, just do this : 

mvn eclipse:clean

mvn eclipse:eclipse

This worked well for me.

How to clear/remove observable bindings in Knockout.js?

I had a memory leak problem recently and ko.cleanNode(element); wouldn't do it for me -ko.removeNode(element); did. Javascript + Knockout.js memory leak - How to make sure object is being destroyed?

Declare and Initialize String Array in VBA

In the specific case of a String array you could initialize the array using the Split Function as it returns a String array rather than a Variant array:

Dim arrWsNames() As String
arrWsNames = Split("Value1,Value2,Value3", ",")

This allows you to avoid using the Variant data type and preserve the desired type for arrWsNames.

How to add some non-standard font to a website?

You can add some fonts via Google Web Fonts.

Technically, the fonts are hosted at Google and you link them in the HTML header. Then, you can use them freely in CSS with @font-face (read about it).

For example:

In the <head> section:

 <link href=' http://fonts.googleapis.com/css?family=Droid+Sans' rel='stylesheet' type='text/css'>

Then in CSS:

h1 { font-family: 'Droid Sans', arial, serif; }

The solution seems quite reliable (even Smashing Magazine uses it for an article title.). There are, however, not so many fonts available so far in Google Font Directory.

AndroidStudio gradle proxy

If build failed due to gradle proxy setting then simply putting my proxy IP address and port number will solve. It worked for me. File -> setting -> http proxy -> manual configuration -> Host name: your proxy IP, port number: your proxy port number.

..The underlying connection was closed: An unexpected error occurred on a receive

To expand on Bartho Bernsmann's answer, I should like to add that one can have a universal, future-proof implementation at the expense of a little reflection:

static void AllowAllSecurityPrototols()
{   int                  i, n;
    Array                types;
    SecurityProtocolType combined;

    types = Enum.GetValues( typeof( SecurityProtocolType ) ); 
    combined = ( SecurityProtocolType )types.GetValue( 0 );

    n = types.Length;
    for( i = 1; i < n; i += 1 )
    {   combined |= ( SecurityProtocolType )types.GetValue( i );  }

    ServicePointManager.SecurityProtocol = combined;
}

I invoke this method in the static constructor of the class that accesses the internet.

How to accept Date params in a GET request to Spring MVC Controller?

If you want to use a PathVariable, you can use an example method below (all methods are and do the same):

//You can consume the path .../users/added-since1/2019-04-25
@GetMapping("/users/added-since1/{since}")
public String userAddedSince1(@PathVariable("since") @DateTimeFormat(pattern = "yyyy-MM-dd") Date since) {
    return "Date: " + since.toString(); //The output is "Date: Thu Apr 25 00:00:00 COT 2019"
}

//You can consume the path .../users/added-since2/2019-04-25
@RequestMapping("/users/added-since2/{since}")
public String userAddedSince2(@PathVariable("since") @DateTimeFormat(iso = DateTimeFormat.ISO.DATE) Date since) {
    return "Date: " + since.toString(); //The output is "Date: Wed Apr 24 19:00:00 COT 2019"
}

//You can consume the path .../users/added-since3/2019-04-25
@RequestMapping("/users/added-since3/{since}")
public String userAddedSince3(@PathVariable("since") @DateTimeFormat(pattern = "yyyy-MM-dd") Date since) {
    return "Date: " + since.toString(); //The output is "Date: Thu Apr 25 00:00:00 COT 2019"
}

Can you style html form buttons with css?

Yeah, it's pretty simple:

input[type="submit"]{
  background: #fff;
  border: 1px solid #000;
  text-shadow: 1px 1px 1px #000;
}

I recommend giving it an ID or a class so that you can target it more easily.

"string could not resolved" error in Eclipse for C++ (Eclipse can't resolve standard library)

I had the same problem. Adding include path does work for all except std::string.

I noticed in the mingw-Toolchain many system header files *.tcc

I added filetype *.tcc as "C++ Header File" in Preferences > C/C++/ File Types. Now std::string can be resolved from the internal index and Code Analyzer. Perhaps this is added to Eclipse CDT by default in feature.

I hope this helps to someone...

PS: I'm using Eclipse Mars, mingw gcc 4.8.1, Own Makefile, no Eclipse Makefilebuilder.

Get safe area inset top and bottom heights

In iOS 11 there is a method that tells when the safeArea has changed.

override func viewSafeAreaInsetsDidChange() {
    super.viewSafeAreaInsetsDidChange()
    let top = view.safeAreaInsets.top
    let bottom = view.safeAreaInsets.bottom
}

Is it possible to CONTINUE a loop from an exception?

In the construct you have provided, you don't need a CONTINUE. Once the exception is handled, the statement after the END is performed, assuming your EXCEPTION block doesn't terminate the procedure. In other words, it will continue on to the next iteration of the user_rec loop.

You also need to SELECT INTO a variable inside your BEGIN block:

SELECT attr INTO v_attr FROM attribute_table...

Obviously you must declare v_attr as well...

To find first N prime numbers in python

I am not familiar with Python so I am writing the C counter part(too lazy to write pseudo code.. :P) To find the first n prime numbers.. // prints all the primes.. not bothering to make an array and return it etc..

void find_first_n_primes(int n){
   int count = 0;
   for(int i=2;count<=n;i++){
     factFlag == 0; //flag for factor count... 
     for(int k=2;k<sqrt(n)+1;k++){
       if(i%k == 0) // factor found..
        factFlag++;
     }
      if(factFlag==0)// no factors found hence prime..
        {
         Print(i);   // prime displayed..
         count++;
        }
   }
}

Force re-download of release dependency using Maven

If you really want to force-download all dependencies, you can try to re-initialise the entire maven repository. Like in this article already described, you could use:

mvn -Dmaven.repo.local=$HOME/.my/other/repository clean install

C# Generics and Type Checking

You can do typeOf(T), but I would double check your method and make sure your not violating single responsability here. This would be a code smell, and that's not to say it shouldn't be done but that you should be cautious.

The point of generics is being able to build type-agnostic algorthims were you don't care what the type is or as long as it fits within a certain set of criteria. Your implementation isn't very generic.

Multiple conditions in if statement shell script

if using /bin/sh you can use:

if [ <condition> ] && [ <condition> ]; then
    ...
fi

if using /bin/bash you can use:

if [[ <condition> && <condition> ]]; then
    ...
fi

Align items in a stack panel?

Could not get this working using a DockPanel quite the way I wanted and reversing the flow direction of a StackPanel is troublesome. Using a grid is not an option as items inside of it may be hidden at runtime and thus I do not know the total number of columns at design time. The best and simplest solution I could come up with is:

<Grid>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="*" />
        <ColumnDefinition Width="Auto" />
    </Grid.ColumnDefinitions>
    <StackPanel Grid.Column="1" Orientation="Horizontal">
        <!-- Right aligned controls go here -->
    </StackPanel>
</Grid>

This will result in controls inside of the StackPanel being aligned to the right side of the available space regardless of the number of controls - both at design and runtime. Yay! :)

How to format a DateTime in PowerShell

If you got here to use this in cmd.exe (in a batch file):

powershell -Command (Get-Date).ToString('yyyy-MM-dd')

When to use %r instead of %s in Python?

%r shows with quotes:

It will be like:

I said: 'There are 10 types of people.'.

If you had used %s it would have been:

I said: There are 10 types of people..

jQuery: Change button text on click

This should work for you:

    $('.SeeMore2').click(function(){
        var $this = $(this);
        $this.toggleClass('SeeMore2');
        if($this.hasClass('SeeMore2')){
            $this.text('See More');         
        } else {
            $this.text('See Less');
        }
});

How do I rename the extension for a bunch of files?

You can also make a function in Bash, add it to .bashrc or something and then use it wherever you want.

change-ext() {
    for file in *.$1; do mv "$file" "$(basename "$file" .$1).$2"; done
}

Usage:

change-ext css scss

Source of code in function: https://stackoverflow.com/a/1224786/6732111

Insert auto increment primary key to existing table

I was facing the same problem so what I did I dropped the field for the primary key then I recreated it and made sure that it is auto incremental . That worked for me . I hope it helps others

Change width of select tag in Twitter Bootstrap

This works for me to reduce select tag's width;

<select id ="Select1" class="input-small">

You can use any one of these classes;

class="input-small"

class="input-medium"

class="input-large"

class="input-xlarge"

class="input-xxlarge"

Exporting result of select statement to CSV format in DB2

I tried this and got a ';'-delimited csv file:

--#SET TERMINATOR % 
EXPORT TO result.csv OF DEL MODIFIED BY CHARDEL;
SELECT * FROM A

How to copy a map?

As stated in seong's comment:

Also see http://golang.org/doc/effective_go.html#maps. The important part is really the "reference to underlying data structure". This also applies to slices.

However, none of the solutions here seem to offer a solution for a proper deep copy that also covers slices.

I've slightly altered Francesco Casula's answer to accommodate for both maps and slices.

This should cover both copying your map itself, as well as copying any child maps or slices. Both of which are affected by the same "underlying data structure" issue. It also includes a utility function for performing the same type of Deep Copy on a slice directly.

Keep in mind that the slices in the resulting map will be of type []interface{}, so when using them, you will need to use type assertion to retrieve the value in the expected type.

Example Usage

copy := CopyableMap(originalMap).DeepCopy()

Source File (util.go)

package utils

type CopyableMap   map[string]interface{}
type CopyableSlice []interface{}

// DeepCopy will create a deep copy of this map. The depth of this
// copy is all inclusive. Both maps and slices will be considered when
// making the copy.
func (m CopyableMap) DeepCopy() map[string]interface{} {
    result := map[string]interface{}{}

    for k,v := range m {
        // Handle maps
        mapvalue,isMap := v.(map[string]interface{})
        if isMap {
            result[k] = CopyableMap(mapvalue).DeepCopy()
            continue
        }

        // Handle slices
        slicevalue,isSlice := v.([]interface{})
        if isSlice {
            result[k] = CopyableSlice(slicevalue).DeepCopy()
            continue
        }

        result[k] = v
    }

    return result
}

// DeepCopy will create a deep copy of this slice. The depth of this
// copy is all inclusive. Both maps and slices will be considered when
// making the copy.
func (s CopyableSlice) DeepCopy() []interface{} {
    result := []interface{}{}

    for _,v := range s {
        // Handle maps
        mapvalue,isMap := v.(map[string]interface{})
        if isMap {
            result = append(result, CopyableMap(mapvalue).DeepCopy())
            continue
        }

        // Handle slices
        slicevalue,isSlice := v.([]interface{})
        if isSlice {
            result = append(result, CopyableSlice(slicevalue).DeepCopy())
            continue
        }

        result = append(result, v)
    }

    return result
}

Test File (util_tests.go)

package utils

import (
    "testing"

    "github.com/stretchr/testify/require"
)

func TestCopyMap(t *testing.T) {
    m1 := map[string]interface{}{
        "a": "bbb",
        "b": map[string]interface{}{
            "c": 123,
        },
        "c": []interface{} {
            "d", "e", map[string]interface{} {
                "f": "g",
            },
        },
    }

    m2 := CopyableMap(m1).DeepCopy()

    m1["a"] = "zzz"
    delete(m1, "b")
    m1["c"].([]interface{})[1] = "x"
    m1["c"].([]interface{})[2].(map[string]interface{})["f"] = "h"

    require.Equal(t, map[string]interface{}{
        "a": "zzz", 
        "c": []interface{} {
            "d", "x", map[string]interface{} {
                "f": "h",
            },
        },
    }, m1)
    require.Equal(t, map[string]interface{}{
        "a": "bbb",
        "b": map[string]interface{}{
            "c": 123,
        },
        "c": []interface{} {
            "d", "e", map[string]interface{} {
                "f": "g",
            },
        },
    }, m2)
}

Response::json() - Laravel 5.1

After enough googling I found the answer from controller you need only a backslash like return \Response::json(['success' => 'hi, atiq']); . Or you can just return the array return array('success' => 'hi, atiq'); which will be rendered as json in Laravel version 5.2 .

Copy data from one column to other column (which is in a different table)

I think that all previous answers are correct, this below code is very valid specially if you have to update multiple rows at once, note: it's PL/SQL 

DECLARE
    CURSOR myCursor IS 
      Select contacts.BusinessCountry 
      From contacts c WHERE c.Key = t.Key;
    ---------------------------------------------------------------------
BEGIN
    FOR resultValue IN myCursor LOOP
        Update tblindiantime t
        Set CountryName=resultValue.BusinessCountry 
        where t.key=resultValue.key;
    END LOOP;
END;

I wish this could help.

Can't import javax.servlet.annotation.WebServlet

If you are using IBM RAD, then ensure the to remove any j2ee.jar in your projects build path -> libraries tab, and then click on "add external jar" and select the j2ee.jar that is shipped with RAD.

Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect)

I know this is an old question, but some of us are still hitting it and look at the sky wondering how. Here is one kind of issue that I faced.

We have a queue manager that polls data and gives it to handlers for processing. To avoid picking up the same events again, the queue manager locks the record in the database with a LOCKED state.

    void poll() {
        record = dao.getLockedEntity();
        queue(record);
    }

this method wasn't transactional but dao.getLockedEntity() was transactional with REQUIRED.

All good and on the road, after few months in production, it failed with an optimistic locking exception.

After lots of debugging and checking in details we could find out that some one has changed the code like this:

    @Transactional(propagation=Propagation.REQUIRED, readOnly=false)
    void poll() {
        record = dao.getLockedEntity();
        queue(record);              
    }

So the record was queued even before the transaction in dao.getLockedEntity() gets committed (it uses the same transaction of poll method) and the object was changed underneath by the handlers (different threads) by the time the poll() method transaction gets committed.

We fixed the issue and it looks good now.

I thought of sharing it because optimistic lock exceptions can be confusing and are difficult to debug. Someone might get benefited from my experience.

Regards, Lyju

Error: No module named psycopg2.extensions

The first thing to do is to install the dependencies. 

sudo apt-get build-dep python-psycopg2

After that go inside your virtualenv and use 

pip install psycopg2-binary

These two commands should solve the problem.

Netbeans - Error: Could not find or load main class

I had the same issue once. The problem was not in the code. The cause was... renaming the project folder to some other non supporting name. My project name was "MobStick" and I renamed it to "MobStick - May 26, 2014 04:00PM". Renaming it back to normal solved my problem.

ImportError: No module named 'bottle' - PyCharm

The settings are changed for PyCharm 5+.

  • Go to File > Default Settings
  • In left sidebar, click Default Project > Project Interpreter
  • At bottom of window, click + to install or - to uninstall.
  • If we click +, a new window opens where we can decrease the results by entering the package name/keyword.
  • Install the package.

  • Go to File > Invalidate caches/restart and click Invalidate and Restart to apply changes and restart PyCharm.

    Settings

    Install package

SQL Combine Two Columns in Select Statement

 
SELECT StaffId,(Title+''+FirstName+''+LastName) AS FullName 
FROM StaffInformation

Where do you write with in the brackets this will be appear in the one single column. Where do you want a dot into the middle of the Title and First Name write syntax below,

SELECT StaffId,(Title+'.'+FirstName+''+LastName) AS FullName 
FROM StaffInformation

These syntax works with MS SQL Server 2008 R2 Express Edition.

Selecting Folder Destination in Java?

try something like this

JFileChooser chooser = new JFileChooser();
chooser.setCurrentDirectory(new java.io.File("."));
chooser.setDialogTitle("select folder");
chooser.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
chooser.setAcceptAllFileFilterUsed(false);

add a string prefix to each value in a string column using Pandas

You can use pandas.Series.map :

df['col'].map('str{}'.format)

It will apply the word "str" before all your values.

Unresolved external symbol in object files

Check you are including all the source files within your solution that you are referencing.

If you are not including the source file (and thus the implementation) for the class Field in your project it won't be built and you will be unable to link during compilation.

Alternatively, perhaps you are using a static or dynamic library and have forgotten to tell the linker about the .libs?

Are iframes considered 'bad practice'?

It's 'bad practice' to use them without understanding their drawbacks. Adzm's post sums them up very well.

On the flipside, gmail makes heavy use of iFrames in the background for some of it's cooler features (like the automatic file upload). If you're aware of the limitations of iFrames I don't believe you should feel any compunction about using them.

What is an instance variable in Java?

An instance variable is a variable that is a member of an instance of a class (i.e., associated with something created with a new), whereas a class variable is a member of the class itself.

Every instance of a class will have its own copy of an instance variable, whereas there is only one of each static (or class) variable, associated with the class itself.

What’s the difference between a class variable and an instance variable?

This test class illustrates the difference:

public class Test {
   
    public static String classVariable = "I am associated with the class";
    public String instanceVariable = "I am associated with the instance";
    
    public void setText(String string){
        this.instanceVariable = string;
    }
    
    public static void setClassText(String string){
        classVariable = string;
    }
    
    public static void main(String[] args) {
        Test test1 = new Test();
        Test test2 = new Test();
        
        // Change test1's instance variable
        test1.setText("Changed");
        System.out.println(test1.instanceVariable); // Prints "Changed"
        // test2 is unaffected
        System.out.println(test2.instanceVariable); // Prints "I am associated with the instance"
        
        // Change class variable (associated with the class itself)
        Test.setClassText("Changed class text");
        System.out.println(Test.classVariable); // Prints "Changed class text"
        
        // Can access static fields through an instance, but there still is only one
        // (not best practice to access static variables through instance)
        System.out.println(test1.classVariable); // Prints "Changed class text"
        System.out.println(test2.classVariable); // Prints "Changed class text"
    }
}

check if array is empty (vba excel)

Adding into this: it depends on what your array is defined as. Consider:

dim a() as integer
dim b() as string
dim c() as variant

'these doesn't work
if isempty(a) then msgbox "integer arrays can be empty"
if isempty(b) then msgbox "string arrays can be empty"

'this is because isempty can only be tested on classes which have an .empty property

'this do work
if isempty(c) then msgbox "variants can be empty"

So, what can we do? In VBA, we can see if we can trigger an error and somehow handle it, for example

dim a() as integer
dim bEmpty as boolean

bempty=false

on error resume next
bempty=not isnumeric(ubound(a))
on error goto 0

But this is really clumsy... A nicer solution is to declare a boolean variable (a public or module level is best). When the array is first initialised, then set this variable. Because it's a variable declared at the same time, if it loses it's value, then you know that you need to reinitialise your array. However, if it is initialised, then all you're doing is checking the value of a boolean, which is low cost. It depends on whether being low cost matters, and if you're going to be needing to check it often.

option explicit

'declared at module level
dim a() as integer
dim aInitialised as boolean

sub DoSomethingWithA()
if not aInitialised then InitialiseA
'you can now proceed confident that a() is intialised
end sub

sub InitialiseA()
'insert code to do whatever is required to initialise A
'e.g. 
redim a(10)
a(1)=123
'...
aInitialised=true
end sub

The last thing you can do is create a function; which in this case will need to be dependent on the clumsy on error method.

function isInitialised(byref a() as variant) as boolean
isInitialised=false
on error resume next
isinitialised=isnumeric(ubound(a))
end function

How to enable C++11/C++0x support in Eclipse CDT?

I solved it this way on a Mac. I used Homebrew to install the latest version of gcc/g++. They land in /usr/local/bin with includes in /usr/local/include.

I CD'd into /usr/local/bin and made a symlink from g++@7whatever to just g++ cause that @ bit is annoying.

Then I went to MyProject -> Properties -> C/C++ Build -> Settings -> GCC C++ Compiler and changed the command from "g++" to "/usr/local/bin/g++". If you decide not to make the symbolic link, you can be more specific.

Do the same thing for the linker.

Apply and Apply and Close. Let it rebuild the index. For a while, it showed a daunting number of errors, but I think that was while building indexes. While I was figuring out the errors, they all disappeared without further action.

I think without verifying that you could also go into Eclipse -> Properties -> C/C++ -> Core Build Toolchains and edit those with different paths, but I'm not sure what that will do.

Removing leading and trailing spaces from a string

To add to the problem, how to extend this formatting to process extra spaces between words of the string.

Actually, this is a simpler case than accounting for multiple leading and trailing white-space characters. All you need to do is remove duplicate adjacent white-space characters from the entire string.

The predicate for adjacent white space would simply be:

auto by_space = [](unsigned char a, unsigned char b) {
    return std::isspace(a) and std::isspace(b);
};

and then you can get rid of those duplicate adjacent white-space characters with std::unique, and the erase-remove idiom:

// s = "       This       is       a sample   string     "  
s.erase(std::unique(std::begin(s), std::end(s), by_space), 
        std::end(s));
// s = " This is a sample string "

This does potentially leave an extra white-space character at the front and/or the back. This can be removed quite easily:

if (std::size(s) && std::isspace(s.back()))
    s.pop_back();

if (std::size(s) && std::isspace(s.front()))
    s.erase(0, 1);

Here's a demo.

What is the difference/usage of homebrew, macports or other package installation tools?

Currently, Macports has many more packages (~18.6 K) than there are Homebrew formulae (~3.1K), owing to its maturity. Homebrew is slowly catching up though.

Macport packages tend to be maintained by a single person.

Macports can keep multiple versions of packages around, and you can enable or disable them to test things out. Sometimes this list can get corrupted and you have to manually edit it to get things back in order, although this is not too hard.

Both package managers will ask to be regularly updated. This can take some time.

Note: you can have both package managers on your system! It is not one or the other. Brew might complain but Macports won't.

Also, if you are dealing with python or ruby packages, use a virtual environment wherever possible.

Using jQuery to build table rows from AJAX response(json)

Here is a complete answer from hmkcode.com

If we have such JSON data

// JSON Data
var articles = [
    { 
        "title":"Title 1",
        "url":"URL 1",
        "categories":["jQuery"],
        "tags":["jquery","json","$.each"]
    },
    {
        "title":"Title 2",
        "url":"URL 2",
        "categories":["Java"],
        "tags":["java","json","jquery"]
    }
];

And we want to view in this Table structure

<table id="added-articles" class="table">
            <tr>
                <th>Title</th>
                <th>Categories</th>
                <th>Tags</th>
            </tr>
        </table>

The following JS code will fill create a row for each JSON element

// 1. remove all existing rows
$("tr:has(td)").remove();

// 2. get each article
$.each(articles, function (index, article) {

    // 2.2 Create table column for categories
    var td_categories = $("<td/>");

    // 2.3 get each category of this article
    $.each(article.categories, function (i, category) {
        var span = $("<span/>");
        span.text(category);
        td_categories.append(span);
    });

    // 2.4 Create table column for tags
   var td_tags = $("<td/>");

    // 2.5 get each tag of this article    
    $.each(article.tags, function (i, tag) {
        var span = $("<span/>");
        span.text(tag);
        td_tags.append(span);
    });

    // 2.6 Create a new row and append 3 columns (title+url, categories, tags)
    $("#added-articles").append($('<tr/>')
            .append($('<td/>').html("<a href='"+article.url+"'>"+article.title+"</a>"))
            .append(td_categories)
            .append(td_tags)
    ); 
});

what is the use of fflush(stdin) in c programming

It's an unportable way to remove all data from the input buffer till the next newline. I've seen it used in cases like that:

char c;
char s[32];
puts("Type a char");
c=getchar();
fflush(stdin);
puts("Type a string");
fgets(s,32,stdin);

Without the fflush(), if you type a character, say "a", and the hit enter, the input buffer contains "a\n", the getchar() peeks the "a", but the "\n" remains in the buffer, so the next fgets() will find it and return an empty string without even waiting for user input.

However, note that this use of fflush() is unportable. I've tested right now on a Linux machine, and it does not work, for example.

What's the difference between 'git merge' and 'git rebase'?

I found one really interesting article on git rebase vs merge, thought of sharing it here

  • If you want to see the history completely same as it happened, you should use merge. Merge preserves history whereas rebase rewrites it.
  • Merging adds a new commit to your history
  • Rebasing is better to streamline a complex history, you are able to change the commit history by interactive rebase.

Apache and Node.js on the Same Server

Great question!

There are many websites and free web apps implemented in PHP that run on Apache, lots of people use it so you can mash up something pretty easy and besides, its a no-brainer way of serving static content. Node is fast, powerful, elegant, and a sexy tool with the raw power of V8 and a flat stack with no in-built dependencies.

I also want the ease/flexibility of Apache and yet the grunt and elegance of Node.JS, why can't I have both?

Fortunately with the ProxyPass directive in the Apache httpd.conf its not too hard to pipe all requests on a particular URL to your Node.JS application.

ProxyPass /node http://localhost:8000

Also, make sure the following lines are NOT commented out so you get the right proxy and submodule to reroute http requests:

LoadModule proxy_module modules/mod_proxy.so
LoadModule proxy_http_module modules/mod_proxy_http.so

Then run your Node app on port 8000!

var http = require('http');
http.createServer(function (req, res) {
  res.writeHead(200, {'Content-Type': 'text/plain'});
  res.end('Hello Apache!\n');
}).listen(8000, '127.0.0.1');

Then you can access all Node.JS logic using the /node/ path on your url, the rest of the website can be left to Apache to host your existing PHP pages:

enter image description here

Now the only thing left is convincing your hosting company let your run with this configuration!!!

Is it possible to have SSL certificate for IP address, not domain name?

The short answer is yes, as long as it is a public IP address.

Issuance of certificates to reserved IP addresses is not allowed, and all certificates previously issued to reserved IP addresses were revoked as of 1 October 2016.

According to the CA Browser forum, there may be compatibility issues with certificates for IP addresses unless the IP address is in both the commonName and subjectAltName fields. This is due to legacy SSL implementations which are not aligned with RFC 5280, notably, Windows OS prior to Windows 10.

Sources:

  1. Guidance on IP Addresses In Certificates CA Browser Forum
  2. Baseline Requirements 1.4.1 CA Browser Forum
  3. The (soon to be) not-so Common Name unmitigatedrisk.com
  4. RFC 5280 IETF

Note: an earlier version of this answer stated that all IP address certificates would be revoked on 1 October 2016. Thanks to Navin for pointing out the error.

What is “assert” in JavaScript?

Assertion throws error message if first attribute is false, and the second attribute is the message to be thrown.

console.assert(condition,message);

There are many comments saying assertion does not exist in JavaScript but console.assert() is the assert function in JavaScript The idea of assertion is to find why/where the bug occurs.

console.assert(document.getElementById("title"), "You have no element with ID 'title'");
console.assert(document.getElementById("image"), "You have no element with ID 'image'");

Here depending on the message you can find what the bug is. These error messages will be displayed to console in red color as if we called console.error();

You can use assertions to test your functions eg:

console.assert(myAddFunction(5,8)===(5+8),"Failed on 5 and 8");

Note the condition can be anything like != < > etc

This is commonly used to test if the newly created function works as expected by providing some test cases and is not meant for production.

To see more functions in console execute console.log(console);

How to call external JavaScript function in HTML

If a <script> has a src then the text content of the element will be not be executed as JS (although it will appear in the DOM).

You need to use multiple script elements.

  1. a <script> to load the external script

  2. a <script> to hold your inline code (with the call to the function in the external script)

    scroll_messages();

How to uncheck checked radio button

You might consider adding an additional radio button to each group labeled 'none' or the like. This can create a consistent user experience without complicating the development process.

MISCONF Redis is configured to save RDB snapshots

Check your Redis log before taking any action. Some of the solutions in this thread may erase your Redis data, so be careful about what you are doing.

In my case, the machine was running out of RAM. This also can happen when there is no more free disk space on the host.

Call a VBA Function into a Sub Procedure

Here are some of the different ways you can call things in Microsoft Access:

To call a form sub or function from a module

The sub in the form you are calling MUST be public, as in:

Public Sub DoSomething()
  MsgBox "Foo"
End Sub

Call the sub like this:

Call Forms("form1").DoSomething

The form must be open before you make the call.

To call an event procedure, you should call a public procedure within the form, and call the event procedure within this public procedure.

To call a subroutine in a module from a form

Public Sub DoSomethingElse()
  MsgBox "Bar"
End Sub

...just call it directly from your event procedure:

Call DoSomethingElse

To call a subroutine from a form without using an event procedure

If you want, you can actually bind the function to the form control's event without having to create an event procedure under the control. To do this, you first need a public function in the module instead of a sub, like this:

Public Function DoSomethingElse()
  MsgBox "Bar"
End Function

Then, if you have a button on the form, instead of putting [Event Procedure] in the OnClick event of the property window, put this:

=DoSomethingElse()

When you click the button, it will call the public function in the module.

To call a function instead of a procedure

If calling a sub looks like this:

Call MySub(MyParameter)

Then calling a function looks like this:

Result=MyFunction(MyFarameter)

where Result is a variable of type returned by the function.

NOTE: You don't always need the Call keyword. Most of the time, you can just call the sub like this:

MySub(MyParameter)

Tab key == 4 spaces and auto-indent after curly braces in Vim

From the VIM wiki:

:set tabstop=4
:set shiftwidth=4
:set expandtab

Generator expressions vs. list comprehensions

John's answer is good (that list comprehensions are better when you want to iterate over something multiple times). However, it's also worth noting that you should use a list if you want to use any of the list methods. For example, the following code won't work:

def gen():
    return (something for something in get_some_stuff())

print gen()[:2]     # generators don't support indexing or slicing
print [5,6] + gen() # generators can't be added to lists

Basically, use a generator expression if all you're doing is iterating once. If you want to store and use the generated results, then you're probably better off with a list comprehension.

Since performance is the most common reason to choose one over the other, my advice is to not worry about it and just pick one; if you find that your program is running too slowly, then and only then should you go back and worry about tuning your code.

Angular 2: How to access an HTTP response body?

 
.subscribe(data => {   
            console.log(data);
            let body:string = JSON.parse(data['_body']);`

angularjs - using {{}} binding inside ng-src but ng-src doesn't load

Changing the ng-src value is actually very simple. Like this:

<html ng-app>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.0.6/angular.min.js"></script>
</head>
<body>
<img ng-src="{{img_url}}">
<button ng-click="img_url = 'https://farm4.staticflickr.com/3261/2801924702_ffbdeda927_d.jpg'">Click</button>
</body>
</html>

Here is a jsFiddle of a working example: http://jsfiddle.net/Hx7B9/2/

Oracle SQL Developer: Unable to find a JVM

I also had the same problem after installing 32 bit version of java it solved.

Simple timeout in java

Nowadays you can use

try {
    String s = CompletableFuture.supplyAsync(() -> br.readLine())
                                .get(1, TimeUnit.SECONDS);
} catch (TimeoutException e) {
    System.out.println("Time out has occurred");
} catch (InterruptedException | ExecutionException e) {
    // Handle
}

How to search if dictionary value contains certain string with Python

 
import re
for i in range(len(myDict.values())):
    for j in range(len(myDict.values()[i])):
         match=re.search(r'Mary', myDict.values()[i][j])
         if match:
                 print match.group() #Mary
                 print myDict.keys()[i] #firstName
                 print myDict.values()[i][j] #Mary-Ann

What is the difference between a hash join and a merge join (Oracle RDBMS )?

A "sort merge" join is performed by sorting the two data sets to be joined according to the join keys and then merging them together. The merge is very cheap, but the sort can be prohibitively expensive especially if the sort spills to disk. The cost of the sort can be lowered if one of the data sets can be accessed in sorted order via an index, although accessing a high proportion of blocks of a table via an index scan can also be very expensive in comparison to a full table scan.

A hash join is performed by hashing one data set into memory based on join columns and reading the other one and probing the hash table for matches. The hash join is very low cost when the hash table can be held entirely in memory, with the total cost amounting to very little more than the cost of reading the data sets. The cost rises if the hash table has to be spilled to disk in a one-pass sort, and rises considerably for a multipass sort.

(In pre-10g, outer joins from a large to a small table were problematic performance-wise, as the optimiser could not resolve the need to access the smaller table first for a hash join, but the larger table first for an outer join. Consequently hash joins were not available in this situation).

The cost of a hash join can be reduced by partitioning both tables on the join key(s). This allows the optimiser to infer that rows from a partition in one table will only find a match in a particular partition of the other table, and for tables having n partitions the hash join is executed as n independent hash joins. This has the following effects:

  1. The size of each hash table is reduced, hence reducing the maximum amount of memory required and potentially removing the need for the operation to require temporary disk space.
  2. For parallel query operations the amount of inter-process messaging is vastly reduced, reducing CPU usage and improving performance, as each hash join can be performed by one pair of PQ processes.
  3. For non-parallel query operations the memory requirement is reduced by a factor of n, and the first rows are projected from the query earlier.

You should note that hash joins can only be used for equi-joins, but merge joins are more flexible.

In general, if you are joining large amounts of data in an equi-join then a hash join is going to be a better bet.

This topic is very well covered in the documentation.

http://download.oracle.com/docs/cd/B28359_01/server.111/b28274/optimops.htm#i51523

12.1 docs: https://docs.oracle.com/database/121/TGSQL/tgsql_join.htm

Batchfile to create backup and rename with timestamp

try this:

ren "File 1-1" "File 1 - %date:/=-% %time::=-%"

What is a daemon thread in Java?

Daemon threads are generally known as "Service Provider" thread. These threads should not be used to execute program code but system code. These threads run parallel to your code but JVM can kill them anytime. When JVM finds no user threads, it stops it and all daemon threads terminate instantly. We can set non-daemon thread to daemon using : 

setDaemon(true)

Screenshot sizes for publishing android app on Google Play

At last! I got the answer to this, the size to edit it in photoshop is: 379x674

You are welcome

Android: How to stretch an image to the screen width while maintaining aspect ratio?

I just read the source code for ImageView and it is basically impossible without using the subclassing solutions in this thread. In ImageView.onMeasure we get to these lines:

        // Get the max possible width given our constraints
        widthSize = resolveAdjustedSize(w + pleft + pright, mMaxWidth, widthMeasureSpec);

        // Get the max possible height given our constraints
        heightSize = resolveAdjustedSize(h + ptop + pbottom, mMaxHeight, heightMeasureSpec);

Where h and w are the dimensions of the image, and p* is the padding.

And then:

private int resolveAdjustedSize(int desiredSize, int maxSize,
                               int measureSpec) {
    ...
    switch (specMode) {
        case MeasureSpec.UNSPECIFIED:
            /* Parent says we can be as big as we want. Just don't be larger
               than max size imposed on ourselves.
            */
            result = Math.min(desiredSize, maxSize);

So if you have a layout_height="wrap_content" it will set widthSize = w + pleft + pright, or in other words, the maximum width is equal to the image width.

This means that unless you set an exact size, images are NEVER enlarged. I consider this to be a bug, but good luck getting Google to take notice or fix it. Edit: Eating my own words, I submitted a bug report and they say it has been fixed in a future release!

Another solution

Here is another subclassed workaround, but you should (in theory, I haven't really tested it much!) be able to use it anywhere you ImageView. To use it set layout_width="match_parent", and layout_height="wrap_content". It is quite a lot more general than the accepted solution too. E.g. you can do fit-to-height as well as fit-to-width.

import android.content.Context;
import android.util.AttributeSet;
import android.widget.ImageView;

// This works around the issue described here: http://stackoverflow.com/a/12675430/265521
public class StretchyImageView extends ImageView
{

    public StretchyImageView(Context context)
    {
        super(context);
    }

    public StretchyImageView(Context context, AttributeSet attrs)
    {
        super(context, attrs);
    }

    public StretchyImageView(Context context, AttributeSet attrs, int defStyle)
    {
        super(context, attrs, defStyle);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
    {
        // Call super() so that resolveUri() is called.
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);

        // If there's no drawable we can just use the result from super.
        if (getDrawable() == null)
            return;

        final int widthSpecMode = MeasureSpec.getMode(widthMeasureSpec);
        final int heightSpecMode = MeasureSpec.getMode(heightMeasureSpec);

        int w = getDrawable().getIntrinsicWidth();
        int h = getDrawable().getIntrinsicHeight();
        if (w <= 0)
            w = 1;
        if (h <= 0)
            h = 1;

        // Desired aspect ratio of the view's contents (not including padding)
        float desiredAspect = (float) w / (float) h;

        // We are allowed to change the view's width
        boolean resizeWidth = widthSpecMode != MeasureSpec.EXACTLY;

        // We are allowed to change the view's height
        boolean resizeHeight = heightSpecMode != MeasureSpec.EXACTLY;

        int pleft = getPaddingLeft();
        int pright = getPaddingRight();
        int ptop = getPaddingTop();
        int pbottom = getPaddingBottom();

        // Get the sizes that ImageView decided on.
        int widthSize = getMeasuredWidth();
        int heightSize = getMeasuredHeight();

        if (resizeWidth && !resizeHeight)
        {
            // Resize the width to the height, maintaining aspect ratio.
            int newWidth = (int) (desiredAspect * (heightSize - ptop - pbottom)) + pleft + pright;
            setMeasuredDimension(newWidth, heightSize);
        }
        else if (resizeHeight && !resizeWidth)
        {
            int newHeight = (int) ((widthSize - pleft - pright) / desiredAspect) + ptop + pbottom;
            setMeasuredDimension(widthSize, newHeight);
        }
    }
}

What is phtml, and when should I use a .phtml extension rather than .php?

It is a file ext that some folks used for a while to denote that it was PHP generated HTML. As servers like Apache don't care what you use as a file ext as long as it is mapped to something, you could go ahead and call all your PHP files .jimyBobSmith and it would happily run them. PHTML just happened to be a trend that caught on for a while.

"error: assignment to expression with array type error" when I assign a struct field (C)

Please check this example here: Accessing Structure Members

There is explained that the right way to do it is like this: 

strcpy(s1.name , "Egzona");
printf( "Name : %s\n", s1.name);

Simple insecure two-way data "obfuscation"?

I combined what I found the best from several answers and comments.

  • Random initialization vector prepended to crypto text (@jbtule)
  • Use TransformFinalBlock() instead of MemoryStream (@RenniePet)
  • No pre-filled keys to avoid anyone copy & pasting a disaster
  • Proper dispose and using patterns

Code:

/// <summary>
/// Simple encryption/decryption using a random initialization vector
/// and prepending it to the crypto text.
/// </summary>
/// <remarks>Based on multiple answers in http://stackoverflow.com/questions/165808/simple-two-way-encryption-for-c-sharp </remarks>
public class SimpleAes : IDisposable
{
    /// <summary>
    ///     Initialization vector length in bytes.
    /// </summary>
    private const int IvBytes = 16;

    /// <summary>
    ///     Must be exactly 16, 24 or 32 bytes long.
    /// </summary>
    private static readonly byte[] Key = Convert.FromBase64String("FILL ME WITH 24 (2 pad chars), 32 OR 44 (1 pad char) RANDOM CHARS"); // Base64 has a blowup of four-thirds (33%)

    private readonly UTF8Encoding _encoder;
    private readonly ICryptoTransform _encryptor;
    private readonly RijndaelManaged _rijndael;

    public SimpleAes()
    {
        _rijndael = new RijndaelManaged {Key = Key};
        _rijndael.GenerateIV();
        _encryptor = _rijndael.CreateEncryptor();
        _encoder = new UTF8Encoding();
    }

    public string Decrypt(string encrypted)
    {
        return _encoder.GetString(Decrypt(Convert.FromBase64String(encrypted)));
    }

    public void Dispose()
    {
        _rijndael.Dispose();
        _encryptor.Dispose();
    }

    public string Encrypt(string unencrypted)
    {
        return Convert.ToBase64String(Encrypt(_encoder.GetBytes(unencrypted)));
    }

    private byte[] Decrypt(byte[] buffer)
    {
        // IV is prepended to cryptotext
        byte[] iv = buffer.Take(IvBytes).ToArray();
        using (ICryptoTransform decryptor = _rijndael.CreateDecryptor(_rijndael.Key, iv))
        {
            return decryptor.TransformFinalBlock(buffer, IvBytes, buffer.Length - IvBytes);
        }
    }

    private byte[] Encrypt(byte[] buffer)
    {
        // Prepend cryptotext with IV
        byte [] inputBuffer = _encryptor.TransformFinalBlock(buffer, 0, buffer.Length); 
        return _rijndael.IV.Concat(inputBuffer).ToArray();
    }
}

Update 2015-07-18: Fixed mistake in private Encrypt() method by comments of @bpsilver and @Evereq. IV was accidentally encrypted, is now prepended in clear text as expected by Decrypt().

What does the regex \S mean in JavaScript?

/\S/.test(string) returns true if and only if there's a non-space character in string. Tab and newline count as spaces.

How to detect DataGridView CheckBox event change?

You can force the cell to commit the value as soon as you click the checkbox and then catch the CellValueChanged event. The CurrentCellDirtyStateChanged fires as soon as you click the checkbox.

The following code works for me:

private void grid_CurrentCellDirtyStateChanged(object sender, EventArgs e)
    {
        SendKeys.Send("{tab}");
    }

You can then insert your code in the CellValueChanged event.

Closure in Java 7

Java Closures are going to be a part of J2SE 8 and is set to be released by the end of 2012.

Java 8's closures support include the concept of Lambda Expressions, Method Reference, Constructor Reference and the Default Methods.

For more information and working examples for this please visit: http://amitrp.blogspot.in/2012/08/at-first-sight-with-closures-in-java.html

How do I UPDATE from a SELECT in SQL Server?

The other way is to use a derived table:

UPDATE t
SET t.col1 = a.col1
    ,t.col2 = a.col2
FROM (
SELECT id, col1, col2 FROM @tbl2) a
INNER JOIN @tbl1 t ON t.id = a.id

Sample data

DECLARE @tbl1 TABLE (id INT, col1 VARCHAR(10), col2 VARCHAR(10))
DECLARE @tbl2 TABLE (id INT, col1 VARCHAR(10), col2 VARCHAR(10))

INSERT @tbl1 SELECT 1, 'a', 'b' UNION SELECT 2, 'b', 'c'

INSERT @tbl2 SELECT 1, '1', '2' UNION SELECT 2, '3', '4'

UPDATE t
SET t.col1 = a.col1
    ,t.col2 = a.col2
FROM (
SELECT id, col1, col2 FROM @tbl2) a
INNER JOIN @tbl1 t ON t.id = a.id

SELECT * FROM @tbl1
SELECT * FROM @tbl2

How can I add a custom HTTP header to ajax request with js or jQuery?

Assuming JQuery ajax, you can add custom headers like - 

$.ajax({
  url: url,
  beforeSend: function(xhr) {
    xhr.setRequestHeader("custom_header", "value");
  },
  success: function(data) {
  }
});

C# Convert a Base64 -> byte[]

I've written an extension method for this purpose:

public static byte[] FromBase64Bytes(this byte[] base64Bytes)
{
    string base64String = Encoding.UTF8.GetString(base64Bytes, 0, base64Bytes.Length);
    return Convert.FromBase64String(base64String);
}

Call it like this:

byte[] base64Bytes = .......
byte[] regularBytes = base64Bytes.FromBase64Bytes();

I hope it helps someone.

Best way to Bulk Insert from a C# DataTable

Here's how I do it using a DataTable. This is a working piece of TEST code.

using (SqlConnection con = new SqlConnection(connStr))
{
    con.Open();

    // Create a table with some rows. 
    DataTable table = MakeTable();

    // Get a reference to a single row in the table. 
    DataRow[] rowArray = table.Select();

    using (SqlBulkCopy bulkCopy = new SqlBulkCopy(con))
    {
        bulkCopy.DestinationTableName = "dbo.CarlosBulkTestTable";

        try
        {
            // Write the array of rows to the destination.
            bulkCopy.WriteToServer(rowArray);
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.Message);
        }

    }

}//using

What exactly is a Context in Java?

A Context represents your environment. It represents the state surrounding where you are in your system.

For example, in web programming in Java, you have a Request, and a Response. These are passed to the service method of a Servlet.

A property of the Servlet is the ServletConfig, and within that is a ServletContext.

The ServletContext is used to tell the servlet about the Container that the Servlet is within.

So, the ServletContext represents the servlets environment within its container.

Similarly, in Java EE, you have EBJContexts that elements (like session beans) can access to work with their containers.

Those are two examples of contexts used in Java today.

Edit --

You mention Android.

Look here: http://developer.android.com/reference/android/content/Context.html

You can see how this Context gives you all sorts of information about where the Android app is deployed and what's available to it.

How do I link to Google Maps with a particular longitude and latitude?

It´s out of the scope of the question, but I think it might be also interesting to know how to link to a route. The query would look like this:

https://www.google.es/maps/dir/'52.51758801683297,13.397978515625027'/'52.49083837044266,13.369826049804715'

How to overcome TypeError: unhashable type: 'list'

The TypeError is happening because k is a list, since it is created using a slice from another list with the line k = list[0:j]. This should probably be something like k = ' '.join(list[0:j]), so you have a string instead.

In addition to this, your if statement is incorrect as noted by Jesse's answer, which should read if k not in d or if not k in d (I prefer the latter).

You are also clearing your dictionary on each iteration since you have d = {} inside of your for loop.

Note that you should also not be using list or file as variable names, since you will be masking builtins.

Here is how I would rewrite your code:

d = {}
with open("filename.txt", "r") as input_file:
    for line in input_file:
        fields = line.split()
        j = fields.index("x")
        k = " ".join(fields[:j])
        d.setdefault(k, []).append(" ".join(fields[j+1:]))

The dict.setdefault() method above replaces the if k not in d logic from your code.

Java: How to resolve java.lang.NoClassDefFoundError: javax/xml/bind/JAXBException

add javax.xml.bind dependency in pom.xml

    <dependency>
        <groupId>javax.xml.bind</groupId>
        <artifactId>jaxb-api</artifactId>
        <version>2.3.0</version>
    </dependency>

How can I generate a list or array of sequential integers in Java?

You could use Guava Ranges

You can get a SortedSet by using

ImmutableSortedSet<Integer> set = Ranges.open(1, 5).asSet(DiscreteDomains.integers());
// set contains [2, 3, 4]

Image comparison - fast algorithm

This post was the starting point of my solution, lots of good ideas here so I though I would share my results. The main insight is that I've found a way to get around the slowness of keypoint-based image matching by exploiting the speed of phash.

For the general solution, it's best to employ several strategies. Each algorithm is best suited for certain types of image transformations and you can take advantage of that.

At the top, the fastest algorithms; at the bottom the slowest (though more accurate). You might skip the slow ones if a good match is found at the faster level.

  • file-hash based (md5,sha1,etc) for exact duplicates
  • perceptual hashing (phash) for rescaled images
  • feature-based (SIFT) for modified images

I am having very good results with phash. The accuracy is good for rescaled images. It is not good for (perceptually) modified images (cropped, rotated, mirrored, etc). To deal with the hashing speed we must employ a disk cache/database to maintain the hashes for the haystack.

The really nice thing about phash is that once you build your hash database (which for me is about 1000 images/sec), the searches can be very, very fast, in particular when you can hold the entire hash database in memory. This is fairly practical since a hash is only 8 bytes.

For example, if you have 1 million images it would require an array of 1 million 64-bit hash values (8 MB). On some CPUs this fits in the L2/L3 cache! In practical usage I have seen a corei7 compare at over 1 Giga-hamm/sec, it is only a question of memory bandwidth to the CPU. A 1 Billion-image database is practical on a 64-bit CPU (8GB RAM needed) and searches will not exceed 1 second!

For modified/cropped images it would seem a transform-invariant feature/keypoint detector like SIFT is the way to go. SIFT will produce good keypoints that will detect crop/rotate/mirror etc. However the descriptor compare is very slow compared to hamming distance used by phash. This is a major limitation. There are a lot of compares to do, since there are maximum IxJxK descriptor compares to lookup one image (I=num haystack images, J=target keypoints per haystack image, K=target keypoints per needle image).

To get around the speed issue, I tried using phash around each found keypoint, using the feature size/radius to determine the sub-rectangle. The trick to making this work well, is to grow/shrink the radius to generate different sub-rect levels (on the needle image). Typically the first level (unscaled) will match however often it takes a few more. I'm not 100% sure why this works, but I can imagine it enables features that are too small for phash to work (phash scales images down to 32x32).

Another issue is that SIFT will not distribute the keypoints optimally. If there is a section of the image with a lot of edges the keypoints will cluster there and you won't get any in another area. I am using the GridAdaptedFeatureDetector in OpenCV to improve the distribution. Not sure what grid size is best, I am using a small grid (1x3 or 3x1 depending on image orientation).

You probably want to scale all the haystack images (and needle) to a smaller size prior to feature detection (I use 210px along maximum dimension). This will reduce noise in the image (always a problem for computer vision algorithms), also will focus detector on more prominent features.

For images of people, you might try face detection and use it to determine the image size to scale to and the grid size (for example largest face scaled to be 100px). The feature detector accounts for multiple scale levels (using pyramids) but there is a limitation to how many levels it will use (this is tunable of course).

The keypoint detector is probably working best when it returns less than the number of features you wanted. For example, if you ask for 400 and get 300 back, that's good. If you get 400 back every time, probably some good features had to be left out.

The needle image can have less keypoints than the haystack images and still get good results. Adding more doesn't necessarily get you huge gains, for example with J=400 and K=40 my hit rate is about 92%. With J=400 and K=400 the hit rate only goes up to 96%.

We can take advantage of the extreme speed of the hamming function to solve scaling, rotation, mirroring etc. A multiple-pass technique can be used. On each iteration, transform the sub-rectangles, re-hash, and run the search function again.

JavaScript: Collision detection

You can try jquery-collision. Full disclosure: I just wrote this and released it. I didn't find a solution, so I wrote it myself.

It allows you to do:

var hit_list = $("#ball").collision("#someobject0");

which will return all the "#someobject0"'s that overlap with "#ball".

Set background image in CSS using jquery

Use :

 $(this).parent().css("background-image", "url(/images/r-srchbg_white.png) no-repeat;");

instead of

 $(this).parent().css("background", "url(/images/r-srchbg_white.png) no-repeat;");

More examples you cand see here

FATAL ERROR: Ineffective mark-compacts near heap limit Allocation failed - JavaScript heap out of memory in ionic 3

For me it was a problem with firebase package.

Only add "@firebase/database": "0.2.1", for your package.json, reinstall node_modules and works.

How to save a Seaborn plot into a file

The suggested solutions are incompatible with Seaborn 0.8.1

giving the following errors because the Seaborn interface has changed:

AttributeError: 'AxesSubplot' object has no attribute 'fig'
When trying to access the figure

AttributeError: 'AxesSubplot' object has no attribute 'savefig'
when trying to use the savefig directly as a function

The following calls allow you to access the figure (Seaborn 0.8.1 compatible):

swarm_plot = sns.swarmplot(...)
fig = swarm_plot.get_figure()
fig.savefig(...)

as seen previously in this answer.

UPDATE: I have recently used PairGrid object from seaborn to generate a plot similar to the one in this example. In this case, since GridPlot is not a plot object like, for example, sns.swarmplot, it has no get_figure() function. It is possible to directly access the matplotlib figure by

fig = myGridPlotObject.fig

Like previously suggested in other posts in this thread.

Which characters make a URL invalid?

Several of Unicode character ranges are valid HTML5, although it might still not be a good idea to use them.

E.g., href docs say http://www.w3.org/TR/html5/links.html#attr-hyperlink-href:

The href attribute on a and area elements must have a value that is a valid URL potentially surrounded by spaces.

Then the definition of "valid URL" points to http://url.spec.whatwg.org/, which says it aims to:

Align RFC 3986 and RFC 3987 with contemporary implementations and obsolete them in the process.

That document defines URL code points as:

ASCII alphanumeric, "!", "$", "&", "'", "(", ")", "*", "+", ",", "-", ".", "/", ":", ";", "=", "?", "@", "_", "~", and code points in the ranges U+00A0 to U+D7FF, U+E000 to U+FDCF, U+FDF0 to U+FFFD, U+10000 to U+1FFFD, U+20000 to U+2FFFD, U+30000 to U+3FFFD, U+40000 to U+4FFFD, U+50000 to U+5FFFD, U+60000 to U+6FFFD, U+70000 to U+7FFFD, U+80000 to U+8FFFD, U+90000 to U+9FFFD, U+A0000 to U+AFFFD, U+B0000 to U+BFFFD, U+C0000 to U+CFFFD, U+D0000 to U+DFFFD, U+E1000 to U+EFFFD, U+F0000 to U+FFFFD, U+100000 to U+10FFFD.

The term "URL code points" is then used in the statement:

If c is not a URL code point and not "%", parse error.

in a several parts of the parsing algorithm, including the schema, authority, relative path, query and fragment states: so basically the entire URL.

Also, the validator http://validator.w3.org/ passes for URLs like "??", and does not pass for URLs with characters like spaces "a b"

Of course, as mentioned by Stephen C, it is not just about characters but also about context: you have to understand the entire algorithm. But since class "URL code points" is used on key points of the algorithm, it that gives a good idea of what you can use or not.

See also: Unicode characters in URLs

How to convert std::string to LPCSTR?

 
std::string myString("SomeValue");
LPSTR lpSTR = const_cast<char*>(myString.c_str());

myString is the input string and lpSTR is it's LPSTR equivalent.

Is there any difference between a GUID and a UUID?

Not really. GUID is more Microsoft-centric whereas UUID is used more widely (e.g., as in the urn:uuid: URN scheme, and in CORBA).

How to recompile with -fPIC

I had this problem when building FFMPEG static libraries (e.g. libavcodec.a) for Android x86_64 target platform (using Android NDK clang). When statically linking with my library the problem occured although all FFMPEG C -> object files (*.o) were compiled with -fPIC compile option:

x86_64/libavcodec.a(h264_qpel_10bit.o): 
requires dynamic R_X86_64_PC32 reloc against 'ff_pw_1023' 
which may overflow at runtime; recompile with -fPIC

The problem occured only for libavcodec.a and libswscale.a.

Source of this problem is that FFMPEG has assembler optimizations for x86* platforms e.g. the reported problem cause is in libavcodec/h264_qpel_10bit.asm -> h264_qpel_10bit.o.

When producing X86-64 bit static library (e.g. libavcodec.a) it looks like assembler files (e.g. libavcodec/h264_qpel_10bit.asm) uses some x86 (32bit) assembler commands which are incompatible when statically linking with x86-64 bit target library since they don't support required relocation type.

Possible solutions:

  1. compile all ffmpeg files with no assembler optimizations (for ffmpeg this is configure option: --disable-asm)
  2. produce dynamic libraries (e.g. libavcodec.so) and link them in your final library dynamically

I chose 1) and it solved the problem.

Reference: https://tecnocode.co.uk/2014/10/01/dynamic-relocs-runtime-overflows-and-fpic/

SQL Query - Concatenating Results into One String

@AlexanderMP's answer is correct, but you can also consider handling nulls with coalesce:

declare @CodeNameString  nvarchar(max)
set @CodeNameString = null
SELECT @CodeNameString = Coalesce(@CodeNameString + ', ', '') + cast(CodeName as varchar) from AccountCodes  
select @CodeNameString

JQuery or JavaScript: How determine if shift key being pressed while clicking anchor tag hyperlink?

 
var shiftDown = false;
this.onkeydown = function(evt){
    var evt2 = evt || window.event;
    var keyCode = evt2.keyCode || evt2.which;       
    if(keyCode==16)shiftDown = true;
}
this.onkeyup = function(){
    shiftDown = false;
}

demo

How to abort an interactive rebase if --abort doesn't work?

Try to follow the advice you see on the screen, and first reset your master's HEAD to the commit it expects.

git update-ref refs/heads/master b918ac16a33881ce00799bea63d9c23bf7022d67

Then, abort the rebase again.

Prevent nginx 504 Gateway timeout using PHP set_time_limit()

Try this link, it has a better solution on how to fix this. So the steps are:

  1. Open your nginx.conf file located in /etc/nginx directory.

  2. Add this below piece of code under http { section:

    client_header_timeout 3000;
client_body_timeout 3000;
fastcgi_read_timeout 3000;
client_max_body_size 32m;
fastcgi_buffers 8 128k;
fastcgi_buffer_size 128k;

    Note: If its already present , change the values according.

  3. Reload Nginx and php5-fpm.

    $ service nginx reload
$ service php5-fpm reload

    If the error persists, consider increasing the values.

Extract string between two strings in java

Your regex looks correct, but you're splitting with it instead of matching with it. You want something like this:

// Untested code
Matcher matcher = Pattern.compile("<%=(.*?)%>").matcher(str);
while (matcher.find()) {
    System.out.println(matcher.group());
}

How to make an "alias" for a long path?

Maybe it's better to use links

Soft Link

Symbolic or soft link (files or directories, more flexible and self documenting)

#      Source                            Link
ln -s /home/jake/doc/test/2000/something /home/jake/xxx

Hard Link

Hard link (files only, less flexible and not self documenting)

#    Source                            Link
ln /home/jake/doc/test/2000/something /home/jake/xxx

How to create a link to a directory

Hint: If you need not to see the link in your home you can start it with a dot . ; then it will be hidden by default then you can access it like

cd ~/.myHiddelLongDirLink

How can I convert IPV6 address to IPV4 address?

The IPAddress Java library can accomplish what you are describing here.

IPv6 addresses are 16 bytes. Using that library, if you are starting with a 16-byte array you can construct the IPv6 address object:

IPv6Address addr = new IPv6Address(bytes); //bytes is byte[16]

From there you can check if the address is IPv4 mapped, IPv4 compatible, IPv4 translated, and so on (there are many possible ways IPv6 represents IPv4 addresses). In most cases, if an IPv6 address represents an IPv4 address, the ipv4 address is in the lower 4 bytes, and so you can get the derived IPv4 address as follows. Afterwards, you can convert back to bytes, which will be just 4 bytes for IPv4.

    if(addr.isIPv4Compatible() || addr.isIPv4Mapped()) {
        IPv4Address derivedIpv4Address = addr.getEmbeddedIPv4Address();
        byte ipv4Bytes[] = derivedIpv4Address.getBytes();
        ...
     }

The javadoc is available at the link.

Twitter Bootstrap 3 Sticky Footer

Referring to the official Boostrap3 sticky footer example, there is no need to add <div id="push"></div>, and the CSS is simpler.

The CSS used in the official example is:

/* Sticky footer styles
-------------------------------------------------- */

html,
body {
  height: 100%;
  /* The html and body elements cannot have any padding or margin. */
}

/* Wrapper for page content to push down footer */
#wrap {
  min-height: 100%;
  height: auto;
  /* Negative indent footer by its height */
  margin: 0 auto -60px;
  /* Pad bottom by footer height */
  padding: 0 0 60px;
}

/* Set the fixed height of the footer here */
#footer {
  height: 60px;
  background-color: #f5f5f5;
}

and the essential HTML:

<body>

    <!-- Wrap all page content here -->
    <div id="wrap">

      <!-- Begin page content -->
      <div class="container">

      </div>
    </div>

    <div id="footer">
      <div class="container">

      </div>
    </div>
</body>

You can find the link for this css in the sticky-footer example's source code.

<!-- Custom styles for this template -->
<link href="sticky-footer.css" rel="stylesheet">

Full URL : http://getbootstrap.com/examples/sticky-footer/sticky-footer.css

Angular bootstrap datepicker date format does not format ng-model value

After checking the above answers, I came up with this and it worked perfectly without having to add an extra attribute to your markup

angular.module('app').directive('datepickerPopup', function(dateFilter) {
    return {
        restrict: 'EAC',
        require: 'ngModel',
        link: function(scope, element, attr, ngModel) {
            ngModel.$parsers.push(function(viewValue) {
                return dateFilter(viewValue, 'yyyy-MM-dd');
            });
        }
    }
});

Database Diagram Support Objects cannot be Installed ... no valid owner

right click on your Database , then select properties . select the option in compatibility levels choose sql 2005[90] instead of 2008 if you are working with Microsoft sql 2008. then select the file and write ( sa ) in owner`s textbox. it will work probably

Creating a UIImage from a UIColor to use as a background image for UIButton

Add the dots to all values:

[[UIColor colorWithRed:222./255. green:227./255. blue: 229./255. alpha:1] CGColor]) ;

Otherwise, you are dividing float by int.

sqlite database default time value 'now'

according to dr. hipp in a recent list post:

CREATE TABLE whatever(
     ....
     timestamp DATE DEFAULT (datetime('now','localtime')),
     ...
);

How can I reference a commit in an issue comment on GitHub?

If you are trying to reference a commit in another repo than the issue is in, you can prefix the commit short hash with reponame@.

Suppose your commit is in the repo named dev, and the GitLab issue is in the repo named test. You can leave a comment on the issue and reference the commit by dev@e9c11f0a (where e9c11f0a is the first 8 letters of the sha hash of the commit you want to link to) if that makes sense.

UIDevice uniqueIdentifier deprecated - What to do now?

 
+ (NSString *) getUniqueUUID {
    NSError * error;
    NSString * uuid = [KeychainUtils getPasswordForUsername:kBuyassUser andServiceName:kIdOgBetilngService error:&error];
    if (error) {
    NSLog(@"Error geting unique UUID for this device! %@", [error localizedDescription]);
    return nil;
    }
    if (!uuid) {
        DLog(@"No UUID found. Creating a new one.");
        uuid = [IDManager GetUUID];
        uuid = [Util md5String:uuid];
        [KeychainUtils storeUsername:USER_NAME andPassword:uuid forServiceName:SERVICE_NAME updateExisting:YES error:&error];
        if (error) {
            NSLog(@"Error getting unique UUID for this device! %@", [error localizedDescription]);
            return nil;
        }
    }
    return uuid;
}

How to count the number of true elements in a NumPy bool array

That question solved a quite similar question for me and I thought I should share :

In raw python you can use sum() to count True values in a list :

>>> sum([True,True,True,False,False])
3

But this won't work :

>>> sum([[False, False, True], [True, False, True]])
TypeError...

Swift alert view with OK and Cancel: which button tapped?

small update for swift 5:

let refreshAlert = UIAlertController(title: "Refresh", message: "All data will be lost.", preferredStyle: UIAlertController.Style.alert)

    refreshAlert.addAction(UIAlertAction(title: "Ok", style: .default, handler: { (action: UIAlertAction!) in
          print("Handle Ok logic here")
    }))

    refreshAlert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: { (action: UIAlertAction!) in
          print("Handle Cancel Logic here")
    }))

    self.present(refreshAlert, animated: true, completion: nil)

How to get Map data using JDBCTemplate.queryForMap

queryForMap is appropriate if you want to get a single row. You are selecting without a where clause, so you probably want to queryForList. The error is probably indicative of the fact that queryForMap wants one row, but you query is retrieving many rows.

Check out the docs. There is a queryForList that takes just sql; the return type is a

List<Map<String,Object>>.

So once you have the results, you can do what you are doing. I would do something like

List results = template.queryForList(sql);

for (Map m : results){
   m.get('userid');
   m.get('username');
}

I'll let you fill in the details, but I would not iterate over keys in this case. I like to explicit about what I am expecting.

If you have a User object, and you actually want to load User instances, you can use the queryForList that takes sql and a class type

queryForList(String sql, Class<T> elementType)

(wow Spring has changed a lot since I left Javaland.)

How to change Named Range Scope

An alternative way is to "hack" the Excel file for 2007 or higher, although it is advisable to take care if you are doing this, and keep a backup of the original:

First save the Excel spreadsheet as an .xlsx or .xlsm file (not binary). rename the file to .zip, then unzip. Go to the xl folder in the zip structure and open workbook.xml in Wordpad or a similar text editor. Named ranges are found in the definedName tags. Local scoping is defined by localSheetId="x" (the sheet IDs can be found by pressing Alt-F11 in Excel, with the spreadsheet open, to get to the VBA window, and then looking at the Project pane). Hidden ranges are defined by hidden="1", so just delete the hidden="1" to unhide, for example.

Now rezip the folder structure, taking care to maintain the integrity of the folder structure, and rename back to .xlsx or .xlsm.

This is probably not the best solution if you need to change the scope of or hide/unhide a large number of defined ranges, though it works fine for making one or two small tweaks.

Git - remote: Repository not found

I had the same issue and found out that I had another key file in ~/.ssh for a different GitHub repository. Somehow it was used instead of the new one.

Why do table names in SQL Server start with "dbo"?

dbo is the default schema in SQL Server. You can create your own schemas to allow you to better manage your object namespace.

Dropdownlist width in IE

In jQuery this works fairly well. Assume the dropdown has id="dropdown".

$(document).ready(function(){

    $("#dropdown").mousedown(function(){
    if($.browser.msie) {
        $(this).css("width","auto");
    }
    });
    $("#dropdown").change(function(){
    if ($.browser.msie) {
        $(this).css("width","175px");
    }
    });

});

Remove trailing zeros

The following code could be used to not use the string type:

int decimalResult = 789.500
while (decimalResult>0 && decimalResult % 10 == 0)
{
    decimalResult = decimalResult / 10;
}
return decimalResult;

Returns 789.5

How do I get the last character of a string using an Excel function?

No need to apologize for asking a question! Try using the RIGHT function. It returns the last n characters of a string.

=RIGHT(A1, 1)

How to get element by classname or id

If you want to find the button only by its class name and using jQLite only, you can do like below:

var myListButton = $document.find('button').filter(function() {
    return angular.element(this).hasClass('multi-files');
});

Hope this helps. :)

How do you add CSS with Javascript?

Shortest One Liner

_x000D_
_x000D_ 
// One liner function:
const addCSS = s => document.head.appendChild(document.createElement("style")).innerHTML=s;

// Usage: 
addCSS("body{ background:red; }")
_x000D_
_x000D_
_x000D_

How to format html table with inline styles to look like a rendered Excel table?

This is quick-and-dirty (and not formally valid HTML5), but it seems to work -- and it is inline as per the question:

<table border='1' style='border-collapse:collapse'>

No further styling of <tr>/<td> tags is required (for a basic table grid).

How to include a font .ttf using CSS?

I know this is an old post but this solved my problem.

_x000D_
_x000D_ 
@font-face{_x000D_
  font-family: "Font Name";_x000D_
  src: url("../fonts/font-name.ttf") format("truetype");_x000D_
}
_x000D_
_x000D_
_x000D_

notice src:url("../fonts/font-name.ttf"); we use two periods to go back to the root directory and then into the fonts folder or wherever your file is located.

hope this helps someone down the line:) happy coding

Read Numeric Data from a Text File in C++

The input operator for number skips leading whitespace, so you can just read the number in a loop:

while (myfile >> a)
{
    // ...
}

How do I clear the previous text field value after submitting the form with out refreshing the entire page?

You can set the value of the element to blank

document.getElementById('elementId').value='';

JavaScript get clipboard data on paste event (Cross browser)

Simple solution:

document.onpaste = function(e) {
    var pasted = e.clipboardData.getData('Text');
    console.log(pasted)
}

How to start debug mode from command prompt for apache tomcat server?

  1. From your IDE, create a remote debug configuration, configure it for the default JPDA Tomcat port which is port 8000.

  2. From the command line:

    Linux:

    cd apache-tomcat/bin
export JPDA_SUSPEND=y
./catalina.sh jpda run

    Windows:

    cd apache-tomcat\bin
set JPDA_SUSPEND=y
catalina.bat jpda run

  3. Execute the remote debug configuration from your IDE, and Tomcat will start running and you are now able to set breakpoints in the IDE.

Note:

The JPDA_SUSPEND=y line is optional, it is useful if you want that Apache Tomcat doesn't start its execution until step 3 is completed, useful if you want to troubleshoot application initialization issues.

Producer/Consumer threads using a Queue

Java 5+ has all the tools you need for this kind of thing. You will want to:

  1. Put all your Producers in one ExecutorService;
  2. Put all your Consumers in another ExecutorService;
  3. If necessary, communicate between the two using a BlockingQueue.

I say "if necessary" for (3) because from my experience it's an unnecessary step. All you do is submit new tasks to the consumer executor service. So:

final ExecutorService producers = Executors.newFixedThreadPool(100);
final ExecutorService consumers = Executors.newFixedThreadPool(100);
while (/* has more work */) {
  producers.submit(...);
}
producers.shutdown();
producers.awaitTermination(Long.MAX_VALUE, TimeUnit.NANOSECONDS);
consumers.shutdown();
consumers.awaitTermination(Long.MAX_VALUE, TimeUnit.NANOSECONDS);

So the producers submit directly to consumers.

Getting a 500 Internal Server Error on Laravel 5+ Ubuntu 14.04

If you use vagrant, try this:

First remove config.php in current/vendor.

Run these command: 

php artisan config:clear
php artisan clear-compiled
php artisan optimize

NOT RUN php artisan config:cache.

Hope this help.

Android - how to replace part of a string by another string?

MAY BE INTERESTING TO YOU:

In java, string objects are immutable. Immutable simply means unmodifiable or unchangeable.

Once string object is created its data or state can't be changed but a new string object is created.

Function is not defined - uncaught referenceerror

Thought I would mention this because it took a while for me to fix this issue and I couldn't find the answer anywhere on SO. The code I was working on worked for a co-worker but not for me (I was getting this same error). It worked for me in Chrome, but not in Edge.

I was able to get it working by clearing the cache in Edge.

This may not be the answer to this specific question, but I thought I would mention it in case it saves someone else a little time.

Completely remove MariaDB or MySQL from CentOS 7 or RHEL 7

systemd

sudo systemctl stop mysqld.service && sudo yum remove -y mariadb mariadb-server && sudo rm -rf /var/lib/mysql /etc/my.cnf

sysvinit

sudo service mysql stop && sudo apt-get remove mariadb mariadb-server && sudo rm -rf /var/lib/mysql /etc/my.cnf

Copy data from one existing row to another existing row in SQL?

Use SELECT to Insert records

INSERT tracking (userID, courseID, course, bookmark, course_date, posttest, post_attempts, post_score, post_date, complete, complete_date, exempted, exempted_date, exempted_reason, emailSent) 
SELECT userID, 11, course, bookmark, course_date, posttest, post_attempts, post_score, post_date, complete, complete_date, exempted, exempted_date, exempted_reason, emailSent
FROM tracking WHERE courseID = 6 AND course_date > '08-01-2008'

Testing web application on Mac/Safari when I don't own a Mac

Meanwhile, MacOS High Sierra can be run in VirtualBox (on a PC) for Free. It's not really fast but it works for general browser testing.

How to setup see here: https://www.howtogeek.com/289594/how-to-install-macos-sierra-in-virtualbox-on-windows-10/

I'm using this for a while now and it works quite well

Error in Python script "Expected 2D array, got 1D array instead:"?

The X and Y matrix of Independent Variable and Dependent Variable respectively to DataFrame from int64 Type so that it gets converted from 1D array to 2D array.. i.e X=pd.DataFrame(X) and Y=pd.dataFrame(Y) where pd is of pandas class in python. and thus feature scaling in-turn doesn't lead to any error!

What is the difference between compileSdkVersion and targetSdkVersion?

compileSdkVersion

The compileSdkVersion is the version of the API the app is compiled against. This means you can use Android API features included in that version of the API (as well as all previous versions, obviously). If you try and use API 16 features but set compileSdkVersion to 15, you will get a compilation error. If you set compileSdkVersion to 16 you can still run the app on a API 15 device as long as your app's execution paths do not attempt to invoke any APIs specific to API 16.

targetSdkVersion

The targetSdkVersion has nothing to do with how your app is compiled or what APIs you can utilize. The targetSdkVersion is supposed to indicate that you have tested your app on (presumably up to and including) the version you specify. This is more like a certification or sign off you are giving the Android OS as a hint to how it should handle your app in terms of OS features.

For example, as the documentation states:

For example, setting this value to "11" or higher allows the system to apply a new default theme (Holo) to your app when running on Android 3.0 or higher...

The Android OS, at runtime, may change how your app is stylized or otherwise executed in the context of the OS based on this value. There are a few other known examples that are influenced by this value and that list is likely to only increase over time.

For all practical purposes, most apps are going to want to set targetSdkVersion to the latest released version of the API. This will ensure your app looks as good as possible on the most recent Android devices. If you do not specify the targetSdkVersion, it defaults to the minSdkVersion.

How to Truncate a string in PHP to the word closest to a certain number of characters?

This is how i did it:

$string = "I appreciate your service & idea to provide the branded toys at a fair rent price. This is really a wonderful to watch the kid not just playing with variety of toys but learning faster compare to the other kids who are not using the BooksandBeyond service. We wish you all the best";

print_r(substr($string, 0, strpos(wordwrap($string, 250), "\n")));

Python List vs. Array - when to use?

The array module is kind of one of those things that you probably don't have a need for if you don't know why you would use it (and take note that I'm not trying to say that in a condescending manner!). Most of the time, the array module is used to interface with C code. To give you a more direct answer to your question about performance:

Arrays are more efficient than lists for some uses. If you need to allocate an array that you KNOW will not change, then arrays can be faster and use less memory. GvR has an optimization anecdote in which the array module comes out to be the winner (long read, but worth it).

On the other hand, part of the reason why lists eat up more memory than arrays is because python will allocate a few extra elements when all allocated elements get used. This means that appending items to lists is faster. So if you plan on adding items, a list is the way to go.

TL;DR I'd only use an array if you had an exceptional optimization need or you need to interface with C code (and can't use pyrex).

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;">

Difference between using Throwable and Exception in a try catch

By catching Throwable it includes things that subclass Error. You should generally not do that, except perhaps at the very highest "catch all" level of a thread where you want to log or otherwise handle absolutely everything that can go wrong. It would be more typical in a framework type application (for example an application server or a testing framework) where it can be running unknown code and should not be affected by anything that goes wrong with that code, as much as possible.

PowerShell To Set Folder Permissions

Referring to Gamaliel 's answer: $args is an array of the arguments that are passed into a script at runtime - as such cannot be used the way Gamaliel is using it. This is actually working:

$myPath = 'C:\whatever.file'
# get actual Acl entry
$myAcl = Get-Acl "$myPath"
$myAclEntry = "Domain\User","FullControl","Allow"
$myAccessRule = New-Object System.Security.AccessControl.FileSystemAccessRule($myAclEntry)
# prepare new Acl
$myAcl.SetAccessRule($myAccessRule)
$myAcl | Set-Acl "$MyPath"
# check if added entry present
Get-Acl "$myPath" | fl

Default keystore file does not exist?

Use This for MAC users

keytool -list -v -keystore ~/.android/debug.keystore -alias androiddebugkey -storepass android -keypass android

Hadoop "Unable to load native-hadoop library for your platform" warning

 
export JAVA_HOME=/home/hadoop/software/java/jdk1.7.0_80
export HADOOP_HOME=/usr/local/hadoop
export HADOOP_COMMON_LIB_NATIVE_DIR=$HADOOP_HOME/lib/native
export HADOOP_OPTS="-Djava.library.path=$HADOOP_COMMON_LIB_NATIVE_DIR"

Pass values of checkBox to controller action in asp.net mvc4

If a checkbox is checked, then the postback values will contain a key-value pair of the form [InputName]=[InputValue]

If a checkbox is not checked, then the posted form contains no reference to the checkbox at all.

Knowing this, the following will work:

In the markup code:

 <input id="responsable" name="checkResp" value="true" type="checkbox" />

And your action method signature:

public ActionResult Index( string responsables, bool checkResp = false)

This will work because when the checkbox is checked, the postback will contain checkResp=true, and if the checkbox is not checked the parameter will default to false.

Video streaming over websockets using JavaScript

It's definitely conceivable but I am not sure we're there yet. In the meantime, I'd recommend using something like Silverlight with IIS Smooth Streaming. Silverlight is plugin-based, but it works on Windows/OSX/Linux. Some day the HTML5 <video> element will be the way to go, but that will lack support for a little while.

Retrofit 2: Get JSON from Response body

you can change your interface with code given below, if you need json String response..

@FormUrlEncoded
@POST("/api/level")
Call<JsonObject> checkLevel(@Field("id") int id);

and retrofit function with this

Call<JsonObject> call = api.checkLevel(1);
    call.enqueue(new Callback<JsonObject>() {
        @Override
        public void onResponse(Call<JsonObject> call, Response<JsonObject> response) {
            Log.d("res", response.body().toString());
        }

        @Override
        public void onFailure(Call<JsonObject> call, Throwable t) {
            Log.d("error",t.getMessage());
        }
    });

How do you get the selected value of a Spinner?

mySpinner.getItemAtPosition(mySpinner.getSelectedItemPosition()) works based on Rich's description.

Sequel Pro Alternative for Windows

I use SQLYog at home and work. It turns out they DO have a free open-source version, though sadly they've been trying to hide that fact for the last few years.

You can download the open-source version from https://github.com/webyog/sqlyog-community - just click the "Download SQLyog Community Version" link.

How to select current date in Hive SQL

 
select from_unixtime(unix_timestamp(current_date, 'yyyyMMdd'),'yyyy-MM-dd');

current_date - current date

yyyyMMdd - my systems current date format;

yyyy-MM-dd - if you wish to change the format to a diff one.

PHP: How to get referrer URL?

Underscore. Not space.

$_SERVER['HTTP_REFERER']

jQuery same click event for multiple elements

Another alternative, assuming your elements are stored as variables (which is often a good idea if you're accessing them multiple times in a function body):

function disableMinHeight() {
    var $html = $("html");
    var $body = $("body");
    var $slideout = $("#slideout");

    $html.add($body).add($slideout).css("min-height", 0);
};

Takes advantage of jQuery chaining and allows you to use references.

PHPMailer character encoding issues

If you are 100% sure $message contain ISO-8859-1 you can use utf8_encode as David says. Otherwise use mb_detect_encoding and mb_convert_encoding on $message.

Also take note that

$mail -> charSet = "UTF-8";

Should be replaced by:

$mail->CharSet = 'UTF-8';

And placed after the instantiation of the class (after the new). The properties are case sensitive! See the PHPMailer doc fot the list & exact spelling.

Also the default encoding of PHPMailer is 8bit which can be problematic with UTF-8 data. To fix this you can do:

$mail->Encoding = 'base64';

Take note that 'quoted-printable' would probably work too in these cases (and maybe even 'binary'). For more details you can read RFC1341 - Content-Transfer-Encoding Header Field.

Repository access denied. access via a deployment key is read-only

Steps:

  1. Create ssh keys on source server

    ssh-keygen

  2. Cat and copy id_rsa.pub located under ~./ssh directory

  3. Go to Bitbucket, if you have already set the access keys for repository(s) then delete existing public key(s)
  4. Go to Bitbucket avatar> Bitbucket settings> SSH Keys (under Security, left pane)> Click on 'Add Keys'> paste the public key.

  5. Check if it works by running below command on the source server

    git remote show origin

  6. For fetch and push from the source server, if the protocol is 'https' then you have to change it to 'git+ssh' by running below command

    git remote set-url origin git+ssh://<bitbucketaccount>@bitbucket.org/<accountname>/repo.git

  7. Check if you can do push to the repo.

Done!

Converting double to string

Just use the following:

doublevalue+"";

This will work for any data type.

Example:

Double dd=10.09;
String ss=dd+"";

What's the difference between "Write-Host", "Write-Output", or "[console]::WriteLine"?

For usages of Write-Host, PSScriptAnalyzer produces the following diagnostic:

Avoid using Write-Host because it might not work in all hosts, does not work when there is no host, and (prior to PS 5.0) cannot be suppressed, captured, or redirected. Instead, use Write-Output, Write-Verbose, or Write-Information.

See the documentation behind that rule for more information. Excerpts for posterity:

The use of Write-Host is greatly discouraged unless in the use of commands with the Show verb. The Show verb explicitly means "show on the screen, with no other possibilities".

Commands with the Show verb do not have this check applied.

Jeffrey Snover has a blog post Write-Host Considered Harmful in which he claims Write-Host is almost always the wrong thing to do because it interferes with automation and provides more explanation behind the diagnostic, however the above is a good summary.

How do you check current view controller class in Swift?

Try this

if self is MyViewController {        

}

Failed to run sdkmanager --list with Java 9

Apparently if you use "commandlinetools" version greater than 3.6.0 you may use JDK11+ to install Android SDK components.

They are available here: https://developer.android.com/studio#command-tools

Official issue tracker saying it is fixed: https://issuetracker.google.com/issues/122210344#comment11

symfony2 twig path with parameter url creation

Set the default value for the active argument in the route.

Making text bold using attributed string in swift

This is the best way that I have come up with. Add a function you can call from anywhere and add it to a file without a class like Constants.swift and then you can embolden words within any string, on numerous occasions by calling just ONE LINE of code:

To go in a constants.swift file:

import Foundation
import UIKit

func addBoldText(fullString: NSString, boldPartOfString: NSString, font: UIFont!, boldFont: UIFont!) -> NSAttributedString {
   let nonBoldFontAttribute = [NSFontAttributeName:font!]
   let boldFontAttribute = [NSFontAttributeName:boldFont!]
   let boldString = NSMutableAttributedString(string: fullString as String, attributes:nonBoldFontAttribute)
   boldString.addAttributes(boldFontAttribute, range: fullString.rangeOfString(boldPartOfString as String))
   return boldString
}

Then you can just call this one line of code for any UILabel:

self.UILabel.attributedText = addBoldText("Check again in 30 DAYS to find more friends", boldPartOfString: "30 DAYS", font: normalFont!, boldFont: boldSearchFont!)


//Mark: Albeit that you've had to define these somewhere:

let normalFont = UIFont(name: "INSERT FONT NAME", size: 15)
let boldFont = UIFont(name: "INSERT BOLD FONT", size: 15)

How to Avoid Response.End() "Thread was being aborted" Exception during the Excel file download

I removed the linkbutton from the UpdatePanel and also commented the Response.End() Success!!!

How to split a long array into smaller arrays, with JavaScript

Another implementation:

const arr = ["H", "o", "w", " ", "t", "o", " ", "s", "p", "l", "i", "t", " ", "a", " ", "l", "o", "n", "g", " ", "a", "r", "r", "a", "y", " ", "i", "n", "t", "o", " ", "s", "m", "a", "l", "l", "e", "r", " ", "a", "r", "r", "a", "y", "s", ",", " ", "w", "i", "t", "h", " ", "J", "a", "v", "a", "S", "c", "r", "i", "p", "t"];

const size = 3; 
const res = arr.reduce((acc, curr, i) => {
  if ( !(i % size)  ) {    // if index is 0 or can be divided by the `size`...
    acc.push(arr.slice(i, i + size));   // ..push a chunk of the original array to the accumulator
  }
  return acc;
}, []);

// => [["H", "o", "w"], [" ", "t", "o"], [" ", "s", "p"], ["l", "i", "t"], [" ", "a", " "], ["l", "o", "n"], ["g", " ", "a"], ["r", "r", "a"], ["y", " ", "i"], ["n", "t", "o"], [" ", "s", "m"], ["a", "l", "l"], ["e", "r", " "], ["a", "r", "r"], ["a", "y", "s"], [",", " ", "w"], ["i", "t", "h"], [" ", "J", "a"], ["v", "a", "S"], ["c", "r", "i"], ["p", "t"]]

NB - This does not modify the original array.

Or, if you prefer a functional, 100% immutable (although there's really nothing bad in mutating in place like done above) and self-contained method:

function splitBy(size, list) {
  return list.reduce((acc, curr, i, self) => {
    if ( !(i % size)  ) {  
      return [
          ...acc,
          self.slice(i, i + size),
        ];
    }
    return acc;
  }, []);
}

How do I replace whitespaces with underscore?

Python has a built in method on strings called replace which is used as so:

string.replace(old, new)

So you would use:

string.replace(" ", "_")

I had this problem a while ago and I wrote code to replace characters in a string. I have to start remembering to check the python documentation because they've got built in functions for everything.

Adding items to an object through the .push() method

Another way of doing it would be:

stuff = Object.assign(stuff, {$(this).attr('value'):$(this).attr('checked')});

Read more here: Object.assign()

correct PHP headers for pdf file download

 
$name = 'file.pdf';
//file_get_contents is standard function
$content = file_get_contents($name);
header('Content-Type: application/pdf');
header('Content-Length: '.strlen( $content ));
header('Content-disposition: inline; filename="' . $name . '"');
header('Cache-Control: public, must-revalidate, max-age=0');
header('Pragma: public');
header('Expires: Sat, 26 Jul 1997 05:00:00 GMT');
header('Last-Modified: '.gmdate('D, d M Y H:i:s').' GMT');
echo $content;

Pyspark: Exception: Java gateway process exited before sending the driver its port number

I go this error fixed by using the below code. I had setup the SPARK_HOME though. You may follow this simple steps from eproblems website

spark_home = os.environ.get('SPARK_HOME', None)

What does "atomic" mean in programming?

It's something that "appears to the rest of the system to occur instantaneously", and falls under categorisation of Linearizability in computing processes. To quote that linked article further:

Atomicity is a guarantee of isolation from concurrent processes. Additionally, atomic operations commonly have a succeed-or-fail definition — they either successfully change the state of the system, or have no apparent effect.

So, for instance, in the context of a database system, one can have 'atomic commits', meaning that you can push a changeset of updates to a relational database and those changes will either all be submitted, or none of them at all in the event of failure, in this way data does not become corrupt, and consequential of locks and/or queues, the next operation will be a different write or a read, but only after the fact. In the context of variables and threading this is much the same, applied to memory.

Your quote highlights that this need not be expected behaviour in all instances.

How to create a md5 hash of a string in C?

Here's a complete example:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#if defined(__APPLE__)
#  define COMMON_DIGEST_FOR_OPENSSL
#  include <CommonCrypto/CommonDigest.h>
#  define SHA1 CC_SHA1
#else
#  include <openssl/md5.h>
#endif

char *str2md5(const char *str, int length) {
    int n;
    MD5_CTX c;
    unsigned char digest[16];
    char *out = (char*)malloc(33);

    MD5_Init(&c);

    while (length > 0) {
        if (length > 512) {
            MD5_Update(&c, str, 512);
        } else {
            MD5_Update(&c, str, length);
        }
        length -= 512;
        str += 512;
    }

    MD5_Final(digest, &c);

    for (n = 0; n < 16; ++n) {
        snprintf(&(out[n*2]), 16*2, "%02x", (unsigned int)digest[n]);
    }

    return out;
}

    int main(int argc, char **argv) {
        char *output = str2md5("hello", strlen("hello"));
        printf("%s\n", output);
        free(output);
        return 0;
    }

Accessing dict_keys element by index in Python3

In many cases, this may be an XY Problem. Why are you indexing your dictionary keys by position? Do you really need to? Until recently, dictionaries were not even ordered in Python, so accessing the first element was arbitrary.

I just translated some Python 2 code to Python 3:

keys = d.keys()
for (i, res) in enumerate(some_list):
    k = keys[i]
    # ...

which is not pretty, but not very bad either. At first, I was about to replace it by the monstrous

    k = next(itertools.islice(iter(keys), i, None))

before I realised this is all much better written as

for (k, res) in zip(d.keys(), some_list):

which works just fine.

I believe that in many other cases, indexing dictionary keys by position can be avoided. Although dictionaries are ordered in Python 3.7, relying on that is not pretty. The code above only works because the contents of some_list had been recently produced from the contents of d.

Have a hard look at your code if you really need to access a disk_keys element by index. Perhaps you don't need to.

Enable/Disable Anchor Tags using AngularJS

Disclaimer:

The OP has made this comment on another answer:

We can have ngDisabled for buttons or input tags; by using CSS we can make the button to look like anchor tag but that doesn't help much! I was more keen on looking how it can be done using directive approach or angular way of doing it?

You can use a variable inside the scope of your controller to disable the links/buttons according to the last button/link that you've clicked on by using ng-click to set the variable at the correct value and ng-disabled to disable the button when needed according to the value in the variable.

I've updated your Plunker to give you an idea.

But basically, it's something like this:

 <div>
       <button ng-click="create()" ng-disabled="state === 'edit'">CREATE</button><br/>
       <button ng-click="edit()" ng-disabled="state === 'create'">EDIT</button><br/>
       <button href="" ng-click="delete()" ng-disabled="state === 'create' || state === 'edit'">DELETE</button>
    </div>

What's the difference between .bashrc, .bash_profile, and .environment?

A good place to look at is the man page of bash. Here's an online version. Look for "INVOCATION" section.

How can I install packages using pip according to the requirements.txt file from a local directory?

I work with a lot of systems that have been mucked by developers "following directions they found on the Internet". It is extremely common that your pip and your python are not looking at the same paths/site-packages. For this reason, when I encounter oddness I start by doing this:

$ python -c 'import sys; print(sys.path)'
['', '/usr/lib/python2.7', '/usr/lib/python2.7/plat-x86_64-linux-gnu',
'/usr/lib/python2.7/lib-tk', '/usr/lib/python2.7/lib-old',
'/usr/lib/python2.7/lib-dynload', '/usr/local/lib/python2.7/dist-packages',
'/usr/lib/python2.7/dist-packages']

$ pip --version
pip 9.0.1 from /usr/local/lib/python2.7/dist-packages (python 2.7)

That is a happy system.

Below is an unhappy system. (Or at least it's a blissfully ignorant system that causes others to be unhappy.)

$ pip --version
pip 9.0.1 from /usr/local/lib/python3.6/site-packages (python 3.6)

$ python -c 'import sys; print(sys.path)'
['', '/usr/local/Cellar/python/2.7.13/Frameworks/Python.framework/Versions/2.7/lib/python27.zip',
'/usr/local/Cellar/python/2.7.13/Frameworks/Python.framework/Versions/2.7/lib/python2.7',
'/usr/local/Cellar/python/2.7.13/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-darwin',
'/usr/local/Cellar/python/2.7.13/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-mac',
'/usr/local/Cellar/python/2.7.13/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-mac/lib-scriptpackages',
'/usr/local/Cellar/python/2.7.13/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-tk',
'/usr/local/Cellar/python/2.7.13/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-old',
'/usr/local/Cellar/python/2.7.13/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-dynload',
'/usr/local/lib/python2.7/site-packages']

$ which pip pip2 pip3
/usr/local/bin/pip
/usr/local/bin/pip3

It is unhappy because pip is (python3.6 and) using /usr/local/lib/python3.6/site-packages while python is (python2.7 and) using /usr/local/lib/python2.7/site-packages

When I want to make sure I'm installing requirements to the right python, I do this:

$ which -a python python2 python3
/usr/local/bin/python
/usr/bin/python
/usr/local/bin/python2
/usr/local/bin/python3

$ /usr/bin/python -m pip install -r requirements.txt

You've heard, "If it ain't broke, don't try to fix it." The DevOps version of that is, "If you didn't break it and you can work around it, don't try to fix it."

How to get rid of underline for Link component of React Router?

There is the nuclear approach which is in your App.css (or counterpart)

a{
  text-decoration: none;
}

which prevents underline for all <a> tags which is the root cause of this problem

How to create a scrollable Div Tag Vertically?

Well, your code worked for me (running Chrome 5.0.307.9 and Firefox 3.5.8 on Ubuntu 9.10), though I switched

overflow-y: scroll;

to

overflow-y: auto;

Demo page over at: http://davidrhysthomas.co.uk/so/tableDiv.html.

xhtml below:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">

<head>
    <META http-equiv="Content-Type" content="text/html; charset=UTF-8">

    <title>Div in table</title>
    <link rel="stylesheet" type="text/css" href="css/stylesheet.css" />

        <style type="text/css" media="all">

        th      {border-bottom: 2px solid #ccc; }

        th,td       {padding: 0.5em 1em; 
                margin: 0;
                border-collapse: collapse;
                }

        tr td:first-child
                {border-right: 2px solid #ccc; } 

        td > div    {width: 249px;
                height: 299px;
                background-color:Gray;
                overflow-y: auto;
                max-width:230px;
                max-height:100px;
                }
        </style>

    <script type="text/javascript" src="js/jquery.js"></script>

    <script type="text/javascript">

    </script>

</head>

<body>

<div>

    <table>

        <thead>
            <tr><th>This is column one</th><th>This is column two</th><th>This is column three</th>
        </thead>



        <tbody>
            <tr><td>This is row one</td><td>data point 2.1</td><td>data point 3.1</td>
            <tr><td>This is row two</td><td>data point 2.2</td><td>data point 3.2</td>
            <tr><td>This is row three</td><td>data point 2.3</td><td>data point 3.3</td>
            <tr><td>This is row four</td><td><div><p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Vestibulum ultricies mattis dolor. Class aptent taciti sociosqu ad litora torquent per conubia nostra, per inceptos himenaeos. Vestibulum a accumsan purus. Vivamus semper tempus nisi et convallis. Aliquam pretium rutrum lacus sed auctor. Phasellus viverra elit vel neque lacinia ut dictum mauris aliquet. Etiam elementum iaculis lectus, laoreet tempor ligula aliquet non. Mauris ornare adipiscing feugiat. Vivamus condimentum luctus tortor venenatis fermentum. Maecenas eu risus nec leo vehicula mattis. In nisi nibh, fermentum vitae tincidunt non, mattis eu metus. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Nunc vel est purus. Ut accumsan, elit non lacinia porta, nibh magna pretium ligula, sed iaculis metus tortor aliquam urna. Duis commodo tincidunt aliquam. Maecenas in augue ut ligula sodales elementum quis vitae risus. Vivamus mollis blandit magna, eu fringilla velit auctor sed.</p></div></td><td>data point 3.4</td>
            <tr><td>This is row five</td><td>data point 2.5</td><td>data point 3.5</td>
            <tr><td>This is row six</td><td>data point 2.6</td><td>data point 3.6</td>
            <tr><td>This is row seven</td><td>data point 2.7</td><td>data point 3.7</td>
        </body>



    </table>

</div>

</body>

</html>

Compare two Byte Arrays? (Java)

Since I wanted to compare two arrays for a unit Test and I arrived on this answer I thought I could share.

You can also do it with:

@Test
public void testTwoArrays() {
  byte[] array = new BigInteger("1111000011110001", 2).toByteArray();
  byte[] secondArray = new BigInteger("1111000011110001", 2).toByteArray();

  Assert.assertArrayEquals(array, secondArray);
}

And you could check on Comparing arrays in JUnit assertions for more infos.

How do I fix a NoSuchMethodError?

Above answer explains very well ..just to add one thing If you are using using eclipse use ctrl+shift+T and enter package structure of class (e.g. : gateway.smpp.PDUEventListener ), you will find all jars/projects where it's present. Remove unnecessary jars from classpath or add above in class path. Now it will pick up correct one.

How to encode the plus (+) symbol in a URL

It's safer to always percent-encode all characters except those defined as "unreserved" in RFC-3986.

unreserved = ALPHA / DIGIT / "-" / "." / "_" / "~"

So, percent-encode the plus character and other special characters.

The problem that you are having with pluses is because, according to RFC-1866 (HTML 2.0 specification), paragraph 8.2.1. subparagraph 1., "The form field names and values are escaped: space characters are replaced by `+', and then reserved characters are escaped"). This way of encoding form data is also given in later HTML specifications, look for relevant paragraphs about application/x-www-form-urlencoded.

How do I get list of all tables in a database using TSQL?

 
SELECT name 
FROM sysobjects 
WHERE xtype='U' 
ORDER BY name;

(SQL Server 2000 standard; still supported in SQL Server 2005.)

Textarea to resize based on content length

One method is to do it without JavaScript and this is something like this:

    <textarea style="overflow: visible" />

Python 2.7: %d, %s, and float()

See String Formatting Operations:

%d is the format code for an integer. %f is the format code for a float.

%s prints the str() of an object (What you see when you print(object)).

%r prints the repr() of an object (What you see when you print(repr(object)).

For a float %s, %r and %f all display the same value, but that isn't the case for all objects. The other fields of a format specifier work differently as well:

>>> print('%10.2s' % 1.123) # print as string, truncate to 2 characters in a 10-place field.
        1.
>>> print('%10.2f' % 1.123) # print as float, round to 2 decimal places in a 10-place field.
      1.12

How to generate and validate a software license key?

You can use a free third party solution to handle this for you such as Quantum-Key.Net It's free and handles payments via paypal through a web sales page it creates for you, key issuing via email and locks key use to a specific computer to prevent piracy.

Your should also take care to obfuscate/encrypt your code or it can easily be reverse engineered using software such as De4dot and .NetReflector. A good free code obfuscator is ConfuserEx wich is fast and simple to use and more effective than expensive alternatives.

You should run your finished software through De4Dot and .NetReflector to reverse-engineer it and see what a cracker would see if they did the same thing and to make sure you have not left any important code exposed or undisguised.

Your software will still be crackable but for the casual cracker it may well be enough to put them off and these simple steps will also prevent your code being extracted and re-used.

https://quantum-key.net

How to use ConfuserEx?

https://github.com/0xd4d/de4dot

https://www.red-gate.com/dynamic/products/dotnet-development/reflector/download

How do I compare two DateTime objects in PHP 5.2.8?

As of PHP 7.x, you can use the following:

$aDate = new \DateTime('@'.(time()));
$bDate = new \DateTime('@'.(time() - 3600));

$aDate <=> $bDate; // => 1, `$aDate` is newer than `$bDate`

How to properly express JPQL "join fetch" with "where" clause as JPA 2 CriteriaQuery?

I will show visually the problem, using the great example from James answer and adding the alternative solution.

When you do the follow query, without the FETCH:

Select e from Employee e 
join e.phones p 
where p.areaCode = '613'

You will have the follow results from Employee as you expected:

EmployeeId EmployeeName PhoneId PhoneAreaCode
1 James 5 613
1 James 6 416

But when you add the FETCH word on JOIN, this is what happens:

EmployeeId EmployeeName PhoneId PhoneAreaCode
1 James 5 613

The generated SQL is the same for the two queries, but the Hibernate removes on memory the 416 register when you use WHERE on the FETCH join.

So, to bring all phones and apply the WHERE correctly, you need to have two JOINs: one for the WHERE and another for the FETCH. Like:

Select e from Employee e 
join e.phones p 
join fetch e.phones      //no alias, to not commit the mistake
where p.areaCode = '613'

How to change color in circular progress bar?

for me theme wasn't working with accentColor. But it did work with colorControlActivated

    <style name="Progressbar.White" parent="AppTheme">
        <item name="colorControlActivated">@color/white</item>
    </style>

  <ProgressBar
        android:layout_width="@dimen/d_40"
        android:layout_height="@dimen/d_40"
        android:indeterminate="true"
        android:theme="@style/Progressbar.White"/>

Html: Difference between cell spacing and cell padding

This is the simple answer I can give.

enter image description here