Programs & Examples On #Memory alignment

Memory alignment means that objects and variables reside at particular offsets in the system's memory.

What Vim command(s) can be used to quote/unquote words?

surround.vim is going to be your easiest answer. If you are truly set against using it, here are some examples for what you can do. Not necessarily the most efficient, but that's why surround.vim was written.

  • Quote a word, using single quotes
    ciw'Ctrl+r"'
    • ciw - Delete the word the cursor is on, and end up in insert mode.
    • ' - add the first quote.
    • Ctrl+r" - Insert the contents of the " register, aka the last yank/delete.
    • ' - add the closing quote.

  • Unquote a word that's enclosed in single quotes
    di'hPl2x
    • di' - Delete the word enclosed by single quotes.
    • hP - Move the cursor left one place (on top of the opening quote) and put the just deleted text before the quote.
    • l - Move the cursor right one place (on top of the opening quote).
    • 2x - Delete the two quotes.

  • Change single quotes to double quotes
    va':s/\%V'\%V/"/g
    • va' - Visually select the quoted word and the quotes.
    • :s/ - Start a replacement.
    • \%V'\%V - Only match single quotes that are within the visually selected region.
    • /"/g - Replace them all with double quotes.

PreparedStatement with Statement.RETURN_GENERATED_KEYS

You can either use the prepareStatement method taking an additional int parameter

PreparedStatement ps = con.prepareStatement(sql, Statement.RETURN_GENERATED_KEYS)

For some JDBC drivers (for example, Oracle) you have to explicitly list the column names or indices of the generated keys:

PreparedStatement ps = con.prepareStatement(sql, new String[]{"USER_ID"})

Selecting element by data attribute with jQuery

I haven't seen a JavaScript answer without jQuery. Hopefully it helps someone.

_x000D_
_x000D_
var elements = document.querySelectorAll('[data-customerID="22"]');_x000D_
_x000D_
elements[0].innerHTML = 'it worked!';
_x000D_
<a data-customerID='22'>test</a>
_x000D_
_x000D_
_x000D_

Info:

Get error message if ModelState.IsValid fails?

Try this

if (ModelState.IsValid)
{
    //go on as normal
}
else
{
    var errors = ModelState.Select(x => x.Value.Errors)
                           .Where(y=>y.Count>0)
                           .ToList();
}

errors will be a list of all the errors.

If you want to display the errors to the user, all you have to do is return the model to the view and if you haven't removed the Razor @Html.ValidationFor() expressions, it will show up.

if (ModelState.IsValid)
{
    //go on as normal
}
else
{
    return View(model);
}

The view will show any validation errors next to each field and/or in the ValidationSummary if it's present.

target="_blank" vs. target="_new"

I know this is an old question and the correct answer, use _blank, has been mentioned several times, but using <a target="somesite.com" target="_blank">Link</a> is a security risk.

It is recommended (performance benefits) to use:

<a href="somesite.com" target="_blank" rel="noopener noreferrer">Link</a>

Show an image preview before upload

Here I did with jQuery using FileReader API.

Html Markup:

<input id="fileUpload" type="file" multiple />
<div id="image-holder"></div>

jQuery:

Here in jQuery code,first I check for file extension. i.e valid image file to be processed, then will check whether the browser support FileReader API is yes then only processed else display respected message

$("#fileUpload").on('change', function () {

     //Get count of selected files
     var countFiles = $(this)[0].files.length;

     var imgPath = $(this)[0].value;
     var extn = imgPath.substring(imgPath.lastIndexOf('.') + 1).toLowerCase();
     var image_holder = $("#image-holder");
     image_holder.empty();

     if (extn == "gif" || extn == "png" || extn == "jpg" || extn == "jpeg") {
         if (typeof (FileReader) != "undefined") {

             //loop for each file selected for uploaded.
             for (var i = 0; i < countFiles; i++) {

                 var reader = new FileReader();
                 reader.onload = function (e) {
                     $("<img />", {
                         "src": e.target.result,
                             "class": "thumb-image"
                     }).appendTo(image_holder);
                 }

                 image_holder.show();
                 reader.readAsDataURL($(this)[0].files[i]);
             }

         } else {
             alert("This browser does not support FileReader.");
         }
     } else {
         alert("Pls select only images");
     }
 });

Detailed Article: How to Preview Image before upload it, jQuery, HTML5 FileReader() with Live Demo

Remote branch is not showing up in "git branch -r"

Unfortunately, git branch -a and git branch -r do not show you all remote branches, if you haven't executed a "git fetch".

git remote show origin works consistently all the time. Also git show-ref shows all references in the Git repository. However, it works just like the git branch command.

How to call MVC Action using Jquery AJAX and then submit form in MVC?

Use preventDefault() to stop the event of submit button and in ajax call success submit the form using submit():

$('#btnSave').click(function (e) {
    e.preventDefault(); // <------------------ stop default behaviour of button
    var element = this;    
    $.ajax({
        url: "/Home/SaveDetailedInfo",
        type: "POST",
        data: JSON.stringify({ 'Options': someData}),
        dataType: "json",
        traditional: true,
        contentType: "application/json; charset=utf-8",
        success: function (data) {
            if (data.status == "Success") {
                alert("Done");
                $(element).closest("form").submit(); //<------------ submit form
            } else {
                alert("Error occurs on the Database level!");
            }
        },
        error: function () {
            alert("An error has occured!!!");
        }
    });
});

Can you target <br /> with css?

BR generates a line-break and it is only a line-break. As this element has no content, there are only few styles that make sense to apply on it, like clear or position. You can set BR's border but you won't see it as it has no visual dimension.

If you like to visually separate two sentences, then you probably want to use the horizontal ruler which is intended for this goal. Since you cannot change the markup, I'm afraid using only CSS you cannot achieve this.

It seems, it has been already discussed on other forums. Extract from Re: Setting the height of a BR element using CSS:

[T]his leads to a somewhat odd status for BR in that on the one hand it is not being treated as a normal element, but instead as an instance of \A in generated content, but on the other hand it is being treated as a normal element in that (a limited subset of) CSS properties are being allowed on it.

I also found a clarification in the CSS 1 specification (no higher level spec mentions it):

The current CSS1 properties and values cannot describe the behavior of the ‘BR’ element. In HTML, the ‘BR’ element specifies a line break between words. In effect, the element is replaced by a line break. Future versions of CSS may handle added and replaced content, but CSS1-based formatters must treat ‘BR’ specially.

Grant Wagner's tests show that there is no way to style BR as you can do with other elements. There is also a site online where you can test the results in your browser.

Update

pelms made some further investigations, and pointed out that IE8 (on Win7) and Chrome 2/Safari 4b allows you to style BR somewhat. And indeed, I checked the IE demo page with IE Net Renderer's IE8 engine, and it worked.

Update 2 c69 made some further investigations, and it turns out you can style the marker for br quite heavily (though, not cross-browser), yet this will not affect the line-break itself, because it seem to belong to parent container.

Finding three elements in an array whose sum is closest to a given number

I did this in n^3, my pseudocode is below;

//Create a hashMap with key as Integer and value as ArrayList //iterate through list using a for loop, for each value in list iterate again starting from next value;

for (int i=0; i<=arr.length-1 ; i++){
    for (int j=i+1; j<=arr.length-1;j++){

//if the sum of arr[i] and arr[j] is less than desired sum then there is potential to find a third digit so do another for loop

      if (arr[i]+arr[j] < sum){
        for (int k= j+1; k<=arr.length-1;k++)

//in this case we are now looking for the third value; if the sum of arr[i] and arr[j] and arr[k] is the desired sum then add these to the HashMap by making the arr[i] the key and then adding arr[j] and arr[k] into the ArrayList in the value of that key

          if (arr[i]+arr[j]+arr[k] ==  sum){              
              map.put(arr[i],new ArrayList<Integer>());
              map.get(arr[i]).add(arr[j]);
              map.get(arr[i]).add(arr[k]);}

after this you now have a dictionary that has all the entries representing the three values adding to the desired sum. Extract all these entries using HashMap functions. This worked perfectly.

Condition within JOIN or WHERE

For inner joins I have not really noticed a difference (but as with all performance tuning, you need to check against your database under your conditions).

However where you put the condition makes a huge difference if you are using left or right joins. For instance consider these two queries:

SELECT *
FROM dbo.Customers AS CUS 
LEFT JOIN dbo.Orders AS ORD 
ON CUS.CustomerID = ORD.CustomerID
WHERE ORD.OrderDate >'20090515'

SELECT *
FROM dbo.Customers AS CUS 
LEFT JOIN dbo.Orders AS ORD 
ON CUS.CustomerID = ORD.CustomerID
AND ORD.OrderDate >'20090515'

The first will give you only those records that have an order dated later than May 15, 2009 thus converting the left join to an inner join.

The second will give those records plus any customers with no orders. The results set is very different depending on where you put the condition. (Select * is for example purposes only, of course you should not use this in production code.)

The exception to this is when you want to see only the records in one table but not the other. Then you use the where clause for the condition not the join.

SELECT *
FROM dbo.Customers AS CUS 
LEFT JOIN dbo.Orders AS ORD 
ON CUS.CustomerID = ORD.CustomerID
WHERE ORD.OrderID is null

Angular 4: How to include Bootstrap?

To install the latest use $ npm i --save bootstrap@next

pip3: command not found but python3-pip is already installed

For Kali, you must use this code after the update.

$sudo python3 get-pip.py

or if you write this, it also works but not supported anymore. So don't use:

$sudo python get-pip.py

Insert multiple values using INSERT INTO (SQL Server 2005)

You can also use the following syntax:-

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

From here

How do I convert a datetime to date?

Answer updated to Python 3.7 and more

Here is how you can turn a date-and-time object

(aka datetime.datetime object, the one that is stored inside models.DateTimeField django model field)

into a date object (aka datetime.date object):

from datetime import datetime

#your date-and-time object
# let's supposed it is defined as
datetime_element = datetime(2020, 7, 10, 12, 56, 54, 324893)

# where
# datetime_element = datetime(year, month, day, hour, minute, second, milliseconds)

# WHAT YOU WANT: your date-only object
date_element = datetime_element.date()

And just to be clear, if you print those elements, here is the output :

print(datetime_element)

2020-07-10 12:56:54.324893


print(date_element)

2020-07-10

Can jQuery read/write cookies to a browser?

You'll need the cookie plugin, which provides several additional signatures to the cookie function.

$.cookie('cookie_name', 'cookie_value') stores a transient cookie (only exists within this session's scope, while $.cookie('cookie_name', 'cookie_value', 'cookie_expiration") creates a cookie that will last across sessions - see http://www.stilbuero.de/2006/09/17/cookie-plugin-for-jquery/ for more information on the JQuery cookie plugin.

If you want to set cookies that are used for the entire site, you'll need to use JavaScript like this:

document.cookie = "name=value; expires=date; domain=domain; path=path; secure"

I am not able launch JNLP applications using "Java Web Start"?

Is this an application to which you have the code? Java 6u14 included a change to the way it handles jar security that for us caused very similar issues. If your jars are signed and work with Java 6u13 or below, you might consider either refactoring your code to work around this update or requiring Java 6u13 or below. Unfortunately I don't recall exactly what we did to resolve the issue - it was panic mode at the time.

Again, if you have the code you have tools to work with. You can put in System.out.println statements in your startup routines - anything console output is displayed in the command window when you run the JNLP from the command line. Otherwise you might consider using a nice logger like log4j to get a better idea of the point of failure.

You may also consider removing the application entirely and downloading it anew. Java Web Start has a Control Panel applet that allows you to see the URL your app is downloading from (could be the wrong one), uninstall the app, set security options, etc.

How to write multiple conditions of if-statement in Robot Framework

Just make sure put single space before and after "and" Keyword..

Java compiler level does not match the version of the installed Java project facet

Assuming that you are using the m2e plugin in Eclipse, you'll need to specify the source and target versions as 1.6 for maven-compiler-plugin. m2e uses these values to determine the project's Java compiler level. A snippet of the POM is shown below:

<build>
  <plugins>
    <plugin>
      <artifactId>maven-compiler-plugin</artifactId>
        <configuration>
          <source>1.6</source>
          <target>1.6</target>
        </configuration>
    </plugin>
  </plugins>
</build>

Alternatively, you can specify the maven.compiler.source and maven.compiler.target properties with values of 1.6, that happen to be the equivalent:

<properties>
    <maven.compiler.target>1.6</maven.compiler.target>
    <maven.compiler.source>1.6</maven.compiler.source>
</properties>

Using AND/OR in if else PHP statement

i think i am having a bit of confusion here. :) But seems no one else have ..

Are you asking which one to use in this scenario? If Yes then And is the correct answer.

If you are asking about how the operators are working, then

In php both AND, && and OR, || will work in the same way. If you are new in programming and php is one of your first languages them i suggest using AND and OR, because it increases readability and reduces confusion when you check back. But if you are familiar with any other languages already then you might already have familiarized the && and || operators.

Format number to always show 2 decimal places

Convert a number into a string, keeping only two decimals:

var num = 5.56789;
var n = num.toFixed(2);

The result of n will be:

5.57

Why am I getting "Received fatal alert: protocol_version" or "peer not authenticated" from Maven Central?

The following command helped me (executing on bash before running mvn)

export MAVEN_OPTS=-Dhttps.protocols=TLSv1,TLSv1.1,TLSv1.2

How should I escape commas and speech marks in CSV files so they work in Excel?

Below are the rules if you believe it's random. A utility function can be created on the basis of these rules.

  1. If the value contains a comma, newline or double quote, then the String value should be returned enclosed in double quotes.

  2. Any double quote characters in the value should be escaped with another double quote.

  3. If the value does not contain a comma, newline or double quote, then the String value should be returned unchanged.

Meaning of Open hashing and Closed hashing

The name open addressing refers to the fact that the location ("address") of the element is not determined by its hash value. (This method is also called closed hashing).

In separate chaining, each bucket is independent, and has some sort of ADT (list, binary search trees, etc) of entries with the same index. In a good hash table, each bucket has zero or one entries, because we need operations of order O(1) for insert, search, etc.

This is a example of separate chaining using C++ with a simple hash function using mod operator (clearly, a bad hash function)

Hide/encrypt password in bash file to stop accidentally seeing it

Although this is not a built in Unix solution, I've implemented a solution for this using a shell script that can be included in whatever shell script you are using. This is usable on POSIX compliant setups. (sh, bash, ksh, zsh) The full description is available in the github repo -> https://github.com/plyint/encpass.sh. This solution will auto-generate a key for your script and store the key and your password (or other secrets) in a hidden directory under your user (i.e. ~/.encpass).

In your script you just need to source encpass.sh and then call the get_secret method. For example:

#!/bin/sh
. encpass.sh
password=$(get_secret)

Pasted below is lite version of the code for encpass.sh(you can get the full version over on github) for easier visibility:

 #!/bin/sh
 ################################################################################
 # Copyright (c) 2020 Plyint, LLC <[email protected]>. All Rights Reserved.
 # This file is licensed under the MIT License (MIT). 
 # Please see LICENSE.txt for more information.
 # 
 # DESCRIPTION: 
 # This script allows a user to encrypt a password (or any other secret) at 
 # runtime and then use it, decrypted, within a script.  This prevents shoulder 
 # surfing passwords and avoids storing the password in plain text, which could 
 # inadvertently be sent to or discovered by an individual at a later date.
 #
 # This script generates an AES 256 bit symmetric key for each script (or user-
 # defined bucket) that stores secrets.  This key will then be used to encrypt 
 # all secrets for that script or bucket.  encpass.sh sets up a directory 
 # (.encpass) under the user's home directory where keys and secrets will be 
 # stored.
 #
 # For further details, see README.md or run "./encpass ?" from the command line.
 #
 ################################################################################

 encpass_checks() {
    [ -n "$ENCPASS_CHECKS" ] && return

    if [ -z "$ENCPASS_HOME_DIR" ]; then
        ENCPASS_HOME_DIR="$HOME/.encpass"
    fi
    [ ! -d "$ENCPASS_HOME_DIR" ] && mkdir -m 700 "$ENCPASS_HOME_DIR"

    if [ -f "$ENCPASS_HOME_DIR/.extension" ]; then
        # Extension enabled, load it...
        ENCPASS_EXTENSION="$(cat "$ENCPASS_HOME_DIR/.extension")"
        ENCPASS_EXT_FILE="encpass-$ENCPASS_EXTENSION.sh"
        if [ -f "./extensions/$ENCPASS_EXTENSION/$ENCPASS_EXT_FILE" ]; then
            # shellcheck source=/dev/null
          . "./extensions/$ENCPASS_EXTENSION/$ENCPASS_EXT_FILE"
        elif [ ! -z "$(command -v encpass-"$ENCPASS_EXTENSION".sh)" ]; then 
            # shellcheck source=/dev/null
            . "$(command -v encpass-$ENCPASS_EXTENSION.sh)"
        else
            encpass_die "Error: Extension $ENCPASS_EXTENSION could not be found."
        fi

        # Extension specific checks, mandatory function for extensions
        encpass_"${ENCPASS_EXTENSION}"_checks
    else
        # Use default OpenSSL implementation
        if [ ! -x "$(command -v openssl)" ]; then
            echo "Error: OpenSSL is not installed or not accessible in the current path." \
                "Please install it and try again." >&2
            exit 1
        fi

        [ ! -d "$ENCPASS_HOME_DIR/keys" ] && mkdir -m 700 "$ENCPASS_HOME_DIR/keys"
        [ ! -d "$ENCPASS_HOME_DIR/secrets" ] && mkdir -m 700 "$ENCPASS_HOME_DIR/secrets"
        [ ! -d "$ENCPASS_HOME_DIR/exports" ] && mkdir -m 700 "$ENCPASS_HOME_DIR/exports"

    fi

   ENCPASS_CHECKS=1
 }

 # Checks if the enabled extension has implented the passed function and if so calls it
 encpass_ext_func() {
   [ ! -z "$ENCPASS_EXTENSION" ] && ENCPASS_EXT_FUNC="$(command -v "encpass_${ENCPASS_EXTENSION}_$1")" || return
    [ ! -z "$ENCPASS_EXT_FUNC" ] && shift && $ENCPASS_EXT_FUNC "$@" 
 }

 # Initializations performed when the script is included by another script
 encpass_include_init() {
    encpass_ext_func "include_init" "$@"
    [ ! -z "$ENCPASS_EXT_FUNC" ] && return

    if [ -n "$1" ] && [ -n "$2" ]; then
        ENCPASS_BUCKET=$1
        ENCPASS_SECRET_NAME=$2
    elif [ -n "$1" ]; then
        if [ -z "$ENCPASS_BUCKET" ]; then
          ENCPASS_BUCKET=$(basename "$0")
        fi
        ENCPASS_SECRET_NAME=$1
    else
        ENCPASS_BUCKET=$(basename "$0")
        ENCPASS_SECRET_NAME="password"
    fi
 }

 encpass_generate_private_key() {
    ENCPASS_KEY_DIR="$ENCPASS_HOME_DIR/keys/$ENCPASS_BUCKET"

    [ ! -d "$ENCPASS_KEY_DIR" ] && mkdir -m 700 "$ENCPASS_KEY_DIR"

    if [ ! -f "$ENCPASS_KEY_DIR/private.key" ]; then
        (umask 0377 && printf "%s" "$(openssl rand -hex 32)" >"$ENCPASS_KEY_DIR/private.key")
    fi
 }

 encpass_set_private_key_abs_name() {
    ENCPASS_PRIVATE_KEY_ABS_NAME="$ENCPASS_HOME_DIR/keys/$ENCPASS_BUCKET/private.key"
    [ ! -n "$1" ] && [ ! -f "$ENCPASS_PRIVATE_KEY_ABS_NAME" ] && encpass_generate_private_key
 }

 encpass_set_secret_abs_name() {
    ENCPASS_SECRET_ABS_NAME="$ENCPASS_HOME_DIR/secrets/$ENCPASS_BUCKET/$ENCPASS_SECRET_NAME.enc"
    [ ! -n "$1" ] && [ ! -f "$ENCPASS_SECRET_ABS_NAME" ] && set_secret
 }

 encpass_rmfifo() {
    trap - EXIT
    kill "$1" 2>/dev/null
    rm -f "$2"
 }

 encpass_mkfifo() {
    fifo="$ENCPASS_HOME_DIR/$1.$$"
    mkfifo -m 600 "$fifo" || encpass_die "Error: unable to create named pipe"
    printf '%s\n' "$fifo"
 }

 get_secret() {
    encpass_checks
    encpass_ext_func "get_secret" "$@"; [ ! -z "$ENCPASS_EXT_FUNC" ] && return

    [ "$(basename "$0")" != "encpass.sh" ] && encpass_include_init "$1" "$2"

    encpass_set_private_key_abs_name
    encpass_set_secret_abs_name
    encpass_decrypt_secret "$@"
 }

 set_secret() {
    encpass_checks

    encpass_ext_func "set_secret" "$@"; [ ! -z "$ENCPASS_EXT_FUNC" ] && return

    if [ "$1" != "reuse" ] || { [ -z "$ENCPASS_SECRET_INPUT" ] && [ -z "$ENCPASS_CSECRET_INPUT" ]; }; then
        echo "Enter $ENCPASS_SECRET_NAME:" >&2
        stty -echo
        read -r ENCPASS_SECRET_INPUT
        stty echo
        echo "Confirm $ENCPASS_SECRET_NAME:" >&2
        stty -echo
        read -r ENCPASS_CSECRET_INPUT
        stty echo

        # Use named pipe to securely pass secret to openssl
        fifo="$(encpass_mkfifo set_secret_fifo)"
    fi

    if [ "$ENCPASS_SECRET_INPUT" = "$ENCPASS_CSECRET_INPUT" ]; then
        encpass_set_private_key_abs_name
        ENCPASS_SECRET_DIR="$ENCPASS_HOME_DIR/secrets/$ENCPASS_BUCKET"

        [ ! -d "$ENCPASS_SECRET_DIR" ] && mkdir -m 700 "$ENCPASS_SECRET_DIR"

        # Generate IV and create secret file
        printf "%s" "$(openssl rand -hex 16)" > "$ENCPASS_SECRET_DIR/$ENCPASS_SECRET_NAME.enc"
        ENCPASS_OPENSSL_IV="$(cat "$ENCPASS_SECRET_DIR/$ENCPASS_SECRET_NAME.enc")"

        echo "$ENCPASS_SECRET_INPUT" > "$fifo" &
        # Allow expansion now so PID is set
        # shellcheck disable=SC2064
        trap "encpass_rmfifo $! $fifo" EXIT HUP TERM INT TSTP

        # Append encrypted secret to IV in the secret file
        openssl enc -aes-256-cbc -e -a -iv "$ENCPASS_OPENSSL_IV" \
            -K "$(cat "$ENCPASS_HOME_DIR/keys/$ENCPASS_BUCKET/private.key")" \
            -in "$fifo" 1>> "$ENCPASS_SECRET_DIR/$ENCPASS_SECRET_NAME.enc"
    else
        encpass_die "Error: secrets do not match.  Please try again."
    fi
 }

 encpass_decrypt_secret() {
    encpass_ext_func "decrypt_secret" "$@"; [ ! -z "$ENCPASS_EXT_FUNC" ] && return

    if [ -f "$ENCPASS_PRIVATE_KEY_ABS_NAME" ]; then
        ENCPASS_DECRYPT_RESULT="$(dd if="$ENCPASS_SECRET_ABS_NAME" ibs=1 skip=32 2> /dev/null | openssl enc -aes-256-cbc \
            -d -a -iv "$(head -c 32 "$ENCPASS_SECRET_ABS_NAME")" -K "$(cat "$ENCPASS_PRIVATE_KEY_ABS_NAME")" 2> /dev/null)"
        if [ ! -z "$ENCPASS_DECRYPT_RESULT" ]; then
            echo "$ENCPASS_DECRYPT_RESULT"
        else
            # If a failed unlock command occurred and the user tries to show the secret
            # Present either a locked or failed decrypt error.
            if [ -f "$ENCPASS_HOME_DIR/keys/$ENCPASS_BUCKET/private.lock" ]; then 
            echo "**Locked**"
            else
                # The locked file wasn't present as expected.  Let's display a failure
            echo "Error: Failed to decrypt"
            fi
        fi
    elif [ -f "$ENCPASS_HOME_DIR/keys/$ENCPASS_BUCKET/private.lock" ]; then
        echo "**Locked**"
    else
        echo "Error: Unable to decrypt. The key file \"$ENCPASS_PRIVATE_KEY_ABS_NAME\" is not present."
    fi
 }

 encpass_die() {
   echo "$@" >&2
   exit 1
 }
 #LITE

No increment operator (++) in Ruby?

I don't think that notation is available because—unlike say PHP or C—everything in Ruby is an object.

Sure you could use $var=0; $var++ in PHP, but that's because it's a variable and not an object. Therefore, $var = new stdClass(); $var++ would probably throw an error.

I'm not a Ruby or RoR programmer, so I'm sure someone can verify the above or rectify it if it's inaccurate.

Suppress output of a function

Use the capture.output() function. It works very much like a one-off sink() and unlike invisible(), it can suppress more than just print messages. Set the file argument to /dev/null on UNIX or NUL on windows. For example, considering Dirk's note:

> invisible(cat("Hi\n"))
Hi

> capture.output( cat("Hi\n"), file='NUL')
> 

Difference between partition key, composite key and clustering key in Cassandra?

The primary key in Cassandra usually consists of two parts - Partition key and Clustering columns.

primary_key((partition_key), clustering_col )

Partition key - The first part of the primary key. The main aim of a partition key is to identify the node which stores the particular row.

CREATE TABLE phone_book ( phone_num int, name text, age int, city text, PRIMARY KEY ((phone_num, name), age);

Here, (phone_num, name) is the partition key. While inserting the data, the hash value of the partition key is generated and this value decides which node the row should go into.

Consider a 4 node cluster, each node has a range of hash values it can store. (Write) INSERT INTO phone_book VALUES (7826573732, ‘Joey’, 25, ‘New York’);

Now, the hash value of the partition key is calculated by Cassandra partitioner. say, hash value(7826573732, ‘Joey’) ? 12 , now, this row will be inserted in Node C.

(Read) SELECT * FROM phone_book WHERE phone_num=7826573732 and name=’Joey’;

Now, again the hash value of the partition key (7826573732,’Joey’) is calculated, which is 12 in our case which resides in Node C, from which the read is done.

  1. Clustering columns - Second part of the primary key. The main purpose of having clustering columns is to store the data in a sorted order. By default, the order is ascending.

There can be more than one partition key and clustering columns in a primary key depending on the query you are solving.

primary_key((pk1, pk2), col 1,col2)

Prevent form redirect OR refresh on submit?

Here:

function submitClick(e)
{
     e.preventDefault();
     $("#messageSent").slideDown("slow");
     setTimeout('$("#messageSent").slideUp();
     $("#contactForm").slideUp("slow")', 2000);
}

$(document).ready(function() {
    $('#contactSend').click(submitClick);
});

Instead of using the onClick event, you'll use bind an 'click' event handler using jQuery to the submit button (or whatever button), which will take submitClick as a callback. We pass the event to the callback to call preventDefault, which is what will prevent the click from submitting the form.

COPYing a file in a Dockerfile, no such file or directory?

Seems that the commands:

docker build -t imagename .

and:

docker build -t imagename - < Dockerfile2

are not executed the same way. If you want to build 2 docker images from within one folder with Dockerfile and Dockerfile2, the COPY command cannot be used in the second example using stdin (< Dockerfile2). Instead you have to use:

docker build -t imagename -f Dockerfile2 .

Then COPY does work as expected.

Binding Combobox Using Dictionary as the Datasource

I know this is a pretty old topic, but I also had a same problem.

My solution:

how we fill the combobox:

foreach (KeyValuePair<int, string> item in listRegion)
{
    combo.Items.Add(item.Value);
    combo.ValueMember = item.Value.ToString();
    combo.DisplayMember = item.Key.ToString();
    combo.SelectedIndex = 0;
}

and that's how we get inside:

 MessageBox.Show(combo_region.DisplayMember.ToString());

I hope it help someone

How to place and center text in an SVG rectangle

If you are creating the SVG programmatically you can simplify it and do something like this:

  <g>
      <rect x={x} y={y} width={width} height={height} />
      <text
          x={x + width / 2}
          y={y + height / 2}
          dominant-baseline="middle"
          text-anchor="middle"
      >
          {label}
      </text>
  </g>

XAMPP - Error: MySQL shutdown unexpectedly

First you need to keep copy of following somewhere in your hard disk.

C:\xampp\mysql\backup

C:\xampp\mysql\data

After that

Copy every thing inside "C:\xampp\mysql\backup" and paste and replace it in
"C:\xampp\mysql\data"

Now your mysql will work in phpmyadmin but your tables will show "Table not found in engine"

For this you will have to go to the copy of "backup and data folders" which have created in your hard disk and there in the data folder copy "ibdata1" file and past and replace in the "C:\xampp\mysql\data".

Now your tables data will be available.

Remove Datepicker Function dynamically

Well I had the same issue and tried "destroy" but that not worked for me. Then I found following work around My HTML was:

<input placeholder="Select Date" id="MyControlId" class="form-control datepicker" type="text" />

Jquery That work for me:

$('#MyControlId').data('datepicker').remove();

Java 8 optional: ifPresent return object orElseThrow exception

Actually what you are searching is: Optional.map. Your code would then look like:

object.map(o -> "result" /* or your function */)
      .orElseThrow(MyCustomException::new);

I would rather omit passing the Optional if you can. In the end you gain nothing using an Optional here. A slightly other variant:

public String getString(Object yourObject) {
  if (Objects.isNull(yourObject)) { // or use requireNonNull instead if NullPointerException suffices
     throw new MyCustomException();
  }
  String result = ...
  // your string mapping function
  return result;
}

If you already have the Optional-object due to another call, I would still recommend you to use the map-method, instead of isPresent, etc. for the single reason, that I find it more readable (clearly a subjective decision ;-)).

Where are Magento's log files located?

These code lines can help you quickly enable log setting in your magento site.

INSERT INTO `core_config_data` (`config_id`, `scope`, `scope_id`, `path`, `value`) VALUES
('', 'default', 0, 'dev/log/active', '1'),
('', 'default', 0, 'dev/log/file', 'system.log'),
('', 'default', 0, 'dev/log/exception_file', 'exception.log');

Then you can see them inside the folder: /var/log under root installation.

More detail in this blog

jQuery - Uncaught RangeError: Maximum call stack size exceeded

your fadeIn() function calls the fadeOut() function, which calls the fadeIn() function again. the recursion is in the JS.

How to merge multiple dicts with same key or different key?

Here is one approach you can use which would work even if both dictonaries don't have same keys:

d1 = {'a':'test','b':'btest','d':'dreg'}
d2 = {'a':'cool','b':'main','c':'clear'}

d = {}

for key in set(d1.keys() + d2.keys()):
    try:
        d.setdefault(key,[]).append(d1[key])        
    except KeyError:
        pass

    try:
        d.setdefault(key,[]).append(d2[key])          
    except KeyError:
        pass

print d

This would generate below input:

{'a': ['test', 'cool'], 'c': ['clear'], 'b': ['btest', 'main'], 'd': ['dreg']}

preg_match(); - Unknown modifier '+'

You need to use delimiters with regexes in PHP. You can use the often used /, but PHP lets you use any matching characters, so @ and # are popular.

Further Reading.

If you are interpolating variables inside your regex, be sure to pass the delimiter you chose as the second argument to preg_quote().

Target a css class inside another css class

I use div instead of tables and am able to target classes within the main class, as below:

CSS

.main {
    .width: 800px;
    .margin: 0 auto;
    .text-align: center;
}
.main .table {
    width: 80%;
}
.main .row {
   / ***something ***/
}
.main .column {
    font-size: 14px;
    display: inline-block;
}
.main .left {
    width: 140px;
    margin-right: 5px;
    font-size: 12px;
}
.main .right {
    width: auto;
    margin-right: 20px;
    color: #fff;
    font-size: 13px;
    font-weight: normal;
}

HTML

<div class="main">
    <div class="table">
        <div class="row">
            <div class="column left">Swing Over Bed</div>
            <div class="column right">650mm</div>
            <div class="column left">Swing In Gap</div>
            <div class="column right">800mm</div>
        </div>
    </div>
</div>

If you want to style a particular "cell" exclusively you can use another sub-class or the id of the div e.g:

.main #red { color: red; }

<div class="main">
    <div class="table">
        <div class="row">
            <div id="red" class="column left">Swing Over Bed</div>
            <div class="column right">650mm</div>
            <div class="column left">Swing In Gap</div>
            <div class="column right">800mm</div>
        </div>
    </div>
</div>

Get Character value from KeyCode in JavaScript... then trim

I know this is an old question, but I came across it today searching for a pre-packaged solution to this problem, and found nothing that really met my needs.

Here is a solution (English only) that correctly supports Upper Case (shifted), Lower Case, punctuation, number keypad, etc.

It also allows for simple and straight-forward identification of - and reaction to - non-printable keys, like ESC, Arrows, Function keys, etc.

https://jsfiddle.net/5hhu896g/1/

keyboardCharMap and keyboardNameMap are the key to making this work

Thanks to DaveAlger for saving me some typing - and much discovery! - by providing the Named Key Array.

html table cell width for different rows

with 5 columns and colspan, this is possible (click here) (but doesn't make much sense to me):

<table width="100%" border="1" bgcolor="#ffffff">
    <colgroup>
        <col width="25%">
        <col width="25%">
        <col width="25%">
        <col width="5%">
        <col width="20%">
    </colgroup>
    <tr>
        <td>25</td>
        <td colspan="2">50</td>
        <td colspan="2">25</td>     
    </tr>
    <tr>
        <td colspan="2">50</td>
        <td colspan="2">30</td>
        <td>20</td>
    </tr>
</table>

number several equations with only one number

How about something like:

\documentclass{article}

\usepackage{amssymb,amsmath}

\begin{document}

\begin{equation}\label{A_Label}
  \begin{split}
    w^T x_i + b \geqslant 1-\xi_i \text{ if } y_i &= 1, \\
    w^T x_i + b \leqslant -1+\xi_i \text{ if } y_i &= -1
  \end{split}
\end{equation}

\end{document}

which produces:

enter image description here

How do I retrieve a textbox value using JQuery?

You need to use the val() function to get the textbox value. text does not exist as a property only as a function and even then its not the correct function to use in this situation.

var from = $("input#fromAddress").val()

val() is the standard function for getting the value of an input.

jQuery detect if textarea is empty

Andy E's answer helped me get the correct way to working for me:

$.each(["input[type=text][value=]", "textarea"], function (index, element) {
if (!$(element).val() || !$(element).text()) {
 $(element).css("background-color", "rgba(255,227,3, 0.2)");
}
});

This !$(element).val() did not catch an empty textarea for me. but that whole bang (!) thing did work when combined with text.

Convert to absolute value in Objective-C

You can use this function to get the absolute value:

+(NSNumber *)absoluteValue:(NSNumber *)input {
  return [NSNumber numberWithDouble:fabs([input doubleValue])];
}

What is @ModelAttribute in Spring MVC?

I know I am late to the party, but I'll quote like they say, "better be late than never". So let us get going, Everybody has their own ways to explain things, let me try to sum it up and simple it up for you in a few steps with an example; Suppose you have a simple form, form.jsp

<form:form action="processForm" modelAttribute="student">
First Name : <form:input path="firstName" /> 
<br><br>
Last Name : <form:input path="lastName" />
<br><br>
<input type="submit" value="submit"/>
</form:form>

path="firstName" path="lastName" These are the fields/properties in the StudentClass when the form is called their getters are called but once submitted their setters are called and their values are set in the bean that was indicated in the modelAttribute="student" in the form tag.

We have StudentController that includes the following methods;

@RequestMapping("/showForm")
public String showForm(Model theModel){ //Model is used to pass data between 
//controllers and views
    theModel.addAttribute("student", new Student()); //attribute name, value
return "form";
}

@RequestMapping("/processForm")
public String processForm(@ModelAttribute("student") Student theStudent){
    System.out.println("theStudent :"+ theStudent.getLastName());
return "form-details";
}

//@ModelAttribute("student") Student theStudent
//Spring automatically populates the object data with form data all behind the 
//scenes 

now finally we have a form-details.jsp

<b>Student Information</b>
${student.firstName}
${student.lastName}

So back to the question What is @ModelAttribute in Spring MVC? A sample definition from the source for you, http://www.baeldung.com/spring-mvc-and-the-modelattribute-annotation The @ModelAttribute is an annotation that binds a method parameter or method return value to a named model attribute and then exposes it to a web view.

What actually happens is it gets all the values of your form those were submitted by it and then holds them for you to bind or assign them to the object. It works same like the @RequestParameter where we only get a parameter and assign the value to some field. Only difference is @ModelAttribute holds all form data rather than a single parameter. It creates a bean for you that holds form submitted data to be used by the developer later on.

To recap the whole thing. Step 1 : A request is sent and our method showForm runs and a model, a temporary bean is set with the name student is forwarded to the form. theModel.addAttribute("student", new Student());

Step 2 : modelAttribute="student" on form submission model changes the student and now it holds all parameters of the form

Step 3 : @ModelAttribute("student") Student theStudent We fetch the values being hold by @ModelAttribute and assign the whole bean/object to Student.

Step 4 : And then we use it as we bid, just like showing it on the page etc like I did

I hope it helps you to understand the concept. Thanks

How to get UTF-8 working in Java webapps?

I'm with a similar problem, but, in filenames of a file I'm compressing with apache commons. So, i resolved it with this command:

convmv --notest -f cp1252 -t utf8 * -r

it works very well for me. Hope it help anyone ;)

How to check if a string "StartsWith" another string?

You can use ECMAScript 6's String.prototype.startsWith() method, but it's not yet supported in all browsers. You'll want to use a shim/polyfill to add it on browsers that don't support it. Creating an implementation that complies with all the details laid out in the spec is a little complicated. If you want a faithful shim, use either:

Once you've shimmed the method (or if you're only supporting browsers and JavaScript engines that already have it), you can use it like this:

_x000D_
_x000D_
   console.log("Hello World!".startsWith("He")); // true
    
var haystack = "Hello world";
var prefix = 'orl';
console.log(haystack.startsWith(prefix)); // false
_x000D_
_x000D_
_x000D_

SQL Server date format yyyymmdd

DECLARE @v DATE= '3/15/2013'

SELECT CONVERT(VARCHAR(10), @v, 112)

you can convert any date format or date time format to YYYYMMDD with no delimiters

How to get last items of a list in Python?

You can use negative integers with the slicing operator for that. Here's an example using the python CLI interpreter:

>>> a = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]
>>> a
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]
>>> a[-9:]
[4, 5, 6, 7, 8, 9, 10, 11, 12]

the important line is a[-9:]

Remove last character from string. Swift language

Swift 4.0 (also Swift 5.0)

var str = "Hello, World"                           // "Hello, World"
str.dropLast()                                     // "Hello, Worl" (non-modifying)
str                                                // "Hello, World"
String(str.dropLast())                             // "Hello, Worl"

str.remove(at: str.index(before: str.endIndex))    // "d"
str                                                // "Hello, Worl" (modifying)

Swift 3.0

The APIs have gotten a bit more swifty, and as a result the Foundation extension has changed a bit:

var name: String = "Dolphin"
var truncated = name.substring(to: name.index(before: name.endIndex))
print(name)      // "Dolphin"
print(truncated) // "Dolphi"

Or the in-place version:

var name: String = "Dolphin"
name.remove(at: name.index(before: name.endIndex))
print(name)      // "Dolphi"

Thanks Zmey, Rob Allen!

Swift 2.0+ Way

There are a few ways to accomplish this:

Via the Foundation extension, despite not being part of the Swift library:

var name: String = "Dolphin"
var truncated = name.substringToIndex(name.endIndex.predecessor())
print(name)      // "Dolphin"
print(truncated) // "Dolphi"

Using the removeRange() method (which alters the name):

var name: String = "Dolphin"    
name.removeAtIndex(name.endIndex.predecessor())
print(name) // "Dolphi"

Using the dropLast() function:

var name: String = "Dolphin"
var truncated = String(name.characters.dropLast())
print(name)      // "Dolphin"
print(truncated) // "Dolphi"

Old String.Index (Xcode 6 Beta 4 +) Way

Since String types in Swift aim to provide excellent UTF-8 support, you can no longer access character indexes/ranges/substrings using Int types. Instead, you use String.Index:

let name: String = "Dolphin"
let stringLength = count(name) // Since swift1.2 `countElements` became `count`
let substringIndex = stringLength - 1
name.substringToIndex(advance(name.startIndex, substringIndex)) // "Dolphi"

Alternatively (for a more practical, but less educational example) you can use endIndex:

let name: String = "Dolphin"
name.substringToIndex(name.endIndex.predecessor()) // "Dolphi"

Note: I found this to be a great starting point for understanding String.Index

Old (pre-Beta 4) Way

You can simply use the substringToIndex() function, providing it one less than the length of the String:

let name: String = "Dolphin"
name.substringToIndex(countElements(name) - 1) // "Dolphi"

case-insensitive matching in xpath?

XPath 2 has a lower-case (and upper-case) string function. That's not quite the same as case-insensitive, but hopefully it will be close enough:

//CD[lower-case(@title)='empire burlesque']

If you are using XPath 1, there is a hack using translate.

C# code to validate email address

There are a lot of strong answers here. However, I recommend that we take a step back. @Cogwheel answers the question https://stackoverflow.com/a/1374644/388267. Nevertheless, it could be costly in a bulk validation scenario, if many of the email address being validated are invalid. I suggest that we employ a bit of logic before we enter into his try-catch block. I know that the following code could be written using RegEx but that could be costly for new developers to understand. This is my twopence worth:

    public static bool IsEmail(this string input)
    {
        if (string.IsNullOrWhiteSpace(input)) return false;

        // MUST CONTAIN ONE AND ONLY ONE @
        var atCount = input.Count(c => c == '@');
        if (atCount != 1) return false;

        // MUST CONTAIN PERIOD
        if (!input.Contains(".")) return false;

        // @ MUST OCCUR BEFORE LAST PERIOD
        var indexOfAt = input.IndexOf("@", StringComparison.Ordinal);
        var lastIndexOfPeriod = input.LastIndexOf(".", StringComparison.Ordinal);
        var atBeforeLastPeriod = lastIndexOfPeriod > indexOfAt;
        if (!atBeforeLastPeriod) return false;

        // CODE FROM COGWHEEL'S ANSWER: https://stackoverflow.com/a/1374644/388267 
        try
        {
            var addr = new System.Net.Mail.MailAddress(input);
            return addr.Address == input;
        }
        catch
        {
            return false;
        }
    }

JSON forEach get Key and Value

Assuming that obj is a pre-constructed object (and not a JSON string), you can achieve this with the following:

Object.keys(obj).forEach(function(key){
   console.log(key + '=' + obj[key]);
});

PHP split alternative?

  • preg_split if you need to split by regular expressions.
  • str_split if you need to split by characters.
  • explode if you need to split by something simple.

Also for the future, if you ever want to know what PHP wants you to use if something is deprecated you can always check out the function in the manual and it will tell you alternatives.

Access host database from a docker container

From the 18.03 docs:

I want to connect from a container to a service on the host

The host has a changing IP address (or none if you have no network access). From 18.03 onwards our recommendation is to connect to the special DNS name host.docker.internal, which resolves to the internal IP address used by the host.

The gateway is also reachable as gateway.docker.internal.

EXAMPLE: Here's what I use for my MySQL connection string inside my container to access the MySQL instance on my host:

mysql://host.docker.internal:3306/my_awesome_database

How to add default signature in Outlook

I figured out a way, but it may be too sloppy for most. I've got a simple Db and I want it to be able to generate emails for me, so here's the down and dirty solution I used:

I found that the beginning of the body text is the only place I see the "<div class=WordSection1>" in the HTMLBody of a new email, so I just did a simple replace, replacing

"<div class=WordSection1><p class=MsoNormal><o:p>"

with

"<div class=WordSection1><p class=MsoNormal><o:p>" & sBody

where sBody is the body content I want inserted. Seems to work so far.

.HTMLBody = Replace(oEmail.HTMLBody, "<div class=WordSection1><p class=MsoNormal><o:p>", "<div class=WordSection1><p class=MsoNormal><o:p>" & sBody)

What's a good, free serial port monitor for reverse-engineering?

I hear a lot of good things about com0com, which is a software port emulator. You can "connect" a physical serial port through it, so that your software uses the (monitored) virtual port, and forwards all traffic to/from a physical port. I haven't used it myself, but I've seen it recommended here on SO a lot.

Intermediate language used in scalac?

maybe this will help you out:

http://lampwww.epfl.ch/~paltherr/phd/altherr-phd.pdf

or this page:

www.scala-lang.org/node/6372‎

Where is the <conio.h> header file on Linux? Why can't I find <conio.h>?

That is because is does not exist, since it is bounded to Windows.

Use the standard functions from <stdio.h> instead, such as getc

The suggested ncurses library is good if you want to write console-based GUIs, but I don't think it is what you want.

Can't drop table: A foreign key constraint fails

I realize this is stale for a while and an answer had been selected, but how about the alternative to allow the foreign key to be NULL and then choose ON DELETE SET NULL.

Basically, your table should be changed like so:

ALTER TABLE 'bericht' DROP FOREIGN KEY 'your_foreign_key';

ALTER TABLE 'bericht' ADD CONSTRAINT 'your_foreign_key' FOREIGN KEY ('column_foreign_key') REFERENCES 'other_table' ('column_parent_key') ON UPDATE CASCADE ON DELETE SET NULL;

Personally I would recommend using both "ON UPDATE CASCADE" as well as "ON DELETE SET NULL" to avoid unnecessary complications, however your set up may dictate a different approach.

Hope this helps.

ERROR 1049 (42000): Unknown database

Its a common error which happens when we try to access a database which doesn't exist. So create the database using

CREATE DATABASE blog_development;

The error commonly occours when we have dropped the database using

DROP DATABASE blog_development;

and then try to access the database.

How do you change library location in R?

I've used this successfully inside R script:

library("reshape2",lib.loc="/path/to/R-packages/")

useful if for whatever reason libraries are in more than one place.

Pass array to mvc Action via AJAX

The answer to use the 'traditional' option is correct. I'm just providing some more background info for this who wish to learn more.

From the jQuery documentation:

As of jQuery 1.8, the $.param() method no longer uses jQuery.ajaxSettings.traditional as its default setting and will default to false.

You can also read more here: http://michaelsync.net/2012/04/05/tips-asp-net-mvc-javascriptserializer-3-questions-and-3-answers and http://haacked.com/archive/2008/10/23/model-binding-to-a-list.aspx

HTH

How can I quickly and easily convert spreadsheet data to JSON?

Assuming you really mean easiest and are not necessarily looking for a way to do this programmatically, you can do this:

  1. Add, if not already there, a row of "column Musicians" to the spreadsheet. That is, if you have data in columns such as:

    Rory Gallagher      Guitar
    Gerry McAvoy        Bass
    Rod de'Ath          Drums
    Lou Martin          Keyboards
    Donkey Kong Sioux   Self-Appointed Semi-official Stomper
    

    Note: you might want to add "Musician" and "Instrument" in row 0 (you might have to insert a row there)

  2. Save the file as a CSV file.

  3. Copy the contents of the CSV file to the clipboard

  4. Go to http://www.convertcsv.com/csv-to-json.htm

  5. Verify that the "First row is column names" checkbox is checked

  6. Paste the CSV data into the content area

  7. Mash the "Convert CSV to JSON" button

    With the data shown above, you will now have:

    [
      {
        "MUSICIAN":"Rory Gallagher",
        "INSTRUMENT":"Guitar"
      },
      {
        "MUSICIAN":"Gerry McAvoy",
        "INSTRUMENT":"Bass"
      },
      {
        "MUSICIAN":"Rod D'Ath",
        "INSTRUMENT":"Drums"
      },
      {
        "MUSICIAN":"Lou Martin",
        "INSTRUMENT":"Keyboards"
      }
      {
        "MUSICIAN":"Donkey Kong Sioux",
        "INSTRUMENT":"Self-Appointed Semi-Official Stomper"
      }
    ]
    

    With this simple/minimalistic data, it's probably not required, but with large sets of data, it can save you time and headache in the proverbial long run by checking this data for aberrations and abnormalcy.

  8. Go here: http://jsonlint.com/

  9. Paste the JSON into the content area

  10. Pres the "Validate" button.

If the JSON is good, you will see a "Valid JSON" remark in the Results section below; if not, it will tell you where the problem[s] lie so that you can fix it/them.

How to remove an item from an array in Vue.js

You're using splice in a wrong way.

The overloads are:

array.splice(start)

array.splice(start, deleteCount)

array.splice(start, deleteCount, itemForInsertAfterDeletion1, itemForInsertAfterDeletion2, ...)

Start means the index that you want to start, not the element you want to remove. And you should pass the second parameter deleteCount as 1, which means: "I want to delete 1 element starting at the index {start}".

So you better go with:

deleteEvent: function(event) {
  this.events.splice(this.events.indexOf(event), 1);
}

Also, you're using a parameter, so you access it directly, not with this.event.

But in this way you will look up unnecessary for the indexOf in every delete, for solving this you can define the index variable at your v-for, and then pass it instead of the event object.

That is:

v-for="(event, index) in events"
...

<button ... @click="deleteEvent(index)"

And:

deleteEvent: function(index) {
  this.events.splice(index, 1);
}

PHP namespaces and "use"

If you need to order your code into namespaces, just use the keyword namespace:

file1.php

namespace foo\bar;

In file2.php

$obj = new \foo\bar\myObj();

You can also use use. If in file2 you put

use foo\bar as mypath;

you need to use mypath instead of bar anywhere in the file:

$obj  = new mypath\myObj();

Using use foo\bar; is equal to use foo\bar as bar;.

Change a HTML5 input's placeholder color with CSS

Here is the solution with CSS selectors

::-webkit-input-placeholder { /* WebKit, Blink, Edge */
    color:    #909;
}
:-moz-placeholder { /* Mozilla Firefox 4 to 18 */
   color:    #909;
   opacity:  1;
}
::-moz-placeholder { /* Mozilla Firefox 19+ */
   color:    #909;
   opacity:  1;
}
::-ms-input-placeholder { /* Microsoft Edge */
   color:    #909;
}
:-ms-input-placeholder { /* Internet Explorer 10-11 */
   color:    #909;
}
  • WebKit, Blink (Safari, Google Chrome, Opera 15+) and Microsoft Edge are using a pseudo-element:
    ::-webkit-input-placeholder.
  • Mozilla Firefox 4 to 18 is using a pseudo-class:
    :-moz-placeholder (one colon).
    Mozilla Firefox 19+ is using a pseudo-element:
    ::-moz-placeholder, but the old selector will still work for a while.
  • Internet Explorer 10 and 11 are using a pseudo-class:
    :-ms-input-placeholder.
  • Internet Explorer 9 and lower does not support the placeholder attribute at all, while Opera 12 and lower do not support any CSS selector for placeholders.

JavaScript chop/slice/trim off last character in string

You can use slice! You just have to make sure you know how to use it. Positive #s are relative to the beginning, negative numbers are relative to the end.

js>"12345.00".slice(0,-1)
12345.0

How to read and write INI file with Python3?

ConfigObj is a good alternative to ConfigParser which offers a lot more flexibility:

  • Nested sections (subsections), to any level
  • List values
  • Multiple line values
  • String interpolation (substitution)
  • Integrated with a powerful validation system including automatic type checking/conversion repeated sections and allowing default values
  • When writing out config files, ConfigObj preserves all comments and the order of members and sections
  • Many useful methods and options for working with configuration files (like the 'reload' method)
  • Full Unicode support

It has some draw backs:

  • You cannot set the delimiter, it has to be =… (pull request)
  • You cannot have empty values, well you can but they look liked: fuabr = instead of just fubar which looks weird and wrong.

MySQL string replace

UPDATE your_table
SET your_field = REPLACE(your_field, 'articles/updates/', 'articles/news/')
WHERE your_field LIKE '%articles/updates/%'

Now rows that were like

http://www.example.com/articles/updates/43

will be

http://www.example.com/articles/news/43

http://www.electrictoolbox.com/mysql-find-replace-text/

How to specify the bottom border of a <tr>?

tr td 
{
    border-bottom: 2px solid silver;
}

or if you want the border inside the TR tag, you can do this:

tr td {
    box-shadow: inset 0px -2px 0px silver;
}

Unable to find velocity template resources

Great question - I solved my issue today as follows using Ecilpse:

  1. Put your template in the same folder hierarchy as your source code (not in a separate folder hierarchy even if you include it in the build path) as below: Where to put your template file

  2. In your code simply use the following lines of code (assuming you just want the date to be passed as data):

    VelocityEngine ve = new VelocityEngine();
    ve.setProperty(RuntimeConstants.RESOURCE_LOADER, "classpath");
    ve.setProperty("classpath.resource.loader.class", ClasspathResourceLoader.class.getName());
    ve.init();
    VelocityContext context = new VelocityContext();
    context.put("date", getMyTimestampFunction());
    Template t = ve.getTemplate( "templates/email_html_new.vm" );
    StringWriter writer = new StringWriter();
    t.merge( context, writer );
    

See how first we tell VelocityEngine to look in the classpath. Without this it wouldn't know where to look.

Cannot use string offset as an array in php

Since the release PHP 7.1+, is not more possible to assign a value for an array as follow:

$foo = ""; 
$foo['key'] = $foo2; 

because as of PHP 7.1.0, applying the empty index operator on a string throws a fatal error. Formerly, the string was silently converted to an array.

Git push rejected "non-fast-forward"

I had this problem! I tried: git fetch + git merge, but dont resolved! I tried: git pull, and also dont resolved

Then I tried this and resolved my problem (is similar of answer of Engineer):

git fetch origin master:tmp
git rebase tmp
git push origin HEAD:master
git branch -D tmp

changing permission for files and folder recursively using shell command in mac

By using CHMOD yes:

For Recursive file:

chmod -R 777 foldername or pathname

For non recursive:

chmod 777 foldername or pathname

Get querystring from URL using jQuery

An easy way to do this with some jQuery and straight JavaScript, just view your console in Chrome or Firefox to see the output...

  var queries = {};
  $.each(document.location.search.substr(1).split('&'),function(c,q){
    var i = q.split('=');
    queries[i[0].toString()] = i[1].toString();
  });
  console.log(queries);

Available text color classes in Bootstrap

You can use text classes:

.text-primary
.text-secondary
.text-success
.text-danger
.text-warning
.text-info
.text-light
.text-dark
.text-muted
.text-white

use text classes in any tag where needed.

<p class="text-primary">.text-primary</p>
<p class="text-secondary">.text-secondary</p>
<p class="text-success">.text-success</p>
<p class="text-danger">.text-danger</p>
<p class="text-warning">.text-warning</p>
<p class="text-info">.text-info</p>
<p class="text-light bg-dark">.text-light</p>
<p class="text-dark">.text-dark</p>
<p class="text-muted">.text-muted</p>
<p class="text-white bg-dark">.text-white</p>

You can add your own classes or modify above classes as your requirement.

Using LIKE operator with stored procedure parameters

EG : COMPARE TO VILLAGE NAME

ALTER PROCEDURE POSMAST
(@COLUMN_NAME VARCHAR(50))
AS
SELECT * FROM TABLE_NAME
WHERE 
village_name LIKE + @VILLAGE_NAME + '%';

Error in installation a R package

I had the same problem with e1071 package. Just close any other R sessions running parallelly and you will be good to go.

Facebook Android Generate Key Hash

UPDATED ANSWER (Generating through code) Simpler method :

In my experience, openssl always being troublesome, I tried the second method suggested by facebook. And it's wonderful. This is the best method to get the hash key.

Second option is to print out the key hash sent to Facebook and use that value. Make the following changes to the onCreate() method in your main activity:

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        try {
            PackageInfo info = getPackageManager().getPackageInfo(
                    "com.facebook.samples.loginhowto", 
                    PackageManager.GET_SIGNATURES);
            for (Signature signature : info.signatures) {
                MessageDigest md = MessageDigest.getInstance("SHA");
                md.update(signature.toByteArray());
                Log.d("KeyHash:", Base64.encodeToString(md.digest(), Base64.DEFAULT));
                }
        } catch (NameNotFoundException e) {

        } catch (NoSuchAlgorithmException e) {

        }
        ...other operations

}//end of onCreate

Replace com.facebook.samples.loginhowto with your own package name ( package name in Manifest.xml).

Official link - https://developers.facebook.com/docs/android/login-with-facebook/ ( See the bottom of the page)

OLD ANSWER (Generating Keyhash using openssl )

  1. to generate signature you need openssl installed on your pc. If you don’t have one download openssl from here
  2. In C: , Create openssl folder
  3. extract the contents of downloaded openssl zip file into openssl folder in C:drive
  4. open Command prompt
  5. move to bin of openssl i.e C:\openssl\bin in command prompt
  6. run the following command to generate your keyhash. While generating hashkey it should ask you password.

    keytool -exportcert -alias androiddebugkey -keystore "C:\Users\Anhsirk.android\debug.keystore" | openssl sha1 -binary | openssl base64

NOTE: in the above code note that , you need to give your path to user ( i.e in my case it is C:\Users\Anhsirk , you just need to change this for your user account.

Give password as android

. If it don’t ask for password your keystore path is incorrect.

If everything works fine, it should give you the hashkey below.

enter image description here

Convert string to int array using LINQ

This post asked a similar question and used LINQ to solve it, maybe it will help you out too.

string s1 = "1;2;3;4;5;6;7;8;9;10;11;12";
int[] ia = s1.Split(';').Select(n => Convert.ToInt32(n)).ToArray();

Show pop-ups the most elegant way

It's funny because I'm learning Angular myself and was watching some video's from their channel on Youtube. The speaker mentions your exact problem in this video https://www.youtube.com/watch?v=ZhfUv0spHCY#t=1681 around the 28:30 minute mark.

It comes down to placing that particular piece of code in a service rather then a controller.

My guess would be to inject new popup elements into the DOM and handle them separate instead of showing and hiding the same element. This way you can have multiple popups.

The whole video is very interesting to watch as well :-)

Filtering a list based on a list of booleans

With numpy:

In [128]: list_a = np.array([1, 2, 4, 6])
In [129]: filter = np.array([True, False, True, False])
In [130]: list_a[filter]

Out[130]: array([1, 4])

or see Alex Szatmary's answer if list_a can be a numpy array but not filter

Numpy usually gives you a big speed boost as well

In [133]: list_a = [1, 2, 4, 6]*10000
In [134]: fil = [True, False, True, False]*10000
In [135]: list_a_np = np.array(list_a)
In [136]: fil_np = np.array(fil)

In [139]: %timeit list(itertools.compress(list_a, fil))
1000 loops, best of 3: 625 us per loop

In [140]: %timeit list_a_np[fil_np]
10000 loops, best of 3: 173 us per loop

how do I insert a column at a specific column index in pandas?

df.insert(loc, column_name, value)

This will work if there is no other column with the same name. If a column, with your provided name already exists in the dataframe, it will raise a ValueError.

You can pass an optional parameter allow_duplicates with True value to create a new column with already existing column name.

Here is an example:



    >>> df = pd.DataFrame({'b': [1, 2], 'c': [3,4]})
    >>> df
       b  c
    0  1  3
    1  2  4
    >>> df.insert(0, 'a', -1)
    >>> df
       a  b  c
    0 -1  1  3
    1 -1  2  4
    >>> df.insert(0, 'a', -2)
    Traceback (most recent call last):
      File "", line 1, in 
      File "C:\Python39\lib\site-packages\pandas\core\frame.py", line 3760, in insert
        self._mgr.insert(loc, column, value, allow_duplicates=allow_duplicates)
      File "C:\Python39\lib\site-packages\pandas\core\internals\managers.py", line 1191, in insert
        raise ValueError(f"cannot insert {item}, already exists")
    ValueError: cannot insert a, already exists
    >>> df.insert(0, 'a', -2,  allow_duplicates = True)
    >>> df
       a  a  b  c
    0 -2 -1  1  3
    1 -2 -1  2  4

Change the "No file chosen":

Something like this could work

input(type='file', name='videoFile', value = "Choose a video please")

How to detect the end of loading of UITableView

To know when a table view finishes loading its content, we first need to have a basic understanding of how the views are put on screen.

In the life cycle of an app, there are 4 key moments :

  1. The app receives an event (touch, timer, block dispatched etc)
  2. The app handles the event (it modifies a constraint, starts an animation, changes background etc)
  3. The app computes the new view hierarchy
  4. The app renders the view hierarchy and displays it

The 2 and 3 times are totally separated. Why ? For performance reasons, we don't want to perform all the computations (done at 3) each time a modification is done.

So, I think you are facing a case like this :

tableView.reloadData()
tableView.visibleCells.count // wrong count oO

What’s wrong here?

A table view reloads its content lazily. Actually, if you call reloadData multiple times it won’t create performance issues. The table view only recomputes its content size based on its delegate implementation and waits the moment 3 to loads its cells. This time is called a layout pass.

Okay, how to get involved in the layout pass?

During the layout pass, the app computes all the frames of the view hierarchy. To get involved, you can override the dedicated methods layoutSubviews, updateLayoutConstraints etc in a UIView subclass and the equivalent methods in a view controller subclass.

That’s exactly what a table view does. It overrides layoutSubviews and based on your delegate implementation adds or removes cells. It calls cellForRow right before adding and laying out a new cell, willDisplay right after. If you called reloadData or just added the table view to the hierarchy, the tables view adds as many cells as necessary to fill its frame at this key moment.

Alright, but now, how to know when a tables view has finished reloading its content?

We can rephrase this question: how to know when a table view has finished laying out its subviews?

The easiest way is to get into the layout of the table view :

class MyTableView: UITableView {
    func layoutSubviews() {
        super.layoutSubviews()
        // the displayed cells are loaded
    }
}

Note that this method is called many times in the life cycle of the table view. Because of the scroll and the dequeue behavior of the table view, cells are modified, removed and added often. But it works, right after the super.layoutSubviews(), cells are loaded. This solution is equivalent to wait the willDisplay event of the last index path. This event is called during the execution of layoutSubviews of the table view when a cell is added.

Another way is to be notified when the app finishes a layout pass.

As described in the documentation, you can use an option of the UIView.animate(withDuration:completion):

tableView.reloadData()
UIView.animate(withDuration: 0) {
    // layout done
}

This solution works but the screen will refresh once between the time the layout is done and the time the block is executed. This is equivalent to the DispatchMain.async solution but specified.

Alternatively, I would prefer to force the layout of the table view

There is a dedicated method to force any view to compute immediately its subview frames layoutIfNeeded:

tableView.reloadData()
table.layoutIfNeeded()
// layout done

Be careful however, doing so will remove the lazy loading used by the system. Calling those methods repeatedly could create performance issues. Make sure that they won’t be called before the frame of the table view is computed, otherwise the table view will be loaded again and you won’t be notified.


I think there is no perfect solution. Subclassing classes could lead to trubles. A layout pass starts from the top and goes to the bottom so it’s not easy to get notified when all the layout is done. And layoutIfNeeded() could create performance issues etc.

Best way to "negate" an instanceof

ok just my two cents, use a is string method:

public static boolean isString(Object thing) {
    return thing instanceof String;
}

public void someMethod(Object thing){
    if (!isString(thing)) {
        return null;
    }
    log.debug("my thing is valid");
}

How do you underline a text in Android XML?

There are different ways to achieve underlined text in an Android TextView.

1.<u>This is my underlined text</u> or

I just want to underline <u>this</u> word

2.You can do the same programmatically.

`textView.setPaintFlags(textView.getPaintFlags() | Paint.UNDERLINE_TEXT_FLAG);`

3.It can be done by creating a SpannableString and then setting it as the TextView text property

SpannableString text = new SpannableString("Voglio sottolineare solo questa parola");
text.setSpan(new UnderlineSpan(), 25, 6, 0);
textView.setText(text);

Align two inline-blocks left and right on same line

I think one possible solution to this is to use display: table:

.header {
  display: table;
  width: 100%;
  box-sizing: border-box;
}

.header > * {
  display: table-cell;
}

.header > *:last-child {
  text-align: right;  
}

h1 {
  font-size: 32px;
}

nav {
  vertical-align: baseline;
}

JSFiddle: http://jsfiddle.net/yxxrnn7j/1/

CSS: auto height on containing div, 100% height on background div inside containing div

In 2018 a lot of browsers support the Flexbox and Grid which are very powerful CSS display modes that overshine classical methods such as Faux Columns or Tabular Displays (which are treated later in this answer).

In order to implement this with the Grid, it is enough to specify display: grid and grid-template-columns on the container. The grid-template-columns depends on the number of columns you have, in this example I will use 3 columns, hence the property will look: grid-template-columns: auto auto auto, which basically means that each of the columns will have auto width.

Full working example with Grid:

_x000D_
_x000D_
html, body {_x000D_
    padding: 0;_x000D_
    margin: 0;_x000D_
}_x000D_
_x000D_
.grid-container {_x000D_
    display: grid;_x000D_
    grid-template-columns: auto auto auto;_x000D_
    width: 100%;_x000D_
}_x000D_
_x000D_
.grid-item {_x000D_
    padding: 20px;_x000D_
}_x000D_
_x000D_
.a {_x000D_
    background-color: DarkTurquoise;_x000D_
}_x000D_
_x000D_
.b {_x000D_
    background-color: LightSalmon;_x000D_
}_x000D_
_x000D_
.c {_x000D_
    background-color: LightSteelBlue;_x000D_
}
_x000D_
<!DOCTYPE html>_x000D_
<html>_x000D_
<head>_x000D_
    <title>Three Columns with Grid</title>_x000D_
    <link rel="stylesheet" type="text/css" href="style.css">_x000D_
</head>_x000D_
<body>_x000D_
_x000D_
    <div class="grid-container">_x000D_
        <div class="grid-item a">_x000D_
            <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Maecenas id sapien auctor, faucibus felis et, commodo magna. Sed eu molestie nibh, ac tincidunt turpis. Pellentesque accumsan nunc non arcu tincidunt auctor eget ut magna. In vel est egestas, ultricies dui a, gravida diam. Vivamus tempor facilisis lectus nec porta.</p>_x000D_
        </div>_x000D_
        <div class="grid-item b">_x000D_
            <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Maecenas id sapien auctor, faucibus felis et, commodo magna. Sed eu molestie nibh, ac tincidunt turpis. Pellentesque accumsan nunc non arcu tincidunt auctor eget ut magna. In vel est egestas, ultricies dui a, gravida diam. Vivamus tempor facilisis lectus nec porta. Donec commodo elit mattis, bibendum turpis eu, malesuada nunc. Vestibulum sit amet dui tincidunt, mattis nisl et, tincidunt eros. Vivamus eu ultrices sapien. Integer leo arcu, lobortis sed tellus in, euismod ultricies massa. Mauris gravida quis ligula nec dignissim. Proin elementum mattis fringilla. Donec id malesuada orci, eu aliquam ipsum. Vestibulum fermentum elementum egestas. Quisque sit amet tempor mi.</p>_x000D_
        </div>_x000D_
        <div class="grid-item c">_x000D_
            <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Maecenas id sapien auctor, faucibus felis et, commodo magna. Sed eu molestie nibh, ac tincidunt turpis.</p>_x000D_
        </div>_x000D_
    </div>_x000D_
</body>_x000D_
</html>
_x000D_
_x000D_
_x000D_

Another way would be to use the Flexbox by specifying display: flex on the container of the columns, and giving the columns a relevant width. In the example that I will be using, which is with 3 columns, you basically need to split 100% in 3, so it's 33.3333% (close enough, who cares about 0.00003333... which isn't visible anyway).

Full working example using Flexbox:

_x000D_
_x000D_
html, body {_x000D_
    padding: 0;_x000D_
    margin: 0;_x000D_
}_x000D_
_x000D_
.flex-container {_x000D_
    display: flex;_x000D_
    width: 100%;_x000D_
}_x000D_
_x000D_
.flex-column {_x000D_
    padding: 20px;_x000D_
    width: 33.3333%;_x000D_
}_x000D_
_x000D_
.a {_x000D_
    background-color: DarkTurquoise;_x000D_
}_x000D_
_x000D_
.b {_x000D_
    background-color: LightSalmon;_x000D_
}_x000D_
_x000D_
.c {_x000D_
    background-color: LightSteelBlue;_x000D_
}
_x000D_
<!DOCTYPE html>_x000D_
<html>_x000D_
<head>_x000D_
    <title>Three Columns with Flexbox</title>_x000D_
    <link rel="stylesheet" type="text/css" href="style.css">_x000D_
</head>_x000D_
<body>_x000D_
_x000D_
    <div class="flex-container">_x000D_
        <div class="flex-column a">_x000D_
            <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Maecenas id sapien auctor, faucibus felis et, commodo magna. Sed eu molestie nibh, ac tincidunt turpis. Pellentesque accumsan nunc non arcu tincidunt auctor eget ut magna. In vel est egestas, ultricies dui a, gravida diam. Vivamus tempor facilisis lectus nec porta.</p>_x000D_
        </div>_x000D_
        <div class="flex-column b">_x000D_
            <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Maecenas id sapien auctor, faucibus felis et, commodo magna. Sed eu molestie nibh, ac tincidunt turpis. Pellentesque accumsan nunc non arcu tincidunt auctor eget ut magna. In vel est egestas, ultricies dui a, gravida diam. Vivamus tempor facilisis lectus nec porta. Donec commodo elit mattis, bibendum turpis eu, malesuada nunc. Vestibulum sit amet dui tincidunt, mattis nisl et, tincidunt eros. Vivamus eu ultrices sapien. Integer leo arcu, lobortis sed tellus in, euismod ultricies massa. Mauris gravida quis ligula nec dignissim. Proin elementum mattis fringilla. Donec id malesuada orci, eu aliquam ipsum. Vestibulum fermentum elementum egestas. Quisque sit amet tempor mi.</p>_x000D_
        </div>_x000D_
        <div class="flex-column c">_x000D_
            <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Maecenas id sapien auctor, faucibus felis et, commodo magna. Sed eu molestie nibh, ac tincidunt turpis.</p>_x000D_
        </div>_x000D_
    </div>_x000D_
</body>_x000D_
</html>
_x000D_
_x000D_
_x000D_

The Flexbox and Grid are supported by all major browsers since 2017/2018, fact also confirmed by caniuse.com: Can I use grid, Can I use flex.

There are also a number of classical solutions, used before the age of Flexbox and Grid, like OneTrueLayout Technique, Faux Columns Technique, CSS Tabular Display Technique and there is also a Layering Technique.

I do not recommend using these methods for they have a hackish nature and are not so elegant in my opinion, but it is good to know them for academic reasons.

A solution for equally height-ed columns is the CSS Tabular Display Technique that means to use the display:table feature. It works for Firefox 2+, Safari 3+, Opera 9+ and IE8.

The code for the CSS Tabular Display:

_x000D_
_x000D_
#container {_x000D_
  display: table;_x000D_
  background-color: #CCC;_x000D_
  margin: 0 auto;_x000D_
}_x000D_
_x000D_
.row {_x000D_
  display: table-row;_x000D_
}_x000D_
_x000D_
.col {_x000D_
  display: table-cell;_x000D_
}_x000D_
_x000D_
#col1 {_x000D_
  background-color: #0CC;_x000D_
  width: 200px;_x000D_
}_x000D_
_x000D_
#col2 {_x000D_
  background-color: #9F9;_x000D_
  width: 300px;_x000D_
}_x000D_
_x000D_
#col3 {_x000D_
  background-color: #699;_x000D_
  width: 200px;_x000D_
}
_x000D_
<div id="container">_x000D_
  <div id="rowWraper" class="row">_x000D_
    <div id="col1" class="col">_x000D_
      Column 1<br />Lorem ipsum<br />ipsum lorem_x000D_
    </div>_x000D_
    <div id="col2" class="col">_x000D_
      Column 2<br />Eco cologna duo est!_x000D_
    </div>_x000D_
    <div id="col3" class="col">_x000D_
      Column 3_x000D_
    </div>_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Even if there is a problem with the auto-expanding of the width of the table-cell it can be resolved easy by inserting another div withing the table-cell and giving it a fixed width. Anyway, the over-expanding of the width happens in the case of using extremely long words (which I doubt anyone would use a, let's say, 600px long word) or some div's who's width is greater than the table-cell's width.

The Faux Column Technique is the most popular classical solution to this problem, but it has some drawbacks such as, you have to resize the background tiled image if you want to resize the columns and it is also not an elegant solution.

The OneTrueLayout Technique consists of creating a padding-bottom of an extreme big height and cut it out by bringing the real border position to the "normal logical position" by applying a negative margin-bottom of the same huge value and hiding the extent created by the padding with overflow: hidden applied to the content wraper. A simplified example would be:

Working example:

_x000D_
_x000D_
.wraper {_x000D_
    overflow: hidden; /* This is important */_x000D_
}_x000D_
_x000D_
.floatLeft {_x000D_
    float: left;_x000D_
}_x000D_
_x000D_
.block {_x000D_
    padding-left: 20px;_x000D_
    padding-right: 20px;_x000D_
    padding-bottom: 30000px; /* This is important */_x000D_
    margin-bottom: -30000px; /* This is important */_x000D_
    width: 33.3333%;_x000D_
    box-sizing: border-box; /* This is so that the padding right and left does not affect the width */_x000D_
}_x000D_
_x000D_
.a {_x000D_
    background-color: DarkTurquoise;_x000D_
}_x000D_
_x000D_
.b {_x000D_
    background-color: LightSalmon;_x000D_
}_x000D_
_x000D_
.c {_x000D_
    background-color: LightSteelBlue;_x000D_
}
_x000D_
<html>_x000D_
<head>_x000D_
  <title>OneTrueLayout</title>_x000D_
</head>_x000D_
<body>_x000D_
    <div class="wraper">_x000D_
        <div class="block floatLeft a">_x000D_
            <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Cras malesuada ipsum pretium tellus condimentum aliquam. Donec eget tempor mi, a consequat enim. Mauris a massa id nisl sagittis iaculis.</p>_x000D_
        </div>_x000D_
        <div class="block floatLeft b">_x000D_
            <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Cras malesuada ipsum pretium tellus condimentum aliquam. Donec eget tempor mi, a consequat enim. Mauris a massa id nisl sagittis iaculis. Duis mattis diam vitae tellus ornare, nec vehicula elit luctus. In auctor urna ac ante bibendum, a gravida nunc hendrerit. Praesent sed pellentesque lorem. Nam neque ante, egestas ut felis vel, faucibus tincidunt risus. Maecenas egestas diam massa, id rutrum metus lobortis non. Sed quis tellus sed nulla efficitur pharetra. Fusce semper sapien neque. Donec egestas dolor magna, ut efficitur purus porttitor at. Mauris cursus, leo ac porta consectetur, eros quam aliquet erat, condimentum luctus sapien tellus vel ante. Vivamus vestibulum id lacus vel tristique.</p>_x000D_
        </div>_x000D_
        <div class="block floatLeft c">_x000D_
            <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Cras malesuada ipsum pretium tellus condimentum aliquam. Donec eget tempor mi, a consequat enim. Mauris a massa id nisl sagittis iaculis. Duis mattis diam vitae tellus ornare, nec vehicula elit luctus. In auctor urna ac ante bibendum, a gravida nunc hendrerit.</p>_x000D_
        </div>_x000D_
    </div>_x000D_
</body>_x000D_
</html>
_x000D_
_x000D_
_x000D_

The Layering Technique must be a very neat solution that involves absolute positioning of div's withing a main relative positioned wrapper div. It basically consists of a number of child divs and the main div. The main div has imperatively position: relative to it's css attribute collection. The children of this div are all imperatively position:absolute. The children must have top and bottom set to 0 and left-right dimensions set to accommodate the columns with each another. For example if we have two columns, one of width 100px and the other one of 200px, considering that we want the 100px in the left side and the 200px in the right side, the left column must have {left: 0; right: 200px} and the right column {left: 100px; right: 0;}

In my opinion the unimplemented 100% height within an automated height container is a major drawback and the W3C should consider revising this attribute (which since 2018 is solvable with Flexbox and Grid).

Other resources: link1, link2, link3, link4, link5 (important)

How to get the first element of an array?

Declare a prototype to get first array element as:

Array.prototype.first = function () {
   return this[0];
};

Then use it as:

var array = [0, 1, 2, 3];
var first = array.first();
var _first = [0, 1, 2, 3].first();

Or simply (:

first = array[0];

What is referencedColumnName used for in JPA?

Quoting API on referencedColumnName:

The name of the column referenced by this foreign key column.

Default (only applies if single join column is being used): The same name as the primary key column of the referenced table.

Q/A

Where this would be used?

When there is a composite PK in referenced table, then you need to specify column name you are referencing.

How to rollback just one step using rake db:migrate

For starters

rake db:rollback will get you back one step

then

rake db:rollback STEP=n

Will roll you back n migrations where n is the number of recent migrations you want to rollback.

More references here.

How do I wait for a promise to finish before returning the variable of a function?

You're not actually using promises here. Parse lets you use callbacks or promises; your choice.

To use promises, do the following:

query.find().then(function() {
    console.log("success!");
}, function() {
    console.log("error");
});

Now, to execute stuff after the promise is complete, you can just execute it inside the promise callback inside the then() call. So far this would be exactly the same as regular callbacks.

To actually make good use of promises is when you chain them, like this:

query.find().then(function() {
    console.log("success!");

    return new Parse.Query(Obj).get("sOmE_oBjEcT");
}, function() {
    console.log("error");
}).then(function() {
    console.log("success on second callback!");
}, function() {
    console.log("error on second callback");
});

How to add a new column to an existing sheet and name it?

For your question as asked

Columns(3).Insert
Range("c1:c4") = Application.Transpose(Array("Loc", "uk", "us", "nj"))

If you had a way of automatically looking up the data (ie matching uk against employer id) then you could do that in VBA

What JSON library to use in Scala?

Number 7 on the list is Jackson, not using Jerkson. It has support for Scala objects, (case classes etc).

Below is an example of how I use it.

object MyJacksonMapper extends JacksonMapper
val jsonString = MyJacksonMapper.serializeJson(myObject)
val myNewObject = MyJacksonMapper.deserializeJson[MyCaseClass](jsonString)

This makes it very simple. In addition is the XmlSerializer and support for JAXB Annotations is very handy.

This blog post describes it's use with JAXB Annotations and the Play Framework.

http://krasserm.blogspot.co.uk/2012/02/using-jaxb-for-xml-and-json-apis-in.html

Here is my current JacksonMapper.

trait JacksonMapper {

  def jsonSerializer = {
    val m = new ObjectMapper()
    m.registerModule(DefaultScalaModule)
    m
  }

  def xmlSerializer = {
    val m = new XmlMapper()
    m.registerModule(DefaultScalaModule)
    m
  }

  def deserializeJson[T: Manifest](value: String): T = jsonSerializer.readValue(value, typeReference[T])
  def serializeJson(value: Any) = jsonSerializer.writerWithDefaultPrettyPrinter().writeValueAsString(value)
  def deserializeXml[T: Manifest](value: String): T = xmlSerializer.readValue(value, typeReference[T])
  def serializeXml(value: Any) = xmlSerializer.writeValueAsString(value)

  private[this] def typeReference[T: Manifest] = new TypeReference[T] {
    override def getType = typeFromManifest(manifest[T])
  }

  private[this] def typeFromManifest(m: Manifest[_]): Type = {
     if (m.typeArguments.isEmpty) { m.erasure }
     else new ParameterizedType {
       def getRawType = m.erasure

       def getActualTypeArguments = m.typeArguments.map(typeFromManifest).toArray

       def getOwnerType = null
     }
  }
}   

java Arrays.sort 2d array

import java.util.*;

public class Arrays2
{
    public static void main(String[] args)
    {
        int small, row = 0, col = 0, z;
        int[][] array = new int[5][5];

        Random rand = new Random();
        for(int i = 0; i < array.length; i++)
        {
            for(int j = 0; j < array[i].length; j++)
            {
                array[i][j] = rand.nextInt(100);
                System.out.print(array[i][j] + " ");
            }
            System.out.println();
        }

        System.out.println("\n");


        for(int k = 0; k < array.length; k++)
        {
            for(int p = 0; p < array[k].length; p++)
            {
                small = array[k][p];
                for(int i = k; i < array.length; i++)
                {
                    if(i == k)
                        z = p + 1;
                    else
                        z = 0;
                    for(;z < array[i].length; z++)
                    {
                        if(array[i][z] <= small)
                        {
                            small = array[i][z];
                            row = i;
                            col = z;
                        }
                    }
                }
            array[row][col] = array[k][p];
            array[k][p] = small;
            System.out.print(array[k][p] + " ");
            }
            System.out.println();
        }
    }
}

Good Luck

How can I specify a display?

The way that X works is the same as the way any network program works. You have a server of some description (in this case, the X display server) which runs on a specific machine, and you have X clients (like firefox) that try to connect to that server to get their information displayed.

Often (on "home" machines), the client and server run on the same box and there's only one server, but X is powerful enough that this doesn't need to happen. It was built with the server/client separation built in from the start.

This allows you to do such wondrous things such as log on to your box (in text mode) halfway around the planet, tell it that the display server is the box you're currently on and, voila, the windows suddenly start appearing locally.

In order for a client to interact with a user, it needs to know how to find the server. There are a number of ways to do this. Many clients allow the -display or --displayoption to specify it:

xeyes -display paxbox1.paxco.com:0.0

Many will use the DISPLAY environment variable if a display isn't specifically given. You can set this variable like any other:

DISPLAY=paxbox1.paxco.com:0.0; export DISPLAY # in .profile
export DISPLAY=paxbox1.paxco.com:0.0 # in your shell
DISPLAY=paxbox1.paxco.com:0.0 firefox & # for that command (shell permitting)

The first part of the DISPLAY variable is just the address of the display server machine. It follows the same rule as any other IP address; it can be a resolvable DNS name (including localhost) or a specific IP address (such as 192.168.10.55).

The second part is X-specific. It gives the X "display" (X server) number and screen number to use. The first (display number) generally refers to a group of devices containing one or more screens but with a single keyboard and mouse (i.e., one input stream). The screen number generally gives the specific screen within that group.

An example would be:

+----------------------------------------+
|paxbox1.paxco.com|                      |
+-----------------+                      |
|                                        |
|  +----------+----+  +----------+----+  |
|  |Display :0|    |  |Display :1|    |  |
|  +----------+    |  +----------+    |  |
|  |               |  |               |  |
|  | +-----------+ |  |               |  |
|  | |Screen :0.0| |  |               |  |
|  | +-----------+ |  |               |  |
|  | +-----------+ |  |               |  |
|  | |Screen :0.1| |  |               |  |
|  | +-----------+ |  |               |  |
|  | +-----------+ |  | +-----------+ |  |
|  | |Screen :0.2| |  | |Screen :1.0| |  |
|  | +-----------+ |  | +-----------+ |  |
|  | +-----------+ |  | +-----------+ |  |
|  | |Screen :0.3| |  | |Screen :1.1| |  |
|  | +-----------+ |  | +-----------+ |  |
|  | +-----------+ |  | +-----------+ |  |
|  | | Keyboard  | |  | |  Keyboard | |  |
|  | +-----------+ |  | +-----------+ |  |
|  | +-----------+ |  | +-----------+ |  |
|  | |   Mouse   | |  | |   Mouse   | |  |
|  | +-----------+ |  | +-----------+ |  |
|  +---------------+  +---------------+  |
|                                        |
+----------------------------------------+

Here you have a single machine (paxbox1.paxco.com) with two display servers. The first has four screens and the second has two. The possibilities are then:

DISPLAY=paxbox1.paxco.com:0.0
DISPLAY=paxbox1.paxco.com:0.1
DISPLAY=paxbox1.paxco.com:0.2
DISPLAY=paxbox1.paxco.com:0.3
DISPLAY=paxbox1.paxco.com:1.0
DISPLAY=paxbox1.paxco.com:1.1

depending on where you want your actual windows to appear and which input devices you want to use.

Crop image in PHP

imagecopyresampled() will take a rectangular area from $src_image of width $src_w and height $src_h at position ($src_x, $src_y) and place it in a rectangular area of $dst_image of width $dst_w and height $dst_h at position ($dst_x, $dst_y).

If the source and destination coordinates and width and heights differ, appropriate stretching or shrinking of the image fragment will be performed. The coordinates refer to the upper left corner.

This function can be used to copy regions within the same image. But if the regions overlap, the results will be unpredictable.

- Edit -

If $src_w and $src_h are smaller than $dst_w and $dst_h respectively, thumb image will be zoomed in. Otherwise it will be zoomed out.

<?php
$dst_x = 0;   // X-coordinate of destination point
$dst_y = 0;   // Y-coordinate of destination point
$src_x = 100; // Crop Start X position in original image
$src_y = 100; // Crop Srart Y position in original image
$dst_w = 160; // Thumb width
$dst_h = 120; // Thumb height
$src_w = 260; // Crop end X position in original image
$src_h = 220; // Crop end Y position in original image

// Creating an image with true colors having thumb dimensions (to merge with the original image)
$dst_image = imagecreatetruecolor($dst_w, $dst_h);
// Get original image
$src_image = imagecreatefromjpeg('images/source.jpg');
// Cropping
imagecopyresampled($dst_image, $src_image, $dst_x, $dst_y, $src_x, $src_y, $dst_w, $dst_h, $src_w, $src_h);
// Saving
imagejpeg($dst_image, 'images/crop.jpg');
?>

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

If you are trying to export display using su and it still doesn't work. This is what worked for me. Try X11 forwarding for sudo users.

Connect the remote host using the -X option with ssh.

# ssh -X root@remote-host

Now list the coockie set for the current user.

# xauth list $DISPLAY
    node01.thegeekdiary.com/unix:10  MIT-MAGIC-COOKIE-1  dacbc5765ec54a1d7115a172147866aa
# echo $DSIPLAY
    localhost:10.0

Switch to another user account using sudo. Add the cookie from the command output above to the sudo user.

# sudo su - [user]
# xauth add node01.thegeekdiary.com/unix:10  MIT-MAGIC-COOKIE-1  dacbc5765ec54a1d7115a172147866aa

Export the display from step 2 again for the sudo user. Try the command xclock to verify if the x client applications are working as expected.

# export DISPLAY=localhost:10.0

source: https://www.thegeekdiary.com/how-to-set-x11-forwarding-export-remote-display-for-users-who-switch-accounts-using-sudo/

Can I pass parameters by reference in Java?

Another option is to use an array, e.g. void method(SomeClass[] v) { v[0] = ...; } but 1) the array must be initialized before method invoked, 2) still one cannot implement e.g. swap method in this way... This way is used in JDK, e.g. in java.util.concurrent.atomic.AtomicMarkableReference.get(boolean[]).

Sending emails in Node.js?

You could always use AlphaMail (disclosure: I'm one of the developers behind it).

Just install with NPM:

npm install alphamail

Sign up for a AlphaMail account. Get a token, and then you can start sending with the AlphaMail service.

var alphamail = require('alphamail');

var emailService = new alphamail.EmailService()
    .setServiceUrl('http://api.amail.io/v1/')
    .setApiToken('YOUR-ACCOUNT-API-TOKEN-HERE');

var person = {
    id: 1234,
    userName: "jdoe75",
    name: {
        first: "John",
        last: "Doe"
    },
    dateOfBirth: 1975
};

emailService.queue(new alphamail.EmailMessagePayload()
    .setProjectId(12345) // ID of your AlphaMail project (determines template, options, etc)
    .setSender(new alphamail.EmailContact("Sender Company Name", "[email protected]"))
    .setReceiver(new alphamail.EmailContact("John Doe", "[email protected]"))
    .setBodyObject(person) // Any serializable object
);

And in the AlphaMail GUI (Dashboard) you'll be able to edit the template with the data you sent:

<html>
    <body>
        <b>Name:</b> <# payload.name.last " " payload.name.first #><br>
        <b>Date of Birth:</b> <# payload.dateOfBirth #><br>

        <# if (payload.id != null) { #>
            <a href="http://company.com/sign-up">Sign Up Free!</a>
        <# } else { #>
            <a href="http://company.com/login?username=<# urlencode(payload.userName) #>">Sign In</a>
        <# } #>
    </body>
</html>

The templates are written in Comlang, it's a simple template language specifically designed for emails.

Clearing localStorage in javascript?

Here is a function that will allow you to remove all localStorage items with exceptions. You will need jQuery for this function. You can download the gist.

You can call it like this

let clearStorageExcept = function(exceptions) {
  let keys = [];
  exceptions = [].concat(exceptions); // prevent undefined

  // get storage keys
  $.each(localStorage, (key) => {
    keys.push(key);
  });

  // loop through keys
  for (let i = 0; i < keys.length; i++) {
    let key = keys[i];
    let deleteItem = true;

    // check if key excluded
    for (let j = 0; j < exceptions.length; j++) {
      let exception = exceptions[j];
      if (key == exception) {
        deleteItem = false;
      }
    }

    // delete key
    if (deleteItem) {
      localStorage.removeItem(key);
    }
  }
};

Reverse ip, find domain names on ip address

They're just trawling lists of web sites, and recording the resulting IP addresses in a database.

All you're seeing is the reverse mapping of that list. It's not guaranteed to be a full list (indeed more often than not it won't be) because it's impossible to learn every possible web site address.

multiple packages in context:component-scan, spring config

If x.y.z is the common package then you can use:

<context:component-scan base-package="x.y.z.*">

it will include all the package that is start with x.y.z like: x.y.z.controller,x.y.z.service etc.

Dynamically Fill Jenkins Choice Parameter With Git Branches In a Specified Repo

You may try this, This list dynamic branch names in dropdown w.r.t inputted Git Repo.

Jenkins Plugins required:

  1. Validating String Parameter
  2. Active Choices

OPTION 1: Jenkins File:

    properties([
        [$class: 'JobRestrictionProperty'], parameters([validatingString(defaultValue: 'https://github.com/kubernetes/kubernetes.git', description: 'Input Git Repo (https) Url', failedValidationMessage: 'Invalid Git Url. Retry again', name: 'GIT_REPO', regex: 'https://.*'), [$class: 'CascadeChoiceParameter', choiceType: 'PT_SINGLE_SELECT', description: 'Select Git Branch Name', filterLength: 1, filterable: false, name: 'BRANCH_NAME', randomName: 'choice-parameter-8292706885056518', referencedParameters: 'GIT_REPO', script: [$class: 'GroovyScript', fallbackScript: [classpath: [], sandbox: false, script: 'return[\'Error - Unable to retrive Branch name\']'], script: [classpath: [], sandbox: false, script: ''
                            'def GIT_REPO_SRC = GIT_REPO.tokenize(\'/\')
                            GIT_REPO_FULL = GIT_REPO_SRC[-2] + \'/\' + GIT_REPO_SRC[-1]
                            def GET_LIST = ("git ls-remote --heads [email protected]:${GIT_REPO_FULL}").execute()
                            GET_LIST.waitFor()
                            BRANCH_LIST = GET_LIST.in.text.readLines().collect {
                                it.split()[1].replaceAll("refs/heads/", "").replaceAll("refs/tags/", "").replaceAll("\\\\^\\\\{\\\\}", "")
                            }
                            return BRANCH_LIST ''
                            ']]]]), throttleJobProperty(categories: [], limitOneJobWithMatchingParams: false, maxConcurrentPerNode: 0, maxConcurrentTotal: 0, paramsToUseForLimit: '
                            ', throttleEnabled: false, throttleOption: '
                            project '), [$class: '
                            JobLocalConfiguration ', changeReasonComment: '
                            ']])
    try {
        node('master') {
            stage('Print Variables') {
                echo "Branch Name: ${BRANCH_NAME}"
            }
    }
    catch (e) {
        currentBuild.result = "FAILURE"
        print e.getMessage();
        print e.getStackTrace();
    }



OPTION 2: Jenkins UI

enter image description here

enter image description here



Sample Output:

enter image description here

Replacing all non-alphanumeric characters with empty strings

Try

return value.replaceAll("[^A-Za-z0-9]", "");

or

return value.replaceAll("[\\W]|_", "");

How to copy commits from one branch to another?

git cherry-pick : Apply the changes introduced by some existing commits

Assume we have branch A with (X, Y, Z) commits. We need to add these commits to branch B. We are going to use the cherry-pick operations.

When we use cherry-pick, we should add commits on branch B in the same chronological order that the commits appear in Branch A.

cherry-pick does support a range of commits, but if you have merge commits in that range, it gets really complicated

git checkout B
git cherry-pick SHA-COMMIT-X
git cherry-pick SHA-COMMIT-Y
git cherry-pick SHA-COMMIT-Z

Example of workflow :

enter image description here

We can use cherry-pick with options

-e or --edit : With this option, git cherry-pick will let you edit the commit message prior to committing.

-n or --no-commit : Usually the command automatically creates a sequence of commits. This flag applies the changes necessary to cherry-pick each named commit to your working tree and the index, without making any commit. In addition, when this option is used, your index does not have to match the HEAD commit. The cherry-pick is done against the beginning state of your index.

Here an interesting article concerning cherry-pick.

How to fix curl: (60) SSL certificate: Invalid certificate chain

Another cause of this can be duplicate keys in your KeyChain. I've seen this problem on two macs where there were duplicate "DigiCert High Assurance EV Root CA". One was in the login keychain, the other in the system one. Removing the certificate from the login keychain solved the problem.

This affected Safari browser as well as git on the command line.

How do you determine the size of a file in C?

And if you're building a Windows app, use the GetFileSizeEx API as CRT file I/O is messy, especially for determining file length, due to peculiarities in file representations on different systems ;)

Joining pandas dataframes by column names

you can use the left_on and right_on options as follows:

pd.merge(frame_1, frame_2, left_on='county_ID', right_on='countyid')

I was not sure from the question if you only wanted to merge if the key was in the left hand dataframe. If that is the case then the following will do that (the above will in effect do a many to many merge)

pd.merge(frame_1, frame_2, how='left', left_on='county_ID', right_on='countyid')

Maximum value for long integer

A) For a cheap comparison / arithmetics dummy use math.inf. Or math.nan, which compares FALSE in any direction (including nan == nan) except identity check (is) and renders any arithmetics (like nan - nan) nan. Or a reasonably high real integer number according to your use case (e.g. sys.maxsize). For a bitmask dummy (e.g. in mybits & bitmask) use -1.

B) To get the platform primitive maximum signed long int (or long long):

>>> 256 ** sys.int_info.sizeof_digit // 2 - 1  # Python’s internal primitive
2147483647
>>> 256 ** ctypes.sizeof(ctypes.c_long) // 2 - 1  # CPython
2147483647
>>> 256 ** ctypes.sizeof(ctypes.c_longlong) // 2 - 1  # CPython
9223372036854775807
>>> 2**63 - 1  # Java / JPython primitive long
9223372036854775807

C) The maximum Python integer could be estimated by a long running loop teasing for a memory overflow (try 256**int(8e9) - can be stopped by KeyboardInterrupt). But it cannot not be used reasonably, because its representation already consumes all the memory and its much greater than sys.float_info.max.

How to access your website through LAN in ASP.NET

If you use IIS Express via Visual Studio instead of the builtin ASP.net host, you can achieve this.

Binding IIS Express to an IP Address

Plotting a fast Fourier transform in Python

The high spike that you have is due to the DC (non-varying, i.e. freq = 0) portion of your signal. It's an issue of scale. If you want to see non-DC frequency content, for visualization, you may need to plot from the offset 1 not from offset 0 of the FFT of the signal.

Modifying the example given above by @PaulH

import numpy as np
import matplotlib.pyplot as plt
import scipy.fftpack

# Number of samplepoints
N = 600
# sample spacing
T = 1.0 / 800.0
x = np.linspace(0.0, N*T, N)
y = 10 + np.sin(50.0 * 2.0*np.pi*x) + 0.5*np.sin(80.0 * 2.0*np.pi*x)
yf = scipy.fftpack.fft(y)
xf = np.linspace(0.0, 1.0/(2.0*T), N/2)

plt.subplot(2, 1, 1)
plt.plot(xf, 2.0/N * np.abs(yf[0:N/2]))
plt.subplot(2, 1, 2)
plt.plot(xf[1:], 2.0/N * np.abs(yf[0:N/2])[1:])

The output plots: Ploting FFT signal with DC and then when removing it (skipping freq = 0)

Another way, is to visualize the data in log scale:

Using:

plt.semilogy(xf, 2.0/N * np.abs(yf[0:N/2]))

Will show: enter image description here

Converting <br /> into a new line for use in a text area

Try this one

<?php
    $text = "Hello <br /> Hello again <br> Hello again again <br/> Goodbye <BR>";
    $breaks = array("<br />","<br>","<br/>");  
    $text = str_ireplace($breaks, "\r\n", $text);  
?>  
<textarea><?php echo $text; ?></textarea>

Resize Google Maps marker icon image

As mentionned in comments, this is the updated solution in favor of Icon object with documentation.

Use Icon object

var icon = {
    url: "../res/sit_marron.png", // url
    scaledSize: new google.maps.Size(50, 50), // scaled size
    origin: new google.maps.Point(0,0), // origin
    anchor: new google.maps.Point(0, 0) // anchor
};

 posicion = new google.maps.LatLng(latitud,longitud)
 marker = new google.maps.Marker({
  position: posicion,
  map: map,
  icon: icon
 });

How to: Add/Remove Class on mouseOver/mouseOut - JQuery .hover?

You forgot the dot of class selector of result class.

Live Demo

$(".result").hover(
  function () {
    $(this).addClass("result_hover");
  },
  function () {
    $(this).removeClass("result_hover");
  }
);

You can use toggleClass on hover event

Live Demo

 $(".result").hover(function () {
    $(this).toggleClass("result_hover");
 });

Evenly distributing n points on a sphere

What you are looking for is called a spherical covering. The spherical covering problem is very hard and solutions are unknown except for small numbers of points. One thing that is known for sure is that given n points on a sphere, there always exist two points of distance d = (4-csc^2(\pi n/6(n-2)))^(1/2) or closer.

If you want a probabilistic method for generating points uniformly distributed on a sphere, it's easy: generate points in space uniformly by Gaussian distribution (it's built into Java, not hard to find the code for other languages). So in 3-dimensional space, you need something like

Random r = new Random();
double[] p = { r.nextGaussian(), r.nextGaussian(), r.nextGaussian() };

Then project the point onto the sphere by normalizing its distance from the origin

double norm = Math.sqrt( (p[0])^2 + (p[1])^2 + (p[2])^2 ); 
double[] sphereRandomPoint = { p[0]/norm, p[1]/norm, p[2]/norm };

The Gaussian distribution in n dimensions is spherically symmetric so the projection onto the sphere is uniform.

Of course, there's no guarantee that the distance between any two points in a collection of uniformly generated points will be bounded below, so you can use rejection to enforce any such conditions that you might have: probably it's best to generate the whole collection and then reject the whole collection if necessary. (Or use "early rejection" to reject the whole collection you've generated so far; just don't keep some points and drop others.) You can use the formula for d given above, minus some slack, to determine the min distance between points below which you will reject a set of points. You'll have to calculate n choose 2 distances, and the probability of rejection will depend on the slack; it's hard to say how, so run a simulation to get a feel for the relevant statistics.

Access: Move to next record until EOF

If you want cmd buttons that loop through the form's records, try adding this code to your cmdNext_Click and cmdPrevious_Click VBA. I have found it works well and copes with BOF / EOF issues:

On Error Resume Next

DoCmd.GoToRecord , , acNext

On Error Goto 0


On Error Resume Next

DoCmd.GoToRecord , , acPrevious

On Error Goto 0

Good luck! PT

How can I create a border around an Android LinearLayout?

Try this:

For example, let's define res/drawable/my_custom_background.xml as:

(create this layout in your drawable folder) layout_border.xml

  <?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <shape android:shape="rectangle">
            <stroke android:width="2dp" android:height="2dp"
                android:color="#FF0000" />
            <solid android:color="#000000" />
            <padding android:left="1dp" android:top="1dp" android:right="1dp"
                android:bottom="1dp" />

            <corners android:radius="1dp" android:bottomRightRadius="5dp"
                android:bottomLeftRadius="0dp" android:topLeftRadius="5dp"
                android:topRightRadius="0dp" />
        </shape>
    </item>

</layer-list>

main.xml

<LinearLayout 
    android:layout_gravity="center"
    android:layout_width="200dp" 
    android:layout_height="200dp"   
    android:background="@drawable/layout_border" />
</LinearLayout>

div background color, to change onhover

you could just contain the div in anchor tag like this:

_x000D_
_x000D_
a{_x000D_
  text-decoration:none;_x000D_
  color:#ffffff;_x000D_
}_x000D_
a div{_x000D_
  width:100px;_x000D_
  height:100px;_x000D_
  background:#ff4500;_x000D_
}_x000D_
a div:hover{_x000D_
  background:#0078d7;_x000D_
}
_x000D_
<body>_x000D_
<a href="http://example.com">_x000D_
<div>_x000D_
Hover me_x000D_
</div>_x000D_
</a>_x000D_
</body>
_x000D_
_x000D_
_x000D_

How to dismiss the dialog with click on outside of the dialog?

This code is use for when use click on dialogbox that time hidesoftinput and when user click outer side of dialogbox that time both softinput and dialogbox are close.

dialog = new Dialog(act) {
    @Override
    public boolean onTouchEvent(MotionEvent event) {
        // Tap anywhere to close dialog.
        Rect dialogBounds = new Rect();
        getWindow().getDecorView().getHitRect(dialogBounds);
        if (!dialogBounds.contains((int) event.getX(),
                (int) event.getY())) {
            // You have clicked the grey area
            InputMethodManager inputMethodManager = (InputMethodManager) act
                    .getSystemService(act.INPUT_METHOD_SERVICE);
            inputMethodManager.hideSoftInputFromWindow(dialog
                    .getCurrentFocus().getWindowToken(), 0);
            dialog.dismiss();
            // stop activity closing
        } else {
            InputMethodManager inputMethodManager = (InputMethodManager) act
                    .getSystemService(act.INPUT_METHOD_SERVICE);
            inputMethodManager.hideSoftInputFromWindow(dialog
                    .getCurrentFocus().getWindowToken(), 0);
        }

        return true;
    }
};

Best way to do Version Control for MS Excel

It depends on what level of integration you want, I've used Subversion/TortoiseSVN which seems fine for simple usage. I have also added in keywords but there seems to be a risk of file corruption. There's an option in Subversion to make the keyword substitutions fixed length and as far as I understand it will work if the fixed length is even but not odd. In any case you don't get any useful sort of diff functionality, I think there are commercial products that will do 'diff'. I did find something that did diff based on converting stuff to plain text and comparing that, but it wasn't very nice.

"Unable to get the VLookup property of the WorksheetFunction Class" error

I was just having this issue with my own program. I turned out that the value I was searching for was not in my reference table. I fixed my reference table, and then the error went away.

Automatically start a Windows Service on install

Despite following the accepted answer exactly, I was still unable to get the service to start-- I was instead given a failure message during installation stating that the service that was just installed could not be started, as it did not exist, despite using this.serviceInstaller.ServiceName rather than a literal...

I eventually found an alternative solution that makes use of the command line:

private void serviceInstaller_AfterInstall(object sender, InstallEventArgs e) {
        ProcessStartInfo startInfo = new ProcessStartInfo();
        startInfo.WindowStyle = ProcessWindowStyle.Hidden;
        startInfo.FileName = "cmd.exe";
        startInfo.Arguments = "/C sc start " + this.serviceInstaller.ServiceName;

        Process process = new Process();
        process.StartInfo = startInfo;
        process.Start();
    }

Angular 2 - How to navigate to another route using this.router.parent.navigate('/about')?

Also can use without parent

say router definition like:

{path:'/about',    name: 'About',   component: AboutComponent}

then can navigate by name instead of path

goToAboutPage() {
    this.router.navigate(['About']); // here "About" is name not path
}

Updated for V2.3.0

In Routing from v2.0 name property no more exist. route define without name property. so you should use path instead of name. this.router.navigate(['/path']) and no leading slash for path so use path: 'about' instead of path: '/about'

router definition like:

{path:'about', component: AboutComponent}

then can navigate by path

goToAboutPage() {
    this.router.navigate(['/about']); // here "About" is path
}

How to get parameter on Angular2 route in Angular way?

As of Angular 6+, this is handled slightly differently than in previous versions. As @BeetleJuice mentions in the answer above, paramMap is new interface for getting route params, but the execution is a bit different in more recent versions of Angular. Assuming this is in a component:

private _entityId: number;

constructor(private _route: ActivatedRoute) {
    // ...
}

ngOnInit() {
    // For a static snapshot of the route...
    this._entityId = this._route.snapshot.paramMap.get('id');

    // For subscribing to the observable paramMap...
    this._route.paramMap.pipe(
        switchMap((params: ParamMap) => this._entityId = params.get('id'))
    );

    // Or as an alternative, with slightly different execution...
    this._route.paramMap.subscribe((params: ParamMap) =>  {
        this._entityId = params.get('id');
    });
}

I prefer to use both because then on direct page load I can get the ID param, and also if navigating between related entities the subscription will update properly.

Source in Angular Docs

ListView inside ScrollView is not scrolling on Android

Dont give scroll view to ListView, coz it has that setting default

<ListView
    android:cacheColorHint="#00000000"
    android:id="@+id/ListView01"
    android:layout_height="wrap_content"
    android:layout_width="fill_parent" />

Full width layout with twitter bootstrap

The easiest way with BS3 is to reset the max-width and padding set by BS3 CSS simply like this. You get again a container-fluid :

.container{
  max-width:100%;
  padding:0;
}

Why isn't sizeof for a struct equal to the sum of sizeof of each member?

It can do so if you have implicitly or explicitly set the alignment of the struct. A struct that is aligned 4 will always be a multiple of 4 bytes even if the size of its members would be something that's not a multiple of 4 bytes.

Also a library may be compiled under x86 with 32-bit ints and you may be comparing its components on a 64-bit process would would give you a different result if you were doing this by hand.

How to embed images in html email

This is the code I'm using to embed images into HTML mail and PDF documents.

<?php
$logo_path = 'http://localhost/img/logo.jpg';
$type = pathinfo($logo_path, PATHINFO_EXTENSION);
$image_contents = file_get_contents($logo_path);
$image64 = 'data:image/' . $type . ';base64,' . base64_encode($image_contents);

echo '<img src="' . $image64 .'" />';
?>

What is a callback in java

A callback is commonly used in asynchronous programming, so you could create a method which handles the response from a web service. When you call the web service, you could pass the method to it so that when the web service responds, it call's the method you told it ... it "calls back".

In Java this can commonly be done through implementing an interface and passing an object (or an anonymous inner class) that implements it. You find this often with transactions and threading - such as the Futures API.

http://docs.oracle.com/javase/1.5.0/docs/api/java/util/concurrent/Future.html

A general tree implementation?

anytree

I recommend https://pypi.python.org/pypi/anytree

Example

from anytree import Node, RenderTree

udo = Node("Udo")
marc = Node("Marc", parent=udo)
lian = Node("Lian", parent=marc)
dan = Node("Dan", parent=udo)
jet = Node("Jet", parent=dan)
jan = Node("Jan", parent=dan)
joe = Node("Joe", parent=dan)

print(udo)
Node('/Udo')
print(joe)
Node('/Udo/Dan/Joe')

for pre, fill, node in RenderTree(udo):
    print("%s%s" % (pre, node.name))
Udo
+-- Marc
¦   +-- Lian
+-- Dan
    +-- Jet
    +-- Jan
    +-- Joe

print(dan.children)
(Node('/Udo/Dan/Jet'), Node('/Udo/Dan/Jan'), Node('/Udo/Dan/Joe'))

Features

anytree has also a powerful API with:

  • simple tree creation
  • simple tree modification
  • pre-order tree iteration
  • post-order tree iteration
  • resolve relative and absolute node paths
  • walking from one node to an other.
  • tree rendering (see example above)
  • node attach/detach hookups

Objective-C Static Class Level variables

Another possibility would be to have a little NSNumber subclass singleton.

How can I initialize an ArrayList with all zeroes in Java?

// apparently this is broken. Whoops for me!
java.util.Collections.fill(list,new Integer(0));

// this is better
Integer[] data = new Integer[60];
Arrays.fill(data,new Integer(0));
List<Integer> list = Arrays.asList(data);

Vue.js redirection to another page

So, what I was looking for was only where to put the window.location.href and the conclusion I came to was that the best and fastest way to redirect is in routes (that way, we do not wait for anything to load before we redirect).

Like this:

routes: [
    {
        path: "/",
        name: "ExampleRoot",
        component: exampleComponent,
        meta: {
            title: "_exampleTitle"
        },
        beforeEnter: () => {
            window.location.href = 'https://www.myurl.io';
        }
    }]

Maybe it will help someone..

PHP Swift mailer: Failed to authenticate on SMTP using 2 possible authenticators

First check if there is any connectivity problem and you can reach the SMTP server:

In terminal type:

telnet servername portnumber 

If you receive the 220 response you can reach the SMTP server and there is no connectivity problem but if the connection to the server failed see what's wrong in your network.

If the server needs auth try to authenticate on the server by username and password and see if something goes wrong.

At last see if the server requires encryption and if yes openssl and other stuff are configured correctly.

Reading string by char till end of line C/C++

You want to use single quotes:

if(c=='\0')

Double quotes (") are for strings, which are sequences of characters. Single quotes (') are for individual characters.

However, the end-of-line is represented by the newline character, which is '\n'.

Note that in both cases, the backslash is not part of the character, but just a way you represent special characters. Using backslashes you can represent various unprintable characters and also characters which would otherwise confuse the compiler.

Is it possible to access to google translate api for free?

Yes, you can use GT for free. See the post with explanation. And look at repo on GitHub.

UPD 19.03.2019 Here is a version for browser on GitHub.

Sass .scss: Nesting and multiple classes?

You can use the parent selector reference &, it will be replaced by the parent selector after compilation:

For your example:

.container {
    background:red;
    &.desc{
       background:blue;
    }
}

/* compiles to: */
.container {
    background: red;
}
.container.desc {
    background: blue;
}

The & will completely resolve, so if your parent selector is nested itself, the nesting will be resolved before replacing the &.

This notation is most often used to write pseudo-elements and -classes:

.element{
    &:hover{ ... }
    &:nth-child(1){ ... }
}

However, you can place the & at virtually any position you like*, so the following is possible too:

.container {
    background:red;
    #id &{
       background:blue;
    }
}

/* compiles to: */
.container {
    background: red;
}
#id .container {
    background: blue;
}

However be aware, that this somehow breaks your nesting structure and thus may increase the effort of finding a specific rule in your stylesheet.

*: No other characters than whitespaces are allowed in front of the &. So you cannot do a direct concatenation of selector+& - #id& would throw an error.

Read file from line 2 or skip header row

If you want to read multiple CSV files starting from line 2, this works like a charm

for files in csv_file_list:
        with open(files, 'r') as r: 
            next(r)                  #skip headers             
            rr = csv.reader(r)
            for row in rr:
                #do something

(this is part of Parfait's answer to a different question)

Count textarea characters

For those wanting a simple solution without jQuery, here's a way.

textarea and message container to put in your form:

<textarea onKeyUp="count_it()" id="text" name="text"></textarea>
Length <span id="counter"></span>

JavaScript:

<script>
function count_it() {
    document.getElementById('counter').innerHTML = document.getElementById('text').value.length;
}
count_it();
</script>

The script counts the characters initially and then for every keystroke and puts the number in the counter span.

Martin

Find a value anywhere in a database

Based on bnkdev's answer I modified Narayana's Code to search all columns even numeric ones.

It'll run slower, but this version actually finds all matches not just those found in text columns.

I can't thank this guy enough. Saved me days of searching by hand!

CREATE PROC SearchAllTables 
(
@SearchStr nvarchar(100)
)
AS
BEGIN

-- Copyright © 2002 Narayana Vyas Kondreddi. All rights reserved.
-- Purpose: To search all columns of all tables for a given search string
-- Written by: Narayana Vyas Kondreddi
-- Site: http://vyaskn.tripod.com
-- Tested on: SQL Server 7.0 and SQL Server 2000
-- Date modified: 28th July 2002 22:50 GMT


CREATE TABLE #Results (ColumnName nvarchar(370), ColumnValue nvarchar(3630))

SET NOCOUNT ON

DECLARE @TableName nvarchar(256), @ColumnName nvarchar(128), @SearchStr2 nvarchar(110)
SET  @TableName = ''
SET @SearchStr2 = QUOTENAME('%' + @SearchStr + '%','''')

WHILE @TableName IS NOT NULL
BEGIN
    SET @ColumnName = ''
    SET @TableName = 
    (
        SELECT MIN(QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME))
        FROM    INFORMATION_SCHEMA.TABLES
        WHERE       TABLE_TYPE = 'BASE TABLE'
            AND QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME) > @TableName
            AND OBJECTPROPERTY(
                    OBJECT_ID(
                        QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME)
                         ), 'IsMSShipped'
                           ) = 0
    )

    WHILE (@TableName IS NOT NULL) AND (@ColumnName IS NOT NULL)
    BEGIN
        SET @ColumnName =
        (
            SELECT MIN(QUOTENAME(COLUMN_NAME))
            FROM    INFORMATION_SCHEMA.COLUMNS
            WHERE       TABLE_SCHEMA    = PARSENAME(@TableName, 2)
                AND TABLE_NAME  = PARSENAME(@TableName, 1)                  
                AND QUOTENAME(COLUMN_NAME) > @ColumnName
        )

        IF @ColumnName IS NOT NULL
        BEGIN
            INSERT INTO #Results
            EXEC
            (
                'SELECT ''' + @TableName + '.' + @ColumnName + ''', LEFT(CONVERT(varchar(max), ' + @ColumnName + '), 3630) 
                FROM ' + @TableName + ' (NOLOCK) ' +
                ' WHERE CONVERT(varchar(max), ' + @ColumnName + ') LIKE ' + @SearchStr2
            )
        END
    END 
END

SELECT ColumnName, ColumnValue FROM #Results
END

How to show Bootstrap table with sort icon

You could try using FontAwesome. It contains a sort-icon (http://fontawesome.io/icon/sort/).

To do so, you would

  1. need to include fontawesome:

    <link href="//maxcdn.bootstrapcdn.com/font-awesome/4.1.0/css/font-awesome.min.css" rel="stylesheet">
    
  2. and then simply use the fontawesome-icon instead of the default-bootstrap-icons in your th's:

    <th><b>#</b> <i class="fa fa-fw fa-sort"></i></th>
    

Hope that helps.

Multiple ping script in Python

I'm a beginner and wrote a script to ping multiple hosts.To ping multiple host you can use ipaddress module.

import ipaddress
from subprocess import Popen, PIPE

net4 = ipaddress.ip_network('192.168.2.0/24')
for x in net4.hosts():
    x = str(x)
    hostup = Popen(["ping", "-c1", x], stdout=PIPE)
    output = hostup.communicate()[0]
    val1 = hostup.returncode
 if val1 == 0:
    print(x, "is pinging")
 else:
    print(x, "is not responding")

How do I use installed packages in PyCharm?

For PyCharm Community Edition 2016.3.2 it is:

"Project Interpreter" -> Top right settings icon -> "More".

Then on the right side there should be a packages icon. When hovering over it it should say "Show paths for selected interpreter". Click it.

Then click the "Add" button or press "alt+insert" to add a new path.

Python: No acceptable C compiler found in $PATH when installing python

Get someone with access to the root account on that server to run sudo apt-get install build-essential. If you don't know who has root access, contact the support team for your shared hosting and ask them.

Edit: If you aren't allowed access to root, you aren't ever going to get it working. You'll have to change hosting provider I'm afraid.

Pass a datetime from javascript to c# (Controller)

There is a toJSON() method in javascript returns a string representation of the Date object. toJSON() is IE8+ and toISOString() is IE9+. Both results in YYYY-MM-DDTHH:mm:ss.sssZ format.

var date = new Date();    
    $.ajax(
       {
           type: "POST",
           url: "/Group/Refresh",
           contentType: "application/json; charset=utf-8",
           data: "{ 'MyDate': " + date.toJSON() + " }",
           success: function (result) {
               //do something
           },
           error: function (req, status, error) {
               //error                        
           }
       });

Equivalent of .bat in mac os

The common convention would be to put it in a .sh file that looks like this -

#!/bin/bash
java -cp  ".;./supportlibraries/Framework_Core.jar;... etc

Note that '\' become '/'.

You could execute as

sh myfile.sh

or set the x bit on the file

chmod +x myfile.sh

and then just call

myfile.sh

Saving an Excel sheet in a current directory with VBA

VBA has a CurDir keyword that will return the "current directory" as stored in Excel. I'm not sure all the things that affect the current directory, but definitely opening or saving a workbook will change it.

MyWorkbook.SaveAs CurDir & Application.PathSeparator & "MySavedWorkbook.xls"

This assumes that the sheet you want to save has never been saved and you want to define the file name in code.

How to check if directory exists in %PATH%?

I took your implementation using the for loop and extended it into something that iterates through all elements of the path. Each iteration of the for loop removes the first element of the path (%p) from the entire path (held in %q and %r).

@echo off
SET MYPATHCOPY=%PATH%

:search
for /f "delims=; tokens=1,2*" %%p in ("%MYPATHCOPY%") do (
   @echo %%~p
   SET MYPATHCOPY=%%~q;%%~r
)

if "%MYPATHCOPY%"==";" goto done;
goto search;

:done

Sample output:

Z:\>path.bat
C:\Program Files\Microsoft DirectX SDK (November 2007)\Utilities\Bin\x86
c:\program files\imagemagick-6.3.4-q16
C:\WINDOWS\system32
C:\WINDOWS
C:\SFU\common\
c:\Program Files\Debugging Tools for Windows
C:\Program Files\Nmap

Typescript: Type X is missing the following properties from type Y length, pop, push, concat, and 26 more. [2740]

This error could also be because you are not subscribing to the Observable.

Example, instead of:

this.products = this.productService.getProducts();

do this:

   this.productService.getProducts().subscribe({
    next: products=>this.products = products,
    error: err=>this.errorMessage = err
   });

can not find module "@angular/material"

That's what solved this problem for me.

I used:

npm install --save @angular/material @angular/cdk
npm install --save @angular/animations

but INSIDE THE APPLICATION'S FOLDER.

Source: https://medium.com/@ismapro/first-steps-with-angular-cli-and-angular-material-5a90406e9a4

XPath: Get parent node from child node

Just as an alternative, you can use ancestor.

//*[title="50"]/ancestor::store

It's more powerful than parent since it can get even the grandparent or great great grandparent

How to increase MaximumErrorCount in SQL Server 2008 Jobs or Packages?

If I have open a package in BIDS ("Business Intelligence Development Studio", the tool you use to design the packages), and do not select any item in it, I have a "Properties" pane in the bottom right containing - among others, the MaximumErrorCount property. If you do not see it, maybe it is minimized and you have to open it (have a look at tabs in the right).

If you cannot find it this way, try the menu: View/Properties Window.

Or try the F4 key.

Convert interface{} to int

Best avoid casting by declaring f to be f the correct type to correspond to the JSON.

How to split elements of a list?

I had to split a list for feature extraction in two parts lt,lc:

ltexts = ((df4.ix[0:,[3,7]]).values).tolist()
random.shuffle(ltexts)

featsets = [(act_features((lt)),lc) 
              for lc, lt in ltexts]

def act_features(atext):
  features = {}
  for word in nltk.word_tokenize(atext):
     features['cont({})'.format(word.lower())]=True
  return features

Permission denied error while writing to a file in Python

I write python script with IDLE3.8(python 3.8.0) I have solved this question: if the path is shelve.open('C:\\database.dat') it will be PermissionError: [Errno 13] Permission denied: 'C:\\database.dat.dat'. But when I test to set the path as shelve.open('E:\\database.dat') That is OK!!! Then I test all the drive(such as C,D,F...) on my computer,Only when the Path set in Disk

C:\\

will get the permission denied error. So I think this is a protect path in windows to avoid python script to change or read files in system Disk(Disk C)

event.returnValue is deprecated. Please use the standard event.preventDefault() instead

If you using Bootstrap:

The current version of Bootstrap (3.0.2) (with jQuery 1.10.2 & Chrome) seems to generate this warning as well.

(It does so on Twitter too, BTW.)

Update

The current version of Bootstrap (3.1.0) no longer seems to generate this warning.

Build Android Studio app via command line

Only for MAC Users

Extending Vji's answer.

Step by step procedure:

  1. Open Terminal
  2. Change your directory to your Project(cd PathOfYourProject)
  3. Copy and paste this command and hit enter:

    chmod +x gradlew
    
  4. As Vji suggested:

    ./gradlew task-name
    

    DON'T FORGOT TO ADD .(DOT) BEFORE /gradlew

installing apache: no VCRUNTIME140.dll

I had same problem, my issue was that downloaded Apache 2.4 but 32 bits. Then re-download 64bits version and it's works.

I hope it helps you

Using prepared statements with JDBCTemplate

I'd factor out the prepared statement handling to at least a method. In this case, because there are no results it is fairly simple (and assuming that the connection is an instance variable that doesn't change):

private PreparedStatement updateSales;
public void updateSales(int sales, String cof_name) throws SQLException {
    if (updateSales == null) {
        updateSales = con.prepareStatement(
            "UPDATE COFFEES SET SALES = ? WHERE COF_NAME LIKE ?");
    }
    updateSales.setInt(1, sales);
    updateSales.setString(2, cof_name);
    updateSales.executeUpdate();
}

At that point, it is then just a matter of calling:

updateSales(75, "Colombian");

Which is pretty simple to integrate with other things, yes? And if you call the method many times, the update will only be constructed once and that will make things much faster. Well, assuming you don't do crazy things like doing each update in its own transaction...

Note that the types are fixed. This is because for any particular query/update, they should be fixed so as to allow the database to do its job efficiently. If you're just pulling arbitrary strings from a CSV file, pass them in as strings. There's also no locking; far better to keep individual connections to being used from a single thread instead.

Using the HTML5 "required" attribute for a group of checkboxes?

I added an invisible radio to a group of checkboxes. When at least one option is checked, the radio is also set to check. When all options are canceled, the radio is also set to cancel. Therefore, the form uses the radio prompt "Please check at least one option"

  • You can't use display: none because radio can't be focused.
  • I make the radio size equal to the entire checkboxes size, so it's more obvious when prompted.

HTML

<form>
  <div class="checkboxs-wrapper">
    <input id="radio-for-checkboxes" type="radio" name="radio-for-required-checkboxes" required/>
    <input type="checkbox" name="option[]" value="option1"/>
    <input type="checkbox" name="option[]" value="option2"/>
    <input type="checkbox" name="option[]" value="option3"/>
  </div>
  <input type="submit" value="submit"/>
</form>

Javascript

var inputs = document.querySelectorAll('[name="option[]"]')
var radioForCheckboxes = document.getElementById('radio-for-checkboxes')
function checkCheckboxes () {
    var isAtLeastOneServiceSelected = false;
    for(var i = inputs.length-1; i >= 0; --i) {
        if (inputs[i].checked) isAtLeastOneCheckboxSelected = true;
    }
    radioForCheckboxes.checked = isAtLeastOneCheckboxSelected
}
for(var i = inputs.length-1; i >= 0; --i) {
    inputs[i].addEventListener('change', checkCheckboxes)
}

CSS

.checkboxs-wrapper {
  position: relative;
}
.checkboxs-wrapper input[name="radio-for-required-checkboxes"] {
    position: absolute;
    margin: 0;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    -webkit-appearance: none;
    pointer-events: none;
    border: none;
    background: none;
}

https://jsfiddle.net/codus/q6ngpjyc/9/

PHP: convert spaces in string into %20?

Use the rawurlencode function instead.

Android Studio gradle takes too long to build

Found an easy and best way to build gradle

go to your app >> open your gradle.properties and change few lines from it [remove #]

else you may copy paste my below snippet as well

    # Project-wide Gradle settings.

# IDE (e.g. Android Studio) users:
# Gradle settings configured through the IDE *will override*
# any settings specified in this file.

# For more details on how to configure your build environment visit
# http://www.gradle.org/docs/current/userguide/build_environment.html

# Specifies the JVM arguments used for the daemon process.
# The setting is particularly useful for tweaking memory settings.
# Default value: -Xmx2048m -XX:MaxPermSize=512m
 org.gradle.jvmargs=-Xmx4096m -XX:MaxPermSize=1024m -XX:+HeapDumpOnOutOfMemoryError -Dfile.encoding=UTF-8

# When configured, Gradle will run in incubating parallel mode.
# This option should only be used with decoupled projects. More details, visit
# http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects
 org.gradle.parallel=true

it worked for me earlier it take almost 2-3 minutes now it is taking only 5-6 second

in above scenario my mac machine have 8GB ram so i assigned 4gb for gradle

Find the server name for an Oracle database

If you don't have access to the v$ views (as suggested by Quassnoi) there are two alternatives

select utl_inaddr.get_host_name from dual

and

select sys_context('USERENV','SERVER_HOST') from dual

Personally I'd tend towards the last as it doesn't require any grants/privileges which makes it easier from stored procedures.

Find elements inside forms and iframe using Java and Selenium WebDriver

On Selenium >= 3.41 (C#) the rigth syntax is:

webDriver = webDriver.SwitchTo().Frame(webDriver.FindElement(By.Name("icontent")));

Parallel.ForEach vs Task.Factory.StartNew

The first is a much better option.

Parallel.ForEach, internally, uses a Partitioner<T> to distribute your collection into work items. It will not do one task per item, but rather batch this to lower the overhead involved.

The second option will schedule a single Task per item in your collection. While the results will be (nearly) the same, this will introduce far more overhead than necessary, especially for large collections, and cause the overall runtimes to be slower.

FYI - The Partitioner used can be controlled by using the appropriate overloads to Parallel.ForEach, if so desired. For details, see Custom Partitioners on MSDN.

The main difference, at runtime, is the second will act asynchronous. This can be duplicated using Parallel.ForEach by doing:

Task.Factory.StartNew( () => Parallel.ForEach<Item>(items, item => DoSomething(item)));

By doing this, you still take advantage of the partitioners, but don't block until the operation is complete.

Python 2,3 Convert Integer to "bytes" Cleanly

You can use the struct's pack:

In [11]: struct.pack(">I", 1)
Out[11]: '\x00\x00\x00\x01'

The ">" is the byte-order (big-endian) and the "I" is the format character. So you can be specific if you want to do something else:

In [12]: struct.pack("<H", 1)
Out[12]: '\x01\x00'

In [13]: struct.pack("B", 1)
Out[13]: '\x01'

This works the same on both python 2 and python 3.

Note: the inverse operation (bytes to int) can be done with unpack.

disable past dates on datepicker

this works for me,

$(function() { $('.datepicker').datepicker({ startDate: '-0m', autoclose: true }); });

Convert seconds to hh:mm:ss in Python

Code that does what was requested, with examples, and showing how cases he didn't specify are handled:

def format_seconds_to_hhmmss(seconds):
    hours = seconds // (60*60)
    seconds %= (60*60)
    minutes = seconds // 60
    seconds %= 60
    return "%02i:%02i:%02i" % (hours, minutes, seconds)

def format_seconds_to_mmss(seconds):
    minutes = seconds // 60
    seconds %= 60
    return "%02i:%02i" % (minutes, seconds)

minutes = 60
hours = 60*60
assert format_seconds_to_mmss(7*minutes + 30) == "07:30"
assert format_seconds_to_mmss(15*minutes + 30) == "15:30"
assert format_seconds_to_mmss(1000*minutes + 30) == "1000:30"

assert format_seconds_to_hhmmss(2*hours + 15*minutes + 30) == "02:15:30"
assert format_seconds_to_hhmmss(11*hours + 15*minutes + 30) == "11:15:30"
assert format_seconds_to_hhmmss(99*hours + 15*minutes + 30) == "99:15:30"
assert format_seconds_to_hhmmss(500*hours + 15*minutes + 30) == "500:15:30"

You can--and probably should--store this as a timedelta rather than an int, but that's a separate issue and timedelta doesn't actually make this particular task any easier.

How do I loop through rows with a data reader in C#?

while (dr.Read())
{
    for (int i = 0; i < dr.FieldCount; i++)
    {
        subjob.Items.Add(dr[i]);
    }
}

to read rows in one colunmn

Installing SciPy with pip

To install scipy on windows follow these instructions:-

Step-1 : Press this link http://www.lfd.uci.edu/~gohlke/pythonlibs/#scipy to download a scipy .whl file (e.g. scipy-0.17.0-cp34-none-win_amd64.whl).

Step-2: Go to the directory where that download file is there from the command prompt (cd folder-name ).

Step-3: Run this command:

pip install scipy-0.17.0-cp27-none-win_amd64.whl

Regular vs Context Free Grammars

A grammar is context-free if all production rules have the form: A (that is, the left side of a rule can only be a single variable; the right side is unrestricted and can be any sequence of terminals and variables). We can define a grammar as a 4-tuple where V is a finite set (variables), _ is a finite set (terminals), S is the start variable, and R is a finite set of rules, each of which is a mapping V
regular grammar is either right or left linear, whereas context free grammar is basically any combination of terminals and non-terminals. hence we can say that regular grammar is a subset of context-free grammar. After these properties we can say that Context Free Languages set also contains Regular Languages set

Resolve Git merge conflicts in favor of their changes during a pull

If you're already in conflicted state, and you want to just accept all of theirs:

git checkout --theirs .
git add .

If you want to do the opposite:

git checkout --ours .
git add .

This is pretty drastic, so make sure you really want to wipe everything out like this before doing it.

How do I debug error ECONNRESET in Node.js?

Try adding these options to socket.io:

const options = { transports: ['websocket'], pingTimeout: 3000, pingInterval: 5000 };

I hope this will help you !

Why can't overriding methods throw exceptions broader than the overridden method?

Well java.lang.Exception extends java.lang.Throwable. java.io.FileNotFoundException extends java.lang.Exception. So if a method throws java.io.FileNotFoundException then in the override method you cannot throw anything higher up the hierarchy than FileNotFoundException e.g. you can't throw java.lang.Exception. You could throw a subclass of FileNotFoundException though. However you would be forced to handle the FileNotFoundException in the overriden method. Knock up some code and give it a try!

The rules are there so you don't lose the original throws declaration by widening the specificity, as the polymorphism means you can invoke the overriden method on the superclass.

Calling one Bash script from another Script passing it arguments with quotes and spaces

You need to use : "$@" (WITH the quotes) or "${@}" (same, but also telling the shell where the variable name starts and ends).

(and do NOT use : $@, or "$*", or $*).

ex:

#testscript1:
echo "TestScript1 Arguments:"
for an_arg in "$@" ; do
   echo "${an_arg}"
done
echo "nb of args: $#"
./testscript2 "$@"   #invokes testscript2 with the same arguments we received

I'm not sure I understood your other requirement ( you want to invoke './testscript2' in single quotes?) so here are 2 wild guesses (changing the last line above) :

'./testscript2' "$@"  #only makes sense if "/path/to/testscript2" containes spaces?

./testscript2 '"some thing" "another"' "$var" "$var2"  #3 args to testscript2

Please give me the exact thing you are trying to do

edit: after his comment saying he attempts tesscript1 "$1" "$2" "$3" "$4" "$5" "$6" to run : salt 'remote host' cmd.run './testscript2 $1 $2 $3 $4 $5 $6'

You have many levels of intermediate: testscript1 on host 1, needs to run "salt", and give it a string launching "testscrit2" with arguments in quotes...

You could maybe "simplify" by having:

#testscript1

#we receive args, we generate a custom script simulating 'testscript2 "$@"'
theargs="'$1'"
shift
for i in "$@" ; do
   theargs="${theargs} '$i'"
done

salt 'remote host' cmd.run "./testscript2 ${theargs}"

if THAt doesn't work, then instead of running "testscript2 ${theargs}", replace THE LAST LINE above by

echo "./testscript2 ${theargs}" >/tmp/runtestscript2.$$  #generate custom script locally ($$ is current pid in bash/sh/...)
scp /tmp/runtestscript2.$$ user@remotehost:/tmp/runtestscript2.$$ #copy it to remotehost
salt 'remotehost' cmd.run "./runtestscript2.$$" #the args are inside the custom script!
ssh user@remotehost "rm /tmp/runtestscript2.$$" #delete the remote one
rm /tmp/runtestscript2.$$ #and the local one

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

What you need to do is to create a new commit with the same details as the current HEAD commit, but with the parent as the previous version of HEAD. git reset --soft will move the branch pointer so that the next commit happens on top of a different commit from where the current branch head is now.

# Move the current head so that it's pointing at the old commit
# Leave the index intact for redoing the commit.
# HEAD@{1} gives you "the commit that HEAD pointed at before 
# it was moved to where it currently points at". Note that this is
# different from HEAD~1, which gives you "the commit that is the
# parent node of the commit that HEAD is currently pointing to."
git reset --soft HEAD@{1}

# commit the current tree using the commit details of the previous
# HEAD commit. (Note that HEAD@{1} is pointing somewhere different from the
# previous command. It's now pointing at the erroneously amended commit.)
git commit -C HEAD@{1}

How to export specific request to file using postman?

To do that you need to leverage the "Collections" feature of Postman. This link could help you: https://learning.getpostman.com/docs/postman/collections/creating_collections/

Here is the way to do it:

  • Create a collection (within tab "Collections")
  • Execute your request
  • Add the request to a collection
  • Share your collection as a file

How to execute a shell script in PHP?

You might have disabled the exec privileges, most of the LAMP packages have those disabled. Check your php.ini for this line:

disable_functions = exec

And remove the exec, shell_exec entries if there are there.

Good Luck!

Is it possible to use raw SQL within a Spring Repository

The @Query annotation allows to execute native queries by setting the nativeQuery flag to true.

Quote from Spring Data JPA reference docs.

Also, see this section on how to do it with a named native query.

How to catch SQLServer timeout exceptions

When a client sends ABORT, no transactions are rolled back. To avoid this behavior we have to use SET_XACT_ABORT ON https://docs.microsoft.com/en-us/sql/t-sql/statements/set-xact-abort-transact-sql?view=sql-server-ver15

If Browser is Internet Explorer: run an alternative script instead

Here is the script i used and it works like a charm. I used the boolean method Ender suggested as the other ones using only the IE specific script adds something to IE but doesn´t take the original code out.

    <script>runFancy = true;</script>
<!--[if IE]>
<script type="text/javascript">
    runFancy = false;
 </script> // <div>The HTML version for IE went here</div>
<![endif]-->

    // Below is the script used for all other browsers:
    <script src="accmenu/acac1.js" charset="utf-8" type="text/javascript"></script><script>ac1init_doc('',0)</script> 

How to check if a key exists in Json Object and get its value

containerObject = new JSONObject(container);
if (containerObject.has("video")) { 
   //get Value of video
}

Text in a flex container doesn't wrap in IE11

As Tyler has suggested in one of the comments here, using

max-width: 100%;

on the child may work (worked for me). Using align-self: stretch only works if you aren't using align-items: center (which I did). width: 100% only works if you haven't multiple childs inside your flexbox which you want to show side by side.

How to compile C++ under Ubuntu Linux?

g++ is the C++ compiler under linux. The code looks right. It is possible that you are missing a library reference which is used as such:

g++ -l{library name here (math fns use "m")} codefile.cpp

List file names based on a filename pattern and file content?

Grep DOES NOT use "wildcards" for search – that's shell globbing, like *.jpg. Grep uses "regular expressions" for pattern matching. While in the shell '*' means "anything", in grep it means "match the previous item zero or more times".

More information and examples here: http://www.regular-expressions.info/reference.html

To answer of your question - you can find files matching some pattern with grep:

find /somedir -type f -print | grep 'LMN2011' # that will show files whose names contain LMN2011

Then you can search their content (case insensitive):

find /somedir -type f -print | grep -i 'LMN2011' | xargs grep -i 'LMN20113456'

If the paths can contain spaces, you should use the "zero end" feature:

find /somedir -type f -print0 | grep -iz 'LMN2011' | xargs -0 grep -i 'LMN20113456'

Simplest way to profile a PHP script

For benchmarking, like in your example, I use the pear Benchmark package. You set markers for measuring. The class also provides a few presentation helpers, or you can process the data as you see fit.

I actually have it wrapped in another class with a __destruct method. When a script exits, the output is logged via log4php to syslog, so I have a lot of performance data to work from.

How can I compare two ordered lists in python?

The expression a == b should do the job.

Paste a multi-line Java String in Eclipse

Okay, I just found the answer (on Stackoverflow, no less).

Eclipse has an option so that copy-paste of multi-line text into String literals will result in quoted newlines:

Preferences/Java/Editor/Typing/ "Escape text when pasting into a string literal"

How to compare LocalDate instances Java 8

LocalDate ld ....;
LocalDateTime ldtime ...;

ld.isEqual(LocalDate.from(ldtime));

Java AES encryption and decryption

You state that you want to encrypt/decrypt a password. I'm not sure exactly of what your specific use case is but, generally, passwords are not stored in a form where they can be decrypted. General practice is to salt the password and use suitably powerful one-way hash (such as PBKDF2).

Take a look at the following link for more information.

http://crackstation.net/hashing-security.htm

JSON and XML comparison

Processing speed may not be the only relevant matter, however, as that's the question, here are some numbers in a benchmark: JSON vs. XML: Some hard numbers about verbosity. For the speed, in this simple benchmark, XML presents a 21% overhead over JSON.

An important note about the verbosity, which is as the article says, the most common complain: this is not so much relevant in practice (neither XML nor JSON data are typically handled by humans, but by machines), even if for the matter of speed, it requires some reasonable more time to compress.

Also, in this benchmark, a big amount of data was processed, and a typical web application won't transmit data chunks of such sizes, as big as 90MB, and compression may not be beneficial (for small enough data chunks, a compressed chunk will be bigger than the uncompressed chunk), so not applicable.

Still, if no compression is involved, JSON, as obviously terser, will weight less over the transmission channel, especially if transmitted through a WebSocket connection, where the absence of the classic HTTP overhead may make the difference at the advantage of JSON, even more significant.

After transmission, data is to be consumed, and this count in the overall processing time. If big or complex enough data are to be transmitted, the lack of a schema automatically checked for by a validating XML parser, may require more check on JSON data; these checks would have to be executed in JavaScript, which is not known to be particularly fast, and so it may present an additional overhead over XML in such cases.

Anyway, only testing will provides the answer for your particular use-case (if speed is really the only matter, and not standard nor safety nor integrity…).

Update 1: worth to mention, is EXI, the binary XML format, which offers compression at less cost than using Gzip, and save processing otherwise needed to decompress compressed XML. EXI is to XML, what BSON is to JSON. Have a quick overview here, with some reference to efficiency in both space and time: EXI: The last binary standard?.

Update 2: there also exists a binary XML performance reports, conducted by the W3C, as efficiency and low memory and CPU footprint, is also a matter for the XML area too: Efficient XML Interchange Evaluation.

Update 2015-03-01

Worth to be noticed in this context, as HTTP overhead was raised as an issue: the IANA has registered the EXI encoding (the efficient binary XML mentioned above), as a a Content Coding for the HTTP protocol (alongside with compress, deflate and gzip). This means EXI is an option which can be expected to be understood by browsers among possibly other HTTP clients. See Hypertext Transfer Protocol Parameters (iana.org).