Programs & Examples On #Jaybird

Jaybird is a JCA/JDBC driver for the Firebird database server. Use this tag for questions about using Jaybird to connect to Firebird.

CFLAGS, CCFLAGS, CXXFLAGS - what exactly do these variables control?

According to the GNU make manual:

CFLAGS: Extra flags to give to the C compiler.
CXXFLAGS: Extra flags to give to the C++ compiler.
CPPFLAGS: Extra flags to give to the C preprocessor and programs that use it (the C and Fortran compilers).

src: https://www.gnu.org/software/make/manual/make.html#index-CFLAGS
note: PP stands for PreProcessor (and not Plus Plus), i.e.

CPP: Program for running the C preprocessor, with results to standard output; default ‘$(CC) -E’.

These variables are used by the implicit rules of make

Compiling C programs
n.o is made automatically from n.c with a recipe of the form
‘$(CC) $(CPPFLAGS) $(CFLAGS) -c’.

Compiling C++ programs
n.o is made automatically from n.cc, n.cpp, or n.C with a recipe of the form
‘$(CXX) $(CPPFLAGS) $(CXXFLAGS) -c’.
We encourage you to use the suffix ‘.cc’ for C++ source files instead of ‘.C’.

src: https://www.gnu.org/software/make/manual/make.html#Catalogue-of-Rules

Android Studio - Gradle sync project failed

I had a "Install build tools and sync" link in the lower right hand corner of my screen. I clicked on that and it fixed the issue.

VBA - Run Time Error 1004 'Application Defined or Object Defined Error'

Assgining a value that starts with a "=" will kick in formula evaluation and gave in my case the above mentioned error #1004. Prepending it with a space was the ticket for me.

Vim: insert the same characters across multiple lines

I would use a macro to record my actions and would then repeat it.

  1. Put your cursor on the first letter in name.
  2. Hit qq to start recording into the q buffer.
  3. Hit i to go into insert mode, type vector_, and then hit Esc to leave insert mode.
  4. Now hit 0 to go back to the beginning of the line.
  5. Now hit j to go down.
  6. Now hit q again to stop recording.

You now have a nice macro.

Type 3@q to execute your macro three times to do the rest of the lines.

Storing a file in a database as opposed to the file system?

We made the decision to store as varbinary for http://www.freshlogicstudios.com/Products/Folders/ halfway expecting performance issues. I can say that we've been pleasantly surprised at how well it's worked out.

An Authentication object was not found in the SecurityContext - Spring 3.2.2

I encountered the same error while using SpringBoot 2.1.4, along with Spring Security 5 (I believe). After one day of trying everything that Google had to offer, I discovered the cause of error in my case. I had a setup of micro-services, with the Auth server being different from the Resource Server. I had the following lines in my application.yml which prevented 'auto-configuration' despite of having included dependencies spring-boot-starter-security, spring-security-oauth2 and spring-security-jwt. I had included the following in the properties (during development) which caused the error.

spring:
  autoconfigure:
    exclude: org.springframework.boot.autoconfigure.security.servlet.SecurityAutoConfiguration

Commenting it out solved it for me.

#spring:
#  autoconfigure:
#    exclude: org.springframework.boot.autoconfigure.security.servlet.SecurityAutoConfiguration

Hope, it helps someone.

How to get character for a given ascii value

It can also be done in some other manner

byte[] pass_byte = Encoding.ASCII.GetBytes("your input value");

and then print result. by using foreach loop.

Hunk #1 FAILED at 1. What's that mean?

It is an error generated by patch. If you would open the .patch file, you'd see that it's organized in a bunch of segments, so-called "hunks". Every hunk identifies corresponding pieces of code (by line numbers) in the old and new version, the differences between those pieces of code, and similarities between them (the "context").

A hunk might fail if the similarities of a hunk don't match what's in the original file. When you see this error, it is almost always because you're using a patch for the wrong version of the code you're patching. There are a few ways to work around this:

  • Get an updated version of libdvdnav that already includes the patch (best option).
  • Get a .patch file for the version of libdvdnav you're patching.
  • Patch manually. For every hunk in the patch, try to locate the corresponding file and lines in libdvdnav, and correct them according to the instructions in the patch.
  • Take the version of libdvdnav that's closer to whatever version the .patch file was intended for (probably a bad idea).

Iterate over the lines of a string

I'm not sure what you mean by "then again by the parser". After the splitting has been done, there's no further traversal of the string, only a traversal of the list of split strings. This will probably actually be the fastest way to accomplish this, so long as the size of your string isn't absolutely huge. The fact that python uses immutable strings means that you must always create a new string, so this has to be done at some point anyway.

If your string is very large, the disadvantage is in memory usage: you'll have the original string and a list of split strings in memory at the same time, doubling the memory required. An iterator approach can save you this, building a string as needed, though it still pays the "splitting" penalty. However, if your string is that large, you generally want to avoid even the unsplit string being in memory. It would be better just to read the string from a file, which already allows you to iterate through it as lines.

However if you do have a huge string in memory already, one approach would be to use StringIO, which presents a file-like interface to a string, including allowing iterating by line (internally using .find to find the next newline). You then get:

import StringIO
s = StringIO.StringIO(myString)
for line in s:
    do_something_with(line)

What does java:comp/env/ do?

There is also a property resourceRef of JndiObjectFactoryBean that is, when set to true, used to automatically prepend the string java:comp/env/ if it is not already present.

<bean id="someId" class="org.springframework.jndi.JndiObjectFactoryBean">
  <property name="jndiName" value="jdbc/loc"/>
  <property name="resourceRef" value="true"/>
</bean>

What does EntityManager.flush do and why do I need to use it?

A call to EntityManager.flush(); will force the data to be persist in the database immediately as EntityManager.persist() will not (depending on how the EntityManager is configured : FlushModeType (AUTO or COMMIT) by default it's set to AUTO and a flush will be done automatically by if it's set to COMMIT the persitence of the data to the underlying database will be delayed when the transaction is commited).

NULL values inside NOT IN clause

IF you want to filter with NOT IN for a subquery containg NULLs justcheck for not null

SELECT blah FROM t WHERE blah NOT IN
        (SELECT someotherBlah FROM t2 WHERE someotherBlah IS NOT NULL )

How to reset a form using jQuery with .reset() method

First line will reset form inputs

$('form#myform').trigger("reset"); //Line1
$('form#myform select').trigger("change"); //Line2

Second one will reset select2

Optional: You can use this if you have different types registered with different events

$('form#myform select, form input[type=checkbox]').trigger("change"); //Line2

Count the number occurrences of a character in a string

An alternative way to get all the character counts without using Counter(), count and regex

counts_dict = {}
for c in list(sentence):
  if c not in counts_dict:
    counts_dict[c] = 0
  counts_dict[c] += 1

for key, value in counts_dict.items():
    print(key, value)

How to return a result (startActivityForResult) from a TabHost Activity?

For start Activity 2 from Activity 1 and get result, you could use startActivityForResult and implement onActivityResult in Activity 1 and use setResult in Activity2.

Intent intent = new Intent(this, Activity2.class);
intent.putExtra(NUMERO1, numero1);
intent.putExtra(NUMERO2, numero2);
//startActivity(intent);
startActivityForResult(intent, MI_REQUEST_CODE);

Find p-value (significance) in scikit-learn LinearRegression

An easy way to pull of the p-values is to use statsmodels regression:

import statsmodels.api as sm
mod = sm.OLS(Y,X)
fii = mod.fit()
p_values = fii.summary2().tables[1]['P>|t|']

You get a series of p-values that you can manipulate (for example choose the order you want to keep by evaluating each p-value):

enter image description here

Easy way to concatenate two byte arrays

The most elegant way to do this is with a ByteArrayOutputStream.

byte a[];
byte b[];

ByteArrayOutputStream outputStream = new ByteArrayOutputStream( );
outputStream.write( a );
outputStream.write( b );

byte c[] = outputStream.toByteArray( );

How to determine if a list of polygon points are in clockwise order?

As also explained in this Wikipedia article Curve orientation, given 3 points p, q and r on the plane (i.e. with x and y coordinates), you can calculate the sign of the following determinant

enter image description here

If the determinant is negative (i.e. Orient(p, q, r) < 0), then the polygon is oriented clockwise (CW). If the determinant is positive (i.e. Orient(p, q, r) > 0), the polygon is oriented counterclockwise (CCW). The determinant is zero (i.e. Orient(p, q, r) == 0) if points p, q and r are collinear.

In the formula above, we prepend the ones in front of the coordinates of p, q and r because we are using homogeneous coordinates.

Split string into list in jinja?

After coming back to my own question after 5 year and seeing so many people found this useful, a little update.

A string variable can be split into a list by using the split function (it can contain similar values, set is for the assignment) . I haven't found this function in the official documentation but it works similar to normal Python. The items can be called via an index, used in a loop or like Dave suggested if you know the values, it can set variables like a tuple.

{% set list1 = variable1.split(';') %}
The grass is {{ list1[0] }} and the boat is {{ list1[1] }}

or

{% set list1 = variable1.split(';') %}
{% for item in list1 %}
    <p>{{ item }}<p/>
{% endfor %} 

or

{% set item1, item2 = variable1.split(';') %}
The grass is {{ item1 }} and the boat is {{ item2 }}

how to put focus on TextBox when the form load?

You cannot set focus to a control if it has not been rendered. Form.Load() occurs before the controls are rendered.

Go to the form's events and double click the "Shown" event. In the form's shown event handler call the control.Focus() method.

    private void myForm_Shown(object sender, EventArgs e)
    {
        // Call textbox's focus method
        txtMyTextbox.Focus();
    }

Java: getMinutes and getHours

int hr=Time.valueOf(LocalTime.now()).getHours();
int minutes=Time.valueOf(LocalTime.now()).getMinutes();

These functions will return int values in hours and minutes.

What is the difference between varchar and nvarchar?

I had a look at the answers and many seem to recommend to use nvarchar over varchar, because space is not a problem anymore, so there is no harm in enabling Unicode for little extra storage. Well, this is not always true when you want to apply an index over your column. SQL Server has a limit of 900 bytes on the size of the field you can index. So if you have a varchar(900) you can still index it, but not varchar(901). With nvarchar, the number of characters is halved, so you can index up to nvarchar(450). So if you are confident you don't need nvarchar, I don't recommend using it.

In general, in databases, I recommend sticking to the size you need, because you can always expand. For example, a colleague at work once thought that there is no harm in using nvarchar(max) for a column, as we have no problem with storage at all. Later on, when we tried to apply an index over this column, SQL Server rejected this. If, however, he started with even varchar(5), we could have simply expanded it later to what we need without such a problem that will require us to do a field migration plan to fix this problem.

How to iterate over a string in C?

Rather than use strlen as suggested above, you can just check for the NULL character:

#include <stdio.h>

int main(int argc, char *argv[])
{
    const char *const pszSource = "This is an example.";
    const char *pszChar = pszSource;

    while (pszChar != NULL && *pszChar != '\0')
    {
        printf("%s", *pszChar);
        ++pszChar;
    }

    getchar();

    return 0;
}

$(this).attr("id") not working

your using this in a function, when you should be using the parameter.

You only use $(this) in callbacks... from selections like

$('a').click(function() {
   alert($(this).href);
})

In closing, the proper way (using your code example) would be to do this

obj.attr('id');

Position last flex item at the end of container

Flexible Box Layout Module - 8.1. Aligning with auto margins

Auto margins on flex items have an effect very similar to auto margins in block flow:

  • During calculations of flex bases and flexible lengths, auto margins are treated as 0.

  • Prior to alignment via justify-content and align-self, any positive free space is distributed to auto margins in that dimension.

Therefore you could use margin-top: auto to distribute the space between the other elements and the last element.

This will position the last element at the bottom.

p:last-of-type {
  margin-top: auto;
}

_x000D_
_x000D_
.container {
  display: flex;
  flex-direction: column;
  border: 1px solid #000;
  min-height: 200px;
  width: 100px;
}
p {
  height: 30px;
  background-color: blue;
  margin: 5px;
}
p:last-of-type {
  margin-top: auto;
}
_x000D_
<div class="container">
  <p></p>
  <p></p>
  <p></p>
</div>
_x000D_
_x000D_
_x000D_

vertical example


Likewise, you can also use margin-left: auto or margin-right: auto for the same alignment horizontally.

p:last-of-type {
  margin-left: auto;
}

_x000D_
_x000D_
.container {
  display: flex;
  width: 100%;
  border: 1px solid #000;
}
p {
  height: 50px;
  width: 50px;
  background-color: blue;
  margin: 5px;
}
p:last-of-type {
  margin-left: auto;
}
_x000D_
<div class="container">
  <p></p>
  <p></p>
  <p></p>
  <p></p>
</div>
_x000D_
_x000D_
_x000D_

horizontal example

How can I remove a character from a string using JavaScript?

For global replacement of '/r', this code worked for me.

mystring = mystring.replace(/\/r/g,'');

Scroll to bottom of div with Vue.js

Here is a simple example using #ref to scroll to the bottom of a div.

_x000D_
_x000D_
/*_x000D_
Defined somewhere:_x000D_
  var vueContent = new Vue({_x000D_
      el: '#vue-content',_x000D_
      ..._x000D_
 */_x000D_
_x000D_
var messageDisplay = vueContent.$refs.messageDisplay;_x000D_
messageDisplay.scrollTop = messageDisplay.scrollHeight;
_x000D_
<div id='vue-content'>_x000D_
  <div ref='messageDisplay' id='messages'>_x000D_
    <div v-for="message in messages">_x000D_
      {{ message }}_x000D_
    </div>_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Notice that by putting ref='messageDisplay' in the HTML, you have access to the element through vueContent.$refs.messageDisplay

How to pass data using NotificationCenter in swift 3.0 and NSNotificationCenter in swift 2.0?

For Swift 3

let imageDataDict:[String: UIImage] = ["image": image]

  // post a notification
  NotificationCenter.default.post(name: NSNotification.Name(rawValue: "notificationName"), object: nil, userInfo: imageDataDict) 
  // `default` is now a property, not a method call

 // Register to receive notification in your class
 NotificationCenter.default.addObserver(self, selector: #selector(self.showSpinningWheel(_:)), name: NSNotification.Name(rawValue: "notificationName"), object: nil)

 // handle notification
 func showSpinningWheel(_ notification: NSNotification) {
        print(notification.userInfo ?? "")
        if let dict = notification.userInfo as NSDictionary? {
            if let id = dict["image"] as? UIImage{
                // do something with your image
            }
        }
 }

For Swift 4

let imageDataDict:[String: UIImage] = ["image": image]

  // post a notification
  NotificationCenter.default.post(name: NSNotification.Name(rawValue: "notificationName"), object: nil, userInfo: imageDataDict) 
  // `default` is now a property, not a method call

 // Register to receive notification in your class
 NotificationCenter.default.addObserver(self, selector: #selector(self.showSpinningWheel(_:)), name: NSNotification.Name(rawValue: "notificationName"), object: nil)

 // handle notification
 @objc func showSpinningWheel(_ notification: NSNotification) {
        print(notification.userInfo ?? "")
        if let dict = notification.userInfo as NSDictionary? {
            if let id = dict["image"] as? UIImage{
                // do something with your image
            }
        }
 }

How to use delimiter for csv in python

ok, here is what i understood from your question. You are writing a csv file from python but when you are opening that file into some other application like excel or open office they are showing the complete row in one cell rather than each word in individual cell. I am right??

if i am then please try this,

import csv

with open(r"C:\\test.csv", "wb") as csv_file:
    writer = csv.writer(csv_file, delimiter =",",quoting=csv.QUOTE_MINIMAL)
    writer.writerow(["a","b"])

you have to set the delimiter = ","

What is the cleanest way to ssh and run multiple commands in Bash?

This can also be done as follows. Put your commands in a script, let's name it commands-inc.sh

#!/bin/bash
ls some_folder
./someaction.sh
pwd

Save the file

Now run it on the remote server.

ssh user@remote 'bash -s' < /path/to/commands-inc.sh

Never failed for me.

"Could not find the main class" error when running jar exported by Eclipse

Run it like this on the command line:

java -jar /path/to/your/jar/jarFile.jar

Python NoneType object is not callable (beginner)

Why does it give me that error?

Because your first parameter you pass to the loop function is None but your function is expecting an callable object, which None object isn't.

Therefore you have to pass the callable-object which is in your case the hi function object.

def hi():     
  print 'hi'

def loop(f, n):         #f repeats n times
  if n<=0:
    return
  else:
    f()             
    loop(f, n-1)    

loop(hi, 5)

Caused by: java.security.UnrecoverableKeyException: Cannot recover key

The private key password defined in your app/config is incorrect. First try verifying the the private key password by changing to another one as follows:

keytool -keypasswd -new changeit -keystore cacerts -storepass changeit -alias someapp -keypass password

The above example changes the password from password to changeit. This command will succeed if the private key password was password.

Simplest way to profile a PHP script

No extensions are needed, just use these two functions for simple profiling.

// Call this at each point of interest, passing a descriptive string
function prof_flag($str)
{
    global $prof_timing, $prof_names;
    $prof_timing[] = microtime(true);
    $prof_names[] = $str;
}

// Call this when you're done and want to see the results
function prof_print()
{
    global $prof_timing, $prof_names;
    $size = count($prof_timing);
    for($i=0;$i<$size - 1; $i++)
    {
        echo "<b>{$prof_names[$i]}</b><br>";
        echo sprintf("&nbsp;&nbsp;&nbsp;%f<br>", $prof_timing[$i+1]-$prof_timing[$i]);
    }
    echo "<b>{$prof_names[$size-1]}</b><br>";
}

Here is an example, calling prof_flag() with a description at each checkpoint, and prof_print() at the end:

prof_flag("Start");

   include '../lib/database.php';
   include '../lib/helper_func.php';

prof_flag("Connect to DB");

   connect_to_db();

prof_flag("Perform query");

   // Get all the data

   $select_query = "SELECT * FROM data_table";
   $result = mysql_query($select_query);

prof_flag("Retrieve data");

   $rows = array();
   $found_data=false;
   while($r = mysql_fetch_assoc($result))
   {
       $found_data=true;
       $rows[] = $r;
   }

prof_flag("Close DB");

   mysql_close();   //close database connection

prof_flag("Done");
prof_print();

Output looks like this:

Start
   0.004303
Connect to DB
   0.003518
Perform query
   0.000308
Retrieve data
   0.000009
Close DB
   0.000049
Done

Oracle: How to find out if there is a transaction pending?

The easiest and most reliable solution is to try and start a transaction and see it if succeeds. If some code already started a transaction but has not yet issued any DML, then the V$TRANSACTION view won't show anything.

In this example below, I handle the exception to raise a user-defined application error. To defer to an existing exception handler, just do a SET TRANSACTION and then immediately COMMIT to undo it.

DECLARE
    transaction_in_progress EXCEPTION;
    PRAGMA EXCEPTION_INIT(transaction_in_progress, -1453);
BEGIN
    SET TRANSACTION NAME 'CHECK_FOR_TRANSACTION_ALREADY_SET';
    COMMIT; -- end transaction
EXCEPTION
    WHEN transaction_in_progress THEN
        RAISE_APPLICATION_ERROR(-20000,'Transaction is already in progress');
END;
/

Correct way to use Modernizr to detect IE?

Well, after doing more research on this topic I ended up using following solution for targeting IE 10+. As IE10&11 are the only browsers which support the -ms-high-contrast media query, that is a good option without any JS:

@media screen and (-ms-high-contrast: active), screen and (-ms-high-contrast: none) {  
   /* IE10+ specific styles go here */  
}

Works perfectly.

Token based authentication in Web API without any user interface

ASP.Net Web API has Authorization Server build-in already. You can see it inside Startup.cs when you create a new ASP.Net Web Application with Web API template.

OAuthOptions = new OAuthAuthorizationServerOptions
{
    TokenEndpointPath = new PathString("/Token"),
    Provider = new ApplicationOAuthProvider(PublicClientId),
    AuthorizeEndpointPath = new PathString("/api/Account/ExternalLogin"),
    AccessTokenExpireTimeSpan = TimeSpan.FromDays(14),
    // In production mode set AllowInsecureHttp = false
    AllowInsecureHttp = true
};

All you have to do is to post URL encoded username and password inside query string.

/Token/userName=johndoe%40example.com&password=1234&grant_type=password

If you want to know more detail, you can watch User Registration and Login - Angular Front to Back with Web API by Deborah Kurata.

Pdf.js: rendering a pdf file using a base64 file source instead of url

from the sourcecode at http://mozilla.github.com/pdf.js/build/pdf.js

/**
 * This is the main entry point for loading a PDF and interacting with it.
 * NOTE: If a URL is used to fetch the PDF data a standard XMLHttpRequest(XHR)
 * is used, which means it must follow the same origin rules that any XHR does
 * e.g. No cross domain requests without CORS.
 *
 * @param {string|TypedAray|object} source Can be an url to where a PDF is
 * located, a typed array (Uint8Array) already populated with data or
 * and parameter object with the following possible fields:
 *  - url   - The URL of the PDF.
 *  - data  - A typed array with PDF data.
 *  - httpHeaders - Basic authentication headers.
 *  - password - For decrypting password-protected PDFs.
 *
 * @return {Promise} A promise that is resolved with {PDFDocumentProxy} object.
 */

So a standard XMLHttpRequest(XHR) is used for retrieving the document. The Problem with this is that XMLHttpRequests do not support data: uris (eg. data:application/pdf;base64,JVBERi0xLjUK...).

But there is the possibility of passing a typed Javascript Array to the function. The only thing you need to do is to convert the base64 string to a Uint8Array. You can use this function found at https://gist.github.com/1032746

var BASE64_MARKER = ';base64,';

function convertDataURIToBinary(dataURI) {
  var base64Index = dataURI.indexOf(BASE64_MARKER) + BASE64_MARKER.length;
  var base64 = dataURI.substring(base64Index);
  var raw = window.atob(base64);
  var rawLength = raw.length;
  var array = new Uint8Array(new ArrayBuffer(rawLength));

  for(var i = 0; i < rawLength; i++) {
    array[i] = raw.charCodeAt(i);
  }
  return array;
}

tl;dr

var pdfAsDataUri = "data:application/pdf;base64,JVBERi0xLjUK..."; // shortened
var pdfAsArray = convertDataURIToBinary(pdfAsDataUri);
PDFJS.getDocument(pdfAsArray)

Gulp command not found after install

I got this working on Win10 using a combination of the answers from above and elsewhere. Posting here for others and future me.

I followed the instructions from here: https://gulpjs.com/docs/en/getting-started/quick-start but on the last step after typing gulp --version I got the message -bash: gulp: command not found

To fix this:

  1. I added %AppData%\npm to my Path environment variable
  2. Closed all gitbash (cmd, powershell, etc...) and restarted gitbash.
  3. Then gulp --version worked

Also, found the below for reasons why not to install gulp globally and how to remove it (not sure if this is advisable though):

what does gulp-"cli" stands for?

How to uninstall Gulp CLI from NPM globally?

Detect if page has finished loading

Without jquery or anything like that beacuse why not ?

var loaded=0;
var loaded1min=0;
document.addEventListener("DOMContentLoaded", function(event) {
   loaded=1;
    setTimeout(function () {
      loaded1min=1;
    }, 60000);
});

Are there any disadvantages to always using nvarchar(MAX)?

The job of the database is to store data so that it can be used by the enterprise. Part of making that data useful is ensuring that it is meaningful. Allowing someone to enter an unlimited number of characters for their first name isn't ensuring meaningful data.

Building these constraints into the business layer is a good idea, but that doesn't ensure that the database will remain intact. The only way to guarantee that the data rules are not violated is to enforce them at the lowest level possible in the database.

jQuery .slideRight effect

Another solution is by using .animate() and appropriate CSS.

e.g.

   $('#mydiv').animate({ marginLeft: "100%"} , 4000);

JS Fiddle

UITableView Cell selected Color?

Swift 4+:

Add following lines in your table cell

let bgColorView = UIView()
bgColorView.backgroundColor =  .red
self.selectedBackgroundView = bgColorView

Finally it should be as below

override func setSelected(_ selected: Bool, animated: Bool)
    {
        super.setSelected(selected, animated: animated)

        // Configure the view for the selected state
        let bgColorView = UIView()
        bgColorView.backgroundColor =  .red
        self.selectedBackgroundView = bgColorView

    }

ReactJS lifecycle method inside a function Component

You can make your own "lifecycle methods" using hooks for maximum nostalgia.

Utility functions:

import { useEffect, useRef } from "react";

export const useComponentDidMount = handler => {
  return useEffect(() => {
    return handler();
  }, []);
};

export const useComponentDidUpdate = (handler, deps) => {
  const isInitialMount = useRef(true);

  useEffect(() => {
    if (isInitialMount.current) {
      isInitialMount.current = false;

      return;
    }

    return handler();
  }, deps);
};

Usage:

import { useComponentDidMount, useComponentDidUpdate } from "./utils";

export const MyComponent = ({ myProp }) => {
  useComponentDidMount(() => {
    console.log("Component did mount!");
  });

  useComponentDidUpdate(() => {
    console.log("Component did update!");
  });

  useComponentDidUpdate(() => {
    console.log("myProp did update!");
  }, [myProp]);
};  

Simple DateTime sql query

Open up the Access File you are trying to export SQL data to. Delete any Queries that are there. Everytime you run SQL Server Import wizard, even if it fails, it creates a Query in the Access DB that has to be deleted before you can run the SQL export Wizard again.

Converting stream of int's to char's in java

Simple casting:

int a = 99;
char c = (char) a;

Is there any reason this is not working for you?

Unicode character as bullet for list-item in CSS

To add a star use the Unicode character 22C6.

I added a space to make a little gap between the li and the star. The code for space is A0.

li:before {
    content: '\22C6\A0';
}

JPA entity without id

I guess your entity_property has a composite key (entity_id, name) where entity_id is a foreign key to entity. If so, you can map it as follows:

@Embeddable
public class EntityPropertyPK {
    @Column(name = "name")
    private String name;

    @ManyToOne
    @JoinColumn(name = "entity_id")
    private Entity entity;

    ...
}

@Entity 
@Table(name="entity_property") 
public class EntityProperty { 
    @EmbeddedId
    private EntityPropertyPK id;

    @Column(name = "value")
    private String value; 

    ...
}

First char to upper case

Regular Expressions (abbreviated "regex" or "reg-ex") is a string that defines a search pattern.

What replaceFirst() does is it uses the regular expression provided in the parameters and replaces the first result from the search with whatever you pass in as the other parameter.

What you want to do is convert the string to an array using the String class' charAt() method, and then use Character.toUpperCase() to change the character to upper case (obviously). Your code would look like this:

char first = Character.toUpperCase(userIdea.charAt(0));
betterIdea = first + userIdea.substring(1);

Or, if you feel comfortable with more complex, one-lined java code:

betterIdea = Character.toUpperCase(userIdea.charAt(0)) + userIdea.substring(1);

Both of these do the same thing, which is converting the first character of userIdea to an upper case character.

When to use virtual destructors?

Virtual destructors are useful when you might potentially delete an instance of a derived class through a pointer to base class:

class Base 
{
    // some virtual methods
};

class Derived : public Base
{
    ~Derived()
    {
        // Do some important cleanup
    }
};

Here, you'll notice that I didn't declare Base's destructor to be virtual. Now, let's have a look at the following snippet:

Base *b = new Derived();
// use b
delete b; // Here's the problem!

Since Base's destructor is not virtual and b is a Base* pointing to a Derived object, delete b has undefined behaviour:

[In delete b], if the static type of the object to be deleted is different from its dynamic type, the static type shall be a base class of the dynamic type of the object to be deleted and the static type shall have a virtual destructor or the behavior is undefined.

In most implementations, the call to the destructor will be resolved like any non-virtual code, meaning that the destructor of the base class will be called but not the one of the derived class, resulting in a resources leak.

To sum up, always make base classes' destructors virtual when they're meant to be manipulated polymorphically.

If you want to prevent the deletion of an instance through a base class pointer, you can make the base class destructor protected and nonvirtual; by doing so, the compiler won't let you call delete on a base class pointer.

You can learn more about virtuality and virtual base class destructor in this article from Herb Sutter.

Iterating through a List Object in JSP

 <c:forEach items="${sessionScope.empL}" var="emp">
            <tr>
                <td>Employee ID: <c:out value="${emp.eid}"/></td>
                <td>Employee Pass: <c:out value="${emp.ename}"/></td>  
            </tr>
        </c:forEach>

java.time.format.DateTimeParseException: Text could not be parsed at index 21

The following worked for me

import java.time.*;
import java.time.format.*;

public class Times {

  public static void main(String[] args) {
    final String dateTime = "2012-02-22T02:06:58.147Z";
    DateTimeFormatter formatter = DateTimeFormatter.ISO_INSTANT;
    final ZonedDateTime parsed = ZonedDateTime.parse(dateTime, formatter.withZone(ZoneId.of("UTC")));
    System.out.println(parsed.toLocalDateTime());
  }
}

and gave me output as

2012-02-22T02:06:58.147

Error System.Data.OracleClient requires Oracle client software version 8.1.7 or greater when installs setup

On your remote machine, System.Data.OracleClient need access to some of the oracle dll which are not part of .Net. Solutions:

  • Install Oracle Client , and add bin location to Path environment varaible of windows OR
  • Copy oraociicus10.dll (Basic-Lite version) or aociei10.dll (Basic version), oci.dll, orannzsbb10.dll and oraocci10.dll from oracle client installable folder to bin folder of application so that application is able to find required dll

On your local machine most probably path to Oracle Client is already added in Path environment variable to there required dll are available to application but not on remote machine

Push an associative item into an array in JavaScript

To make something like associative array in JavaScript you have to use objects. ?

_x000D_
_x000D_
var obj = {}; // {} will create an object
var name = "name";
var val = 2;
obj[name] = val;
console.log(obj);
_x000D_
_x000D_
_x000D_

DEMO: http://jsfiddle.net/bz8pK/1/

How to print multiple lines of text with Python

You can use triple quotes (single ' or double "):

a = """
text
text
text
"""

print(a)

How to get a jqGrid selected row cells value

You can use in this manner also

var rowId =$("#list").jqGrid('getGridParam','selrow');  
var rowData = jQuery("#list").getRowData(rowId);
var colData = rowData['UserId'];   // perticuler Column name of jqgrid that you want to access

How do I profile memory usage in Python?

Disclosure:

  • Applicable on Linux only
  • Reports memory used by the current process as a whole, not individual functions within

But nice because of its simplicity:

import resource
def using(point=""):
    usage=resource.getrusage(resource.RUSAGE_SELF)
    return '''%s: usertime=%s systime=%s mem=%s mb
           '''%(point,usage[0],usage[1],
                usage[2]/1024.0 )

Just insert using("Label") where you want to see what's going on. For example

print(using("before"))
wrk = ["wasting mem"] * 1000000
print(using("after"))

>>> before: usertime=2.117053 systime=1.703466 mem=53.97265625 mb
>>> after: usertime=2.12023 systime=1.70708 mem=60.8828125 mb

Extracting Nupkg files using command line

This worked for me:

Rename-Item -Path A_Package.nupkg -NewName A_Package.zip

Expand-Archive -Path A_Package.zip -DestinationPath C:\Reference

Is there an easy way to convert jquery code to javascript?

I just found this quite impressive tutorial about jquery to javascript conversion from Jeffrey Way on Jan 19th 2012 *Copyright © 2014 Envato* :

http://net.tutsplus.com/tutorials/javascript-ajax/from-jquery-to-javascript-a-reference/

Whether we like it or not, more and more developers are being introduced to the world of JavaScript through jQuery first. In many ways, these newcomers are the lucky ones. They have access to a plethora of new JavaScript APIs, which make the process of DOM traversal (something that many folks depend on jQuery for) considerably easier. Unfortunately, they don’t know about these APIs!

In this article, we’ll take a variety of common jQuery tasks, and convert them to both modern and legacy JavaScript.

I proposed it in a comment to OP, and after his suggestion, i publish it has an answer for everyone to refer to.

Also, Jeffrey Way mentioned about his inspiration witch seems to be a good primer for understanding : http://sharedfil.es/js-48hIfQE4XK.html

Has a teaser, this document comparison of jQuery to javascript :

$(document).ready(function() {
  // code…
});

document.addEventListener("DOMContentLoaded", function() {
  // code…
});

$("a").click(function() {
  // code…
})

[].forEach.call(document.querySelectorAll("a"), function(el) {
  el.addEventListener("click", function() {
    // code…
  });
});

You should take a look.

fatal: bad default revision 'HEAD'

Your repo is yours, what goes on in it is entirely your business until you push or (allow a) fetch or clone. When you deleted your windows repo -- that folder didn't represent your local repo, it was your actual local repo, you deleted everything done in it that was never pushed, fetched or cloned.

edit: Ah, okay, I think I see what's going on here: you pushed to your linux repo but it's not bare and you never worked in it.

Instead of git log, do git log --all. Or git checkoutsome-branch-name.

Then try cloning the repo locally, on your linux box; I bet it works. What are you using to serve your repo on linux? Try cd'ing into its .git directory and git daemon --base-path=. --export-all, if that just sits there then go to your windows box and try git clone git://your.linux.box.ip, if the daemon complains it can't bind add --port=54345 to the daemon invoke and :54345 to the clone url.

How to construct a set out of list items in python?

The most direct solution is this:

s = set(filelist)

The issue in your original code is that the values weren't being assigned to the set. Here's the fixed-up version of your code:

s = set()
for filename in filelist:
    s.add(filename)
print(s)

Uninstall mongoDB from ubuntu

Stop MongoDB

Stop the mongod process by issuing the following command:

sudo service mongod stop

Remove Packages

Remove any MongoDB packages that you had previously installed.

sudo apt-get purge mongodb-org*

Remove Data Directories.

Remove MongoDB databases and log files.

 sudo rm -r /var/log/mongodb /var/lib/mongodb

How to fill OpenCV image with one solid color?

color=(200, 100, 255) # sample of a color 
img = np.full((100, 100, 3), color, np.uint8)

How to validate GUID is a GUID

See if these helps :-

  1. Guid.Parse - Docs
Guid guidResult = Guid.Parse(inputString)
  1. Guid.TryParse - Docs
bool isValid = Guid.TryParse(inputString, out guidOutput)

Truncate (not round) decimal places in SQL Server

I know this question is really old but nobody used sub-strings to round. This as advantage the ability to round really long numbers (limit of your string in SQL server which is usually 8000 characters):

SUBSTRING('123.456', 1, CHARINDEX('.', '123.456') + 2)

Getting the last revision number in SVN?

This should work in Bash, from a working directory. I've used it in Windows with unixutils installed:

svn info |grep Revision: |cut -c11-

How to write "Html.BeginForm" in Razor

The following code works fine:

@using (Html.BeginForm("Upload", "Upload", FormMethod.Post, 
                                      new { enctype = "multipart/form-data" }))
{
    @Html.ValidationSummary(true)
    <fieldset>
        Select a file <input type="file" name="file" />
        <input type="submit" value="Upload" />
    </fieldset>
}

and generates as expected:

<form action="/Upload/Upload" enctype="multipart/form-data" method="post">    
    <fieldset>
        Select a file <input type="file" name="file" />
        <input type="submit" value="Upload" />
    </fieldset>
</form>

On the other hand if you are writing this code inside the context of other server side construct such as an if or foreach you should remove the @ before the using. For example:

@if (SomeCondition)
{
    using (Html.BeginForm("Upload", "Upload", FormMethod.Post, 
                                      new { enctype = "multipart/form-data" }))
    {
        @Html.ValidationSummary(true)
        <fieldset>
            Select a file <input type="file" name="file" />
            <input type="submit" value="Upload" />
        </fieldset>
    }
}

As far as your server side code is concerned, here's how to proceed:

[HttpPost]
public ActionResult Upload(HttpPostedFileBase file) 
{
    if (file != null && file.ContentLength > 0) 
    {
        var fileName = Path.GetFileName(file.FileName);
        var path = Path.Combine(Server.MapPath("~/content/pics"), fileName);
        file.SaveAs(path);
    }
    return RedirectToAction("Upload");
}

"Stack overflow in line 0" on Internet Explorer

Aha!

I had an OnError() event in some code that was setting the image source to a default image path if it wasn't found. Of course, if the default image path wasn't found it would trigger the error handler...

For people who have a similar problem but not the same, I guess the cause of this is most likely to be either an unterminated loop, an event handler that triggers itself or something similar that throws the JavaScript engine into a spin.

How to perform runtime type checking in Dart?

Dart Object type has a runtimeType instance member (source is from dart-sdk v1.14, don't know if it was available earlier)

class Object {
  //...
  external Type get runtimeType;
}

Usage:

Object o = 'foo';
assert(o.runtimeType == String);

How can I recover the return value of a function passed to multiprocessing.Process?

I think the approach suggested by @sega_sai is the better one. But it really needs a code example, so here goes:

import multiprocessing
from os import getpid

def worker(procnum):
    print('I am number %d in process %d' % (procnum, getpid()))
    return getpid()

if __name__ == '__main__':
    pool = multiprocessing.Pool(processes = 3)
    print(pool.map(worker, range(5)))

Which will print the return values:

I am number 0 in process 19139
I am number 1 in process 19138
I am number 2 in process 19140
I am number 3 in process 19139
I am number 4 in process 19140
[19139, 19138, 19140, 19139, 19140]

If you are familiar with map (the Python 2 built-in) this should not be too challenging. Otherwise have a look at sega_Sai's link.

Note how little code is needed. (Also note how processes are re-used).

Check if table exists and if it doesn't exist, create it in SQL Server 2008

Just for contrast, I like using the object_id function as shown below. It's a bit easier to read, and you don't have to worry about sys.objects vs. sysobjects vs. sys.all_objects vs. sys.tables. Basic form:

IF object_id('MyTable') is not null
    PRINT 'Present!'
ELSE
    PRINT 'Not accounted for'

Of course this will show as "Present" if there is any object present with that name. If you want to check just tables, you'd need:

IF object_id('MyTable', 'U') is not null
    PRINT 'Present!'
ELSE
    PRINT 'Not accounted for'

It works for temp tables as well:

IF object_id('tempdb.dbo.#MyTable') is not null
    PRINT 'Present!'
ELSE
    PRINT 'Not accounted for'

FloatingActionButton example with Support Library

If you already added all libraries and it still doesn't work use:

<com.google.android.material.floatingactionbutton.FloatingActionButton
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    app:srcCompat="@drawable/ic_add" 
/>

instead of:

<android.support.design.widget.FloatingActionButton
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   app:srcCompat="@drawable/ic_add"
 />

And all will work fine :)

What is *.o file?

Ink-Jet is right. More specifically, an .o (.obj) -- or object file is a single source file compiled in to machine code (I'm not sure if the "machine code" is the same or similar to an executable machine code). Ultimately, it's an intermediate between an executable program and plain-text source file.

The linker uses the o files to assemble the file executable.

Wikipedia may have more detailed information. I'm not sure how much info you'd like or need.

How to Read and Write from the Serial Port

Note that usage of a SerialPort.DataReceived event is optional. You can set proper timeout using SerialPort.ReadTimeout and continuously call SerialPort.Read() after you wrote something to a port until you get a full response.

Moreover you can use SerialPort.BaseStream property to extract an underlying Stream instance. The benefit of using a Stream is that you can easily utilize various decorators with it:

var port = new SerialPort();
// LoggingStream inherits Stream, implements IDisposable, needen abstract methods and 
// overrides needen virtual methods. 
Stream portStream = new LoggingStream(port.BaseStream);
portStream.Write(...); // Logs write buffer.
portStream.Read(...); // Logs read buffer.

For more information check:

How to vertically align into the center of the content of a div with defined width/height?

I would say to add a paragraph with a period in it and style it like so:

<p class="center">.</p>

<style>
.center {font-size: 0px; margin-bottom: anyPercentage%;}
</style>

You may need to toy around with the percentages to get it right

How do I check if a string contains another string in Objective-C?

With iOS 8 and Swift, we can use localizedCaseInsensitiveContainsString method

 let string: NSString = "Café"
 let substring: NSString = "É"

 string.localizedCaseInsensitiveContainsString(substring) // true

Replace specific characters within strings

      library(stringi)

            group <- c('12357e', '12575e', '12575e', ' 197e18',  'e18947')

            pattern <- "e"  
            replacement <-  ""  
            group <- str_replace(group, pattern, replacement)      
            group    

[1] "12357"  "12575"  "12575"  " 19718" "18947" 

Is there a numpy builtin to reject outliers from a list

I wanted to do something similar, except setting the number to NaN rather than removing it from the data, since if you remove it you change the length which can mess up plotting (i.e. if you're only removing outliers from one column in a table, but you need it to remain the same as the other columns so you can plot them against each other).

To do so I used numpy's masking functions:

def reject_outliers(data, m=2):
    stdev = np.std(data)
    mean = np.mean(data)
    maskMin = mean - stdev * m
    maskMax = mean + stdev * m
    mask = np.ma.masked_outside(data, maskMin, maskMax)
    print('Masking values outside of {} and {}'.format(maskMin, maskMax))
    return mask

Java - Find shortest path between 2 points in a distance weighted map

You can see a complete example using java 8, recursion and streams -> Dijkstra algorithm with java

python "TypeError: 'numpy.float64' object cannot be interpreted as an integer"

I came here with the same Error, though one with a different origin.

It is caused by unsupported float index in 1.12.0 and newer numpy versions even if the code should be considered as valid.

An int type is expected, not a np.float64

Solution: Try to install numpy 1.11.0

sudo pip install -U numpy==1.11.0.

Execution order of events when pressing PrimeFaces p:commandButton

It failed because you used ajax="false". This fires a full synchronous request which in turn causes a full page reload, causing the oncomplete to be never fired (note that all other ajax-related attributes like process, onstart, onsuccess, onerror and update are also never fired).

That it worked when you removed actionListener is also impossible. It should have failed the same way. Perhaps you also removed ajax="false" along it without actually understanding what you were doing. Removing ajax="false" should indeed achieve the desired requirement.


Also is it possible to execute actionlistener and oncomplete simultaneously?

No. The script can only be fired before or after the action listener. You can use onclick to fire the script at the moment of the click. You can use onstart to fire the script at the moment the ajax request is about to be sent. But they will never exactly simultaneously be fired. The sequence is as follows:

  • User clicks button in client
  • onclick JavaScript code is executed
  • JavaScript prepares ajax request based on process and current HTML DOM tree
  • onstart JavaScript code is executed
  • JavaScript sends ajax request from client to server
  • JSF retrieves ajax request
  • JSF processes the request lifecycle on JSF component tree based on process
  • actionListener JSF backing bean method is executed
  • action JSF backing bean method is executed
  • JSF prepares ajax response based on update and current JSF component tree
  • JSF sends ajax response from server to client
  • JavaScript retrieves ajax response
    • if HTTP response status is 200, onsuccess JavaScript code is executed
    • else if HTTP response status is 500, onerror JavaScript code is executed
  • JavaScript performs update based on ajax response and current HTML DOM tree
  • oncomplete JavaScript code is executed

Note that the update is performed after actionListener, so if you were using onclick or onstart to show the dialog, then it may still show old content instead of updated content, which is poor for user experience. You'd then better use oncomplete instead to show the dialog. Also note that you'd better use action instead of actionListener when you intend to execute a business action.

See also:

Get the current first responder without using a private API

If your ultimate aim is just to resign the first responder, this should work: [self.view endEditing:YES]

Send Outlook Email Via Python?

import win32com.client as win32
outlook = win32.Dispatch('outlook.application')
mail = outlook.CreateItem(0)
mail.To = 'To address'
mail.Subject = 'Message subject'
mail.Body = 'Message body'
mail.HTMLBody = '<h2>HTML Message body</h2>' #this field is optional

# To attach a file to the email (optional):
attachment  = "Path to the attachment"
mail.Attachments.Add(attachment)

mail.Send()

Will use your local outlook account to send.

Note if you are trying to do something not mentioned above, look at the COM docs properties/methods: https://msdn.microsoft.com/en-us/vba/outlook-vba/articles/mailitem-object-outlook. In the code above, mail is a MailItem Object.

CSV parsing in Java - working example..?

At a minimum you are going to need to know the column delimiter.

Google Maps Android API v2 - Interactive InfoWindow (like in original android google maps)

I see that this question is already old but still...

We made a sipmle library at our company for achieving what is desired - An interactive info window with views and everything. You can check it out on github.

I hope it helps :)

How can I sharpen an image in OpenCV?

You can also try this filter

sharpen_filter = np.array([[0, -1, 0], [-1, 5, -1], [0, -1, 0]])
sharped_img = cv2.filter2D(image, -1, sharpen_filter)

How can I find the current OS in Python?

If you want user readable data but still detailed, you can use platform.platform()

>>> import platform
>>> platform.platform()
'Linux-3.3.0-8.fc16.x86_64-x86_64-with-fedora-16-Verne'

platform also has some other useful methods:

>>> platform.system()
'Windows'
>>> platform.release()
'XP'
>>> platform.version()
'5.1.2600'

Here's a few different possible calls you can make to identify where you are

import platform
import sys

def linux_distribution():
  try:
    return platform.linux_distribution()
  except:
    return "N/A"

print("""Python version: %s
dist: %s
linux_distribution: %s
system: %s
machine: %s
platform: %s
uname: %s
version: %s
mac_ver: %s
""" % (
sys.version.split('\n'),
str(platform.dist()),
linux_distribution(),
platform.system(),
platform.machine(),
platform.platform(),
platform.uname(),
platform.version(),
platform.mac_ver(),
))

The outputs of this script ran on a few different systems (Linux, Windows, Solaris, MacOS) and architectures (x86, x64, Itanium, power pc, sparc) is available here: https://github.com/hpcugent/easybuild/wiki/OS_flavor_name_version

e.g. Solaris on sparc gave:

Python version: ['2.6.4 (r264:75706, Aug  4 2010, 16:53:32) [C]']
dist: ('', '', '')
linux_distribution: ('', '', '')
system: SunOS
machine: sun4u
platform: SunOS-5.9-sun4u-sparc-32bit-ELF
uname: ('SunOS', 'xxx', '5.9', 'Generic_122300-60', 'sun4u', 'sparc')
version: Generic_122300-60
mac_ver: ('', ('', '', ''), '')

Proper way to restrict text input values (e.g. only numbers)

The inputmask plugin does the best job of this. Its extremely flexible in that you can supply whatever regex you like to restrict input. It also does not require JQuery.

Step 1: Install the plugin:

npm install --save inputmask

Step2: create a directive to wrap the input mask:

import {Directive, ElementRef, Input} from '@angular/core';
import * as Inputmask from 'inputmask';


@Directive({
  selector: '[app-restrict-input]',
})
export class RestrictInputDirective {

  // map of some of the regex strings I'm using (TODO: add your own)
  private regexMap = {
    integer: '^[0-9]*$',
    float: '^[+-]?([0-9]*[.])?[0-9]+$',
    words: '([A-z]*\\s)*',
    point25: '^\-?[0-9]*(?:\\.25|\\.50|\\.75|)$'
  };

  constructor(private el: ElementRef) {}

  @Input('app-restrict-input')
  public set defineInputType(type: string) {
    Inputmask({regex: this.regexMap[type], placeholder: ''})
      .mask(this.el.nativeElement);
  }

}

Step 3:

<input type="text" app-restrict-input="integer">

Check out their github docs for more information.

Get the current URL with JavaScript?

Use window.location for read and write access to the location object associated with the current frame. If you just want to get the address as a read-only string, you may use document.URL, which should contain the same value as window.location.href.

Comparing user-inputted characters in C

I see two problems:

The pointer answer is a null pointer and you are trying to dereference it in scanf, this leads to undefined behavior.

You don't need a char pointer here. You can just use a char variable as:

char answer;
scanf(" %c",&answer);

Next to see if the read character is 'y' or 'Y' you should do:

if( answer == 'y' || answer == 'Y') {
  // user entered y or Y.
}

If you really need to use a char pointer you can do something like:

char var;
char *answer = &var; // make answer point to char variable var.
scanf (" %c", answer);
if( *answer == 'y' || *answer == 'Y') {

How to convert timestamps to dates in Bash?

This version is similar to chiborg's answer, but it eliminates the need for the external tty and cat. It uses date, but could just as easily use gawk. You can change the shebang and replace the double square brackets with single ones and this will also run in sh.

#!/bin/bash
LANG=C
if [[ -z "$1" ]]
then
    if [[ -p /dev/stdin ]]    # input from a pipe
    then
        read -r p
    else
        echo "No timestamp given." >&2
        exit
    fi
else
    p=$1
fi
date -d "@$p" +%c

ERROR 1452: Cannot add or update a child row: a foreign key constraint fails

I was getting this issue even though my parent table had all the values I was referencing in my child table. The issue seemed to be that I could not add multiple child references to a single foreign key. In other words if I had five rows of data referenced the same foreign key, MySQL was only allowing me to upload the first row and giving me the error 1452.

What worked for me was typing the code "SET GLOBAL FOREIGN_KEY_CHECKS=0". After that I closed out of MySQL and then restarted it and I was able to upload all of my data with no errors. I then typed "SET GLOBAL FOREIGN_KEY_CHECKS=1" to set the system back to normal although I'm not entirely sure what FOREIGN_KEY_CHECKS does. Hope this helps!

Increasing (or decreasing) the memory available to R processes

To increase the amount of memory allocated to R you can use memory.limit

memory.limit(size = ...)

Or

memory.size(max = ...)

About the arguments

  • size - numeric. If NA report the memory limit, otherwise request a new limit, in Mb. Only values of up to 4095 are allowed on 32-bit R builds, but see ‘Details’.
  • max - logical. If TRUE the maximum amount of memory obtained from the OS is reported, if FALSE the amount currently in use, if NA the memory limit.

SQL Server : export query as a .txt file

you do this in the SSMS app, not the SQL. In the toolbar select

Query --> Results To --> Results To File

Make a div fill the height of the remaining screen space

There really isn't a sound, cross-browser way to do this in CSS. Assuming your layout has complexities, you need to use JavaScript to set the element's height. The essence of what you need to do is:

Element Height = Viewport height - element.offset.top - desired bottom margin

Once you can get this value and set the element's height, you need to attach event handlers to both the window onload and onresize so that you can fire your resize function.

Also, assuming your content could be larger than the viewport, you will need to set overflow-y to scroll.

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.

jQuery: Scroll down page a set increment (in pixels) on click?

var y = $(window).scrollTop();  //your current y position on the page
$(window).scrollTop(y+150);

how to change background image of button when clicked/focused?

use this code create xml file in drawable folder name:button

<?xml version="1.0" encoding="utf-8"?>
  <selector xmlns:android="http://schemas.android.com/apk/res/android">
  <item 
     android:state_pressed="true" 
     android:drawable="@drawable/buutton_pressed" />
  <item 
     android:drawable="@drawable/button_image" />
</selector>

and in button xml file

 android:background="@drawable/button"

Create a .csv file with values from a Python list

Here is working copy-paste example for Python 3.x with options to define your own delimiter and quote char.

import csv

mylist = ['value 1', 'value 2', 'value 3']

with open('employee_file.csv', mode='w') as employee_file:
    employee_writer = csv.writer(employee_file, delimiter=',', quotechar='"', quoting=csv.QUOTE_ALL)
    employee_writer.writerow(mylist)

This will generate employee_file.csv that looks like this:

"value 1","value 2","value 3"

NOTE:

If quoting is set to csv.QUOTE_MINIMAL, then .writerow() will quote fields only if they contain the delimiter or the quotechar. This is the default case.

If quoting is set to csv.QUOTE_ALL, then .writerow() will quote all fields.

If quoting is set to csv.QUOTE_NONNUMERIC, then .writerow() will quote all fields containing text data and convert all numeric fields to the float data type.

If quoting is set to csv.QUOTE_NONE, then .writerow() will escape delimiters instead of quoting them. In this case, you also must provide a value for the escapechar optional parameter.

Get the client IP address using PHP

It also works fine for internal IP addresses:

 function get_client_ip()
 {
      $ipaddress = '';
      if (getenv('HTTP_CLIENT_IP'))
          $ipaddress = getenv('HTTP_CLIENT_IP');
      else if(getenv('HTTP_X_FORWARDED_FOR'))
          $ipaddress = getenv('HTTP_X_FORWARDED_FOR');
      else if(getenv('HTTP_X_FORWARDED'))
          $ipaddress = getenv('HTTP_X_FORWARDED');
      else if(getenv('HTTP_FORWARDED_FOR'))
          $ipaddress = getenv('HTTP_FORWARDED_FOR');
      else if(getenv('HTTP_FORWARDED'))
          $ipaddress = getenv('HTTP_FORWARDED');
      else if(getenv('REMOTE_ADDR'))
          $ipaddress = getenv('REMOTE_ADDR');
      else
          $ipaddress = 'UNKNOWN';

      return $ipaddress;
 }

inverting image in Python with OpenCV

You can use "tilde" operator to do it:

import cv2
image = cv2.imread("img.png")
image = ~image
cv2.imwrite("img_inv.png",image)

This is because the "tilde" operator (also known as unary operator) works doing a complement dependent on the type of object

for example for integers, its formula is:

x + (~x) = -1

but in this case, opencv use an "uint8 numpy array object" for its images so its range is from 0 to 255

so if we apply this operator to an "uint8 numpy array object" like this:

import numpy as np
x1 = np.array([25,255,10], np.uint8) #for example
x2 = ~x1
print (x2)

we will have as a result:

[230 0 245]

because its formula is:

x2 = 255 - x1

and that is exactly what we want to do to solve the problem.

How can I make PHP display the error instead of giving me 500 Internal Server Error

It's worth noting that if your error is due to .htaccess, for example a missing rewrite_module, you'll still see the 500 internal server error.

Using DISTINCT along with GROUP BY in SQL Server

Perhaps not in the context that you have it, but you could use

SELECT DISTINCT col1,
PERCENTILE_CONT(col2) WITHIN GROUP (ORDER BY col2) OVER (PARTITION BY col1),
PERCENTILE_CONT(col2) WITHIN GROUP (ORDER BY col2) OVER (PARTITION BY col1, col3),
FROM TableA

You would use this to return different levels of aggregation returned in a single row. The use case would be for when a single grouping would not suffice all of the aggregates needed.

Input placeholders for Internet Explorer

TO insert the plugin and check the ie is perfectly workedjquery.placeholder.js

    <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
    <script src="jquery.placeholder.js"></script>
    <script>
        // To test the @id toggling on password inputs in browsers that don’t support changing an input’s @type dynamically (e.g. Firefox 3.6 or IE), uncomment this:
        // $.fn.hide = function() { return this; }
        // Then uncomment the last rule in the <style> element (in the <head>).
        $(function() {
            // Invoke the plugin
            $('input, textarea').placeholder({customClass:'my-placeholder'});
            // That’s it, really.
            // Now display a message if the browser supports placeholder natively
            var html;
            if ($.fn.placeholder.input && $.fn.placeholder.textarea) {
                html = '<strong>Your current browser natively supports <code>placeholder</code> for <code>input</code> and <code>textarea</code> elements.</strong> The plugin won’t run in this case, since it’s not needed. If you want to test the plugin, use an older browser ;)';
            } else if ($.fn.placeholder.input) {
                html = '<strong>Your current browser natively supports <code>placeholder</code> for <code>input</code> elements, but not for <code>textarea</code> elements.</strong> The plugin will only do its thang on the <code>textarea</code>s.';
            }
            if (html) {
                $('<p class="note">' + html + '</p>').insertAfter('form');
            }
        });
    </script>

How can I add items to an empty set in python

When you assign a variable to empty curly braces {} eg: new_set = {}, it becomes a dictionary. To create an empty set, assign the variable to a 'set()' ie: new_set = set()

How do I get the name of the active user via the command line in OS X?

I'm pretty sure the terminal in OS X is just like unix, so the command would be:

whoami

I don't have a mac on me at the moment so someone correct me if I'm wrong.

NOTE - The whoami utility has been obsoleted, and is equivalent to id -un. It will give you the current user

CodeIgniter - File upload required validation

you can solve it by overriding the Run function of CI_Form_Validation

copy this function in a class which extends CI_Form_Validation .

This function will override the parent class function . Here i added only a extra check which can handle file also

/**
 * Run the Validator
 *
 * This function does all the work.
 *
 * @access  public
 * @return  bool
 */
function run($group = '') {
    // Do we even have any data to process?  Mm?
    if (count($_POST) == 0) {
        return FALSE;
    }

    // Does the _field_data array containing the validation rules exist?
    // If not, we look to see if they were assigned via a config file
    if (count($this->_field_data) == 0) {
        // No validation rules?  We're done...
        if (count($this->_config_rules) == 0) {
            return FALSE;
        }

        // Is there a validation rule for the particular URI being accessed?
        $uri = ($group == '') ? trim($this->CI->uri->ruri_string(), '/') : $group;

        if ($uri != '' AND isset($this->_config_rules[$uri])) {
            $this->set_rules($this->_config_rules[$uri]);
        } else {
            $this->set_rules($this->_config_rules);
        }

        // We're we able to set the rules correctly?
        if (count($this->_field_data) == 0) {
            log_message('debug', "Unable to find validation rules");
            return FALSE;
        }
    }

    // Load the language file containing error messages
    $this->CI->lang->load('form_validation');

    // Cycle through the rules for each field, match the
    // corresponding $_POST or $_FILES item and test for errors
    foreach ($this->_field_data as $field => $row) {
        // Fetch the data from the corresponding $_POST or $_FILES array and cache it in the _field_data array.
        // Depending on whether the field name is an array or a string will determine where we get it from.

        if ($row['is_array'] == TRUE) {

            if (isset($_FILES[$field])) {
                $this->_field_data[$field]['postdata'] = $this->_reduce_array($_FILES, $row['keys']);
            } else {
                $this->_field_data[$field]['postdata'] = $this->_reduce_array($_POST, $row['keys']);
            }
        } else {
            if (isset($_POST[$field]) AND $_POST[$field] != "") {
                $this->_field_data[$field]['postdata'] = $_POST[$field];
            } else if (isset($_FILES[$field]) AND $_FILES[$field] != "") {
                $this->_field_data[$field]['postdata'] = $_FILES[$field];
            }
        }

        $this->_execute($row, explode('|', $row['rules']), $this->_field_data[$field]['postdata']);
    }

    // Did we end up with any errors?
    $total_errors = count($this->_error_array);

    if ($total_errors > 0) {
        $this->_safe_form_data = TRUE;
    }

    // Now we need to re-set the POST data with the new, processed data
    $this->_reset_post_array();

    // No errors, validation passes!
    if ($total_errors == 0) {
        return TRUE;
    }

    // Validation fails
    return FALSE;
}

Encoding as Base64 in Java

add this library into your app level dependancies

implementation 'org.apache.commons:commons-collections4:4.4'

How to use refs in React with Typescript

For those looking on how to do it when you have an array of elements:

const textInputRefs = useRef<(HTMLDivElement | null)[]>([])

...

const onClickFocus = (event: React.BaseSyntheticEvent, index: number) => {
    textInputRefs.current[index]?.focus()
};

...

{items.map((item, index) => (
    <textInput
        inputRef={(ref) => textInputs.current[index] = ref}
    />
    <Button
        onClick={event => onClickFocus(event, index)}
    />
}

How to pass parameters or arguments into a gradle task

I would suggest the method presented on the Gradle forum:

def createMinifyCssTask(def brand, def sourceFile, def destFile) {
    return tasks.create("minify${brand}Css", com.eriwen.gradle.css.tasks.MinifyCssTask) {
        source = sourceFile
        dest = destFile
    }
}

I have used this method myself to create custom tasks, and it works very well.

Array versus List<T>: When to use which?

Rather than going through a comparison of the features of each data type, I think the most pragmatic answer is "the differences probably aren't that important for what you need to accomplish, especially since they both implement IEnumerable, so follow popular convention and use a List until you have a reason not to, at which point you probably will have your reason for using an array over a List."

Most of the time in managed code you're going to want to favor collections being as easy to work with as possible over worrying about micro-optimizations.

How to print a stack trace in Node.js?

To print stacktrace of Error in console in more readable way:

console.log(ex, ex.stack.split("\n"));

Example result:

[Error] [ 'Error',
  '    at repl:1:7',
  '    at REPLServer.self.eval (repl.js:110:21)',
  '    at Interface.<anonymous> (repl.js:239:12)',
  '    at Interface.EventEmitter.emit (events.js:95:17)',
  '    at Interface._onLine (readline.js:202:10)',
  '    at Interface._line (readline.js:531:8)',
  '    at Interface._ttyWrite (readline.js:760:14)',
  '    at ReadStream.onkeypress (readline.js:99:10)',
  '    at ReadStream.EventEmitter.emit (events.js:98:17)',
  '    at emitKey (readline.js:1095:12)' ]

Body set to overflow-y:hidden but page is still scrollable in Chrome

Find out the element which is larger than the body (element which is causing the page to scroll) and just set it's position to fixed. NOTE: I'm not talking to change the position of draggable elements. Draggable elements can be dragged out of body only when there's an element larger than body (mostly in width).

How do I make a dictionary with multiple keys to one value?

It is simple. The first thing that you have to understand the design of the Python interpreter. It doesn't allocate memory for all the variables basically if any two or more variable has the same value it just map to that value.

let's go to the code example,

In [6]: a = 10

In [7]: id(a)
Out[7]: 10914656

In [8]: b = 10

In [9]: id(b)
Out[9]: 10914656

In [10]: c = 11

In [11]: id(c)
Out[11]: 10914688

In [12]: d = 21

In [13]: id(d)
Out[13]: 10915008

In [14]: e = 11

In [15]: id(e)
Out[15]: 10914688

In [16]: e = 21

In [17]: id(e)
Out[17]: 10915008

In [18]: e is d
Out[18]: True
In [19]: e = 30

In [20]: id(e)
Out[20]: 10915296

From the above output, variables a and b shares the same memory, c and d has different memory when I create a new variable e and store a value (11) which is already present in the variable c so it mapped to that memory location and doesn't create a new memory when I change the value present in the variable e to 21 which is already present in the variable d so now variables d and e share the same memory location. At last, I change the value in the variable e to 30 which is not stored in any other variable so it creates a new memory for e.

so any variable which is having same value shares the memory.

Not for list and dictionary objects

let's come to your question.

when multiple keys have same value then all shares same memory so the thing that you expect is already there in python.

you can simply use it like this

In [49]: dictionary = {
    ...:     'k1':1,
    ...:     'k2':1,
    ...:     'k3':2,
    ...:     'k4':2}
    ...:     
    ...:     

In [50]: id(dictionary['k1'])
Out[50]: 10914368

In [51]: id(dictionary['k2'])
Out[51]: 10914368

In [52]: id(dictionary['k3'])
Out[52]: 10914400

In [53]: id(dictionary['k4'])
Out[53]: 10914400

From the above output, the key k1 and k2 mapped to the same address which means value one stored only once in the memory which is multiple key single value dictionary this is the thing you want. :P

How to change date format in JavaScript

Using the Datejs library, this can be as easy as:

Date.parse("05/05/2010").toString("MMMM yyyy");
//          parse date             convert to
//                                 string with
//                                 custom format

Update row with data from another row in the same table

If you just need to insert a new row with a data from another row,

    insert into ORDER_ITEM select * from ORDER_ITEM where ITEM_NUMBER =123;

Difference between $(this) and event.target?

There is a difference between $(this) and event.target, and quite a significant one. While this (or event.currentTarget, see below) always refers to the DOM element the listener was attached to, event.target is the actual DOM element that was clicked. Remember that due to event bubbling, if you have

<div class="outer">
  <div class="inner"></div>
</div>

and attach click listener to the outer div

$('.outer').click( handler );

then the handler will be invoked when you click inside the outer div as well as the inner one (unless you have other code that handles the event on the inner div and stops propagation).

In this example, when you click inside the inner div, then in the handler:

  • this refers to the .outer DOM element (because that's the object to which the handler was attached)
  • event.currentTarget also refers to the .outer element (because that's the current target element handling the event)
  • event.target refers to the .inner element (this gives you the element where the event originated)

The jQuery wrapper $(this) only wraps the DOM element in a jQuery object so you can call jQuery functions on it. You can do the same with $(event.target).

Also note that if you rebind the context of this (e.g. if you use Backbone it's done automatically), it will point to something else. You can always get the actual DOM element from event.currentTarget.

The differences between initialize, define, declare a variable

Declaration

Declaration, generally, refers to the introduction of a new name in the program. For example, you can declare a new function by describing it's "signature":

void xyz();

or declare an incomplete type:

class klass;
struct ztruct;

and last but not least, to declare an object:

int x;

It is described, in the C++ standard, at §3.1/1 as:

A declaration (Clause 7) may introduce one or more names into a translation unit or redeclare names introduced by previous declarations.

Definition

A definition is a definition of a previously declared name (or it can be both definition and declaration). For example:

int x;
void xyz() {...}
class klass {...};
struct ztruct {...};
enum { x, y, z };

Specifically the C++ standard defines it, at §3.1/1, as:

A declaration is a definition unless it declares a function without specifying the function’s body (8.4), it contains the extern specifier (7.1.1) or a linkage-specification25 (7.5) and neither an initializer nor a function- body, it declares a static data member in a class definition (9.2, 9.4), it is a class name declaration (9.1), it is an opaque-enum-declaration (7.2), it is a template-parameter (14.1), it is a parameter-declaration (8.3.5) in a function declarator that is not the declarator of a function-definition, or it is a typedef declaration (7.1.3), an alias-declaration (7.1.3), a using-declaration (7.3.3), a static_assert-declaration (Clause 7), an attribute- declaration (Clause 7), an empty-declaration (Clause 7), or a using-directive (7.3.4).

Initialization

Initialization refers to the "assignment" of a value, at construction time. For a generic object of type T, it's often in the form:

T x = i;

but in C++ it can be:

T x(i);

or even:

T x {i};

with C++11.

Conclusion

So does it mean definition equals declaration plus initialization?

It depends. On what you are talking about. If you are talking about an object, for example:

int x;

This is a definition without initialization. The following, instead, is a definition with initialization:

int x = 0;

In certain context, it doesn't make sense to talk about "initialization", "definition" and "declaration". If you are talking about a function, for example, initialization does not mean much.

So, the answer is no: definition does not automatically mean declaration plus initialization.

Removing a list of characters in string

Why not a simple loop?

for i in replace_list:
    string = string.replace(i, '')

Also, avoid naming lists 'list'. It overrides the built-in function list.

Updating state on props change in React Form

componentWillReceiveProps is depcricated since react 16: use getDerivedStateFromProps instead

If I understand correctly, you have a parent component that is passing start_time down to the ModalBody component which assigns it to its own state? And you want to update that time from the parent, not a child component.

React has some tips on dealing with this scenario. (Note, this is an old article that has since been removed from the web. Here's a link to the current doc on component props).

Using props to generate state in getInitialState often leads to duplication of "source of truth", i.e. where the real data is. This is because getInitialState is only invoked when the component is first created.

Whenever possible, compute values on-the-fly to ensure that they don't get out of sync later on and cause maintenance trouble.

Basically, whenever you assign parent's props to a child's state the render method isn't always called on prop update. You have to invoke it manually, using the componentWillReceiveProps method.

componentWillReceiveProps(nextProps) {
  // You don't have to do this check first, but it can help prevent an unneeded render
  if (nextProps.startTime !== this.state.startTime) {
    this.setState({ startTime: nextProps.startTime });
  }
}

Angular - POST uploaded file

First, you have to create your own inline TS-Class, since the FormData Class is not well supported at the moment:

var data : {
  name: string;
  file: File;
} = {
  name: "Name",
  file: inputValue.files[0]
  };

Then you send it to the Server with JSON.stringify(data)

let opts: RequestOptions = new RequestOptions();
opts.method = RequestMethods.Post;
opts.headers = headers;
this.http.post(url,JSON.stringify(data),opts);

How can I access each element of a pair in a pair list?

Use tuple unpacking:

>>> pairs = [("a", 1), ("b", 2), ("c", 3)]
>>> for a, b in pairs:
...    print a, b
... 
a 1
b 2
c 3

See also: Tuple unpacking in for loops.

Best way to do a split pane in HTML

In the old days, you would use frames to achieve this. There are several reasons why this approach is not so good. See Reece's response to Why are HTML frames bad?. See also Jakob Nielson's Why Frames Suck (Most of the Time).

A somewhat newer approach is to use inline frames. This has pluses and minuses as well: Are iframes considered 'bad practice'?

An even better approach is to use fixed positioning. By placing the navigation content (e.g. the favorites links in your example) in a block element (like a div) then applying position:fixed to that element and setting the left, top and bottom properties like this:

#myNav {
    position: fixed;
    left: 0px;
    top: 0px;
    bottom: 0px;
    width: 200px;
}

... you will achieve a vertical column down the left side of the page that will not move when the user scrolls the page.

The rest of the content on the page will not "feel" the presence of this nav element, so it must take into account the 200px of space it occupies. You can do this by placing the rest for the content in another div and setting margin-left:200px;.

How to set cursor to input box in Javascript?

Sometimes you do get focus but no cursor in a text field. In this case you would do this:

document.getElementById(frmObj.id).select();

How do you write multiline strings in Go?

According to the language specification you can use a raw string literal, where the string is delimited by backticks instead of double quotes.

`line 1
line 2
line 3`

Parse HTML table to Python list?

If the HTML is not XML you can't do it with etree. But even then, you don't have to use an external library for parsing a HTML table. In python 3 you can reach your goal with HTMLParser from html.parser. I've the code of the simple derived HTMLParser class here in a github repo.

You can use that class (here named HTMLTableParser) the following way:

import urllib.request
from html_table_parser import HTMLTableParser

target = 'http://www.twitter.com'

# get website content
req = urllib.request.Request(url=target)
f = urllib.request.urlopen(req)
xhtml = f.read().decode('utf-8')

# instantiate the parser and feed it
p = HTMLTableParser()
p.feed(xhtml)
print(p.tables)

The output of this is a list of 2D-lists representing tables. It looks maybe like this:

[[['   ', ' Anmelden ']],
 [['Land', 'Code', 'Für Kunden von'],
  ['Vereinigte Staaten', '40404', '(beliebig)'],
  ['Kanada', '21212', '(beliebig)'],
  ...
  ['3424486444', 'Vodafone'],
  ['  Zeige SMS-Kurzwahlen für andere Länder ']]]

How to add buttons like refresh and search in ToolBar in Android?

Add this line at the top:

"xmlns:app="http://schemas.android.com/apk/res-auto"

and then use:

app:showasaction="ifroom"

PDF Parsing Using Python - extracting formatted and plain texts

That's a difficult problem to solve since visually similar PDFs may have a wildly differing structure depending on how they were produced. In the worst case the library would need to basically act like an OCR. On the other hand, the PDF may contain sufficient structure and metadata for easy removal of tables and figures, which the library can be tailored to take advantage of.

I'm pretty sure there are no open source tools which solve your problem for a wide variety of PDFs, but I remember having heard of commercial software claiming to do exactly what you ask for. I'm sure you'll run into them while googling.

No connection could be made because the target machine actively refused it 127.0.0.1:3446

You don't have to restart the PC. Restart IIS instead.

Run -> 'cmd'(as admin) and type "iisreset"

Print directly from browser without print popup window

This should work, I tried it by myself and it worked for me. If you pass True instead of false, the print dialog will appear.

this.print(false);

Add onclick event to newly added element in JavaScript

Not sure but try :

elemm.addEventListener('click', function(){ alert('blah');}, false);

spring PropertyPlaceholderConfigurer and context:property-placeholder

First, you don't need to define both of those locations. Just use classpath:config/properties/database.properties. In a WAR, WEB-INF/classes is a classpath entry, so it will work just fine.

After that, I think what you mean is you want to use Spring's schema-based configuration to create a configurer. That would go like this:

<context:property-placeholder location="classpath:config/properties/database.properties"/>

Note that you don't need to "ignoreResourceNotFound" anymore. If you need to define the properties separately using util:properties:

<context:property-placeholder properties-ref="jdbcProperties" ignore-resource-not-found="true"/>

There's usually not any reason to define them separately, though.

Erase whole array Python

It's simple:

array = []

will set array to be an empty list. (They're called lists in Python, by the way, not arrays)

If that doesn't work for you, edit your question to include a code sample that demonstrates your problem.

Output PowerShell variables to a text file

The simple solution is to avoid creating an array before piping to Out-File. Rule #1 of PowerShell is that the comma is a special delimiter, and the default behavior is to create an array. Concatenation is done like this.

$computer + "," + $Speed + "," + $Regcheck | out-file -filepath C:\temp\scripts\pshell\dump.txt -append -width 200

This creates an array of three items.

$computer,$Speed,$Regcheck
FYKJ
100
YES

vs. concatenation of three items separated by commas.

$computer + "," + $Speed + "," + $Regcheck
FYKJ,100,YES

How to uninstall a Windows Service when there is no executable for it left on the system?

My favourite way of doing this is to use Sysinternals Autoruns application. Just select the service and press delete.

How to disable HTML links

you cannot disable a link, if you want that click event should not fire then simply Remove the action from that link.

$(td).find('a').attr('href', '');

For More Info :- Elements that can be Disabled

Create File If File Does Not Exist

private List<Url> AddURLToFile(Urls urls, Url url)
{
    string filePath = @"D:\test\file.json";
    urls.UrlList.Add(url);

    //if (!System.IO.File.Exists(filePath))
    //    using (System.IO.File.Delete(filePath));

    System.IO.File.WriteAllText(filePath, JsonConvert.SerializeObject(urls.UrlList));

    //using (StreamWriter sw = (System.IO.File.Exists(filePath)) ? System.IO.File.AppendText(filePath) : System.IO.File.CreateText(filePath))
    //{
    //    sw.WriteLine(JsonConvert.SerializeObject(urls.UrlList));
    //}
    return urls.UrlList;
}

private List<Url> ReadURLToFile()
{
    //  string filePath = Path.Combine(Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location), @"App_Data\file.json");
    string filePath = @"D:\test\file.json";

    List<Url> result = new List<Url>(); ;
    if (!System.IO.File.Exists(filePath))
        using (System.IO.File.CreateText(filePath)) ;



    using (StreamReader file = new StreamReader(filePath))
    {
        result = JsonConvert.DeserializeObject<List<Url>>(file.ReadToEnd());
        file.Close();
    }
    if (result == null)
        result = new List<Url>();

    return result;

}

How to tell if a <script> tag failed to load

my working clean solution (2017)

function loaderScript(scriptUrl){
   return new Promise(function (res, rej) {
    let script = document.createElement('script');
    script.src = scriptUrl;
    script.type = 'text/javascript';
    script.onError = rej;
    script.async = true;
    script.onload = res;
    script.addEventListener('error',rej);
    script.addEventListener('load',res);
    document.head.appendChild(script);
 })

}

As Martin pointed, used like that:

const event = loaderScript("myscript.js")
  .then(() => { console.log("loaded"); })
  .catch(() => { console.log("error"); });

OR

try{
 await loaderScript("myscript.js")
 console.log("loaded"); 
}catch{
 console.log("error");
}

Remove duplicates from a list of objects based on property in Java 8

Another version which is simple

BiFunction<TreeSet<Employee>,List<Employee> ,TreeSet<Employee>> appendTree = (y,x) -> (y.addAll(x))? y:y;

TreeSet<Employee> outputList = appendTree.apply(new TreeSet<Employee>(Comparator.comparing(p->p.getId())),personList);

Is it valid to define functions in JSON results?

The problem is that JSON as a data definition language evolved out of JSON as a JavaScript Object Notation. Since Javascript supports eval on JSON, it is legitimate to put JSON code inside JSON (in that use-case). If you're using JSON to pass data remotely, then I would say it is bad practice to put methods in the JSON because you may not have modeled your client-server interaction well. And, further, when wishing to use JSON as a data description language I would say you could get yourself into trouble by embedding methods because some JSON parsers were written with only data description in mind and may not support method definitions in the structure.

Wikipedia JSON entry makes a good case for not including methods in JSON, citing security concerns:

Unless you absolutely trust the source of the text, and you have a need to parse and accept text that is not strictly JSON compliant, you should avoid eval() and use JSON.parse() or another JSON specific parser instead. A JSON parser will recognize only JSON text and will reject other text, which could contain malevolent JavaScript. In browsers that provide native JSON support, JSON parsers are also much faster than eval. It is expected that native JSON support will be included in the next ECMAScript standard.

TypeError: 'function' object is not subscriptable - Python

It is so simple, you have 2 objects with the same name and when you say: bank_holiday[month] python thinks you wanna run your function and got ERROR.

Just rename your array to bank_holidays <--- add a 's' at the end! like this:

bank_holidays= [1, 0, 1, 1, 2, 0, 0, 1, 0, 0, 0, 2] #gives the list of bank holidays in each month

def bank_holiday(month):
   if month <1 or month > 12:
       print("Error: Out of range")
       return
   print(bank_holidays[month-1],"holiday(s) in this month ")

bank_holiday(int(input("Which month would you like to check out: ")))

jQuery: Best practice to populate drop down?

I've read that using document fragments is performant because it avoids page reflow upon each insertion of DOM element, it's also well supported by all browsers (even IE 6).

_x000D_
_x000D_
var fragment = document.createDocumentFragment();_x000D_
_x000D_
$.each(result, function() {_x000D_
  fragment.appendChild($("<option />").val(this.ImageFolderID).text(this.Name)[0]);_x000D_
});_x000D_
_x000D_
$("#options").append(fragment);
_x000D_
_x000D_
_x000D_

I first read about this in CodeSchool's JavaScript Best Practices course.

Here's a comparison of different approaches, thanks go to the author.

Thymeleaf using path variables to th:href

I was trying to go through a list of objects, display them as rows in a table, with each row being a link. This worked for me. Hope it helps.

// CUSTOMER_LIST is a model attribute
<table>
    <th:block th:each="customer : ${CUSTOMER_LIST}">
        <tr>
            <td><a th:href="@{'/main?id=' + ${customer.id}}" th:text="${customer.fullName}" /></td>
        </tr>
    </th:block>
</table>

What uses are there for "placement new"?

Script engines can use it in the native interface to allocate native objects from scripts. See Angelscript (www.angelcode.com/angelscript) for examples.

What is %2C in a URL?

Check out http://www.asciitable.com/

Look at the Hx, (Hex) column; 2C maps to ,

Any unusual encoding can be checked this way

+----+-----+----+-----+----+-----+----+-----+
| Hx | Chr | Hx | Chr | Hx | Chr | Hx | Chr |
+----+-----+----+-----+----+-----+----+-----+
| 00 | NUL | 20 | SPC | 40 |  @  | 60 |  `  |
| 01 | SOH | 21 |  !  | 41 |  A  | 61 |  a  |
| 02 | STX | 22 |  "  | 42 |  B  | 62 |  b  |
| 03 | ETX | 23 |  #  | 43 |  C  | 63 |  c  |
| 04 | EOT | 24 |  $  | 44 |  D  | 64 |  d  |
| 05 | ENQ | 25 |  %  | 45 |  E  | 65 |  e  |
| 06 | ACK | 26 |  &  | 46 |  F  | 66 |  f  |
| 07 | BEL | 27 |  '  | 47 |  G  | 67 |  g  |
| 08 | BS  | 28 |  (  | 48 |  H  | 68 |  h  |
| 09 | TAB | 29 |  )  | 49 |  I  | 69 |  i  |
| 0A | LF  | 2A |  *  | 4A |  J  | 6A |  j  |
| 0B | VT  | 2B |  +  | 4B |  K  | 6B |  k  |
| 0C | FF  | 2C |  ,  | 4C |  L  | 6C |  l  |
| 0D | CR  | 2D |  -  | 4D |  M  | 6D |  m  |
| 0E | SO  | 2E |  .  | 4E |  N  | 6E |  n  |
| 0F | SI  | 2F |  /  | 4F |  O  | 6F |  o  |
| 10 | DLE | 30 |  0  | 50 |  P  | 70 |  p  |
| 11 | DC1 | 31 |  1  | 51 |  Q  | 71 |  q  |
| 12 | DC2 | 32 |  2  | 52 |  R  | 72 |  r  |
| 13 | DC3 | 33 |  3  | 53 |  S  | 73 |  s  |
| 14 | DC4 | 34 |  4  | 54 |  T  | 74 |  t  |
| 15 | NAK | 35 |  5  | 55 |  U  | 75 |  u  |
| 16 | SYN | 36 |  6  | 56 |  V  | 76 |  v  |
| 17 | ETB | 37 |  7  | 57 |  W  | 77 |  w  |
| 18 | CAN | 38 |  8  | 58 |  X  | 78 |  x  |
| 19 | EM  | 39 |  9  | 59 |  Y  | 79 |  y  |
| 1A | SUB | 3A |  :  | 5A |  Z  | 7A |  z  |
| 1B | ESC | 3B |  ;  | 5B |  [  | 7B |  {  |
| 1C | FS  | 3C |  <  | 5C |  \  | 7C |  |  |
| 1D | GS  | 3D |  =  | 5D |  ]  | 7D |  }  |
| 1E | RS  | 3E |  >  | 5E |  ^  | 7E |  ~  |
| 1F | US  | 3F |  ?  | 5F |  _  | 7F | DEL |
+----+-----+----+-----+----+-----+----+-----+

VBA ADODB excel - read data from Recordset

I am surprised that the connection string works for you, because it is missing a semi-colon. Set is only used with objects, so you would not say Set strNaam.

Set cn = CreateObject("ADODB.Connection")
With cn
 .Provider = "Microsoft.Jet.OLEDB.4.0"
  .ConnectionString = "Data Source=D:\test.xls " & _
  ";Extended Properties=""Excel 8.0;HDR=Yes;"""
.Open
End With
strQuery = "SELECT * FROM [Sheet1$E36:E38]"
Set rs = cn.Execute(strQuery)
Do While Not rs.EOF
  For i = 0 To rs.Fields.Count - 1
    Debug.Print rs.Fields(i).Name, rs.Fields(i).Value
    strNaam = rs.Fields(0).Value
  Next
  rs.MoveNext
Loop
rs.Close

There are other ways, depending on what you want to do, such as GetString (GetString Method Description).

MySQL - ERROR 1045 - Access denied

If you actually have set a root password and you've just lost/forgotten it:

  1. Stop MySQL
  2. Restart it manually with the skip-grant-tables option: mysqld_safe --skip-grant-tables

  3. Now, open a new terminal window and run the MySQL client: mysql -u root

  4. Reset the root password manually with this MySQL command: UPDATE mysql.user SET Password=PASSWORD('password') WHERE User='root'; If you are using MySQL 5.7 (check using mysql --version in the Terminal) then the command is:

    UPDATE mysql.user SET authentication_string=PASSWORD('password')  WHERE  User='root';
    
  5. Flush the privileges with this MySQL command: FLUSH PRIVILEGES;

From http://www.tech-faq.com/reset-mysql-password.shtml

(Maybe this isn't what you need, Abs, but I figure it could be useful for people stumbling across this question in the future)

How to do "If Clicked Else .."

You may actually mean hovering the element by not clicking, right?

jQuery('#id').click(function()
{
    // execute on click
}).hover(function()
{
    // execute on hover
});

Clarify your question then we'll be able to understand better.

Simply if an element isn't being clicked on, do a setInterval to continue the process until clicked.

var checkClick = setInterval(function()
{
    // do something when the element hasn't been clicked yet
}, 2000); // every 2 seconds

jQuery('#id').click(function()
{
    clearInterval(checkClick); // this is optional, but it will
                               // clear the interval once the element
                               // has been clicked on

    // do something else
})

Truncating long strings with CSS: feasible yet?

OK, Firefox 7 implemented text-overflow: ellipsis as well as text-overflow: "string". Final release is planned for 2011-09-27.

What is the difference between window, screen, and document in Javascript?

Window is the main JavaScript object root, aka the global object in a browser, also can be treated as the root of the document object model. You can access it as window

window.screen or just screen is a small information object about physical screen dimensions.

window.document or just document is the main object of the potentially visible (or better yet: rendered) document object model/DOM.

Since window is the global object you can reference any properties of it with just the property name - so you do not have to write down window. - it will be figured out by the runtime.

Chrome/jQuery Uncaught RangeError: Maximum call stack size exceeded

You can also get this error when you have an infinite loop. Make sure that you don't have any unending, recursive self references.

iPhone Navigation Bar Title text color

I am using below code for the iOS 9 and its working fine for me. I have also use shadow color for the title.

self.navigationItem.title = @"MY NAV TITLE";
self.navigationController.navigationBar.barTintColor = [UIColor redColor];
self.navigationController.navigationBar.translucent = NO;
NSShadow *shadow = [[NSShadow alloc] init];
shadow.shadowColor = [UIColor colorWithRed:0.0 green:0.0 blue:0.0 alpha:0.8];
shadow.shadowOffset = CGSizeMake(0, 1);
[self.navigationController.navigationBar setTitleTextAttributes: [NSDictionary dictionaryWithObjectsAndKeys:
                                                       [UIColor colorWithRed:245.0/255.0 green:245.0/255.0 blue:245.0/255.0 alpha:1.0], NSForegroundColorAttributeName,
                                                       shadow, NSShadowAttributeName,
                                                       [UIFont fontWithName:@"HelveticaNeue-Light" size:21.0], NSFontAttributeName, nil]];

May this help you.

Thanks

How to set cookie in node js using express framework?

Not exactly answering your question, but I came across your question, while looking for an answer to an issue that I had. Maybe it will help somebody else.

My issue was that cookies were set in server response, but were not saved by the browser.

The server response came back with cookies set:

Set-Cookie:my_cookie=HelloWorld; Path=/; Expires=Wed, 15 Mar 2017 15:59:59 GMT 

This is how I solved it.

I used fetch in the client-side code. If you do not specify credentials: 'include' in the fetch options, cookies are neither sent to server nor saved by the browser, even though the server response sets cookies.

Example:

var headers = new Headers();
headers.append('Content-Type', 'application/json');
headers.append('Accept', 'application/json');

return fetch('/your/server_endpoint', {
    method: 'POST',
    mode: 'same-origin',
    redirect: 'follow',
    credentials: 'include', // Don't forget to specify this if you need cookies
    headers: headers,
    body: JSON.stringify({
        first_name: 'John',
        last_name: 'Doe'
    })
})

I hope this helps somebody.

Reverse for '*' with arguments '()' and keyword arguments '{}' not found

There are 3 things I can think of off the top of my head:

  1. Just used named urls, it's more robust and maintainable anyway
  2. Try using django.core.urlresolvers.reverse at the command line for a (possibly) better error

    >>> from django.core.urlresolvers import reverse
    >>> reverse('products.views.filter_by_led')
    
  3. Check to see if you have more than one url that points to that view

(WAMP/XAMP) send Mail using SMTP localhost

If any one of you are getting error like following after following answer given by Afwe Wef

 Warning: mail() [<a href='function.mail'>function.mail</a>]: SMTP server response:

 550 The address is not valid. in c:\wamp\www\email.php

Go to php.ini

; For Win32 only.
; http://php.net/sendmail-from
sendmail_from = [email protected]

Enter [email protected] as your email id which you used to configure the hMailserver in front of sendmail_from .

your problem will be solved.

Tested on Wamp server2.2(Apache 2.2.22, php 5.3.13) on windows 8

If you are also getting following error

"APPLICATION"   6364    "2014-03-24 13:13:33.979"   "SMTPDeliverer - Message 2: Relaying to host smtp.gmail.com."
"APPLICATION"   6364    "2014-03-24 13:13:34.415"   "SMTPDeliverer - Message 2: Message could not be delivered. Scheduling it for later delivery in 60 minutes."
"APPLICATION"   6364    "2014-03-24 13:13:34.430"   "SMTPDeliverer - Message 2: Message delivery thread completed."

You might have forgot to change the port from 25 to 465

Simple post to Web Api

It's been quite sometime since I asked this question. Now I understand it more clearly, I'm going to put a more complete answer to help others.

In Web API, it's very simple to remember how parameter binding is happening.

  • if you POST simple types, Web API tries to bind it from the URL
  • if you POST complex type, Web API tries to bind it from the body of the request (this uses a media-type formatter).

  • If you want to bind a complex type from the URL, you'll use [FromUri] in your action parameter. The limitation of this is down to how long your data going to be and if it exceeds the url character limit.

    public IHttpActionResult Put([FromUri] ViewModel data) { ... }

  • If you want to bind a simple type from the request body, you'll use [FromBody] in your action parameter.

    public IHttpActionResult Put([FromBody] string name) { ... }

as a side note, say you are making a PUT request (just a string) to update something. If you decide not to append it to the URL and pass as a complex type with just one property in the model, then the data parameter in jQuery ajax will look something like below. The object you pass to data parameter has only one property with empty property name.

var myName = 'ABC';
$.ajax({url:.., data: {'': myName}});

and your web api action will look something like below.

public IHttpActionResult Put([FromBody] string name){ ... }

This asp.net page explains it all. http://www.asp.net/web-api/overview/formats-and-model-binding/parameter-binding-in-aspnet-web-api

Loop structure inside gnuplot?

Here is the alternative command:

gnuplot -p -e 'plot for [file in system("find . -name \\*.txt -depth 1")] file using 1:2 title file with lines'

How do I get the last inserted ID of a MySQL table in PHP?

there is a function to know what was the last id inserted in the current connection

mysql_query('INSERT INTO FOO(a) VALUES(\'b\')');
$id = mysql_insert_id();

plus using max is a bad idea because it could lead to problems if your code is used at same time in two different sessions.

That function is called mysql_insert_id

How do I extract specific 'n' bits of a 32-bit unsigned integer in C?

#define GENERAL__GET_BITS_FROM_U8(source,lsb,msb) \
    ((uint8_t)((source) & \
        ((uint8_t)(((uint8_t)(0xFF >> ((uint8_t)(7-((uint8_t)(msb) & 7))))) & \
             ((uint8_t)(0xFF << ((uint8_t)(lsb) & 7)))))))

#define GENERAL__GET_BITS_FROM_U16(source,lsb,msb) \
    ((uint16_t)((source) & \
        ((uint16_t)(((uint16_t)(0xFFFF >> ((uint8_t)(15-((uint8_t)(msb) & 15))))) & \
            ((uint16_t)(0xFFFF << ((uint8_t)(lsb) & 15)))))))

#define GENERAL__GET_BITS_FROM_U32(source,lsb,msb) \
    ((uint32_t)((source) & \
        ((uint32_t)(((uint32_t)(0xFFFFFFFF >> ((uint8_t)(31-((uint8_t)(msb) & 31))))) & \
            ((uint32_t)(0xFFFFFFFF << ((uint8_t)(lsb) & 31)))))))

Easy interview question got harder: given numbers 1..100, find the missing number(s) given exactly k are missing

Lets say an ArrayList object(myList) is filled with those numbers and in that, 2 numbers x and y are missing.So the possible solution can be:

int k = 1;
        while (k < 100) {
            if (!myList.contains(k)) {
                System.out.println("Missing No:" + k);
            }
            k++;
        }

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

A very quick and painless way is to use the rimraf npm utility, install it globally first:

> npm i rimraf -g

And then the command from your project root is quite simple (which can be saved to a script file):

projectRoot> rimraf **/bin **/obj

To optimize the desired effect you can leverage the project event targets (the one you could use is BeforeRebuild and make it run the previous command) which are specified in the docs: https://docs.microsoft.com/en-us/visualstudio/msbuild/how-to-extend-the-visual-studio-build-process?view=vs-2017

I like the rimraf utility as it is crossplat and really quick. But, you can also use the RemoveDir command in the .csproj if you decide to go with the target event option. The RemoveDir approach was well explained in another answer here by @Shaman: https://stackoverflow.com/a/22306653/1534753

How to count number of records per day?

select DateAdded, count(CustID)
from tbl
group by DateAdded

about 7-days interval it's DB-depending question

What does "app.run(host='0.0.0.0') " mean in Flask

To answer to your second question. You can just hit the IP address of the machine that your flask app is running, e.g. 192.168.1.100 in a browser on different machine on the same network and you are there. Though, you will not be able to access it if you are on a different network. Firewalls or VLans can cause you problems with reaching your application. If that computer has a public IP, then you can hit that IP from anywhere on the planet and you will be able to reach the app. Usually this might impose some configuration, since most of the public servers are behind some sort of router or firewall.

Django -- Template tag in {% if %} block

{% for source in sources %}
  <tr>
    <td>{{ source }}</td>
    <td>
      {% ifequal title source %}
        Just now!
      {% endifequal %}
    </td>
  </tr>
{% endfor %}

                or


{% for source in sources %}
      <tr>
        <td>{{ source }}</td>
        <td>
          {% if title == source %}
            Just now!
          {% endif %}
        </td>
      </tr>
    {% endfor %}

See Django Doc

rsync error: failed to set times on "/foo/bar": Operation not permitted

The problem in my case was that the "receiver mountpoint" was incorrectly mounted. It was in read-only mode (for some extrange reason). It looked like rsync was copying the files, but it was not. I checked my fstab file and changed mount options to default, re-mount file system and execute rsync again. All fine then.

Get the _id of inserted document in Mongo database in NodeJS

@JSideris, sample code for getting insertedId.

db.collection(COLLECTION).insertOne(data, (err, result) => {
    if (err) 
      return err;
    else 
      return result.insertedId;
  });

Removing unwanted table cell borders with CSS

Set the cellspacing attribute of the table to 0.

You can also use the CSS style, border-spacing: 0, but only if you don't need to support older versions of IE.

Anaconda version with Python 3.5

Per this announcement, Anaconda upgraded to Python 3.6 starting with version 4.3, so... you probably want the 4.2.0 package from the installer archive.

Eclipse won't compile/run java file

This worked for me:

  1. Create a new project
  2. Create a class in it
  3. Add erroneous code, let error come
  4. Now go to your project
  5. Go to Problems window
  6. Double click on a error

It starts showing compilation errors in the code.

php form action php self

This is Perfect. try this one :)

<form name="test" method="post" enctype="multipart/form-data" action="<?php echo $_SERVER['PHP_SELF']; ?>">
/* Html Input Fields */
</form>  

resource error in android studio after update: No Resource Found

if you have :

/Users/james/Development/AndroidProjects/myapp/app/build/intermediates/exploded-aar/com.android.support/appcompat-v7/23.0.0/res/values-v23/values-v23.xml
Error:(2) Error retrieving parent for item: No resource found that matches the given name 'android:TextAppearance.Material.Widget.Button.Inverse'.
Error:(2) Error retrieving parent for item: No resource found that matches the given name 'android:Widget.Material.Button.Colored'.

error , you must change your appcompat , buildtools , sdk to 23 but , if you don't like to change it and must be in 22 do this :

  • compile 23
  • target 22

ld.exe: cannot open output file ... : Permission denied

I had the same behaviour, and fixed it by running Code::Blocks as administrator.

How to save the output of a console.log(object) to a file?

right click on console.. click save as.. its this simple.. you'll get an output text file

wait process until all subprocess finish?

subprocess.call

Automatically waits , you can also use:

p1.wait()

The Response content must be a string or object implementing __toString(), "boolean" given after move to psql

It is being pointed out not directly in the file which is caused the error. But it is actually triggered in a controller file. It happens when a return value from a method defined inside in a controller file is set on a boolean value. It must not be set on a boolean type but on the other hand, it must be set or given a value of a string type. It can be shown as follows :

public function saveFormSummary(Request $request) {
      ... 
      $status = true;
      return $status;
}

Given the return value of a boolean type above in a method, to be able to solve the problem to handle the error specified. Just change the type of the return value into a string type

as follows :

public function saveFormSummary(Request $request) {
      ... 
      $status = "true";
      return $status;
}

how to move elasticsearch data from one server to another

The selected answer makes it sound slightly more complex than it is, the following is what you need (install npm first on your system).

npm install -g elasticdump
elasticdump --input=http://mysrc.com:9200/my_index --output=http://mydest.com:9200/my_index --type=mapping
elasticdump --input=http://mysrc.com:9200/my_index --output=http://mydest.com:9200/my_index --type=data

You can skip the first elasticdump command for subsequent copies if the mappings remain constant.

I have just done a migration from AWS to Qbox.io with the above without any problems.

More details over at:

https://www.npmjs.com/package/elasticdump

Help page (as of Feb 2016) included for completeness:

elasticdump: Import and export tools for elasticsearch

Usage: elasticdump --input SOURCE --output DESTINATION [OPTIONS]

--input
                    Source location (required)
--input-index
                    Source index and type
                    (default: all, example: index/type)
--output
                    Destination location (required)
--output-index
                    Destination index and type
                    (default: all, example: index/type)
--limit
                    How many objects to move in bulk per operation
                    limit is approximate for file streams
                    (default: 100)
--debug
                    Display the elasticsearch commands being used
                    (default: false)
--type
                    What are we exporting?
                    (default: data, options: [data, mapping])
--delete
                    Delete documents one-by-one from the input as they are
                    moved.  Will not delete the source index
                    (default: false)
--searchBody
                    Preform a partial extract based on search results
                    (when ES is the input,
                    (default: '{"query": { "match_all": {} } }'))
--sourceOnly
                    Output only the json contained within the document _source
                    Normal: {"_index":"","_type":"","_id":"", "_source":{SOURCE}}
                    sourceOnly: {SOURCE}
                    (default: false)
--all
                    Load/store documents from ALL indexes
                    (default: false)
--bulk
                    Leverage elasticsearch Bulk API when writing documents
                    (default: false)
--ignore-errors
                    Will continue the read/write loop on write error
                    (default: false)
--scrollTime
                    Time the nodes will hold the requested search in order.
                    (default: 10m)
--maxSockets
                    How many simultaneous HTTP requests can we process make?
                    (default:
                      5 [node <= v0.10.x] /
                      Infinity [node >= v0.11.x] )
--bulk-mode
                    The mode can be index, delete or update.
                    'index': Add or replace documents on the destination index.
                    'delete': Delete documents on destination index.
                    'update': Use 'doc_as_upsert' option with bulk update API to do partial update.
                    (default: index)
--bulk-use-output-index-name
                    Force use of destination index name (the actual output URL)
                    as destination while bulk writing to ES. Allows
                    leveraging Bulk API copying data inside the same
                    elasticsearch instance.
                    (default: false)
--timeout
                    Integer containing the number of milliseconds to wait for
                    a request to respond before aborting the request. Passed
                    directly to the request library. If used in bulk writing,
                    it will result in the entire batch not being written.
                    Mostly used when you don't care too much if you lose some
                    data when importing but rather have speed.
--skip
                    Integer containing the number of rows you wish to skip
                    ahead from the input transport.  When importing a large
                    index, things can go wrong, be it connectivity, crashes,
                    someone forgetting to `screen`, etc.  This allows you
                    to start the dump again from the last known line written
                    (as logged by the `offset` in the output).  Please be
                    advised that since no sorting is specified when the
                    dump is initially created, there's no real way to
                    guarantee that the skipped rows have already been
                    written/parsed.  This is more of an option for when
                    you want to get most data as possible in the index
                    without concern for losing some rows in the process,
                    similar to the `timeout` option.
--inputTransport
                    Provide a custom js file to us as the input transport
--outputTransport
                    Provide a custom js file to us as the output transport
--toLog
                    When using a custom outputTransport, should log lines
                    be appended to the output stream?
                    (default: true, except for `$`)
--help
                    This page

Examples:

# Copy an index from production to staging with mappings:
elasticdump \
  --input=http://production.es.com:9200/my_index \
  --output=http://staging.es.com:9200/my_index \
  --type=mapping
elasticdump \
  --input=http://production.es.com:9200/my_index \
  --output=http://staging.es.com:9200/my_index \
  --type=data

# Backup index data to a file:
elasticdump \
  --input=http://production.es.com:9200/my_index \
  --output=/data/my_index_mapping.json \
  --type=mapping
elasticdump \
  --input=http://production.es.com:9200/my_index \
  --output=/data/my_index.json \
  --type=data

# Backup and index to a gzip using stdout:
elasticdump \
  --input=http://production.es.com:9200/my_index \
  --output=$ \
  | gzip > /data/my_index.json.gz

# Backup ALL indices, then use Bulk API to populate another ES cluster:
elasticdump \
  --all=true \
  --input=http://production-a.es.com:9200/ \
  --output=/data/production.json
elasticdump \
  --bulk=true \
  --input=/data/production.json \
  --output=http://production-b.es.com:9200/

# Backup the results of a query to a file
elasticdump \
  --input=http://production.es.com:9200/my_index \
  --output=query.json \
  --searchBody '{"query":{"term":{"username": "admin"}}}'

------------------------------------------------------------------------------
Learn more @ https://github.com/taskrabbit/elasticsearch-dump`enter code here`

Changing default encoding of Python?

If you get this error when you try to pipe/redirect output of your script

UnicodeEncodeError: 'ascii' codec can't encode characters in position 0-5: ordinal not in range(128)

Just export PYTHONIOENCODING in console and then run your code.

export PYTHONIOENCODING=utf8

Java 8 method references: provide a Supplier capable of supplying a parameterized result

optionalUsers.orElseThrow(() -> new UsernameNotFoundException("Username not found"));

C++ callback using class member

If you have callbacks with different parameters you can use templates as follows:
// compile with: g++ -std=c++11 myTemplatedCPPcallbacks.cpp -o myTemplatedCPPcallbacksApp

#include <functional>     // c++11

#include <iostream>        // due to: cout


using std::cout;
using std::endl;

class MyClass
{
    public:
        MyClass();
        static void Callback(MyClass* instance, int x);
    private:
        int private_x;
};

class OtherClass
{
    public:
        OtherClass();
        static void Callback(OtherClass* instance, std::string str);
    private:
        std::string private_str;
};

class EventHandler
{

    public:
        template<typename T, class T2>
        void addHandler(T* owner, T2 arg2)
        {
            cout << "\nHandler added..." << endl;
            //Let's pretend an event just occured
            owner->Callback(owner, arg2);
         }   

};

MyClass::MyClass()
{
    EventHandler* handler;
    private_x = 4;
    handler->addHandler(this, private_x);
}

OtherClass::OtherClass()
{
    EventHandler* handler;
    private_str = "moh ";
    handler->addHandler(this, private_str );
}

void MyClass::Callback(MyClass* instance, int x)
{
    cout << " MyClass::Callback(MyClass* instance, int x) ==> " 
         << 6 + x + instance->private_x << endl;
}

void OtherClass::Callback(OtherClass* instance, std::string private_str)
{
    cout << " OtherClass::Callback(OtherClass* instance, std::string private_str) ==> " 
         << " Hello " << instance->private_str << endl;
}

int main(int argc, char** argv)
{
    EventHandler* handler;
    handler = new EventHandler();
    MyClass* myClass = new MyClass();
    OtherClass* myOtherClass = new OtherClass();
}

How to open this .DB file?

I don't think there is a way to tell which program to use from just the .db extension. It could even be an encrypted database which can't be opened. You can MS Access, or a sqlite manager.

Edit: Try to rename the file to .txt and open it with a text editor. The first couple of words in the file could tell you the DB Type.

If it is a SQLite database, it will start with "SQLite format 3"

How to create a HTML Cancel button that redirects to a URL

There is no button type="cancel" in html. You can try like this

<a href="http://www.url.com/yourpage.php">Cancel</a>

You can make it look like a button by using CSS style properties.

Easy way to password-protect php page

I would simply look for a $_GET variable and redirect the user if it's not correct.

<?php
$pass = $_GET['pass'];
if($pass != 'my-secret-password') {
  header('Location: http://www.staggeringbeauty.com/');
}
?>

Now, if this page is located at say: http://example.com/secrets/files.php

You can now access it with: http://example.com/secrets/files.php?pass=my-secret-password Keep in mind that this isn't the most efficient or secure way, but nonetheless it is a easy and fast way. (Also, I know my answer is outdated but someone else looking at this question may find it valuable)

java.util.zip.ZipException: duplicate entry during packageAllDebugClassesForMultiDex

I tried all the above solutions but not working for me. I tried update libraries by goto project structure > app. And it works for me! Hope this answer helpful to someone.

jQuery - adding elements into an array

var ids = [];

    $(document).ready(function($) {    
    $(".color_cell").bind('click', function() {
        alert('Test');

        ids.push(this.id);       
    });
});

What's the difference between 'r+' and 'a+' when open file in python?

If you have used them in C, then they are almost same as were in C.

From the manpage of fopen() function : -

  • r+ : - Open for reading and writing. The stream is positioned at the beginning of the file.

  • a+ : - Open for reading and writing. The file is created if it does not exist. The stream is positioned at the end of the file. Subse- quent writes to the file will always end up at the then current end of file, irrespective of any intervening fseek(3) or similar.

set the width of select2 input (through Angular-ui directive)

In my case the select2 would open correctly if there was zero or more pills.

But if there was one or more pills, and I deleted them all, it would shrink to the smallest width. My solution was simply:

$("#myselect").select2({ width: '100%' });      

JPanel vs JFrame in Java

JFrame is the window; it can have one or more JPanel instances inside it. JPanel is not the window.

You need a Swing tutorial:

http://docs.oracle.com/javase/tutorial/uiswing/

Removing All Items From A ComboBox?

Best Way:

Combobox1.items.clear();

batch file Copy files with certain extensions from multiple directories into one directory

Brandon, short and sweet. Also flexible.

set dSource=C:\Main directory\sub directory
set dTarget=D:\Documents
set fType=*.doc
for /f "delims=" %%f in ('dir /a-d /b /s "%dSource%\%fType%"') do (
    copy /V "%%f" "%dTarget%\" 2>nul
)

Hope this helps.

I would add some checks after the copy (using '||') but i'm not sure how "copy /v" reacts when it encounters an error.

you may want to try this:

copy /V "%%f" "%dTarget%\" 2>nul|| echo En error occured copying "%%F".&& exit /b 1

As the copy line. let me know if you get something out of it (in no position to test a copy failure atm..)

How to add a delay for a 2 or 3 seconds

You could use Thread.Sleep() function, e.g.

int milliseconds = 2000;
Thread.Sleep(milliseconds);

that completely stops the execution of the current thread for 2 seconds.

Probably the most appropriate scenario for Thread.Sleep is when you want to delay the operations in another thread, different from the main e.g. :

 MAIN THREAD        --------------------------------------------------------->
 (UI, CONSOLE ETC.)      |                                      |
                         |                                      |
 OTHER THREAD            ----- ADD A DELAY (Thread.Sleep) ------>

For other scenarios (e.g. starting operations after some time etc.) check Cody's answer.

Get current date, given a timezone in PHP?

<?php
date_default_timezone_set('GMT-5');//Set New York timezone
$today = date("F j, Y")
?>

matplotlib does not show my drawings although I call pyplot.show()

Just type:

plt.ion()

See https://www.youtube.com/watch?v=1zmV8lZsHF4 at 23:30 !

plt is used because of my import: import matplotlib.pyplot as plt

I'm using python2.7 on a mac with iTerm2.

Cross-browser window resize event - JavaScript / jQuery

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

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

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

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

Here is the function for completeness.

(function($,sr){

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

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

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

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

})(jQuery,'smartresize');


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

Cannot get to $rootScope

You can not ask for instance during configuration phase - you can ask only for providers.

var app = angular.module('modx', []);

// configure stuff
app.config(function($routeProvider, $locationProvider) {
  // you can inject any provider here
});

// run blocks
app.run(function($rootScope) {
  // you can inject any instance here
});

See http://docs.angularjs.org/guide/module for more info.

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

There are tons of sample code online as to how to do this.

Here is just one example of how to do this: http://geekswithblogs.net/dotNETvinz/archive/2009/04/30/creating-a-simple-registration-form-in-asp.net.aspx

you define the text boxes between the following tag:

<form id="form1" runat="server"> 

you create your textboxes and define them to runat="server" like so:

<asp:TextBox ID="TxtName" runat="server"></asp:TextBox>

define a button to process your logic like so (notice the onclick):

<asp:Button ID="Button1" runat="server" Text="Save" onclick="Button1_Click" />

in the code behind, you define what you want the server to do if the user clicks on the button by defining a method named

protected void Button1_Click(object sender, EventArgs e)

or you could just double click the button in the design view.

Here is a very quick sample of code to insert into a table in the button click event (codebehind)

protected void Button1_Click(object sender, EventArgs e)
{
   string name = TxtName.Text; // Scrub user data

   string connString = ConfigurationManager.ConnectionStrings["yourconnstringInWebConfig"].ConnectionString;
   SqlConnection conn = null;
   try
   {
          conn = new SqlConnection(connString);
          conn.Open();

          using(SqlCommand cmd = new SqlCommand())
          {
                 cmd.Conn = conn;
                 cmd.CommandType = CommandType.Text;
                 cmd.CommandText = "INSERT INTO dummyTable(name) Values (@var)";
                 cmd.Parameters.AddWithValue("@var", name);
                 int rowsAffected = cmd.ExecuteNonQuery();
                 if(rowsAffected ==1)
                 {
                        //Success notification
                 }
                 else
                 {
                        //Error notification
                 }
          }
   }
   catch(Exception ex)
   {
          //log error 
          //display friendly error to user
   }
   finally
   {
          if(conn!=null)
          {
                 //cleanup connection i.e close 
          }
   }
}

How to comment in Vim's config files: ".vimrc"?

"This is a comment in vimrc. It does not have a closing quote 

Source: http://vim.wikia.com/wiki/Backing_up_and_commenting_vimrc