Programs & Examples On #Ddl

Data Definition Language is a subset of SQL to manipulate structural elements of a database, not the content of tables. CREATE, DROP, ALTER and related statements.

Sqlite primary key on multiple columns

Basic :

CREATE TABLE table1 (
    columnA INTEGER NOT NULL,
    columnB INTEGER NOT NULL,
    PRIMARY KEY (columnA, columnB)
);

If your columns are foreign keys of other tables (common case) :

CREATE TABLE table1 (
    table2_id INTEGER NOT NULL,
    table3_id INTEGER NOT NULL,
    FOREIGN KEY (table2_id) REFERENCES table2(id),
    FOREIGN KEY (table3_id) REFERENCES table3(id),
    PRIMARY KEY (table2_id, table3_id)
);

CREATE TABLE table2 (
    id INTEGER NOT NULL,
    PRIMARY KEY id
);

CREATE TABLE table3 (
    id INTEGER NOT NULL,
    PRIMARY KEY id
);

There can be only one auto column

Note also that "key" does not necessarily mean primary key. Something like this will work:

CREATE TABLE book (
    isbn             BIGINT NOT NULL PRIMARY KEY,
    id               INT    NOT NULL AUTO_INCREMENT,
    accepted_terms   BIT(1) NOT NULL,
    accepted_privacy BIT(1) NOT NULL,
    INDEX(id)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

This is a contrived example and probably not the best idea, but it can be very useful in certain cases.

Alter Table Add Column Syntax

Just remove COLUMN from ADD COLUMN

ALTER TABLE Employees
  ADD EmployeeID numeric NOT NULL IDENTITY (1, 1)

ALTER TABLE Employees ADD CONSTRAINT
        PK_Employees PRIMARY KEY CLUSTERED 
        (
          EmployeeID
        ) WITH( STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, 
        ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]

How to delete a column from a table in MySQL

To delete column use this,

ALTER TABLE `tbl_Country` DROP `your_col`

Why use multiple columns as primary keys (composite primary key)

Using a primary key on multiple tables comes in handy when you're using an intermediate table in a relational database.

I'll use a database I once made for an example and specifically three tables within that table. I creäted a database for a webcomic some years ago. One table was called "comics"—a listing of all comics, their titles, image file name, etc. The primary key was "comicnum".

The second table was "characters"—their names and a brief description. The primary key was on "charname".

Since each comic—with some exceptions—had multiple characters and each character appeared within multiple comics, it was impractical to put a column in either "characters" or "comics" to reflect that. Instead, I creäted a third table was called "comicchars", and that was a listing of which characters appeared in which comics. Since this table essentially joined the two tables, it needed but two columns: charname and comicnum, and the primary key was on both.

How can I avoid getting this MySQL error Incorrect column specifier for column COLUMN NAME?

You cannot auto increment the char values. It should be int or long(integers or floating points). Try with this,

CREATE TABLE discussion_topics (
    topic_id int(5) NOT NULL AUTO_INCREMENT,
    project_id char(36) NOT NULL,
    topic_subject VARCHAR(255) NOT NULL,
    topic_content TEXT default NULL,
    date_created DATETIME NOT NULL,
    date_last_post DATETIME NOT NULL,
    created_by_user_id char(36) NOT NULL,
    last_post_user_id char(36) NOT NULL,
    posts_count char(36) default NULL,
    PRIMARY KEY (`topic_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=1;

Hope this helps

dropping a global temporary table

The DECLARE GLOBAL TEMPORARY TABLE statement defines a temporary table for the current connection.

These tables do not reside in the system catalogs and are not persistent.

Temporary tables exist only during the connection that declared them and cannot be referenced outside of that connection.

When the connection closes, the rows of the table are deleted, and the in-memory description of the temporary table is dropped.

For your reference http://docs.oracle.com/javadb/10.6.2.1/ref/rrefdeclaretemptable.html

What are DDL and DML?

DDL

Create,Alter,Drop of (Databases,Tables,Keys,Index,Views,Functions,Stored Procedures)

DML

Insert ,Delete,Update,Truncate of (Tables)

MySQL: ALTER TABLE if column not exists

Use PREPARE/EXECUTE and querying the schema. The host doesn't need to have permission to create or run procedures :

SET @dbname = DATABASE();
SET @tablename = "tableName";
SET @columnname = "colName";
SET @preparedStatement = (SELECT IF(
  (
    SELECT COUNT(*) FROM INFORMATION_SCHEMA.COLUMNS
    WHERE
      (table_name = @tablename)
      AND (table_schema = @dbname)
      AND (column_name = @columnname)
  ) > 0,
  "SELECT 1",
  CONCAT("ALTER TABLE ", @tablename, " ADD ", @columnname, " INT(11);")
));
PREPARE alterIfNotExists FROM @preparedStatement;
EXECUTE alterIfNotExists;
DEALLOCATE PREPARE alterIfNotExists;

Give all permissions to a user on a PostgreSQL database

GRANT USAGE ON SCHEMA schema_name TO user;

How does spring.jpa.hibernate.ddl-auto property exactly work in Spring?

For the record, the spring.jpa.hibernate.ddl-auto property is Spring Data JPA specific and is their way to specify a value that will eventually be passed to Hibernate under the property it knows, hibernate.hbm2ddl.auto.

The values create, create-drop, validate, and update basically influence how the schema tool management will manipulate the database schema at startup.

For example, the update operation will query the JDBC driver's API to get the database metadata and then Hibernate compares the object model it creates based on reading your annotated classes or HBM XML mappings and will attempt to adjust the schema on-the-fly.

The update operation for example will attempt to add new columns, constraints, etc but will never remove a column or constraint that may have existed previously but no longer does as part of the object model from a prior run.

Typically in test case scenarios, you'll likely use create-drop so that you create your schema, your test case adds some mock data, you run your tests, and then during the test case cleanup, the schema objects are dropped, leaving an empty database.

In development, it's often common to see developers use update to automatically modify the schema to add new additions upon restart. But again understand, this does not remove a column or constraint that may exist from previous executions that is no longer necessary.

In production, it's often highly recommended you use none or simply don't specify this property. That is because it's common practice for DBAs to review migration scripts for database changes, particularly if your database is shared across multiple services and applications.

PostgreSQL create table if not exists

I created a generic solution out of the existing answers which can be reused for any table:

CREATE OR REPLACE FUNCTION create_if_not_exists (table_name text, create_stmt text)
RETURNS text AS
$_$
BEGIN

IF EXISTS (
    SELECT *
    FROM   pg_catalog.pg_tables 
    WHERE    tablename  = table_name
    ) THEN
   RETURN 'TABLE ' || '''' || table_name || '''' || ' ALREADY EXISTS';
ELSE
   EXECUTE create_stmt;
   RETURN 'CREATED';
END IF;

END;
$_$ LANGUAGE plpgsql;

Usage:

select create_if_not_exists('my_table', 'CREATE TABLE my_table (id integer NOT NULL);');

It could be simplified further to take just one parameter if one would extract the table name out of the query parameter. Also I left out the schemas.

Create a temporary table in MySQL with an index from a select

CREATE [TEMPORARY] TABLE [IF NOT EXISTS] tbl_name
[(create_definition,...)]
[table_options]
select_statement

Example :

CREATE TEMPORARY TABLE IF NOT EXISTS mytable
(id int(11) NOT NULL, PRIMARY KEY (id)) ENGINE=MyISAM;
INSERT IGNORE INTO mytable SELECT id FROM table WHERE xyz;

Adding multiple columns AFTER a specific column in MySQL

If you want to add a single column after a specific field, then the following MySQL query should work:

ALTER TABLE users
    ADD COLUMN count SMALLINT(6) NOT NULL
    AFTER lastname

If you want to add multiple columns, then you need to use 'ADD' command each time for a column. Here is the MySQL query for this:

ALTER TABLE users
    ADD COLUMN count SMALLINT(6) NOT NULL,
    ADD COLUMN log VARCHAR(12) NOT NULL,
    ADD COLUMN status INT(10) UNSIGNED NOT NULL
    AFTER lastname

Point to note

In the second method, the last ADD COLUMN column should actually be the first column you want to append to the table.

E.g: if you want to add count, log, status in the exact order after lastname, then the syntax would actually be:

ALTER TABLE users
    ADD COLUMN log VARCHAR(12) NOT NULL AFTER lastname,
    ADD COLUMN status INT(10) UNSIGNED NOT NULL AFTER lastname,
    ADD COLUMN count SMALLINT(6) NOT NULL AFTER lastname
    

SQL Column definition : default value and not null redundant?

I would say not.

If the column does accept null values, then there's nothing to stop you inserting a null value into the field. As far as I'm aware, the default value only applies on creation of a new row.

With not null set, then you can't insert a null value into the field as it'll throw an error.

Think of it as a fail safe mechanism to prevent nulls.

How do I get column datatype in Oracle with PL-SQL with low privileges?

select t.data_type 
  from user_tab_columns t 
 where t.TABLE_NAME = 'xxx' 
   and t.COLUMN_NAME='aaa'

How do I use CREATE OR REPLACE?

You can use CORT (www.softcraftltd.co.uk/cort). This tool allows to CREATE OR REPLACE table in Oracle. It looks like:

create /*# or replace */ table MyTable(
  ... -- standard table definition
);

It preserves data.

Delete column from SQLite table

=>Create a new table directly with the following query:

CREATE TABLE table_name (Column_1 TEXT,Column_2 TEXT);

=>Now insert the data into table_name from existing_table with the following query:

INSERT INTO table_name (Column_1,Column_2) FROM existing_table;

=>Now drop the existing_table by following query:

DROP TABLE existing_table;

Simulate CREATE DATABASE IF NOT EXISTS for PostgreSQL?

Upgrade to PostgreSQL 9.5 or greater. If (not) exists was introduced in version 9.5.

Using ALTER to drop a column if it exists in MySQL

There is no language level support for this in MySQL. Here is a work-around involving MySQL information_schema meta-data in 5.0+, but it won't address your issue in 4.0.18.

drop procedure if exists schema_change;

delimiter ';;'
create procedure schema_change() begin

    /* delete columns if they exist */
    if exists (select * from information_schema.columns where table_schema = schema() and table_name = 'table1' and column_name = 'column1') then
        alter table table1 drop column `column1`;
    end if;
    if exists (select * from information_schema.columns where table_schema = schema() and table_name = 'table1' and column_name = 'column2') then
        alter table table1 drop column `column2`;
    end if;

    /* add columns */
    alter table table1 add column `column1` varchar(255) NULL;
    alter table table1 add column `column2` varchar(255) NULL;

end;;

delimiter ';'
call schema_change();

drop procedure if exists schema_change;

I wrote some more detailed information in a blog post.

How do I add a foreign key to an existing SQLite table?

Create a foreign key to the existing SQLLite table:

There is no direct way to do that for SQL LITE. Run the below query to recreate STUDENTS table with foreign keys. Run the query after creating initial STUDENTS table and inserting data into the table.

CREATE TABLE    STUDENTS    (       
    STUDENT_ID  INT NOT NULL,   
    FIRST_NAME  VARCHAR(50) NOT NULL,   
    LAST_NAME   VARCHAR(50) NOT NULL,   
    CITY    VARCHAR(50) DEFAULT NULL,   
    BADGE_NO    INT DEFAULT NULL
    PRIMARY KEY(STUDENT_ID) 
);

Insert data into STUDENTS table.

Then Add FOREIGN KEY : making BADGE_NO as the foreign key of same STUDENTS table

BEGIN;
CREATE TABLE STUDENTS_new (
    STUDENT_ID  INT NOT NULL,   
    FIRST_NAME  VARCHAR(50) NOT NULL,   
    LAST_NAME   VARCHAR(50) NOT NULL,   
    CITY    VARCHAR(50) DEFAULT NULL,   
    BADGE_NO    INT DEFAULT NULL,
    PRIMARY KEY(STUDENT_ID) ,
    FOREIGN KEY(BADGE_NO) REFERENCES STUDENTS(STUDENT_ID)   
);
INSERT INTO STUDENTS_new SELECT * FROM STUDENTS;
DROP TABLE STUDENTS;
ALTER TABLE STUDENTS_new RENAME TO STUDENTS;
COMMIT;

we can add the foreign key from any other table as well.

How to generate entire DDL of an Oracle schema (scriptable)?

You can spool the schema out to a file via SQL*Plus and dbms_metadata package. Then replace the schema name with another one via sed. This works for Oracle 10 and higher.

sqlplus<<EOF
set long 100000
set head off
set echo off
set pagesize 0
set verify off
set feedback off
spool schema.out

select dbms_metadata.get_ddl(object_type, object_name, owner)
from
(
    --Convert DBA_OBJECTS.OBJECT_TYPE to DBMS_METADATA object type:
    select
        owner,
        --Java object names may need to be converted with DBMS_JAVA.LONGNAME.
        --That code is not included since many database don't have Java installed.
        object_name,
        decode(object_type,
            'DATABASE LINK',      'DB_LINK',
            'JOB',                'PROCOBJ',
            'RULE SET',           'PROCOBJ',
            'RULE',               'PROCOBJ',
            'EVALUATION CONTEXT', 'PROCOBJ',
            'CREDENTIAL',         'PROCOBJ',
            'CHAIN',              'PROCOBJ',
            'PROGRAM',            'PROCOBJ',
            'PACKAGE',            'PACKAGE_SPEC',
            'PACKAGE BODY',       'PACKAGE_BODY',
            'TYPE',               'TYPE_SPEC',
            'TYPE BODY',          'TYPE_BODY',
            'MATERIALIZED VIEW',  'MATERIALIZED_VIEW',
            'QUEUE',              'AQ_QUEUE',
            'JAVA CLASS',         'JAVA_CLASS',
            'JAVA TYPE',          'JAVA_TYPE',
            'JAVA SOURCE',        'JAVA_SOURCE',
            'JAVA RESOURCE',      'JAVA_RESOURCE',
            'XML SCHEMA',         'XMLSCHEMA',
            object_type
        ) object_type
    from dba_objects 
    where owner in ('OWNER1')
        --These objects are included with other object types.
        and object_type not in ('INDEX PARTITION','INDEX SUBPARTITION',
           'LOB','LOB PARTITION','TABLE PARTITION','TABLE SUBPARTITION')
        --Ignore system-generated types that support collection processing.
        and not (object_type = 'TYPE' and object_name like 'SYS_PLSQL_%')
        --Exclude nested tables, their DDL is part of their parent table.
        and (owner, object_name) not in (select owner, table_name from dba_nested_tables)
        --Exclude overflow segments, their DDL is part of their parent table.
        and (owner, object_name) not in (select owner, table_name from dba_tables where iot_type = 'IOT_OVERFLOW')
)
order by owner, object_type, object_name;

spool off
quit
EOF

cat schema.out|sed 's/OWNER1/MYOWNER/g'>schema.out.change.sql

Put everything in a script and run it via cron (scheduler). Exporting objects can be tricky when advanced features are used. Don't be surprised if you need to add some more exceptions to the above code.

Truncating a table in a stored procedure

You should know that it is not possible to directly run a DDL statement like you do for DML from a PL/SQL block because PL/SQL does not support late binding directly it only support compile time binding which is fine for DML. hence to overcome this type of problem oracle has provided a dynamic SQL approach which can be used to execute the DDL statements.The dynamic sql approach is about parsing and binding of sql string at the runtime. Also you should rememder that DDL statements are by default auto commit hence you should be careful about any of the DDL statement using the dynamic SQL approach incase if you have some DML (which needs to be commited explicitly using TCL) before executing the DDL in the stored proc/function.

You can use any of the following dynamic sql approach to execute a DDL statement from a pl/sql block.

1) Execute immediate

2) DBMS_SQL package

3) DBMS_UTILITY.EXEC_DDL_STATEMENT (parse_string IN VARCHAR2);

Hope this answers your question with explanation.

How to get the total number of rows of a GROUP BY query?

There are two ways you can count the number of rows.

$query = "SELECT count(*) as total from table1";
$prepare = $link->prepare($query);
$prepare->execute();
$row = $prepare->fetch(PDO::FETCH_ASSOC);
echo $row['total']; // This will return you a number of rows.

Or second way is

$query = "SELECT field1, field2 from table1";
$prepare = $link->prepare($query);
$prepare->execute();
$row = $prepare->fetch(PDO::FETCH_NUM);
echo $rows[0]; // This will return you a number of rows as well.

Byte Array to Image object

BufferedImage img = ImageIO.read(new ByteArrayInputStream(bytes));

Change bundle identifier in Xcode when submitting my first app in IOS

Just edit the Project name by single click on the Top of project navigator window, will work in this case. You need not to try any other thing. :)

Convert Date format into DD/MMM/YYYY format in SQL Server

The accepted answer already gives the best solution using built in formatting methods in 2008.

It should be noted that the results returned is dependent on the language of the login however.

SET language Russian

SELECT replace(CONVERT(NVARCHAR, getdate(), 106), ' ', '/') 

Returns

06/???/2015

at the time of writing.

For people coming across this question on more recent versions of SQL Server a method that avoids this issue - and the need to REPLACE is

FORMAT(GETDATE(),'dd/MMM/yyyy', 'en-us')

On 2005+ it would be possible to write a CLR UDF that accepted a DateTime, Formatting Pattern and Culture to simulate the same.

Pipe output and capture exit status in Bash

There is an internal Bash variable called $PIPESTATUS; it’s an array that holds the exit status of each command in your last foreground pipeline of commands.

<command> | tee out.txt ; test ${PIPESTATUS[0]} -eq 0

Or another alternative which also works with other shells (like zsh) would be to enable pipefail:

set -o pipefail
...

The first option does not work with zsh due to a little bit different syntax.

Error message "unreported exception java.io.IOException; must be caught or declared to be thrown"

When the callee throws an exception i.e. void showfile() throws java.io.IOException the caller should handle it or throw it again.

And also learn naming conventions. A class name should start with a capital letter.

Equivalent to 'app.config' for a library (DLL)

Configuration files are application-scoped and not assembly-scoped. So you'll need to put your library's configuration sections in every application's configuration file that is using your library.

That said, it is not a good practice to get configuration from the application's configuration file, specially the appSettings section, in a class library. If your library needs parameters, they should probably be passed as method arguments in constructors, factory methods, etc. by whoever is calling your library. This prevents calling applications from accidentally reusing configuration entries that were expected by the class library.

That said, XML configuration files are extremely handy, so the best compromise that I've found is using custom configuration sections. You get to put your library's configuration in an XML file that is automatically read and parsed by the framework and you avoid potential accidents.

You can learn more about custom configuration sections on MSDN and also Phil Haack has a nice article on them.

what is difference between success and .done() method of $.ajax

success is the callback that is invoked when the request is successful and is part of the $.ajax call. done is actually part of the jqXHR object returned by $.ajax(), and replaces success in jQuery 1.8.

How to make java delay for a few seconds?

Use Thread.sleep(2000); //2000 for 2 seconds

Allow 2 decimal places in <input type="number">

Step 1: Hook your HTML number input box to an onchange event

myHTMLNumberInput.onchange = setTwoNumberDecimal;

or in the HTML code

<input type="number" onchange="setTwoNumberDecimal" min="0" max="10" step="0.25" value="0.00" />

Step 2: Write the setTwoDecimalPlace method

function setTwoNumberDecimal(event) {
    this.value = parseFloat(this.value).toFixed(2);
}

You can alter the number of decimal places by varying the value passed into the toFixed() method. See MDN docs.

toFixed(2); // 2 decimal places
toFixed(4); // 4 decimal places
toFixed(0); // integer

500 internal server error at GetResponse()

looking at your error message first of all I would suggest you to recompile your whole application, make sure all the required dlls are there in bin folder when you recompile it.

Which characters make a URL invalid?

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

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

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

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

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

That document defines URL code points as:

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

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

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

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

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

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

See also: Unicode characters in URLs

How do I pass named parameters with Invoke-Command?

My solution to this was to write the script block dynamically with [scriptblock]:Create:

# Or build a complex local script with MARKERS here, and do substitutions
# I was sending install scripts to the remote along with MSI packages
# ...for things like Backup and AV protection etc.

$p1 = "good stuff"; $p2 = "better stuff"; $p3 = "best stuff"; $etc = "!"
$script = [scriptblock]::Create("MyScriptOnRemoteServer.ps1 $p1 $p2 $etc")
#strings get interpolated/expanded while a direct scriptblock does not

# the $parms are now expanded in the script block itself
# ...so just call it:
$result = invoke-command $computer -script $script

Passing arguments was very frustrating, trying various methods, e.g.,
-arguments, $using:p1, etc. and this just worked as desired with no problems.

Since I control the contents and variable expansion of the string which creates the [scriptblock] (or script file) this way, there is no real issue with the "invoke-command" incantation.

(It shouldn't be that hard. :) )

Why call super() in a constructor?

There is an implicit call to super() with no arguments for all classes that have a parent - which is every user defined class in Java - so calling it explicitly is usually not required. However, you may use the call to super() with arguments if the parent's constructor takes parameters, and you wish to specify them. Moreover, if the parent's constructor takes parameters, and it has no default parameter-less constructor, you will need to call super() with argument(s).

An example, where the explicit call to super() gives you some extra control over the title of the frame:

class MyFrame extends JFrame
{
    public MyFrame() {
        super("My Window Title");
        ...
    }
}

What is the height of Navigation Bar in iOS 7?

I got this answer from the book Programming iOS 7, section Bar Position and Bar Metrics

If a navigation bar or toolbar — or a search bar (discussed earlier in this chapter) — is to occupy the top of the screen, the iOS 7 convention is that its height should be increased to underlap the transparent status bar. To make this possible, iOS 7 introduces the notion of a bar position.

UIBarPositionTopAttached

Specifies that the bar is at the top of the screen, as well as its containing view. Bars with this position draw their background extended upwards, allowing their background content to show through the status bar. Available in iOS 7.0 and later.

MVC DateTime binding with incorrect date format

I've just found the answer to this with some more exhaustive googling:

Melvyn Harbour has a thorough explanation of why MVC works with dates the way it does, and how you can override this if necessary:

http://weblogs.asp.net/melvynharbour/archive/2008/11/21/mvc-modelbinder-and-localization.aspx

When looking for the value to parse, the framework looks in a specific order namely:

  1. RouteData (not shown above)
  2. URI query string
  3. Request form

Only the last of these will be culture aware however. There is a very good reason for this, from a localization perspective. Imagine that I have written a web application showing airline flight information that I publish online. I look up flights on a certain date by clicking on a link for that day (perhaps something like http://www.melsflighttimes.com/Flights/2008-11-21), and then want to email that link to my colleague in the US. The only way that we could guarantee that we will both be looking at the same page of data is if the InvariantCulture is used. By contrast, if I'm using a form to book my flight, everything is happening in a tight cycle. The data can respect the CurrentCulture when it is written to the form, and so needs to respect it when coming back from the form.

MVC ajax post to controller action method

It's due to you sending one object, and you're expecting two parameters.

Try this and you'll see:

public class UserDetails
{
   public string username { get; set; }
   public string password { get; set; }
}

public JsonResult Login(UserDetails data)
{
   string error = "";
   //the rest of your code
}

How to convert minutes to hours/minutes and add various time values together using jQuery?

Very short code for transferring minutes in two formats!

_x000D_
_x000D_
let format1 = (n) => `${n / 60 ^ 0}:` + n % 60_x000D_
_x000D_
console.log(format1(135)) // "2:15"_x000D_
console.log(format1(55)) // "0:55"_x000D_
_x000D_
let format2 = (n) => `0${n / 60 ^ 0}`.slice(-2) + ':' + ('0' + n % 60).slice(-2)_x000D_
_x000D_
console.log(format2(135)) // "02:15"_x000D_
console.log(format2(5)) // "00:05"
_x000D_
_x000D_
_x000D_

Svn switch from trunk to branch

In my case, I wanted to check out a new branch that has cut recently but it's it big in size and I want to save time and internet bandwidth, as I'm in a slow metered network

so I copped the previous branch that I already checked in

I went to the working directory, and from svn info, I can see it's on the previous branch I did the following command (you can find this command from svn switch --help)

svn switch ^/branches/newBranchName

go check svn info again you can see it is becoming the newBranchName go ahead and svn up

and this how I got the new branch easily, quickly with minimum data transmitting over the internet

hope sharing my case helps and speeds up your work

How do you stop tracking a remote branch in Git?

To remove the upstream for the current branch do:

$ git branch --unset-upstream

This is available for Git v.1.8.0 or newer. (Sources: 1.7.9 ref, 1.8.0 ref)

source

Terminal Commands: For loop with echo

The default shell on OS X is bash. You could write this:

for i in {1..100}; do echo http://www.example.com/${i}.jpg; done

Here is a link to the reference manual of bash concerning loop constructs.

How do I disable the security certificate check in Python requests

If you want to send exactly post request with verify=False option, fastest way is to use this code:

import requests

requests.api.request('post', url, data={'bar':'baz'}, json=None, verify=False)

Error LNK2019 unresolved external symbol _main referenced in function "int __cdecl invoke_main(void)" (?invoke_main@@YAHXZ)

If you use CMake you have to set WIN32 flag in add_executable

add_executable(${name} WIN32 ${source_files})

See CMake Doc for more information.

PATH issue with pytest 'ImportError: No module named YadaYadaYada'

For me the problem was tests.py generated by Django along with tests directory. Removing tests.py solved the problem.

How to get the current time in milliseconds in C Programming

quick answer

#include<stdio.h>   
#include<time.h>   

int main()   
{   
    clock_t t1, t2;  
    t1 = clock();   
    int i;
    for(i = 0; i < 1000000; i++)   
    {   
        int x = 90;  
    }   

    t2 = clock();   

    float diff = ((float)(t2 - t1) / 1000000.0F ) * 1000;   
    printf("%f",diff);   

    return 0;   
}

How do I check if a directory exists? "is_dir", "file_exists" or both?

A way to check if a path is directory can be following:

function isDirectory($path) {
    $all = @scandir($path);
    return $all !== false;
}

NOTE: It will return false for non-existant path too, but works perfectly for UNIX/Windows

Convert integer value to matching Java Enum

There is no way to elegantly handle integer-based enumerated types. You might think of using a string-based enumeration instead of your solution. Not a preferred way all the times, but it still exists.

public enum Port {
  /**
   * The default port for the push server.
   */
  DEFAULT("443"),

  /**
   * The alternative port that can be used to bypass firewall checks
   * made to the default <i>HTTPS</i> port.
   */
  ALTERNATIVE("2197");

  private final String portString;

  Port(final String portString) {
    this.portString = portString;
  }

  /**
   * Returns the port for given {@link Port} enumeration value.
   * @return The port of the push server host.
   */
  public Integer toInteger() {
    return Integer.parseInt(portString);
  }
}

Exit from app when click button in android phonegap?

sorry i can't reply in comment. just FYI, these codes

if (navigator.app) {
navigator.app.exitApp();
}
else if (navigator.device) {
  navigator.device.exitApp();
}
else {
          window.close();
}

i confirm doesn't work. i use phonegap 6.0.5 and cordova 6.2.0

Error when trying to access XAMPP from a network

This solution worked well for me: http://www.apachefriends.org/f/viewtopic.php?f=17&t=50902&p=196185#p196185

Edit /opt/lampp/etc/extra/httpd-xampp.conf and adding Require all granted line at bottom of block <Directory "/opt/lampp/phpmyadmin"> to have the following code:

<Directory "/opt/lampp/phpmyadmin">
  AllowOverride AuthConfig Limit
  Order allow,deny
  Allow from all
  Require all granted
</Directory>

Ruby replace string with captured regex pattern

\1 in double quotes needs to be escaped. So you want either

"Z_sdsd: sdsd".gsub(/^(Z_.*): .*/, "\\1")

or

"Z_sdsd: sdsd".gsub(/^(Z_.*): .*/, '\1')

see the docs on gsub where it says "If it is a double-quoted string, both back-references must be preceded by an additional backslash."

That being said, if you just want the result of the match you can do:

"Z_sdsd: sdsd".scan(/^Z_.*(?=:)/)

or

"Z_sdsd: sdsd"[/^Z_.*(?=:)/]

Note that the (?=:) is a non-capturing group so that the : doesn't show up in your match.

How to copy java.util.list Collection

Use the ArrayList copy constructor, then sort that.

List oldList;
List newList = new ArrayList(oldList);
Collections.sort(newList);

After making the copy, any changes to newList do not affect oldList.

Note however that only the references are copied, so the two lists share the same objects, so changes made to elements of one list affect the elements of the other.

How to install and use "make" in Windows?

  1. Install Msys2 http://www.msys2.org
  2. Follow installation instructions
  3. Install make with $ pacman -S make gettext base-devel
  4. Add C:\msys64\usr\bin\ to your path

Is Python interpreted, or compiled, or both?

Its a big confusion for the people who started working on python and the answers here are a little difficult to comprehend so i'll make it easier.

When we instruct Python to run our script, there are a few steps that Python carries out before our code actually starts crunching away:

  • It is compiled to bytecode.
  • Then it is routed to virtual machine.

When we execute a source code, Python compiles it into a byte code. Compilation is a translation step, and the byte code is a low-level platform-independent representation of source code. Note that the Python byte code is not binary machine code (e.g., instructions for an Intel chip).

Actually, Python translate each statement of the source code into byte code instructions by decomposing them into individual steps. The byte code translation is performed to speed execution. Byte code can be run much more quickly than the original source code statements. It has.pyc extension and it will be written if it can write to our machine.

So, next time we run the same program, Python will load the .pyc file and skip the compilation step unless it's been changed. Python automatically checks the timestamps of source and byte code files to know when it must recompile. If we resave the source code, byte code is automatically created again the next time the program is run.

If Python cannot write the byte code files to our machine, our program still works. The byte code is generated in memory and simply discarded on program exit. But because .pyc files speed startup time, we may want to make sure it has been written for larger programs.

Let's summarize what happens behind the scenes. When a Python executes a program, Python reads the .py into memory, and parses it in order to get a bytecode, then goes on to execute. For each module that is imported by the program, Python first checks to see whether there is a precompiled bytecode version, in a .pyo or .pyc, that has a timestamp which corresponds to its .py file. Python uses the bytecode version if any. Otherwise, it parses the module's .py file, saves it into a .pyc file, and uses the bytecode it just created.

Byte code files are also one way of shipping Python codes. Python will still run a program if all it can find are.pyc files, even if the original .py source files are not there.

Python Virtual Machine (PVM)

Once our program has been compiled into byte code, it is shipped off for execution to Python Virtual Machine (PVM). The PVM is not a separate program. It need not be installed by itself. Actually, the PVM is just a big loop that iterates through our byte code instruction, one by one, to carry out their operations. The PVM is the runtime engine of Python. It's always present as part of the Python system. It's the component that truly runs our scripts. Technically it's just the last step of what is called the Python interpreter.

Seeding the random number generator in Javascript

Combining some of the previous answers, this is the seedable random function you are looking for:

Math.seed = function(s) {
    var mask = 0xffffffff;
    var m_w  = (123456789 + s) & mask;
    var m_z  = (987654321 - s) & mask;

    return function() {
      m_z = (36969 * (m_z & 65535) + (m_z >>> 16)) & mask;
      m_w = (18000 * (m_w & 65535) + (m_w >>> 16)) & mask;

      var result = ((m_z << 16) + (m_w & 65535)) >>> 0;
      result /= 4294967296;
      return result;
    }
}

var myRandomFunction = Math.seed(1234);
var randomNumber = myRandomFunction();

HTML table with horizontal scrolling (first column fixed)

I have a similar table styled like so:

<table style="width:100%; table-layout:fixed">
    <tr>
        <td style="width: 150px">Hello, World!</td>
        <td>
            <div>
                <pre style="margin:0; overflow:scroll">My preformatted content</pre>
            </div>
        </td>
    </tr>
</table>

Where are my postgres *.conf files?

Ubuntu 13.04 installed using software centre :

The location for mine is:

/etc/postgresql/9.1/main/postgresql.conf

This action could not be completed. Try Again (-22421)

For Xcode 8.3.2

i have resolved same issue

"This action could not be completed. Try Again (-22421)"

using following steps...

  1. Quit your xcode (if open)
  2. in Application Folder, Xcode 8.3.2 -->Show Package Contents -->Contents -->Application -->Application Loader (Show package contents) -->Contents -->itms -->bin -->iTMSTransporter (right click and Open with Terminal, it will auto start updating...) after updating open your project, rebuild your archive and upload it again..

For Xcode 9

issue

”This action could not be completed. Try Again (-22421)”

has been Resolved in Xcode 9. Now, we can upload app through Xcode Organizer also.

https://developer.apple.com/library/content/releasenotes/DeveloperTools/RN-Xcode/Chapters/Introduction.html#//apple_ref/doc/uid/TP40001051-CH1-SW876

How to draw a graph in PHP?

Your best bet is to look up php_gd2. It's a fairly decent image library that comes with PHP (just disabled in php.ini), and not only can you output your finished images in a couple formats, it's got enough functions that you should be able to do up a good graph fairly easily.

EDIT: it might help if I gave you a couple useful links:

http://www.libgd.org/ - You can get the latest php_gd2 here
http://ca3.php.net/gd - The php_gd manual.

How to register multiple implementations of the same interface in Asp.Net Core?

Bit late to this party, but here is my solution:...

Startup.cs or Program.cs if Generic Handler...

services.AddTransient<IMyInterface<CustomerSavedConsumer>, CustomerSavedConsumer>();
services.AddTransient<IMyInterface<ManagerSavedConsumer>, ManagerSavedConsumer>();

IMyInterface of T Interface Setup

public interface IMyInterface<T> where T : class, IMyInterface<T>
{
    Task Consume();
}

Concrete implementations of IMyInterface of T

public class CustomerSavedConsumer: IMyInterface<CustomerSavedConsumer>
{
    public async Task Consume();
}

public class ManagerSavedConsumer: IMyInterface<ManagerSavedConsumer>
{
    public async Task Consume();
}

Hopefully if there is any issue with doing it this way, someone will kindly point out why this is the wrong way to do this.

Downloading a file from spring controllers

If you:

  • Don't want to load the whole file into a byte[] before sending to the response;
  • Want/need to send/download it via InputStream;
  • Want to have full control of the Mime Type and file name sent;
  • Have other @ControllerAdvice picking up exceptions for you (or not).

The code below is what you need:

@RequestMapping(value = "/stuff/{stuffId}", method = RequestMethod.GET)
public ResponseEntity<FileSystemResource> downloadStuff(@PathVariable int stuffId)
                                                                      throws IOException {
    String fullPath = stuffService.figureOutFileNameFor(stuffId);
    File file = new File(fullPath);
    long fileLength = file.length(); // this is ok, but see note below

    HttpHeaders respHeaders = new HttpHeaders();
    respHeaders.setContentType("application/pdf");
    respHeaders.setContentLength(fileLength);
    respHeaders.setContentDispositionFormData("attachment", "fileNameIwant.pdf");

    return new ResponseEntity<FileSystemResource>(
        new FileSystemResource(file), respHeaders, HttpStatus.OK
    );
}

More on setContentLength(): First of all, the content-length header is optional per the HTTP 1.1 RFC. Still, if you can provide a value, it is better. To obtain such value, know that File#length() should be good enough in the general case, so it is a safe default choice.
In very specific scenarios, though, it can be slow, in which case you should have it stored previously (e.g. in the DB), not calculated on the fly. Slow scenarios include: if the file is very large, specially if it is on a remote system or something more elaborated like that - a database, maybe.



InputStreamResource

If your resource is not a file, e.g. you pick the data up from the DB, you should use InputStreamResource. Example:

    InputStreamResource isr = new InputStreamResource(new FileInputStream(file));
    return new ResponseEntity<InputStreamResource>(isr, respHeaders, HttpStatus.OK);

SMTP Connect() failed. Message was not sent.Mailer error: SMTP Connect() failed

Remove or comment out the line-

$mail->IsSMTP();

And it will work for you.

I have checked and experimented many answers from different sites but haven't got any solution except the above solution.

C# Inserting Data from a form into an access Database

This answer will help in case, If you are working with Data Bases then mostly take the help of try-catch block statement, which will help and guide you with your code. Here i am showing you that how to insert some values in Data Base with a Button Click Event.

 private void button2_Click(object sender, EventArgs e)
    {
        System.Data.OleDb.OleDbConnection conn = new System.Data.OleDb.OleDbConnection();
        conn.ConnectionString = @"Provider=Microsoft.ACE.OLEDB.12.0;" +
    @"Data source= C:\Users\pir fahim shah\Documents\TravelAgency.accdb";

     try
       {
           conn.Open();
           String ticketno=textBox1.Text.ToString();                 
           String Purchaseprice=textBox2.Text.ToString();
           String sellprice=textBox3.Text.ToString();
           String my_querry = "INSERT INTO Table1(TicketNo,Sellprice,Purchaseprice)VALUES('"+ticketno+"','"+sellprice+"','"+Purchaseprice+"')";

            OleDbCommand cmd = new OleDbCommand(my_querry, conn);
            cmd.ExecuteNonQuery();

            MessageBox.Show("Data saved successfuly...!");
          }
         catch (Exception ex)
         {
             MessageBox.Show("Failed due to"+ex.Message);
         }
         finally
         {
             conn.Close();
         }

Execute action when back bar button of UINavigationController is pressed

NO

override func willMove(toParentViewController parent: UIViewController?) { }

This will get called even if you are segueing to the view controller in which you are overriding this method. In which check if the "parent" is nil of not is not a precise way to be sure of moving back to the correct UIViewController. To determine exactly if the UINavigationController is properly navigating back to the UIViewController that presented this current one, you will need to conform to the UINavigationControllerDelegate protocol.

YES

note: MyViewController is just the name of whatever UIViewController you want to detect going back from.

1) At the top of your file add UINavigationControllerDelegate.

class MyViewController: UIViewController, UINavigationControllerDelegate {

2) Add a property to your class that will keep track of the UIViewController that you are segueing from.

class MyViewController: UIViewController, UINavigationControllerDelegate {

var previousViewController:UIViewController

3) in MyViewController's viewDidLoad method assign self as the delegate for your UINavigationController.

override func viewDidLoad() {
    super.viewDidLoad()
    self.navigationController?.delegate = self
}

3) Before you segue, assign the previous UIViewController as this property.

// In previous UIViewController
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if segue.identifier == "YourSegueID" {
        if let nextViewController = segue.destination as? MyViewController {
            nextViewController.previousViewController = self
        }
    }
}

4) And conform to one method in MyViewController of the UINavigationControllerDelegate

func navigationController(_ navigationController: UINavigationController, willShow viewController: UIViewController, animated: Bool) {
    if viewController == self.previousViewController {
        // You are going back
    }
}

How to use EditText onTextChanged event when I press the number?

put the logic in

afterTextChanged(Editable s) {
    string str = s.toString()
    // use the string str
}

documentation on TextWatcher

Define global constants

Using a property file that is generated during a build is simple and easy. This is the approach that the Angular CLI uses. Define a property file for each environment and use a command during build to determine which file gets copied to your app. Then simply import the property file to use.

https://github.com/angular/angular-cli#build-targets-and-environment-files

What is Cache-Control: private?

Cache-Control: private

Indicates that all or part of the response message is intended for a single user and MUST NOT be cached by a shared cache, such as a proxy server.

From RFC2616 section 14.9.1

Can I use a min-height for table, tr or td?

In CSS 2.1, the effect of 'min-height' and 'max-height' on tables, inline tables, table cells, table rows, and row groups is undefined.

So try wrapping the content in a div, and give the div a min-height jsFiddle here

<table cellspacing="0" cellpadding="0" border="0" style="width:300px">
    <tbody>
        <tr>
            <td>
                <div style="min-height: 100px; background-color: #ccc">
                    Hello World !
                </div>
            </td>
            <td>
                <div style="min-height: 100px; background-color: #f00">
                    Good Morning !
                </div>
            </td>
        </tr>
    </tbody>
</table>

return string with first match Regex

If you only need the first match, then use re.search instead of re.findall:

>>> m = re.search('\d+', 'aa33bbb44')
>>> m.group()
'33'
>>> m = re.search('\d+', 'aazzzbbb')
>>> m.group()
Traceback (most recent call last):
  File "<pyshell#281>", line 1, in <module>
    m.group()
AttributeError: 'NoneType' object has no attribute 'group'

Then you can use m as a checking condition as:

>>> m = re.search('\d+', 'aa33bbb44')
>>> if m:
        print('First number found = {}'.format(m.group()))
    else:
        print('Not Found')


First number found = 33

How do I insert a JPEG image into a python Tkinter window?

from tkinter import *
from PIL import ImageTk, Image

window = Tk()
window.geometry("1000x300")

path = "1.jpg"

image = PhotoImage(Image.open(path))

panel = Label(window, image = image)

panel.pack()

window.mainloop()

'"SDL.h" no such file or directory found' when compiling

header file lives at

/usr/include/SDL/SDL.h

       __OR__

/usr/include/SDL2/SDL.h  #  for SDL2

in your c++ code pull in this header using

#include <SDL.h>

       __OR__

#include <SDL2/SDL.h>    // for SDL2

you have the correct usage of

sdl-config --cflags --libs

       __OR__

sdl2-config --cflags --libs   #  sdl2

which will give you

-I/usr/include/SDL -D_GNU_SOURCE=1 -D_REENTRANT
-L/usr/lib/x86_64-linux-gnu -lSDL

       __OR__

-I/usr/include/SDL2 -D_REENTRANT
-lSDL2

at times you may also see this usage which works for a standard install

pkg-config --cflags --libs sdl

       __OR__

pkg-config --cflags --libs sdl2   #  sdl2

which supplies you with

-D_GNU_SOURCE=1 -D_REENTRANT -I/usr/include/SDL -lSDL

       __OR__

-D_REENTRANT -I/usr/include/SDL2 -lSDL2   #  SDL2

Concatenation of strings in Lua

If you are asking whether there's shorthand version of operator .. - no there isn't. You cannot write a ..= b. You'll have to type it in full: filename = filename .. ".tmp"

Nesting optgroups in a dropdownlist/select

Ok, if anyone ever reads this: the best option is to add four &nbsp;s at each extra level of indentation, it would seem!

so:

_x000D_
_x000D_
<select>_x000D_
 <optgroup label="Level One">_x000D_
  <option> A.1 </option>_x000D_
  <optgroup label="&nbsp;&nbsp;&nbsp;&nbsp;Level Two">_x000D_
   <option>&nbsp;&nbsp;&nbsp;&nbsp; A.B.1 </option>_x000D_
  </optgroup>_x000D_
  <option> A.2 </option>_x000D_
 </optgroup>_x000D_
</select>
_x000D_
_x000D_
_x000D_

How to delete an SMS from the inbox in Android programmatically?

Use one of this method to select the last received SMS and delete it, here in this case i am getting the top most sms and going to delete using thread and id value of sms,

try {
    Uri uri = Uri.parse("content://sms/inbox");
    Cursor c = v.getContext().getContentResolver().query(uri, null, null, null, null);
    int i = c.getCount();

    if (c.moveToFirst()) {
    }
} catch (CursorIndexOutOfBoundsException ee) {
    Toast.makeText(v.getContext(), "Error :" + ee.getMessage(), Toast.LENGTH_LONG).show();
}

MySQL Trigger - Storing a SELECT in a variable

As far I think I understood your question I believe that u can simply declare your variable inside "DECLARE" and then after the "begin" u can use 'select into " you variable" ' statement. the code would look like this:

DECLARE
YourVar  varchar(50);
begin 
select ID into YourVar  from table
where ...

Where is the visual studio HTML Designer?

Go to [Tools, Options], section "Web Forms Designer" and enable the option "Enable Web Forms Designer". That should give you the Design and Split option again.

Does Python have a toString() equivalent, and can I convert a db.Model element to String?

In function post():

todo.author = users.get_current_user()

So, to get str(todo.author), you need str(users.get_current_user()). What is returned by get_current_user() function ?

If it is an object, check does it contain a str()" function?

I think the error lies there.

What does it mean "No Launcher activity found!"

I fixed the problem by adding activity block in the application tag. I created the project using wizard, I don't know why my AdroidManifest.xml file was not containing application block? I added the application block:

<application
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name" >
    <activity
        android:name=".ToDoListActivity"
        android:label="@string/app_name" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>

And I get the desired output on the emulator.

How do I get the first element from an IEnumerable<T> in .net?

If your IEnumerable doesn't expose it's <T> and Linq fails, you can write a method using reflection:

public static T GetEnumeratedItem<T>(Object items, int index) where T : class
{
  T item = null;
  if (items != null)
  {
    System.Reflection.MethodInfo mi = items.GetType()
      .GetMethod("GetEnumerator");
    if (mi != null)
    {
      object o = mi.Invoke(items, null);
      if (o != null)
      {
        System.Reflection.MethodInfo mn = o.GetType()
          .GetMethod("MoveNext");
        if (mn != null)
        {
          object next = mn.Invoke(o, null);
          while (next != null && next.ToString() == "True")
          {
            if (index < 1)
            {
              System.Reflection.PropertyInfo pi = o
                .GetType().GetProperty("Current");
              if (pi != null) item = pi
                .GetValue(o, null) as T;
              break;
            }
            index--;
          }
        }
      }
    }
  }
  return item;
}

How to download a Nuget package without nuget.exe or Visual Studio extension?

Although building the URL or using tools is still possible, it is not needed anymore.

https://www.nuget.org/ currently has a download link named "Download package", that is available even if you don't have an account on the site.

(at the bottom of the right column).


Example of EntityFramework's detail page: https://www.nuget.org/packages/EntityFramework/: (Updated after comment of kwitee.)

Example of EntityFramework's detail page

How does python numpy.where() work?

How do they achieve internally that you are able to pass something like x > 5 into a method?

The short answer is that they don't.

Any sort of logical operation on a numpy array returns a boolean array. (i.e. __gt__, __lt__, etc all return boolean arrays where the given condition is true).

E.g.

x = np.arange(9).reshape(3,3)
print x > 5

yields:

array([[False, False, False],
       [False, False, False],
       [ True,  True,  True]], dtype=bool)

This is the same reason why something like if x > 5: raises a ValueError if x is a numpy array. It's an array of True/False values, not a single value.

Furthermore, numpy arrays can be indexed by boolean arrays. E.g. x[x>5] yields [6 7 8], in this case.

Honestly, it's fairly rare that you actually need numpy.where but it just returns the indicies where a boolean array is True. Usually you can do what you need with simple boolean indexing.

How do I apply a perspective transform to a UIView?

You can only use Core Graphics (Quartz, 2D only) transforms directly applied to a UIView's transform property. To get the effects in coverflow, you'll have to use CATransform3D, which are applied in 3-D space, and so can give you the perspective view you want. You can only apply CATransform3Ds to layers, not views, so you're going to have to switch to layers for this.

Check out the "CovertFlow" sample that comes with Xcode. It's mac-only (ie not for iPhone), but a lot of the concepts transfer well.

How to get a value from a cell of a dataframe?

For pandas 0.10, where iloc is unavalable, filter a DF and get the first row data for the column VALUE:

df_filt = df[df['C1'] == C1val & df['C2'] == C2val]
result = df_filt.get_value(df_filt.index[0],'VALUE')

if there is more then 1 row filtered, obtain the first row value. There will be an exception if the filter result in empty data frame.

TypeError : Unhashable type

You'll find that instances of list do not provide a __hash__ --rather, that attribute of each list is actually None (try print [].__hash__). Thus, list is unhashable.

The reason your code works with list and not set is because set constructs a single set of items without duplicates, whereas a list can contain arbitrary data.

jump to line X in nano editor

I am using nano editor in a Raspberry Pi with Italian OS language and Italian keyboard. Don't know the exact reason, but in this environment the shortcut is:

Ctrl+-

How to wait for 2 seconds?

Try this example:

exec DBMS_LOCK.sleep(5);

This is the whole script:

SELECT TO_CHAR (SYSDATE, 'MM-DD-YYYY HH24:MI:SS') "Start Date / Time" FROM DUAL;

exec DBMS_LOCK.sleep(5);

SELECT TO_CHAR (SYSDATE, 'MM-DD-YYYY HH24:MI:SS') "End Date / Time" FROM DUAL;

Page unload event in asp.net

There is an event Page.Unload. At that moment page is already rendered in HTML and HTML can't be modified. Still, all page objects are available.

Getting full JS autocompletion under Sublime Text

I developed a new plugin called JavaScript Enhancements, that you can find on Package Control. It uses Flow (javascript static type checker from Facebook) under the hood.

Furthermore, it offers smart javascript autocomplete (compared to my other plugin JavaScript Completions), real-time errors, code refactoring and also a lot of features about creating, developing and managing javascript projects.

See the Wiki to know all the features that it offers!

An introduction to this plugin could be found in this css-tricks.com article: Turn Sublime Text 3 into a JavaScript IDE

Just some quick screenshots:

How do I work with a git repository within another repository?

I had issues with subtrees and submodules that the other answers suggest... mainly because I am using SourceTree and it seems fairly buggy.

Instead, I ended up using SymLinks and that seems to work well so I am posting it here as a possible alternative.

There is a complete guide here: http://www.howtogeek.com/howto/16226/complete-guide-to-symbolic-links-symlinks-on-windows-or-linux/

But basically you just need to mklink the two paths in an elevated command prompt. Make sure you use the /J hard link prefix. Something along these lines: mklink /J C:\projects\MainProject\plugins C:\projects\SomePlugin

You can also use relative folder paths and put it in a bat to be executed by each person when they first check out your project.

Example: mklink /J .\Assets\TaqtileTools ..\TaqtileHoloTools

Once the folder has been linked you may need to ignore the folder within your main repository that is referencing it. Otherwise you are good to go.

Note I've deleted my duplicate answer from another post as that post was marked as a duplicate question to this one.

Why is it bad style to `rescue Exception => e` in Ruby?

This blog post explains it perfectly: Ruby's Exception vs StandardError: What's the difference?

Why you shouldn't rescue Exception

The problem with rescuing Exception is that it actually rescues every exception that inherits from Exception. Which is....all of them!

That's a problem because there are some exceptions that are used internally by Ruby. They don't have anything to do with your app, and swallowing them will cause bad things to happen.

Here are a few of the big ones:

  • SignalException::Interrupt - If you rescue this, you can't exit your app by hitting control-c.

  • ScriptError::SyntaxError - Swallowing syntax errors means that things like puts("Forgot something) will fail silently.

  • NoMemoryError - Wanna know what happens when your program keeps running after it uses up all the RAM? Me neither.

begin
  do_something()
rescue Exception => e
  # Don't do this. This will swallow every single exception. Nothing gets past it. 
end

I'm guessing that you don't really want to swallow any of these system-level exceptions. You only want to catch all of your application level errors. The exceptions caused YOUR code.

Luckily, there's an easy way to to this.

Rescue StandardError Instead

All of the exceptions that you should care about inherit from StandardError. These are our old friends:

NoMethodError - raised when you try to invoke a method that doesn't exist

TypeError - caused by things like 1 + ""

RuntimeError - who could forget good old RuntimeError?

To rescue errors like these, you'll want to rescue StandardError. You COULD do it by writing something like this:

begin
  do_something()
rescue StandardError => e
  # Only your app's exceptions are swallowed. Things like SyntaxErrror are left alone. 
end

But Ruby has made it much easier for use.

When you don't specify an exception class at all, ruby assumes you mean StandardError. So the code below is identical to the above code:

begin
  do_something()
rescue => e
  # This is the same as rescuing StandardError
end

How to extract extension from filename string in Javascript?

A variant that works with all of the following inputs:

  • "file.name.with.dots.txt"
  • "file.txt"
  • "file"
  • ""
  • null
  • undefined

would be:

var re = /(?:\.([^.]+))?$/;

var ext = re.exec("file.name.with.dots.txt")[1];   // "txt"
var ext = re.exec("file.txt")[1];                  // "txt"
var ext = re.exec("file")[1];                      // undefined
var ext = re.exec("")[1];                          // undefined
var ext = re.exec(null)[1];                        // undefined
var ext = re.exec(undefined)[1];                   // undefined

Explanation

(?:         # begin non-capturing group
  \.        #   a dot
  (         #   begin capturing group (captures the actual extension)
    [^.]+   #     anything except a dot, multiple times
  )         #   end capturing group
)?          # end non-capturing group, make it optional
$           # anchor to the end of the string

Creating a BLOB from a Base64 string in JavaScript

I'm posting a more declarative way of sync Base64 converting. While async fetch().blob() is very neat and I like this solution a lot, it doesn't work on Internet Explorer 11 (and probably Edge - I haven't tested this one), even with the polyfill - take a look at my comment to Endless' post for more details.

const blobPdfFromBase64String = base64String => {
   const byteArray = Uint8Array.from(
     atob(base64String)
       .split('')
       .map(char => char.charCodeAt(0))
   );
  return new Blob([byteArray], { type: 'application/pdf' });
};

Bonus

If you want to print it you could do something like:

const isIE11 = !!(window.navigator && window.navigator.msSaveOrOpenBlob); // Or however you want to check it
const printPDF = blob => {
   try {
     isIE11
       ? window.navigator.msSaveOrOpenBlob(blob, 'documents.pdf')
       : printJS(URL.createObjectURL(blob)); // http://printjs.crabbly.com/
   } catch (e) {
     throw PDFError;
   }
};

Bonus x 2 - Opening a BLOB file in new tab for Internet Explorer 11

If you're able to do some preprocessing of the Base64 string on the server you could expose it under some URL and use the link in printJS :)

How to avoid "StaleElementReferenceException" in Selenium?

Clean findByAndroidId method that gracefully handles StaleElementReference.

This is heavily based off of jspcal's answer but I had to modify that answer to get it working cleanly with our setup and so I wanted to add it here in case it's helpful to others. If this answer helped you, please go upvote jspcal's answer.

// This loops gracefully handles StateElementReference errors and retries up to 10 times. These can occur when an element, like a modal or notification, is no longer available.
export async function findByAndroidId( id, { assert = wd.asserters.isDisplayed, timeout = 10000, interval = 100 } = {} ) {
  MAX_ATTEMPTS = 10;
  let attempt = 0;

  while( attempt < MAX_ATTEMPTS ) {
    try {
      return await this.waitForElementById( `android:id/${ id }`, assert, timeout, interval );
    }
    catch ( error ) {
      if ( error.message.includes( "StaleElementReference" ) )
        attempt++;
      else
        throw error; // Re-throws the error so the test fails as normal if the assertion fails.
    }
  }
}

How to remove numbers from string using Regex.Replace?

You can do it with a LINQ like solution instead of a regular expression:

string input = "123- abcd33";
string chars = new String(input.Where(c => c != '-' && (c < '0' || c > '9')).ToArray());

A quick performance test shows that this is about five times faster than using a regular expression.

Read data from SqlDataReader

For a single result:

if (reader.Read())
{
    Response.Write(reader[0].ToString());
    Response.Write(reader[1].ToString());
}

For multiple results:

while (reader.Read())
{
    Response.Write(reader[0].ToString());
    Response.Write(reader[1].ToString());
}

How to commit to remote git repository

You just need to make sure you have the rights to push to the remote repository and do

git push origin master

or simply

git push

How can I export Excel files using JavaScript?

To answer your question with a working example:

<script type="text/javascript">
function DownloadJSON2CSV(objArray)
{
    var array = typeof objArray != 'object' ? JSON.parse(objArray) : objArray;

    var str = '';

    for (var i = 0; i < array.length; i++) {
        var line = new Array();

        for (var index in array[i]) {
           line.push('"' + array[i][index] + '"');
        }

        str += line.join(';');
        str += '\r\n';
    }
    window.open( "data:text/csv;charset=utf-8," + encodeURIComponent(str));
}
</script>

jquery - disable click

Raw Javascript can accomplish the same thing pretty quickly also:

document.getElementById("myElement").onclick = function() { return false; } 

Why do some functions have underscores "__" before and after the function name?

From the Python PEP 8 -- Style Guide for Python Code:

Descriptive: Naming Styles

The following special forms using leading or trailing underscores are recognized (these can generally be combined with any case convention):

  • _single_leading_underscore: weak "internal use" indicator. E.g. from M import * does not import objects whose name starts with an underscore.

  • single_trailing_underscore_: used by convention to avoid conflicts with Python keyword, e.g.

    Tkinter.Toplevel(master, class_='ClassName')

  • __double_leading_underscore: when naming a class attribute, invokes name mangling (inside class FooBar, __boo becomes _FooBar__boo; see below).

  • __double_leading_and_trailing_underscore__: "magic" objects or attributes that live in user-controlled namespaces. E.g. __init__, __import__ or __file__. Never invent such names; only use them as documented.

Note that names with double leading and trailing underscores are essentially reserved for Python itself: "Never invent such names; only use them as documented".

Quickly create large file on a Windows system

I found an excellent utility that is configurable at https://github.com/acch/genfiles.

It fills the target file with random data, so there are no problems with sparse files, and for my purposes (testing compression algorithms) it gives a nice level of white noise.

Handler "ExtensionlessUrlHandler-Integrated-4.0" has a bad module "ManagedPipelineHandler" in its module list

For Windows 10 / Windows Server 2016 use the following command:

dism /online /enable-feature /featurename:IIS-ASPNET45 /all

The suggested answers with aspnet_regiis doesn't work on Windows 10 (Creators Update and later) or Windows Server 2016:

C:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_regiis.exe -i
Microsoft (R) ASP.NET RegIIS version 4.0.30319.0
Administration utility to install and uninstall ASP.NET on the local machine.
Copyright (C) Microsoft Corporation. All rights reserved.
Start installing ASP.NET (4.0.30319.0).
This option is not supported on this version of the operating system. Administrators should instead install/uninstall ASP.NET 4.5 with IIS8 using the "Turn Windows Features On/Off" dialog, the Server Manager management tool, or the dism.exe command line tool. For more details please see http://go.microsoft.com/fwlink/?LinkID=216771.
Finished installing ASP.NET (4.0.30319.0).

Interestingly, the "Turn Windows Features On/Off" dialog didn't allow me to untick .NET nor ASP.NET 4.6, and only the above DISM command worked. Not sure whether the featurename is correct, but it worked for me.

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

I believe I have a O(k) time and O(log(k)) space algorithm, given that you have the floor(x) and log2(x) functions for arbitrarily big integers available:

You have an k-bit long integer (hence the log8(k) space) where you add the x^2, where x is the next number you find in the bag: s=1^2+2^2+... This takes O(N) time (which is not a problem for the interviewer). At the end you get j=floor(log2(s)) which is the biggest number you're looking for. Then s=s-j and you do again the above:

for (i = 0 ; i < k ; i++)
{
  j = floor(log2(s));
  missing[i] = j;
  s -= j;
}

Now, you usually don't have floor and log2 functions for 2756-bit integers but instead for doubles. So? Simply, for each 2 bytes (or 1, or 3, or 4) you can use these functions to get the desired numbers, but this adds an O(N) factor to time complexity

How to inspect FormData?

I use the formData.entries() method. I'm not sure about all browser support, but it works fine on Firefox.

Taken from https://developer.mozilla.org/en-US/docs/Web/API/FormData/entries

// Create a test FormData object
var formData = new FormData();
formData.append('key1','value1');
formData.append('key2','value2');

// Display the key/value pairs
for (var pair of formData.entries())
{
 console.log(pair[0]+ ', '+ pair[1]); 
}

There is also formData.get() and formData.getAll() with wider browser support, but they only bring up the Values and not the Key. See the link for more info.

Parse error: syntax error, unexpected T_ECHO in

Missing ; after var_dump($row)

Printing hexadecimal characters in C

You are probably printing from a signed char array. Either print from an unsigned char array or mask the value with 0xff: e.g. ar[i] & 0xFF. The c0 values are being sign extended because the high (sign) bit is set.

Split Strings into words with multiple word boundary delimiters

Here is the answer with some explanation.

st = "Hey, you - what are you doing here!?"

# replace all the non alpha-numeric with space and then join.
new_string = ''.join([x.replace(x, ' ') if not x.isalnum() else x for x in st])
# output of new_string
'Hey  you  what are you doing here  '

# str.split() will remove all the empty string if separator is not provided
new_list = new_string.split()

# output of new_list
['Hey', 'you', 'what', 'are', 'you', 'doing', 'here']

# we can join it to get a complete string without any non alpha-numeric character
' '.join(new_list)
# output
'Hey you what are you doing'

or in one line, we can do like this:

(''.join([x.replace(x, ' ') if not x.isalnum() else x for x in st])).split()

# output
['Hey', 'you', 'what', 'are', 'you', 'doing', 'here']

updated answer

CSS hide scroll bar if not needed

.container {overflow:auto;} will do the trick. If you want to control specific direction, you should set auto for that specific axis. A.E.

.container {overflow-y:auto;} .container {overflow-x:hidden;}

The above code will hide any overflow in the x-axis and generate a scroll-bar when needed on the y-axis.But you have to make sure that you content default height smaller than the container height; if not, the scroll-bar will not be hidden.

C pointer to array/array of pointers disambiguation

int *a[4]; // Array of 4 pointers to int

int (*a)[4]; //a is a pointer to an integer array of size 4

int (*a[8])[5]; //a is an array of pointers to integer array of size 5 

Prevent form redirect OR refresh on submit?

Here:

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

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

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

curl posting with header application/x-www-form-urlencoded

 $curl = curl_init();
 curl_setopt_array($curl, array(
            CURLOPT_URL => "http://example.com",
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_ENCODING => "",
            CURLOPT_MAXREDIRS => 10,
            CURLOPT_TIMEOUT => 30,
            CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
            CURLOPT_CUSTOMREQUEST => "POST",
            CURLOPT_POSTFIELDS => "value1=111&value2=222",
            CURLOPT_HTTPHEADER => array(
                "cache-control: no-cache",
                "content-type: application/x-www-form-urlencoded"
            ),
        ));
 $response = curl_exec($curl);
 $err = curl_error($curl);

 curl_close($curl);

 if (!$err)
 {
      var_dump($response);
 }

Adding a custom header to HTTP request using angular.js

If you want to add your custom headers to ALL requests, you can change the defaults on $httpProvider to always add this header…

app.config(['$httpProvider', function ($httpProvider) {
    $httpProvider.defaults.headers.common = { 
        'Authorization': 'Basic d2VudHdvcnRobWFuOkNoYW5nZV9tZQ==',
        'Accept': 'application/json;odata=verbose'
      };
}]);

text-overflow: ellipsis not working

Just a headsup for anyone who may stumble across this... My h2 was inheriting

text-rendering: optimizelegibility; 
//Changed to text-rendering: none; for fix

which was not allowing ellipsis. Apparently this is very finickey eh?

Extract values in Pandas value_counts()

#!/usr/bin/env python

import pandas as pd

# Make example dataframe
df = pd.DataFrame([(1, 'Germany'),
                   (2, 'France'),
                   (3, 'Indonesia'),
                   (4, 'France'),
                   (5, 'France'),
                   (6, 'Germany'),
                   (7, 'UK'),
                   ],
                  columns=['groupid', 'country'],
                  index=['a', 'b', 'c', 'd', 'e', 'f', 'g'])

# What you're looking for
values = df['country'].value_counts().keys().tolist()
counts = df['country'].value_counts().tolist()

Now, print(df['country'].value_counts()) gives:

France       3
Germany      2
UK           1
Indonesia    1

and print(values) gives:

['France', 'Germany', 'UK', 'Indonesia']

and print(counts) gives:

[3, 2, 1, 1]

How do I install PIL/Pillow for Python 3.6?

For python version 2.x you can simply use

  • pip install pillow

But for python version 3.X you need to specify

  • (sudo) pip3 install pillow

when you enter pip in bash hit tab and you will see what options you have

window.location.reload with clear cache

You can do this a few ways. One, simply add this meta tag to your head:

<meta http-equiv="Cache-control" content="no-cache">

If you want to remove the document from cache, expires meta tag should work to delete it by setting its content attribute to -1 like so:

<meta http-equiv="Expires" content="-1">

http://www.metatags.org/meta_http_equiv_cache_control

Also, IE should give you the latest content for the main page. If you are having issues with external documents, like CSS and JS, add a dummy param at the end of your URLs with the current time in milliseconds so that it's never the same. This way IE, and other browsers, will always serve you the latest version. Here is an example:

<script src="mysite.com/js/myscript.js?12345">

UPDATE 1

After reading the comments I realize you wanted to programmatically erase the cache and not every time. What you could do is have a function in JS like:

eraseCache(){
  window.location = window.location.href+'?eraseCache=true';
}

Then, in PHP let's say, you do something like this:

<head>
<?php
    if (isset($_GET['eraseCache'])) {
        echo '<meta http-equiv="Cache-control" content="no-cache">';
        echo '<meta http-equiv="Expires" content="-1">';
        $cache = '?' . time();
    }
?>
<!-- ... other head HTML -->
<script src="mysite.com/js/script.js<?= $cache ?>"
</head>

This isn't tested, but should work. Basically, your JS function, if invoked, will reload the page, but adds a GET param to the end of the URL. Your site would then have some back-end code that looks for this param. If it exists, it adds the meta tags and a cache variable that contains a timestamp and appends it to the scripts and CSS that you are having caching issues with.

UPDATE 2

The meta tag indeed won't erase the cache on page load. So, technically you would need to run the eraseCache function in JS, once the page loads, you would need to load it again for the changes to take place. You should be able to fix this with your server side language. You could run the same eraseCache JS function, but instead of adding the meta tags, you need to add HTTP Cache headers:

<?php
    header("Cache-Control: no-cache, must-revalidate");
    header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");
?>
<!-- Here you'd start your page... -->

This method works immediately without the need for page reload because it erases the cache before the page loads and also before anything is run.

Dealing with float precision in Javascript

Tackling this task, I'd first find the number of decimal places in x, then round y accordingly. I'd use:

y.toFixed(x.toString().split(".")[1].length);

It should convert x to a string, split it over the decimal point, find the length of the right part, and then y.toFixed(length) should round y based on that length.

Read all files in a folder and apply a function to each data frame

usually i don't use for loop in R, but here is my solution using for loops and two packages : plyr and dostats

plyr is on cran and you can download dostats on https://github.com/halpo/dostats (may be using install_github from Hadley devtools package)

Assuming that i have your first two data.frame (Df.1 and Df.2) in csv files, you can do something like this.

require(plyr)
require(dostats)

files <- list.files(pattern = ".csv")


for (i in seq_along(files)) {

    assign(paste("Df", i, sep = "."), read.csv(files[i]))

    assign(paste(paste("Df", i, sep = ""), "summary", sep = "."), 
           ldply(get(paste("Df", i, sep = ".")), dostats, sum, min, mean, median, max))

}

Here is the output

R> Df1.summary
  .id sum min   mean median max
1   A  34   4 5.6667    5.5   8
2   B  22   1 3.6667    3.0   9
R> Df2.summary
  .id sum min   mean median max
1   A  21   1 3.5000    3.5   6
2   B  16   1 2.6667    2.5   5

How to detect the screen resolution with JavaScript?

just for future reference:

function getscreenresolution()
{
    window.alert("Your screen resolution is: " + screen.height + 'x' + screen.width);
}

How to get all values from python enum class?

Use _member_names_ for a quick easy result if it is just the names, i.e.

Color._member_names_

Also, you have _member_map_ which returns an ordered dictionary of the elements. This function returns a collections.OrderedDict, so you have Color._member_names_.items() and Color._member_names_.values() to play with. E.g.

return list(map(lambda x: x.value, Color._member_map_.values()))

will return all the valid values of Color

Node.js on multi-core machines

Ryan Dahl answers this question in the tech talk he gave at Google last summer. To paraphrase, "just run multiple node processes and use something sensible to allow them to communicate. e.g. sendmsg()-style IPC or traditional RPC".

If you want to get your hands dirty right away, check out the spark2 Forever module. It makes spawning multiple node processes trivially easy. It handles setting up port sharing, so they can each accept connections to the same port, and also auto-respawning if you want to make sure a process is restarted if/when it dies.

UPDATE - 10/11/11: Consensus in the node community seems to be that Cluster is now the preferred module for managing multiple node instances per machine. Forever is also worth a look.

Should MySQL have its timezone set to UTC?

How about making your app agnostic of the server's timezone?

Owing to any of these possible scenarios:

  • You might not have control over the web/database server's timezone settings
  • You might mess up and set the settings incorrectly
  • There are so many settings as described in the other answers, and so many things to keep track of, that you might miss something
  • An update on the server, or a software reset, or another admin, might unknowing reset the servers' timezone to the default - thus breaking your application

All of the above scenarios give rise to breaking of your application's time calculations. Thus it appears that the better approach is to make your application work independent of the server's timezone.

The idea is simply to always create dates in UTC before storing them into the database, and always re-create them from the stored values in UTC as well. This way, the time calculations won't ever be incorrect, because they're always in UTC. This can be achieved by explicity stating the DateTimeZone parameter when creating a PHP DateTime object.

On the other hand, the client side functionality can be configured to convert all dates/times received from the server to the client's timezone. Libraries like moment.js make this super easy to do.

For example, when storing a date in the database, instead of using the NOW() function of MySQL, create the timestamp string in UTC as follows:

// Storing dates
$date = new DateTime('now', new DateTimeZone('UTC'));
$sql = 'insert into table_name (date_column) values ("' . $date . '")';

// Retreiving dates
$sql = 'select date_column from table_name where condition';
$dateInUTC = new DateTime($date_string_from_db, new DateTimeZone('UTC'));

You can set the default timezone in PHP for all dates created, thus eliminating the need to initialize the DateTimeZone class every time you want to create a date.

jQuery UI Color Picker

Make sure you have jQuery UI base and the color picker widget included on your page (as well as a copy of jQuery 1.3):

<link rel="stylesheet" href="http://dev.jquery.com/view/tags/ui/latest/themes/flora/flora.all.css" type="text/css" media="screen" title="Flora (Default)">

<script type="text/javascript" src="http://dev.jquery.com/view/tags/ui/latest/ui/ui.core.js"></script>

<script type="text/javascript" src="http://dev.jquery.com/view/tags/ui/latest/ui/ui.colorpicker.js"></script>

If you have those included, try posting your source so we can see what's going on.

ASP.NET MVC Return Json Result?

It should be :

public async Task<ActionResult> GetSomeJsonData()
{
    var model = // ... get data or build model etc.

    return Json(new { Data = model }, JsonRequestBehavior.AllowGet); 
}

or more simply:

return Json(model, JsonRequestBehavior.AllowGet); 

I did notice that you are calling GetResources() from another ActionResult which wont work. If you are looking to get JSON back, you should be calling GetResources() from ajax directly...

How to convert image file data in a byte array to a Bitmap?

The answer of Uttam didnt work for me. I just got null when I do:

Bitmap bitmap = BitmapFactory.decodeByteArray(bitmapdata, 0, bitmapdata.length);

In my case, bitmapdata only has the buffer of the pixels, so it is imposible for the function decodeByteArray to guess which the width, the height and the color bits use. So I tried this and it worked:

//Create bitmap with width, height, and 4 bytes color (RGBA)    
Bitmap bmp = Bitmap.createBitmap(imageWidth, imageHeight, Bitmap.Config.ARGB_8888);
ByteBuffer buffer = ByteBuffer.wrap(bitmapdata);
bmp.copyPixelsFromBuffer(buffer);

Check https://developer.android.com/reference/android/graphics/Bitmap.Config.html for different color options

Difference between Dictionary and Hashtable

Dictionary is typed (so valuetypes don't need boxing), a Hashtable isn't (so valuetypes need boxing). Hashtable has a nicer way of obtaining a value than dictionary IMHO, because it always knows the value is an object. Though if you're using .NET 3.5, it's easy to write an extension method for dictionary to get similar behavior.

If you need multiple values per key, check out my sourcecode of MultiValueDictionary here: multimap in .NET

Why would you use Expression<Func<T>> rather than Func<T>?

Overly simplified here, but Func is a machine, whereas Expression is a blueprint. :D

Spark - Error "A master URL must be set in your configuration" when submitting an app

I had the same problem, Here is my code before modification :

package com.asagaama

import org.apache.spark.SparkContext
import org.apache.spark.SparkConf
import org.apache.spark.rdd.RDD

/**
  * Created by asagaama on 16/02/2017.
  */
object Word {

  def countWords(sc: SparkContext) = {
    // Load our input data
    val input = sc.textFile("/Users/Documents/spark/testscase/test/test.txt")
    // Split it up into words
    val words = input.flatMap(line => line.split(" "))
    // Transform into pairs and count
    val counts = words.map(word => (word, 1)).reduceByKey { case (x, y) => x + y }
    // Save the word count back out to a text file, causing evaluation.
    counts.saveAsTextFile("/Users/Documents/spark/testscase/test/result.txt")
  }

  def main(args: Array[String]) = {
    val conf = new SparkConf().setAppName("wordCount")
    val sc = new SparkContext(conf)
    countWords(sc)
  }

}

And after replacing :

val conf = new SparkConf().setAppName("wordCount")

With :

val conf = new SparkConf().setAppName("wordCount").setMaster("local[*]")

It worked fine !

Get length of array?

If the variant is empty then an error will be thrown. The bullet-proof code is the following:

Public Function GetLength(a As Variant) As Integer
   If IsEmpty(a) Then
      GetLength = 0
   Else
      GetLength = UBound(a) - LBound(a) + 1
   End If
End Function

Determine SQL Server Database Size

According to SQL2000 help, sp_spaceused includes data and indexes.

This script should do:

CREATE TABLE #t (name SYSNAME, rows CHAR(11), reserved VARCHAR(18), 
data VARCHAR(18), index_size VARCHAR(18), unused VARCHAR(18))

EXEC sp_msforeachtable 'INSERT INTO #t EXEC sp_spaceused ''?'''
-- SELECT * FROM #t ORDER BY name
-- SELECT name, CONVERT(INT, SUBSTRING(data, 1, LEN(data)-3)) FROM #t ORDER BY name
SELECT SUM(CONVERT(INT, SUBSTRING(data, 1, LEN(data)-3))) FROM #t
DROP TABLE #t

Convert Java Object to JsonNode in Jackson

As of Jackson 1.6, you can use:

JsonNode node = mapper.valueToTree(map);

or

JsonNode node = mapper.convertValue(object, JsonNode.class);

Source: is there a way to serialize pojo's directly to treemodel?

Check if Variable is Empty - Angular 2

user:Array[]=[1,2,3];
if(this.user.length)
{
    console.log("user has contents");
}
else{
    console.log("user is empty");
}

NullPointerException in eclipse in Eclipse itself at PartServiceImpl.internalFixContext

I have also encountered this error . Just i opened the new window ie Window -> New Window in eclipse .Then , I closed my old window. This solved my problem.

Rollback to last git commit

If you want to remove newly added contents and files which are already staged (so added to the index) then you use:

git reset --hard

If you want to remove also your latest commit (is the one with the message "blah") then better to use:

git reset --hard HEAD^

To remove the untracked files (so new files not yet added to the index) and folders use:

git clean --force -d

How to Inspect Element using Safari Browser

In your Safari menu bar click Safari > Preferences & then select the Advanced tab.

Select: "Show Develop menu in menu bar"

Now you can click Develop in your menu bar and choose Show Web Inspector

You can also right-click and press "Inspect element".

How to import cv2 in python3?

well, there was 2 issues: 1.instead of pip, pip3 should be used. 2.its better to use virtual env. because i have had multiple python version installed

SQL DATEPART(dw,date) need monday = 1 and sunday = 7

I would suggest that you just write the case statement yourself using datename():

select (case datename(dw, aws.date)
             when 'Monday' then 1
             when 'Tuesday' then 2
             when 'Wednesday' then 3
             when 'Thursday' then 4
             when 'Friday' then 5
             when 'Saturday' then 6
             when 'Sunday' then 7
        end)

At least, this won't change if someone changes the parameter on the day of the week when weeks begin. On the other hand, it is susceptible to the language chosen for SQL Server.

static files with express.js

const path = require('path');

const express = require('express');

const app = new express();
app.use(express.static('/media'));

app.get('/', (req, res) => {
    res.sendFile(path.resolve(__dirname, 'media/page/', 'index.html'));
});

app.listen(4000, () => {
    console.log('App listening on port 4000')
})

Decompile .smali files on an APK

I second that.

Dex2jar will generate a WORKING jar, which you can add as your project source, with the xmls you got from apktool.

However, JDGUI generates .java files which have ,more often than not, errors.

It has got something to do with code obfuscation I guess.

Git Bash doesn't see my PATH

For me the most convenient was to: 1) Create directory "bin" in the root of C: drive 2) Add "C:/bin;" to PATH in "My Computer -> Properties -> Environemtal Variables"

fatal error LNK1169: one or more multiply defined symbols found in game programming

just add /FORCE as linker flag and you're all set.

for instance, if you're working on CMakeLists.txt. Then add following line:

SET(CMAKE_EXE_LINKER_FLAGS  "/FORCE")

Normalize numpy array columns in python

You can use sklearn.preprocessing:

from sklearn.preprocessing import normalize
data = np.array([
    [1000, 10, 0.5],
    [765, 5, 0.35],
    [800, 7, 0.09], ])
data = normalize(data, axis=0, norm='max')
print(data)
>>[[ 1.     1.     1.   ]
[ 0.765  0.5    0.7  ]
[ 0.8    0.7    0.18 ]]

IndentationError expected an indented block

This error also occurs if you have a block with no statements in it

For example:

def my_function():
    for i in range(1,10):


def say_hello():
    return "hello"

Notice that the for block is empty. You can use the pass statement if you want to test the remaining code in the module.

Remove all spaces from a string in SQL Server

replace(replace(column_Name,CHAR(13),''),CHAR(10),'')

Do a "git export" (like "svn export")?

If you want something that works with submodules this might be worth a go.

Note:

  • MASTER_DIR = a checkout with your submodules checked out also
  • DEST_DIR = where this export will end up
  • If you have rsync, I think you'd be able to do the same thing with even less ball ache.

Assumptions:

  • You need to run this from the parent directory of MASTER_DIR ( i.e from MASTER_DIR cd .. )
  • DEST_DIR is assumed to have been created. This is pretty easy to modify to include the creation of a DEST_DIR if you wanted to

cd MASTER_DIR && tar -zcvf ../DEST_DIR/export.tar.gz --exclude='.git*' . && cd ../DEST_DIR/ && tar xvfz export.tar.gz && rm export.tar.gz

async await return Task

Adding the async keyword is just syntactic sugar to simplify the creation of a state machine. In essence, the compiler takes your code;

public async Task MethodName()
{
     return null;
}

And turns it into;

public Task MethodName()
{
     return Task.FromResult<object>(null);
}

If your code has any await keywords, the compiler must take your method and turn it into a class to represent the state machine required to execute it. At each await keyword, the state of variables and the stack will be preserved in the fields of the class, the class will add itself as a completion hook to the task you are waiting on, then return.

When that task completes, your task will be executed again. So some extra code is added to the top of the method to restore the state of variables and jump into the next slab of your code.

See What does async & await generate? for a gory example.

This process has a lot in common with the way the compiler handles iterator methods with yield statements.

How do I do base64 encoding on iOS?

Here's a compact Objective-C version as a Category on NSData. It takes some thinking about...

@implementation NSData (DataUtils)

static char base64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

- (NSString *)newStringInBase64FromData
{
 NSMutableString *dest = [[NSMutableString alloc] initWithString:@""];
 unsigned char * working = (unsigned char *)[self bytes];
 int srcLen = [self length];

 // tackle the source in 3's as conveniently 4 Base64 nibbles fit into 3 bytes
 for (int i=0; i<srcLen; i += 3)
 {
  // for each output nibble
  for (int nib=0; nib<4; nib++)
  {
   // nibble:nib from char:byt
   int byt = (nib == 0)?0:nib-1;
   int ix = (nib+1)*2;

   if (i+byt >= srcLen) break;

   // extract the top bits of the nibble, if valid
   unsigned char curr = ((working[i+byt] << (8-ix)) & 0x3F);

   // extract the bottom bits of the nibble, if valid
   if (i+nib < srcLen) curr |= ((working[i+nib] >> ix) & 0x3F);

   [dest appendFormat:@"%c", base64[curr]];
  }
 }

 return dest;
}

@end

Padding can be added if required by making the scope of 'byt' wider and appending 'dest' with (2-byt) "=" characters before returning.

A Category can then be added to NSString, thus:

@implementation NSString (StringUtils)

- (NSString *)newStringInBase64FromString
{
 NSData *theData = [NSData dataWithBytes:[self UTF8String] length:[self length]]; 

 return [theData newStringInBase64FromData];
}

@end

Android dex gives a BufferOverflowException when building

Try what van said:

Right click your projectandroid toolsandroid support library.

Hope this helps :)

Convert double to float in Java

Convert Double to Float

public static Float convertToFloat(Double doubleValue) {
    return doubleValue == null ? null : doubleValue.floatValue();
}

Convert double to Float

public static Float convertToFloat(double doubleValue) {
    return (float) doubleValue;
}

Is it possible to get element from HashMap by its position?

HashMap has no concept of position so there is no way to get an object by position. Objects in Maps are set and get by keys.

Regex to extract substring, returning 2 results for some reason

match returns an array.

The default string representation of an array in JavaScript is the elements of the array separated by commas. In this case the desired result is in the second element of the array:

var tesst = "afskfsd33j"
var test = tesst.match(/a(.*)j/);
alert (test[1]);

How to format a java.sql Timestamp for displaying?

If you're using MySQL and want the database itself to perform the conversion, use this:

DATE_FORMAT(date,format)

If you prefer to format using Java, use this:

java.text.SimpleDateFormat

SimpleDateFormat dateFormat = new SimpleDateFormat("M/dd/yyyy");
dateFormat.format( new Date() );

How to set data attributes in HTML elements

You can also use the following attr thing;

HTML

<div id="mydiv" data-myval="JohnCena"></div>

Script

 $('#mydiv').attr('data-myval', 'Undertaker'); // sets 
 $('#mydiv').attr('data-myval'); // gets

OR

$('#mydiv').data('myval'); // gets value
$('#mydiv').data('myval','John Cena'); // sets value

error: expected unqualified-id before ‘.’ token //(struct)

The struct's name is ReducedForm; you need to make an object (instance of the struct or class) and use that. Do this:

ReducedForm MyReducedForm;
MyReducedForm.iSimplifiedNumerator = iNumerator/iGreatCommDivisor;
MyReducedForm.iSimplifiedDenominator = iDenominator/iGreatCommDivisor;

I need to convert an int variable to double

I think you should casting variable or use Integer class by call out method doubleValue().

How to load external scripts dynamically in Angular?

@d123546 I faced the same issue and got it working now using ngAfterContentInit (Lifecycle Hook) in the component like this :

import { Component, OnInit, AfterContentInit } from '@angular/core';
import { Router } from '@angular/router';
import { ScriptService } from '../../script.service';

@Component({
    selector: 'app-players-list',
    templateUrl: './players-list.component.html',
    styleUrls: ['./players-list.component.css'],
    providers: [ ScriptService ]
})
export class PlayersListComponent implements OnInit, AfterContentInit {

constructor(private router: Router, private script: ScriptService) {
}

ngOnInit() {
}

ngAfterContentInit() {
    this.script.load('filepicker', 'rangeSlider').then(data => {
    console.log('script loaded ', data);
    }).catch(error => console.log(error));
}

Predicate in Java

A predicate is a function that returns a true/false (i.e. boolean) value, as opposed to a proposition which is a true/false (i.e. boolean) value. In Java, one cannot have standalone functions, and so one creates a predicate by creating an interface for an object that represents a predicate and then one provides a class that implements that interface. An example of an interface for a predicate might be:

public interface Predicate<ARGTYPE>
{
    public boolean evaluate(ARGTYPE arg);
}

And then you might have an implementation such as:

public class Tautology<E> implements Predicate<E>
{
     public boolean evaluate(E arg){
         return true;
     }
}

To get a better conceptual understanding, you might want to read about first-order logic.

Edit
There is a standard Predicate interface (java.util.function.Predicate) defined in the Java API as of Java 8. Prior to Java 8, you may find it convenient to reuse the com.google.common.base.Predicate interface from Guava.

Also, note that as of Java 8, it is much simpler to write predicates by using lambdas. For example, in Java 8 and higher, one can pass p -> true to a function instead of defining a named Tautology subclass like the above.

OSX -bash: composer: command not found

Globally install Composer on OS X 10.11 El Capitan

This command will NOT work in OS X 10.11:

curl -sS https://getcomposer.org/installer | sudo php -- --install-dir=/usr/bin --filename=composer 

Instead, let's write to the /usr/local/bin path for the user:

curl -sS https://getcomposer.org/installer | sudo php -- --install-dir=/usr/local/bin --filename=composer

Now we can access the composer command globally, just like before.

move_uploaded_file gives "failed to open stream: Permission denied" error

I have tried all the solutions above, but the following solved my problem

chcon -R -t httpd_sys_rw_content_t your_file_directory

Use tab to indent in textarea

Simple standalone script:

textarea_enable_tab_indent = function(textarea) {    
    textarea.onkeydown = function(e) {
        if (e.keyCode == 9 || e.which == 9){
            e.preventDefault();
            var oldStart = this.selectionStart;
            var before   = this.value.substring(0, this.selectionStart);
            var selected = this.value.substring(this.selectionStart, this.selectionEnd);
            var after    = this.value.substring(this.selectionEnd);
            this.value = before + "    " + selected + after;
            this.selectionEnd = oldStart + 4;
        }
    }
}

Ruby/Rails: converting a Date to a UNIX timestamp

Solution for Ruby 1.8 when you have an arbitrary DateTime object:

1.8.7-p374 :001 > require 'date'
 => true 
1.8.7-p374 :002 > DateTime.new(2012, 1, 15).strftime('%s')
 => "1326585600"

How to detect when WIFI Connection has been established in Android?

To detect WIFI connection state, I have used CONNECTIVITY_ACTION from ConnectivityManager class so:

    IntentFilter filter=new IntentFilter();
    filter.addAction(ConnectivityManager.CONNECTIVITY_ACTION);
    registerReceiver(receiver, filter);

and from your BroadCastReceiver:

    if (ConnectivityManager.CONNECTIVITY_ACTION.equals(action)) {
        int networkType = intent.getIntExtra(
                android.net.ConnectivityManager.EXTRA_NETWORK_TYPE, -1);
        if (ConnectivityManager.TYPE_WIFI == networkType) {
            NetworkInfo networkInfo = (NetworkInfo) intent
                    .getParcelableExtra(WifiManager.EXTRA_NETWORK_INFO);
            if (networkInfo != null) {
                if (networkInfo.isConnected()) {

                    // TODO: wifi is connected
                } else {
                    // TODO: wifi is not connected
                }
            }
        }

    }

ps:works fine for me:)

Best way to store data locally in .NET (C#)

A fourth option to those you mention are binary files. Although that sounds arcane and difficult, it's really easy with the serialization API in .NET.

Whether you choose binary or XML files, you can use the same serialization API, although you would use different serializers.

To binary serialize a class, it must be marked with the [Serializable] attribute or implement ISerializable.

You can do something similar with XML, although there the interface is called IXmlSerializable, and the attributes are [XmlRoot] and other attributes in the System.Xml.Serialization namespace.

If you want to use a relational database, SQL Server Compact Edition is free and very lightweight and based on a single file.

UTF-8 all the way through

The only thing I would add to these amazing answers is to emphasize on saving your files in utf8 encoding, i have noticed that browsers accept this property over setting utf8 as your code encoding. Any decent text editor will show you this, for example Notepad++ has a menu option for file enconding, it shows you the current encoding and enables you to change it. For all my php files I use utf8 without BOM.

Sometime ago i had someone ask me to add utf8 support for a php/mysql application designed by someone else, i noticed that all files were encoded in ANSI, so I had to use ICONV to convert all files, change the database tables to use the utf8 charset and utf8_general_ci collate, add 'SET NAMES utf8' to the database abstraction layer after the connection (if using 5.3.6 or earlier otherwise you have to use charset=utf8 in the connection string) and change string functions to use the php multibyte string functions equivalent.

AppStore - App status is ready for sale, but not in app store

You have to go to the "Pricing" menu. Even if the availability date is in the past, sometimes you have to set it again for today's date. Apple doesn't tell you to do this, but I found that the app goes live after resetting the dates again, especially if there's been app rejections in the past. I guess it messes up with the dates. Looks like sometimes if you do nothing and just follow the instructions, the app will never go live.

Convert date to datetime in Python

One way to convert from date to datetime that hasn't been mentioned yet:

from datetime import date, datetime
d = date.today()
datetime.strptime(d.strftime('%Y%m%d'), '%Y%m%d')

java comparator, how to sort by integer?

From Java 8 you can use :

Comparator.comparingInt(Dog::getDogAge).reversed();

ALTER DATABASE failed because a lock could not be placed on database

I will add this here in case someone will be as lucky as me.

When reviewing the sp_who2 list of processes note the processes that run not only for the effected database but also for master. In my case the issue that was blocking the database was related to a stored procedure that started a xp_cmdshell.

Check if you have any processes in KILL/RollBack state for master database

SELECT *
FROM sys.sysprocesses
WHERE cmd = 'KILLED/ROLLBACK'

If you have the same issue, just the KILL command will probably not help. You can restarted the SQL server, or better way is to find the cmd.exe under windows processes on SQL server OS and kill it.

Remove title in Toolbar in appcompat-v7

The correct way to hide/change the Toolbar Title is this:

Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
getSupportActionBar().setTitle(null);

This because when you call setSupportActionBar(toolbar);, then the getSupportActionBar() will be responsible of handling everything to the Action Bar, not the toolbar object.

See here

View google chrome's cached pictures

This page contains all the cached urls

chrome://cache

Unfortunately to actually see the file you have to select everything on the page and paste it in this tool: http://www.sensefulsolutions.com/2012/01/viewing-chrome-cache-easy-way.html

Loop through columns and add string lengths as new columns

You can use lapply to pass each column to str_length, then cbind it to your original data.frame...

library(stringr)

out <- lapply( df , str_length )    
df <- cbind( df , out )

#     col1     col2 col1 col2
#1     abc adf qqwe    3    8
#2    abcd        d    4    1
#3       a        e    1    1
#4 abcdefg        f    7    1

How to solve javax.net.ssl.SSLHandshakeException Error?

Now I solved this issue in this way,

import javax.net.ssl.HttpsURLConnection;
import javax.net.ssl.SSLContext;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;
import java.io.OutputStream; 

// Create a trust manager that does not validate certificate chains like the default 

TrustManager[] trustAllCerts = new TrustManager[]{
        new X509TrustManager() {

            public java.security.cert.X509Certificate[] getAcceptedIssuers()
            {
                return null;
            }
            public void checkClientTrusted(java.security.cert.X509Certificate[] certs, String authType)
            {
                //No need to implement.
            }
            public void checkServerTrusted(java.security.cert.X509Certificate[] certs, String authType)
            {
                //No need to implement.
            }
        }
};

// Install the all-trusting trust manager
try 
{
    SSLContext sc = SSLContext.getInstance("SSL");
    sc.init(null, trustAllCerts, new java.security.SecureRandom());
    HttpsURLConnection.setDefaultSSLSocketFactory(sc.getSocketFactory());
} 
catch (Exception e) 
{
    System.out.println(e);
}

Of course this solution should only be used in scenarios, where it is not possible to install the required certifcates using keytool e.g. local testing with temporary certifcates.

Send mail via Gmail with PowerShell V2's Send-MailMessage

I had massive problems with getting any of those scripts to work with sending mail in powershell. Turned out you need to create an app-password for your gmail-account to authenticate in the script. Now it works flawlessly!

Calling Objective-C method from C++ member function?

@DawidDrozd's answer above is excellent.

I would add one point. Recent versions of the Clang compiler complain about requiring a "bridging cast" if attempting to use his code.

This seems reasonable: using a trampoline creates a potential bug: since Objective-C classes are reference counted, if we pass their address around as a void *, we risk having a hanging pointer if the class is garbage collected up while the callback is still active.

Solution 1) Cocoa provides CFBridgingRetain and CFBridgingRelease macro functions which presumably add and subtract one from the reference count of the Objective-C object. We should therefore be careful with multiple callbacks, to release the same number of times as we retain.

// C++ Module
#include <functional>

void cppFnRequiringCallback(std::function<void(void)> callback) {
        callback();
}

//Objective-C Module
#import "CppFnRequiringCallback.h"

@interface MyObj : NSObject
- (void) callCppFunction;
- (void) myCallbackFn;
@end

void cppTrampoline(const void *caller) {
        id callerObjC = CFBridgingRelease(caller);
        [callerObjC myCallbackFn];
}

@implementation MyObj
- (void) callCppFunction {
        auto callback = [self]() {
                const void *caller = CFBridgingRetain(self);
                cppTrampoline(caller);
        };
        cppFnRequiringCallback(callback);
}

- (void) myCallbackFn {
    NSLog(@"Received callback.");
}
@end

Solution 2) The alternative is to use the equivalent of a weak reference (ie. no change to the retain count), without any additional safety.

The Objective-C language provides the __bridge cast qualifier to do this (CFBridgingRetain and CFBridgingRelease seem to be thin Cocoa wrappers over the Objective-C language constructs __bridge_retained and release respectively, but Cocoa does not appear to have an equivalent for __bridge).

The required changes are:

void cppTrampoline(void *caller) {
        id callerObjC = (__bridge id)caller;
        [callerObjC myCallbackFn];
}

- (void) callCppFunction {
        auto callback = [self]() {
                void *caller = (__bridge void *)self;
                cppTrampoline(caller);
        };
        cppFunctionRequiringCallback(callback);
}

How to find what code is run by a button or element in Chrome using Developer Tools

Sounds like the "...and I jump line by line..." part is wrong. Do you StepOver or StepIn and are you sure you don't accidentally miss the relevant call?

That said, debugging frameworks can be tedious for exactly this reason. To alleviate the problem, you can enable the "Enable frameworks debugging support" experiment. Happy debugging! :)

Trigger Change event when the Input value changed programmatically?

If someone is using react, following will be useful:

https://stackoverflow.com/a/62111884/1015678

const valueSetter = Object.getOwnPropertyDescriptor(this.textInputRef, 'value').set;
const prototype = Object.getPrototypeOf(this.textInputRef);
const prototypeValueSetter = Object.getOwnPropertyDescriptor(prototype, 'value').set;
if (valueSetter && valueSetter !== prototypeValueSetter) {
    prototypeValueSetter.call(this.textInputRef, 'new value');
} else {
    valueSetter.call(this.textInputRef, 'new value');
}
this.textInputRef.dispatchEvent(new Event('input', { bubbles: true }));

Implementing INotifyPropertyChanged - does a better way exist?

I think people should pay a little more attention to performance; it really does impact the UI when there are a lot of objects to be bound (think of a grid with 10,000+ rows), or if the object's value changes frequently (real-time monitoring app).

I took various implementation found here and elsewhere and did a comparison; check it out perfomance comparison of INotifyPropertyChanged implementations.


Here is a peek at the result Implemenation vs Runtime

Run-time error '1004' - Method 'Range' of object'_Global' failed

Your range value is incorrect. You are referencing cell "75" which does not exist. You might want to use the R1C1 notation to use numeric columns easily without needing to convert to letters.

http://www.bettersolutions.com/excel/EED883/YI416010881.htm

Range("R" & DataImportRow & "C" & DataImportColumn).Offset(0, 2).Value = iFirstCustomerSales

This should fix your problem.

Is there an upside down caret character?

I'd use a couple of tiny images. Would look better too.

Alternatively, you can try the Character Map utility that comes with Windows or try looking here.

Another solution I've seen is to use the Wingdings font for symbols. That has a lot fo arrows.

Display number always with 2 decimal places in <input>

AngularJS - Input number with 2 decimal places it could help... Filtering:

  1. Set the regular expression to validate the input using ng-pattern. Here I want to accept only numbers with a maximum of 2 decimal places and with a dot separator.
<input type="number" name="myDecimal" placeholder="Decimal" ng-model="myDecimal | number : 2" ng-pattern="/^[0-9]+(\.[0-9]{1,2})?$/" step="0.01" />

Reading forward this was pointed on the next answer ng-model="myDecimal | number : 2".

What is the difference between "long", "long long", "long int", and "long long int" in C++?

Historically, in early C times, when processors had 8 or 16 bit wordlength,intwas identical to todays short(16 bit). In a certain sense, int is a more abstract data type thanchar,short,longorlong long, as you cannot be sure about the bitwidth.

When definingint n;you could translate this with "give me the best compromise of bitwidth and speed on this machine for n". Maybe in the future you should expect compilers to translateintto be 64 bit. So when you want your variable to have 32 bits and not more, better use an explicitlongas data type.

[Edit: #include <stdint.h> seems to be the proper way to ensure bitwidths using the int##_t types, though it's not yet part of the standard.]

Converting String To Float in C#

You can double.Parse("41.00027357629127");

Send inline image in email

I added the complete code below to display images in Gmail,Thunderbird and other email clients :

MailMessage mailWithImg = getMailWithImg();
MySMTPClient.Send(mailWithImg); //* Set up your SMTPClient before!

private MailMessage getMailWithImg()
{
    MailMessage mail = new MailMessage();
    mail.IsBodyHtml = true;
    mail.AlternateViews.Add(getEmbeddedImage("c:/image.png"));
    mail.From = new MailAddress("yourAddress@yourDomain");
    mail.To.Add("recipient@hisDomain");
    mail.Subject = "yourSubject";
    return mail;
}
private AlternateView getEmbeddedImage(String filePath)
 {
    // below line was corrected to include the mediatype so it displays in all 
    // mail clients. previous solution only displays in Gmail the inline images 
    LinkedResource res = new LinkedResource(filePath, MediaTypeNames.Image.Jpeg);  
    res.ContentId = Guid.NewGuid().ToString();
    string htmlBody = @"<img src='cid:" + res.ContentId + @"'/>";
    AlternateView alternateView = AlternateView.CreateAlternateViewFromString(htmlBody,  
     null, MediaTypeNames.Text.Html);
    alternateView.LinkedResources.Add(res);
    return alternateView;
}

Syntax for a single-line Bash infinite while loop

If I can give two practical examples (with a bit of "emotion").

This writes the name of all files ended with ".jpg" in the folder "img":

for f in *; do if [ "${f#*.}" == 'jpg' ]; then echo $f; fi; done

This deletes them:

for f in *; do if [ "${f#*.}" == 'jpg' ]; then rm -r $f; fi; done

Just trying to contribute.

Store text file content line by line into array

You can use this code. This works very fast!

public String[] loadFileToArray(String fileName) throws IOException {
    String s = new String(Files.readAllBytes(Paths.get(fileName)));
    return Arrays.stream(s.split("\n")).toArray(String[]::new);
}

Writing unit tests in Python: How do I start?

nosetests is brilliant solution for unit-testing in python. It supports both unittest based testcases and doctests, and gets you started with it with just simple config file.

Switch on Enum in Java

You might be using the enums incorrectly in the switch cases. In comparison with the above example by CoolBeans.. you might be doing the following:

switch(day) {
    case Day.MONDAY:
        // Something..
        break;
    case Day.FRIDAY:
        // Something friday
        break;
}

Make sure that you use the actual enum values instead of EnumType.EnumValue

Eclipse points out this mistake though..

Error: package or namespace load failed for ggplot2 and for data.table

Faced same issue and solved by :

remove.packages("ggplot2")
install.packages('ggplot2', dependencies = TRUE)

How to use support FileProvider for sharing content to other apps?

just to improve answer given above: if you are getting NullPointerEx:

you can also use getApplicationContext() without context

                List<ResolveInfo> resInfoList = getPackageManager().queryIntentActivities(takePictureIntent, PackageManager.MATCH_DEFAULT_ONLY);
                for (ResolveInfo resolveInfo : resInfoList) {
                    String packageName = resolveInfo.activityInfo.packageName;
                    grantUriPermission(packageName, photoURI, Intent.FLAG_GRANT_WRITE_URI_PERMISSION | Intent.FLAG_GRANT_READ_URI_PERMISSION);
                }

How to iterate a loop with index and element in Swift

Using .enumerate() works, but it does not provide the true index of the element; it only provides an Int beginning with 0 and incrementing by 1 for each successive element. This is usually irrelevant, but there is the potential for unexpected behavior when used with the ArraySlice type. Take the following code:

let a = ["a", "b", "c", "d", "e"]
a.indices //=> 0..<5

let aSlice = a[1..<4] //=> ArraySlice with ["b", "c", "d"]
aSlice.indices //=> 1..<4

var test = [Int: String]()
for (index, element) in aSlice.enumerate() {
    test[index] = element
}
test //=> [0: "b", 1: "c", 2: "d"] // indices presented as 0..<3, but they are actually 1..<4
test[0] == aSlice[0] // ERROR: out of bounds

It's a somewhat contrived example, and it's not a common issue in practice but still I think it's worth knowing this can happen.

Navigation Drawer (Google+ vs. YouTube)

Personally I like the navigationDrawer in Google Drive official app. It just works and works great. I agree that the navigation drawer shouldn't move the action bar because is the key point to open and close the navigation drawer.

If you are still trying to get that behavior I recently create a project Called SherlockNavigationDrawer and as you may expect is the implementation of the Navigation Drawer with ActionBarSherlock and works for pre Honeycomb devices. Check it:

SherlockNavigationDrawer github

Android, canvas: How do I clear (delete contents of) a canvas (= bitmaps), living in a surfaceView?

Draw transparent color with PorterDuff clear mode does the trick for what I wanted.

Canvas.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR)

Find and extract a number from a string

if the number has a decimal points, you can use below

using System;
using System.Text.RegularExpressions;

namespace Rextester
{
    public class Program
    {
        public static void Main(string[] args)
        {
            //Your code goes here
            Console.WriteLine(Regex.Match("anything 876.8 anything", @"\d+\.*\d*").Value);
            Console.WriteLine(Regex.Match("anything 876 anything", @"\d+\.*\d*").Value);
            Console.WriteLine(Regex.Match("$876435", @"\d+\.*\d*").Value);
            Console.WriteLine(Regex.Match("$876.435", @"\d+\.*\d*").Value);
        }
    }
}

results :

"anything 876.8 anything" ==> 876.8

"anything 876 anything" ==> 876

"$876435" ==> 876435

"$876.435" ==> 876.435

Sample : https://dotnetfiddle.net/IrtqVt

How to script FTP upload and download?

I know this is an old question, but I wanted to add something to the answers already here in hopes of helping someone else.

You can script the ftp command with the -s:filename option. The syntax is just a list of commands to pass to the ftp shell, each terminated by a newline. This page has a nice reference to the commands that can be performed with ftp.

Upload/Download Entire Directory Structure

Using the normal ftp doesn't work very well when you need to have an entire directory tree copied to or from a ftp site. So you could use something like these to handle those situations.

These scripts works with the Windows ftp command and allows for uploading and downloading of entire directories from a single command. This makes it pretty self reliant when using on different systems.

Basically what they do is map out the directory structure to be up/downloaded, dump corresponding ftp commands to a file, then execute those commands when the mapping has finished.

ftpupload.bat

@echo off

SET FTPADDRESS=%1
SET FTPUSERNAME=%2
SET FTPPASSWORD=%3
SET LOCALDIR=%~f4
SET REMOTEDIR=%5

if "%FTPADDRESS%" == "" goto FTP_UPLOAD_USAGE
if "%FTPUSERNAME%" == "" goto FTP_UPLOAD_USAGE
if "%FTPPASSWORD%" == "" goto FTP_UPLOAD_USAGE
if "%LOCALDIR%" == "" goto FTP_UPLOAD_USAGE
if "%REMOTEDIR%" == "" goto FTP_UPLOAD_USAGE

:TEMP_NAME
set TMPFILE=%TMP%\%RANDOM%_ftpupload.tmp
if exist "%TMPFILE%" goto TEMP_NAME 

SET INITIALDIR=%CD%

echo user %FTPUSERNAME% %FTPPASSWORD% > %TMPFILE%
echo bin >> %TMPFILE%
echo lcd %LOCALDIR% >> %TMPFILE%

cd %LOCALDIR%

setlocal EnableDelayedExpansion
echo mkdir !REMOTEDIR! >> !TMPFILE!
echo cd %REMOTEDIR% >> !TMPFILE!
echo mput * >> !TMPFILE!
for /d /r %%d in (*) do (
    set CURRENT_DIRECTORY=%%d
    set RELATIVE_DIRECTORY=!CURRENT_DIRECTORY:%LOCALDIR%=!
    echo mkdir "!REMOTEDIR!/!RELATIVE_DIRECTORY:~1!" >> !TMPFILE!
    echo cd "!REMOTEDIR!/!RELATIVE_DIRECTORY:~1!" >> !TMPFILE!
    echo mput "!RELATIVE_DIRECTORY:~1!\*" >> !TMPFILE!
)

echo quit >> !TMPFILE!

endlocal EnableDelayedExpansion

ftp -n -i "-s:%TMPFILE%" %FTPADDRESS%

del %TMPFILE%

cd %INITIALDIR%

goto FTP_UPLOAD_EXIT

:FTP_UPLOAD_USAGE

echo Usage: ftpupload [address] [username] [password] [local directory] [remote directory]
echo.

:FTP_UPLOAD_EXIT

set INITIALDIR=
set FTPADDRESS=
set FTPUSERNAME=
set FTPPASSWORD=
set LOCALDIR=
set REMOTEDIR=
set TMPFILE=
set CURRENT_DIRECTORY=
set RELATIVE_DIRECTORY=

@echo on

ftpget.bat

@echo off

SET FTPADDRESS=%1
SET FTPUSERNAME=%2
SET FTPPASSWORD=%3
SET LOCALDIR=%~f4
SET REMOTEDIR=%5
SET REMOTEFILE=%6

if "%FTPADDRESS%" == "" goto FTP_UPLOAD_USAGE
if "%FTPUSERNAME%" == "" goto FTP_UPLOAD_USAGE
if "%FTPPASSWORD%" == "" goto FTP_UPLOAD_USAGE
if "%LOCALDIR%" == "" goto FTP_UPLOAD_USAGE
if not defined REMOTEDIR goto FTP_UPLOAD_USAGE
if not defined REMOTEFILE goto FTP_UPLOAD_USAGE

:TEMP_NAME
set TMPFILE=%TMP%\%RANDOM%_ftpupload.tmp
if exist "%TMPFILE%" goto TEMP_NAME 

echo user %FTPUSERNAME% %FTPPASSWORD% > %TMPFILE%
echo bin >> %TMPFILE%
echo lcd %LOCALDIR% >> %TMPFILE%

echo cd "%REMOTEDIR%" >> %TMPFILE%
echo mget "%REMOTEFILE%" >> %TMPFILE%
echo quit >> %TMPFILE%

ftp -n -i "-s:%TMPFILE%" %FTPADDRESS%

del %TMPFILE%

goto FTP_UPLOAD_EXIT

:FTP_UPLOAD_USAGE

echo Usage: ftpget [address] [username] [password] [local directory] [remote directory] [remote file pattern]
echo.

:FTP_UPLOAD_EXIT

set FTPADDRESS=
set FTPUSERNAME=
set FTPPASSWORD=
set LOCALDIR=
set REMOTEFILE=
set REMOTEDIR=
set TMPFILE=
set CURRENT_DIRECTORY=
set RELATIVE_DIRECTORY=

@echo on

Mime type for WOFF fonts?

It will be application/font-woff.

see http://www.w3.org/TR/WOFF/#appendix-b (W3C Candidate Recommendation 04 August 2011)

and http://www.w3.org/2002/06/registering-mediatype.html

From Mozilla css font-face notes

In Gecko, web fonts are subject to the same domain restriction (font files must be on the same domain as the page using them), unless HTTP access controls are used to relax this restriction. Note: Because there are no defined MIME types for TrueType, OpenType, and WOFF fonts, the MIME type of the file specified is not considered.

source: https://developer.mozilla.org/en/CSS/@font-face#Notes

Error: TypeError: $(...).dialog is not a function

Here are the complete list of scripts required to get rid of this problem. (Make sure the file exists at the given file path)

   <script src="@Url.Content("~/Scripts/jquery-1.8.2.js")" type="text/javascript">
    </script>
    <script src="@Url.Content("~/Scripts/jquery-ui-1.8.24.js")" type="text/javascript">
    </script>
    <script src="@Url.Content("~/Scripts/jquery.validate.js")" type="text/javascript">
    </script>
    <script src="@Url.Content("~/Scripts/jquery.validate.unobtrusive.js")" type="text/javascript">
    </script>
    <script src="@Url.Content("~/Scripts/jquery.unobtrusive-ajax.js")" type="text/javascript">
    </script>

and also include the below css link in _Layout.cshtml for a stylish popup.

<link rel="stylesheet" type="text/css" href="../../Content/themes/base/jquery-ui.css" />

how to insert a new line character in a string to PrintStream then use a scanner to re-read the file

The linefeed character \n is not the line separator in certain operating systems (such as windows, where it's "\r\n") - my suggestion is that you use \r\n instead, then it'll both see the line-break with only \n and \r\n, I've never had any problems using it.

Also, you should look into using a StringBuilder instead of concatenating the String in the while-loop at BookCatalog.toString(), it is a lot more effective. For instance:

public String toString() {
        BookNode current = front;
        StringBuilder sb = new StringBuilder();
        while (current!=null){
            sb.append(current.getData().toString()+"\r\n ");
            current = current.getNext();
        }
        return sb.toString();
}

How to call a parent class function from derived class function?

If access modifier of base class member function is protected OR public, you can do call member function of base class from derived class. Call to the base class non-virtual and virtual member function from derived member function can be made. Please refer the program.

#include<iostream>
using namespace std;

class Parent
{
  protected:
    virtual void fun(int i)
    {
      cout<<"Parent::fun functionality write here"<<endl;
    }
    void fun1(int i)
    {
      cout<<"Parent::fun1 functionality write here"<<endl;
    }
    void fun2()
    {

      cout<<"Parent::fun3 functionality write here"<<endl;
    }

};

class Child:public Parent
{
  public:
    virtual void fun(int i)
    {
      cout<<"Child::fun partial functionality write here"<<endl;
      Parent::fun(++i);
      Parent::fun2();
    }
    void fun1(int i)
    {
      cout<<"Child::fun1 partial functionality write here"<<endl;
      Parent::fun1(++i);
    }

};
int main()
{
   Child d1;
   d1.fun(1);
   d1.fun1(2);
   return 0;
}

Output:

$ g++ base_function_call_from_derived.cpp
$ ./a.out 
Child::fun partial functionality write here
Parent::fun functionality write here
Parent::fun3 functionality write here
Child::fun1 partial functionality write here
Parent::fun1 functionality write here

downcast and upcast

In case you need to check each of the Employee object whether it is a Manager object, use the OfType method:

List<Employee> employees = new List<Employee>();

//Code to add some Employee or Manager objects..

var onlyManagers = employees.OfType<Manager>();

foreach (Manager m in onlyManagers) {
  // Do Manager specific thing..
}

MongoDB relationships: embed or reference?

If I want to edit a specified comment, how to get its content and its question?

You can query by sub-document: db.question.find({'comments.content' : 'xxx'}).

This will return the whole Question document. To edit the specified comment, you then have to find the comment on the client, make the edit and save that back to the DB.

In general, if your document contains an array of objects, you'll find that those sub-objects will need to be modified client side.

Change multiple files

Another more versatile way is to use find:

sed -i 's/asd/dsg/g' $(find . -type f -name 'xa*')

"’" showing on page instead of " ' "

If someone gets this error on WordPress website, you need to change wp-config db charset:

define('DB_CHARSET', 'utf8mb4_unicode_ci');

instead of:

define('DB_CHARSET', 'utf8mb4');

Server configuration is missing in Eclipse

You need to define the server instance in the Servers view.

In the box at the right bottom, press the Servers tab and add the server there. You by the way don't necessarily need to add it through global IDE preferences. It will be automagically added when you define it in Servers view. The preference you've modified just defines default locations, not the whole server instance itself. If you for instance upgrade/move the server, you can change the physical location there.

Once defining the server in the Servers view, you need to add the newly created server instance to the project through its Server and Targeted runtime preference.

How to find children of nodes using BeautifulSoup

Perhaps you want to do

soup.find("li", { "class" : "test" }).find('a')

npm can't find package.json

Update 2018

This is becoming quite a popular question and my answer (although marked as correct) is no longer valid. Please refer to Deepali's answer below:

npm init

Original Outdated Answer

I think you forgot to setup the directory for express:

express <yourdirectory>

Once you do that you should be able to see a bunch of files, you should then run the command:

npm install -d

Regards.

Python socket.error: [Errno 111] Connection refused

The problem obviously was (as you figured it out) that port 36250 wasn't open on the server side at the time you tried to connect (hence connection refused). I can see the server was supposed to open this socket after receiving SEND command on another connection, but it apparently was "not opening [it] up in sync with the client side".

Well, the main reason would be there was no synchronisation whatsoever. Calling:

cs.send("SEND " + FILE)
cs.close()

would just place the data into a OS buffer; close would probably flush the data and push into the network, but it would almost certainly return before the data would reach the server. Adding sleep after close might mitigate the problem, but this is not synchronisation.

The correct solution would be to make sure the server has opened the connection. This would require server sending you some message back (for example OK, or better PORT 36250 to indicate where to connect). This would make sure the server is already listening.

The other thing is you must check the return values of send to make sure how many bytes was taken from your buffer. Or use sendall.

(Sorry for disturbing with this late answer, but I found this to be a high traffic question and I really didn't like the sleep idea in the comments section.)

Using Mockito to stub and execute methods for testing

SHORT ANSWER

How to do in your case:

int argument = 5; // example with int but could be another type
Mockito.when(mockMyAgent.otherMethod(Mockito.anyInt()).thenReturn(requiredReturnArg(argument));

LONG ANSWER

Actually what you want to do is possible, at least in Java 8. Maybe you didn't get this answer by other people because I am using Java 8 that allows that and this question is before release of Java 8 (that allows to pass functions, not only values to other functions).

Let's simulate a call to a DataBase query. This query returns all the rows of HotelTable that have FreeRoms = X and StarNumber = Y. What I expect during testing, is that this query will give back a List of different hotel: every returned hotel has the same value X and Y, while the other values and I will decide them according to my needs. The following example is simple but of course you can make it more complex.

So I create a function that will give back different results but all of them have FreeRoms = X and StarNumber = Y.

static List<Hotel> simulateQueryOnHotels(int availableRoomNumber, int starNumber) {
    ArrayList<Hotel> HotelArrayList = new ArrayList<>();
    HotelArrayList.add(new Hotel(availableRoomNumber, starNumber, Rome, 1, 1));
    HotelArrayList.add(new Hotel(availableRoomNumber, starNumber, Krakow, 7, 15));
    HotelArrayList.add(new Hotel(availableRoomNumber, starNumber, Madrid, 1, 1));
    HotelArrayList.add(new Hotel(availableRoomNumber, starNumber, Athens, 4, 1));

    return HotelArrayList;
}

Maybe Spy is better (please try), but I did this on a mocked class. Here how I do (notice the anyInt() values):

//somewhere at the beginning of your file with tests...
@Mock
private DatabaseManager mockedDatabaseManager;

//in the same file, somewhere in a test...
int availableRoomNumber = 3;
int starNumber = 4;
// in this way, the mocked queryOnHotels will return a different result according to the passed parameters
when(mockedDatabaseManager.queryOnHotels(anyInt(), anyInt())).thenReturn(simulateQueryOnHotels(availableRoomNumber, starNumber));

LINQ - Full Outer Join

As you've found, Linq doesn't have an "outer join" construct. The closest you can get is a left outer join using the query you stated. To this, you can add any elements of the lastname list that aren't represented in the join:

outerJoin = outerJoin.Concat(lastNames.Select(l=>new
                            {
                                id = l.ID,
                                firstname = String.Empty,
                                surname = l.Name
                            }).Where(l=>!outerJoin.Any(o=>o.id == l.id)));

How to manually reload Google Map with JavaScript

Yes, you can 'refresh' a Google Map like this:

google.maps.event.trigger(map, 'resize');

This basically sends a signal to your map to redraw it.

Hope that helps!

What are the differences between char literals '\n' and '\r' in Java?

The above answers provided are perfect. The LF(\n), CR(\r) and CRLF(\r\n) characters are platform dependent. However, the interpretation for these characters is not only defined by the platforms but also the console that you are using. In Intellij console (Windows), this \r character in this statement System.out.print("Happ\ry"); produces the output y. But, if you use the terminal (Windows), you will get yapp as the output.

Unable to resolve host "<insert URL here>" No address associated with hostname

Also, make sure that your device isn't on airplane mode and/or that data usage is enabled.

Regex to extract URLs from href attribute in HTML with Python

import re

url = '<p>Hello World</p><a href="http://example.com">More Examples</a><a href="http://example2.com">Even More Examples</a>'

urls = re.findall('https?://(?:[-\w.]|(?:%[\da-fA-F]{2}))+', url)

>>> print urls
['http://example.com', 'http://example2.com']

"application blocked by security settings" prevent applets running using oracle SE 7 update 51 on firefox on Linux mint

Just start your browser with superuser rights, and don't forget to set Java's JRE security to medium.

Setting active profile and config location from command line in spring boot

A way that i do this on intellij is setting an environment variable on the command like so:

test setup on intellij

In this case i am setting the profile to test

Mean Squared Error in Numpy?

The standard numpy methods for calculation mean squared error (variance) and its square root (standard deviation) are numpy.var() and numpy.std(), see here and here. They apply to matrices and have the same syntax as numpy.mean().

I suppose that the question and the preceding answers might have been posted before these functions became available.

What does it mean to bind a multicast (UDP) socket?

The "bind" operation is basically saying, "use this local UDP port for sending and receiving data. In other words, it allocates that UDP port for exclusive use for your application. (Same holds true for TCP sockets).

When you bind to "0.0.0.0" (INADDR_ANY), you are basically telling the TCP/IP layer to use all available adapters for listening and to choose the best adapter for sending. This is standard practice for most socket code. The only time you wouldn't specify 0 for the IP address is when you want to send/receive on a specific network adapter.

Similarly if you specify a port value of 0 during bind, the OS will assign a randomly available port number for that socket. So I would expect for UDP multicast, you bind to INADDR_ANY on a specific port number where multicast traffic is expected to be sent to.

The "join multicast group" operation (IP_ADD_MEMBERSHIP) is needed because it basically tells your network adapter to listen not only for ethernet frames where the destination MAC address is your own, it also tells the ethernet adapter (NIC) to listen for IP multicast traffic as well for the corresponding multicast ethernet address. Each multicast IP maps to a multicast ethernet address. When you use a socket to send to a specific multicast IP, the destination MAC address on the ethernet frame is set to the corresponding multicast MAC address for the multicast IP. When you join a multicast group, you are configuring the NIC to listen for traffic sent to that same MAC address (in addition to its own).

Without the hardware support, multicast wouldn't be any more efficient than plain broadcast IP messages. The join operation also tells your router/gateway to forward multicast traffic from other networks. (Anyone remember MBONE?)

If you join a multicast group, all the multicast traffic for all ports on that IP address will be received by the NIC. Only the traffic destined for your binded listening port will get passed up the TCP/IP stack to your app. In regards to why ports are specified during a multicast subscription - it's because multicast IP is just that - IP only. "ports" are a property of the upper protocols (UDP and TCP).

You can read more about how multicast IP addresses map to multicast ethernet addresses at various sites. The Wikipedia article is about as good as it gets:

The IANA owns the OUI MAC address 01:00:5e, therefore multicast packets are delivered by using the Ethernet MAC address range 01:00:5e:00:00:00 - 01:00:5e:7f:ff:ff. This is 23 bits of available address space. The first octet (01) includes the broadcast/multicast bit. The lower 23 bits of the 28-bit multicast IP address are mapped into the 23 bits of available Ethernet address space.

Troubleshooting "Illegal mix of collations" error in mysql

MySQL really dislikes mixing collations unless it can coerce them to the same one (which clearly is not feasible in your case). Can't you just force the same collation to be used via a COLLATE clause? (or the simpler BINARY shortcut if applicable...).

Codesign error: Provisioning profile cannot be found after deleting expired profile

Select the lines in codesigning that are blank under Any iOS SDK and select the right certificate.

Eclipse CDT project built but "Launch Failed. Binary Not Found"

This worked for me.

Go to Project --> Properties --> Run/Debug Settings --> Click on the configuration & click "Edit", it will now open a "Edit Configuration".

Hit on "Search Project" , select the binary file from the "Binaries" and hit ok.

Note : Before doing all this, make sure you have done the below

--> Binary is generated once you execute "Build All" or (Ctrl+B)

jQuery's .on() method combined with the submit event

I had a problem with the same symtoms. In my case, it turned out that my submit function was missing the "return" statement.

For example:

 $("#id_form").on("submit", function(){
   //Code: Action (like ajax...)
   return false;
 })