Programs & Examples On #Rapid prototyping

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

I improved/fixed my extension method.

public  static class ControlsExtensions
{
    public static void ClearControls(this Control frm)
    {
        foreach (Control control in frm.Controls)
        {
            if (control is TextBox)
            {
                control.ResetText();
            }

            if (control.Controls.Count > 0)
            {
                control.ClearControls();
            }
        }
    }
}

How do I turn off Oracle password expiration?

To alter the password expiry policy for a certain user profile in Oracle first check which profile the user is using:

select profile from DBA_USERS where username = '<username>';

Then you can change the limit to never expire using:

alter profile <profile_name> limit password_life_time UNLIMITED;

If you want to previously check the limit you may use:

select resource_name,limit from dba_profiles where profile='<profile_name>';

Correct owner/group/permissions for Apache 2 site files/folders under Mac OS X?

2 month old thread, but better late than never! On 10.6, I have my webserver documents folder set to:

owner:root
group:_www
permission:755

_www is the user that runs apache under Mac OS X. I then added an ACL to allow full permissions to the Administrators group. That way, I can still make any changes with my admin user without having to authenticate as root. Also, when I want to allow the webserver to write to a folder, I can simply chmod to 775, leaving everyone other than root:_www with only read/execute permissions (excluding any ACLs that I have applied)

Python Brute Force algorithm

Use itertools.product, combined with itertools.chain to put the various lengths together:

from itertools import chain, product
def bruteforce(charset, maxlength):
    return (''.join(candidate)
        for candidate in chain.from_iterable(product(charset, repeat=i)
        for i in range(1, maxlength + 1)))

Demonstration:

>>> list(bruteforce('abcde', 2))
['a', 'b', 'c', 'd', 'e', 'aa', 'ab', 'ac', 'ad', 'ae', 'ba', 'bb', 'bc', 'bd', 'be', 'ca', 'cb', 'cc', 'cd', 'ce', 'da', 'db', 'dc', 'dd', 'de', 'ea', 'eb', 'ec', 'ed', 'ee']

This will efficiently produce progressively larger words with the input sets, up to length maxlength.

Do not attempt to produce an in-memory list of 26 characters up to length 10; instead, iterate over the results produced:

for attempt in bruteforce(string.ascii_lowercase, 10):
    # match it against your password, or whatever
    if matched:
        break

How do I use Apache tomcat 7 built in Host Manager gui?

To access "Host Manager" you have to configure "admin-gui" user inside the tomcat-users.xml

Just add the below lines[change username & pwd] :

<role rolename="admin-gui"/>
<user username="admin" password="password" roles="admin-gui"/>

Restart tomcat 7 server and you are done.

How to use if statements in LESS

LESS has guard expressions for mixins, not individual attributes.

So you'd create a mixin like this:

.debug(@debug) when (@debug = true) {
    header {
      background-color: yellow;
      #title {
          background-color: orange;
      }
    }

    article {
      background-color: red;
    }
}

And turn it on or off by calling .debug(true); or .debug(false) (or not calling it at all).

lambda expression for exists within list

I would look at the Join operator:

from r in list join i in listofIds on r.Id equals i select r

I'm not sure how this would be optimized over the Contains methods, but at least it gives the compiler a better idea of what you're trying to do. It's also sematically closer to what you're trying to achieve.

Edit: Extension method syntax for completeness (now that I've figured it out):

var results = listofIds.Join(list, i => i, r => r.Id, (i, r) => r);

Get specific object by id from array of objects in AngularJS

    projectDetailsController.controller('ProjectDetailsCtrl', function ($scope, $routeParams, $http) {
    $http.get('data/projects.json').success(function(data) {

        $scope.projects = data;
        console.log(data);

        for(var i = 0; i < data.length; i++) {
        $scope.project = data[i];
        if($scope.project.name === $routeParams.projectName) {
            console.log('project-details',$scope.project);
        return $scope.project;
        }
        }

    });
});

Not sure if it's really good, but this was helpful for me.. I needed to use $scope to make it work properly.

Getting Checkbox Value in ASP.NET MVC 4

@Html.EditorFor(x => x.Remember)

Will generate:

<input id="Remember" type="checkbox" value="true" name="Remember" />
<input type="hidden" value="false" name="Remember" />

How does it work:

  • If checkbox remains unchecked, the form submits only the hidden value (false)
  • If checked, then the form submits two fields (false and true) and MVC sets true for the model's bool property

<input id="Remember" name="Remember" type="checkbox" value="@Model.Remember" />

This will always send the default value, if checked.

I forgot the password I entered during postgres installation

Add below line to your pg_hba.conf file. which will be present in installation directory of postgres

hostnossl    all          all            0.0.0.0/0  trust   

It will start working.

Run a Docker image as a container

Since you have created an image from the Dockerfile, the image currently is not in active state. In order to work you need to run this image inside a container.

The $ docker images command describes how many images are currently available in the local repository. and

docker ps -a

shows how many containers are currently available, i.e. the list of active and exited containers.

There are two ways to run the image in the container:

$ docker run [OPTIONS] IMAGE[:TAG|@DIGEST] [COMMAND] [ARG...]

In detached mode:

-d=false: Detached mode: Run container in the background, print new container id

In interactive mode:

-i :Keep STDIN open even if not attached

Here is the Docker run command

$ docker run image_name:tag_name

For more clarification on Docker run, you can visit Docker run reference.

It's the best material to understand Docker.

How do I concatenate const/literal strings in C?

The first argument of strcat() needs to be able to hold enough space for the concatenated string. So allocate a buffer with enough space to receive the result.

char bigEnough[64] = "";

strcat(bigEnough, "TEXT");
strcat(bigEnough, foo);

/* and so on */

strcat() will concatenate the second argument with the first argument, and store the result in the first argument, the returned char* is simply this first argument, and only for your convenience.

You do not get a newly allocated string with the first and second argument concatenated, which I'd guess you expected based on your code.

Split a large pandas dataframe

I guess now we can use plain iloc with range for this.

chunk_size = int(df.shape[0] / 4)
for start in range(0, df.shape[0], chunk_size):
    df_subset = df.iloc[start:start + chunk_size]
    process_data(df_subset)
    ....

Unprotect workbook without password

No longer works for spreadsheets Protected with Excel 2013 or later -- they improved the pw hash. So now need to unzip .xlsx and hack the internals.

How to call Stored Procedure in Entity Framework 6 (Code-First)?

Using your example, here are two ways to accomplish this:

1 - Use Stored procedure mapping

Note that this code will work with or without mapping. If you turn off mapping on the entity, EF will generate an insert + select statement.

protected void btnSave_Click(object sender, EventArgs e)
{
     using (var db = DepartmentContext() )
     {
        var department = new Department();

        department.Name = txtDepartment.text.trim();

        db.Departments.add(department);
        db.SaveChanges();

        // EF will populate department.DepartmentId
        int departmentID = department.DepartmentId;
     }
}

2 - Call the stored procedure directly

protected void btnSave_Click(object sender, EventArgs e)
{
     using (var db = DepartmentContext() )
     {
        var name = new SqlParameter("@name", txtDepartment.text.trim());

        //to get this to work, you will need to change your select inside dbo.insert_department to include name in the resultset
        var department = db.Database.SqlQuery<Department>("dbo.insert_department @name", name).SingleOrDefault();

       //alternately, you can invoke SqlQuery on the DbSet itself:
       //var department = db.Departments.SqlQuery("dbo.insert_department @name", name).SingleOrDefault();

        int departmentID = department.DepartmentId;
     }
}

I recommend using the first approach, as you can work with the department object directly and not have to create a bunch of SqlParameter objects.

How to center a window on the screen in Tkinter?

This works also in Python 3.x and centers the window on screen:

from tkinter import *

app = Tk()
app.eval('tk::PlaceWindow . center')
app.mainloop()

What is a difference between unsigned int and signed int in C?

Because it's all just about memory, in the end all the numerical values are stored in binary.

A 32 bit unsigned integer can contain values from all binary 0s to all binary 1s.

When it comes to 32 bit signed integer, it means one of its bits (most significant) is a flag, which marks the value to be positive or negative.

C# - Winforms - Global Variables

The consensus here is to put the global variables in a static class as static members. When you create a new Windows Forms application, it usually comes with a Program class (Program.cs), which is a static class and serves as the main entry point of the application. It lives for the the whole lifetime of the app, so I think it is best to put the global variables there instead of creating a new one.

static class Program
{
    public static string globalString = "This is a global string.";

    /// <summary>
    /// The main entry point for the application.
    /// </summary>
    [STAThread]
    static void Main()
    {
        Application.EnableVisualStyles();
        Application.SetCompatibleTextRenderingDefault(false);
        Application.Run(new Form1());
    }
}

And use it as such:

public partial class Form1 : Form
{
    public Form1()
    {
        Program.globalString = "Accessible in Form1.";

        InitializeComponent();
    }
}

How do I add an active class to a Link from React Router?

The answer by Vijey has a bit of a problem when you're using react-redux for state management and some of the parent components are 'connected' to the redux store. The activeClassName is applied to Link only when the page is refreshed, and is not dynamically applied as the current route changes.

This is to do with the react-redux's connect function, as it suppresses context updates. To disable suppression of context updates, you can set pure: false when calling the connect() method like this:

//your component which has the custom NavLink as its child. 
//(this component may be the any component from the list of 
//parents and grandparents) eg., header

function mapStateToProps(state) {
  return { someprops: state.someprops }
}

export default connect(mapStateToProps, null, null, {
  pure: false
})(Header);

Check the issue here: reactjs#470

Check pure: false documentation here: docs

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?

What is the newline character in the C language: \r or \n?

It's \n. When you're reading or writing text mode files, or to stdin/stdout etc, you must use \n, and C will handle the translation for you. When you're dealing with binary files, by definition you are on your own.

How to encode a string in JavaScript for displaying in HTML?

function htmlEntities(str) {
    return String(str).replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;').replace(/"/g, '&quot;');
}

So then with var unsafestring = "<oohlook&atme>"; you would use htmlEntities(unsafestring);

Text-decoration: none not working

Try placing your text-decoration: none; on your a:hover css.

How to find char in string and get all the indexes?

As the rule of thumb, NumPy arrays often outperform other solutions while working with POD, Plain Old Data. A string is an example of POD and a character too. To find all the indices of only one char in a string, NumPy ndarrays may be the fastest way:

def find1(str, ch):
  # 0.100 seconds for 1MB str 
  npbuf = np.frombuffer(str, dtype=np.uint8) # Reinterpret str as a char buffer
  return np.where(npbuf == ord(ch))          # Find indices with numpy

def find2(str, ch):
  # 0.920 seconds for 1MB str 
  return [i for i, c in enumerate(str) if c == ch] # Find indices with python

SQL Server - Return value after INSERT

You can use scope_identity() to select the ID of the row you just inserted into a variable then just select whatever columns you want from that table where the id = the identity you got from scope_identity()

See here for the MSDN info http://msdn.microsoft.com/en-us/library/ms190315.aspx

Search for a string in all tables, rows and columns of a DB

To "find where the data I get comes from", you can start SQL Profiler, start your report or application, and you will see all the queries issued against your database.

Dividing two integers to produce a float result

Cast the operands to floats:

float ans = (float)a / (float)b;

Using Python 3 in virtualenv

Python 3 has a built-in support for virtual environments - venv. It might be better to use that instead. Referring to the docs:

Creation of virtual environments is done by executing the pyvenv script:

pyvenv /path/to/new/virtual/environment

Update for Python 3.6 and newer:

As pawciobiel correctly comments, pyvenv is deprecated as of Python 3.6 and the new way is:

python3 -m venv /path/to/new/virtual/environment

Trying to git pull with error: cannot open .git/FETCH_HEAD: Permission denied

Look at the owner and group of .git directory with (first go to parent directory of .git) ll .git , look at the group and owner of the directory, add your user to group of of the owner with sudo usermod -a -G yourusername groupsofonwner, then logout => login and everything getting work.

So in summeries

  1. go to parent directory of git

    $cd your path
    
  2. find group owner of the .git direcotry

    $ll .git     
    
  3. add your user to that group

    $usermod -a -G yourusername ownergroupofgit
    
  4. Logout and login to system to this change take effect.

  5. Enjoy it ;)

Append lines to a file using a StreamWriter

I assume you are executing all of the above code each time you write something to the file. Each time the stream for the file is opened, its seek pointer is positioned at the beginning so all writes end up overwriting what was there before.

You can solve the problem in two ways: either with the convenient

file2 = new StreamWriter("c:/file.txt", true);

or by explicitly repositioning the stream pointer yourself:

file2 = new StreamWriter("c:/file.txt");
file2.BaseStream.Seek(0, SeekOrigin.End);

jQuery Selector: Id Ends With?

An example: to select all <a>s with ID ending in _edit:

jQuery("a[id$=_edit]")

or

jQuery("a[id$='_edit']")

jQuery $(this) keyword

When you perform an DOM query through jQuery like $('class-name') it actively searched the DOM for that element and returns that element with all the jQuery prototype methods attached.

When you're within the jQuery chain or event you don't have to rerun the DOM query you can use the context $(this). Like so:

$('.class-name').on('click', (evt) => {
    $(this).hide(); // does not run a DOM query
    $('.class-name').hide() // runs a DOM query
}); 

$(this) will hold the element that you originally requested. It will attach all the jQuery prototype methods again, but will not have to search the DOM again.

Some more information:

Web Performance with jQuery selectors

Quote from a web blog that doesn't exist anymore but I'll leave it in here for history sake:

In my opinion, one of the best jQuery performance tips is to minimize your use of jQuery. That is, find a balance between using jQuery and plain ol’ JavaScript, and a good place to start is with ‘this‘. Many developers use $(this) exclusively as their hammer inside callbacks and forget about this, but the difference is distinct:

When inside a jQuery method’s anonymous callback function, this is a reference to the current DOM element. $(this) turns this into a jQuery object and exposes jQuery’s methods. A jQuery object is nothing more than a beefed-up array of DOM elements.

How to sort in mongoose?

This is what i did, it works fine.

User.find({name:'Thava'}, null, {sort: { name : 1 }})

React JSX: selecting "selected" on selected <select> option

I have a simple solution is following the HTML basic.

<input
  type="select"
  defaultValue=""
  >
  <option value="" disabled className="text-hide">Please select</option>
  <option>value1</option>
  <option>value1</option>
</input>

.text-hide is a bootstrap's class, if you not using bootstrap, here you are:

.text-hide {
  font: 0/0 a;
  color: transparent;
  text-shadow: none;
  background-color: transparent;
  border: 0;
}

Include PHP file into HTML file

Create a .htaccess file in directory and add this code to .htaccess file

AddHandler x-httpd-php .html .htm

or

AddType application/x-httpd-php .html .htm

It will force Apache server to parse HTML or HTM files as PHP Script

How to validate a file upload field using Javascript/jquery

I got this from some forum. I hope it will be useful for you.

<script type="text/javascript">
 function validateFileExtension(fld) {
    if(!/(\.bmp|\.gif|\.jpg|\.jpeg)$/i.test(fld.value)) {
        alert("Invalid image file type.");      
        fld.form.reset();
        fld.focus();        
        return false;   
    }   
    return true; 
 } </script> </head>
 <body> <form ...etc...  onsubmit="return
 validateFileExtension(this.fileField)"> <p> <input type="file"
 name="fileField"  onchange="return validateFileExtension(this)">
 <input type="submit" value="Submit"> </p> </form> </body>

VBScript - How to make program wait until process has finished?

Probably something like this? (UNTESTED)

Sub Sample()
    Dim strWB4, strMyMacro
    strMyMacro = "Sheet1.my_macro_name"

    '
    '~~> Rest of Code
    '

    'loop through the folder and get the file names
    For Each Fil In FLD.Files
        Set x4WB = x1.Workbooks.Open(Fil)
        x4WB.Application.Visible = True

        x1.Run strMyMacro

        x4WB.Close

        Do Until IsWorkBookOpen(Fil) = False
            DoEvents
        Loop
    Next

    '
    '~~> Rest of Code
    '
End Sub

'~~> Function to check if the file is open
Function IsWorkBookOpen(FileName As String)
    Dim ff As Long, ErrNo As Long

    On Error Resume Next
    ff = FreeFile()
    Open FileName For Input Lock Read As #ff
    Close ff
    ErrNo = Err
    On Error GoTo 0

    Select Case ErrNo
    Case 0:    IsWorkBookOpen = False
    Case 70:   IsWorkBookOpen = True
    Case Else: Error ErrNo
    End Select
End Function

"call to undefined function" error when calling class method

You dont have a function named assign(), but a method with this name. PHP is not Java and in PHP you have to make clear, if you want to call a function

assign()

or a method

$object->assign()

In your case the call to the function resides inside another method. $this always refers to the object, in which a method exists, itself.

$this->assign()

Python: Ignore 'Incorrect padding' error when base64 decoding

It seems you just need to add padding to your bytes before decoding. There are many other answers on this question, but I want to point out that (at least in Python 3.x) base64.b64decode will truncate any extra padding, provided there is enough in the first place.

So, something like: b'abc=' works just as well as b'abc==' (as does b'abc=====').

What this means is that you can just add the maximum number of padding characters that you would ever need—which is three (b'===')—and base64 will truncate any unnecessary ones.

This lets you write:

base64.b64decode(s + b'===')

which is simpler than:

base64.b64decode(s + b'=' * (-len(s) % 4))

How to do join on multiple criteria, returning all combinations of both criteria

create table a1
(weddingTable INT(3),
 tableSeat INT(3),
 tableSeatID INT(6),
 Name varchar(10));

insert into a1
 (weddingTable, tableSeat, tableSeatID, Name)
 values (001,001,001001,'Bob'),
 (001,002,001002,'Joe'),
 (001,003,001003,'Dan'),
 (002,001,002001,'Mark');

create table a2
 (weddingTable int(3),
 tableSeat int(3),
 Meal varchar(10));

insert into a2
(weddingTable, tableSeat, Meal)
values 
(001,001,'Chicken'),
(001,002,'Steak'),
(001,003,'Salmon'),
(002,001,'Steak');

select x.*, y.Meal

from a1 as x
JOIN a2 as y ON (x.weddingTable = y.weddingTable) AND (x.tableSeat = y. tableSeat);

How to increase the execution timeout in php?

if what you need to do is specific only for 1 or 2 pages i suggest to use set_time_limit so it did not affect the whole application.

set_time_limit(some_values);

but ofcourse these 2 values (post_max_size & upload_max_filesize) are subject to investigate.

you either can set it via ini_set function

ini_set('post_max_size','20M');
ini_set('upload_max_filesize','2M');

or directly in php.ini file like response above by Hannes, or even set it iin .htaccess like below

php_value upload_max_filesize 2M
php_value post_max_size 20M

Failed to fetch URL https://dl-ssl.google.com/android/repository/addons_list-1.xml, reason: Connection to https://dl-ssl.google.com refused

I had this issue with MacOS. I had to uncheck "use download cache" under Android SDK Manager preferences. This worked. I also recreated the cache folder and set my user as the owner then check user download cache. This also worked.

Running Node.js in apache?

You can always do something shell-scripty like:

#!/usr/bin/node

var header = "Content-type: text/plain\n";
var hi = "Hello World from nodetest!";
console.log(header);
console.log(hi);

exit;

Using an HTTP PROXY - Python

Just wanted to mention, that you also may have to set the https_proxy OS environment variable in case https URLs need to be accessed. In my case it was not obvious to me and I tried for hours to discover this.

My use case: Win 7, jython-standalone-2.5.3.jar, setuptools installation via ez_setup.py

Convert string to int if string is a number

Use IsNumeric. It returns true if it's a number or false otherwise.

Public Sub NumTest()
    On Error GoTo MyErrorHandler

    Dim myVar As Variant
    myVar = 11.2 'Or whatever

    Dim finalNumber As Integer
    If IsNumeric(myVar) Then
        finalNumber = CInt(myVar)
    Else
        finalNumber = 0
    End If

    Exit Sub

MyErrorHandler:
    MsgBox "NumTest" & vbCrLf & vbCrLf & "Err = " & Err.Number & _
        vbCrLf & "Description: " & Err.Description
End Sub

header location not working in my php code

It took me some time to figure this out: My php-file was encoded in UTF-8. And the BOM prevented header location to work properly. In Notepad++ I set the file encoding to "UTF-8 without BOM" and the problem was gone.

Spring Data JPA find by embedded object property

If you are using BookId as an combined primary key, then remember to change your interface from:

public interface QueuedBookRepo extends JpaRepository<QueuedBook, Long> {

to:

public interface QueuedBookRepo extends JpaRepository<QueuedBook, BookId> {

And change the annotation @Embedded to @EmbeddedId, in your QueuedBook class like this:

public class QueuedBook implements Serializable {

@EmbeddedId
@NotNull
private BookId bookId;

...

adding css file with jquery

$('head').append('<link rel="stylesheet" href="style2.css" type="text/css" />');

This should work.

Trigger an action after selection select2

For above v4

$('#yourselect').on("select2:select", function(e) { 
     // after selection of select2 
});

How do I change selected value of select2 dropdown with JqGrid?

My Expected code :

$('#my-select').val('').change();

working perfectly thank to @PanPipes for the usefull one.

Finding the id of a parent div using Jquery

To get the id of the parent div:

$(buttonSelector).parents('div:eq(0)').attr('id');

Also, you can refactor your code quite a bit:

$('button').click( function() {
 var correct = Number($(this).attr('rel'));
 validate(Number($(this).siblings('input').val()), correct);
 $(this).parents('div:eq(0)').html(feedback);
});

Now there is no need for a button-class

explanation
eq(0), means that you will select one element from the jQuery object, in this case element 0, thus the first element. http://docs.jquery.com/Selectors/eq#index
$(selector).siblings(siblingsSelector) will select all siblings (elements with the same parent) that match the siblingsSelector http://docs.jquery.com/Traversing/siblings#expr
$(selector).parents(parentsSelector) will select all parents of the elements matched by selector that match the parent selector. http://docs.jquery.com/Traversing/parents#expr
Thus: $(selector).parents('div:eq(0)'); will match the first parent div of the elements matched by selector.

You should have a look at the jQuery docs, particularly selectors and traversing:

Error: Expression must have integral or unscoped enum type

Your variable size is declared as: float size;

You can't use a floating point variable as the size of an array - it needs to be an integer value.

You could cast it to convert to an integer:

float *temp = new float[(int)size];

Your other problem is likely because you're writing outside of the bounds of the array:

   float *temp = new float[size];

    //Getting input from the user
    for (int x = 1; x <= size; x++){
        cout << "Enter temperature " << x << ": ";

        // cin >> temp[x];
        // This should be:
        cin >> temp[x - 1];
    }

Arrays are zero based in C++, so this is going to write beyond the end and never write the first element in your original code.

How does one Display a Hyperlink in React Native App?

To do this, I would strongly consider wrapping a Text component in a TouchableOpacity. When a TouchableOpacity is touched, it fades (becomes less opaque). This gives the user immediate feedback when touching the text and provides for an improved user experience.

You can use the onPress property on the TouchableOpacity to make the link happen:

<TouchableOpacity onPress={() => Linking.openURL('http://google.com')}>
  <Text style={{color: 'blue'}}>
    Google
  </Text>
</TouchableOpacity>

Git: How to check if a local repo is up to date?

git remote show origin


Enter passphrase for key ....ssh/id_rsa:
* remote origin
  Fetch URL: [email protected]:mamaque/systems.git
  Push  URL: [email protected]:mamaque/systems.git 

  HEAD branch: main
  Remote branch:
    main tracked
   Local ref configured for 'git push':

main pushes to main (up-to-date) Both are up to date
main pushes to main (fast-forwardable) Remote can be updated with Local
main pushes to main (local out of date) Local can be update with Remote

Calling a javascript function in another js file

1st JS:

function fn(){
   alert("Hello! Uncle Namaste...Chalo Kaaam ki Baat p Aate h...");
}

2nd JS:

$.getscript("url or name of 1st Js File",function(){
fn();
});

Hope This Helps... Happy Coding.

How to Auto resize HTML table cell to fit the text size

If you want the cells to resize depending on the content, then you must not specify a width to the table, the rows, or the cells.

If you don't want word wrap, assign the CSS style white-space: nowrap to the cells.

Python constructor and default value

Let's illustrate what's happening here:

Python 3.1.2 (r312:79147, Sep 27 2010, 09:45:41) 
[GCC 4.4.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> class Foo:
...     def __init__(self, x=[]):
...         x.append(1)
... 
>>> Foo.__init__.__defaults__
([],)
>>> f = Foo()
>>> Foo.__init__.__defaults__
([1],)
>>> f2 = Foo()
>>> Foo.__init__.__defaults__
([1, 1],)

You can see that the default arguments are stored in a tuple which is an attribute of the function in question. This actually has nothing to do with the class in question and goes for any function. In python 2, the attribute will be func.func_defaults.

As other posters have pointed out, you probably want to use None as a sentinel value and give each instance it's own list.

Remove trailing zeros from decimal in SQL Server

try this.

select CAST(123.456700 as float),cast(cast(123.4567 as DECIMAL(9,6)) as float)

How to open a second activity on click of button in android app

From Activity : where you are currently ?

To Activity : where you want to go ?

Intent i = new Intent( MainActivity.this, SendPhotos.class); startActivity(i);

Both Activity must be included in manifest file otherwise it will not found the class file and throw Force close.

Edit your Mainactivity.java

crate button's object;

now Write code for click event.

        Button btn = (button)findViewById(R.id.button1);
         btn.LoginButton.setOnClickListener(new View.OnClickListener() 
       {

                @Override
                public void onClick(View v) 
                {
                 //put your intent code here
                }
   });

Hope it will work for you.

How do I remove an object from an array with JavaScript?

var user = [
  { id: 1, name: 'Siddhu' },
  { id: 2, name: 'Siddhartha' },
  { id: 3, name: 'Tiwary' }
];

var recToRemove={ id: 1, name: 'Siddhu' };

user.splice(user.indexOf(recToRemove),1)

postgresql duplicate key violates unique constraint

In my case carate table script is:

CREATE TABLE public."Survey_symptom_binds"
(
    id integer NOT NULL DEFAULT nextval('"Survey_symptom_binds_id_seq"'::regclass),
    survey_id integer,
    "order" smallint,
    symptom_id integer,
    CONSTRAINT "Survey_symptom_binds_pkey" PRIMARY KEY (id)
)

SO:

SELECT nextval('"Survey_symptom_binds_id_seq"'::regclass),
       MAX(id) 
  FROM public."Survey_symptom_binds"; 
  
SELECT nextval('"Survey_symptom_binds_id_seq"'::regclass) less than MAX(id) !!!

Try to fix the proble:

SELECT setval('"Survey_symptom_binds_id_seq"', (SELECT MAX(id) FROM public."Survey_symptom_binds")+1);

Good Luck every one!

.htaccess File Options -Indexes on Subdirectories

htaccess files affect the directory they are placed in and all sub-directories, that is an htaccess file located in your root directory (yoursite.com) would affect yoursite.com/content, yoursite.com/content/contents, etc.

http://www.javascriptkit.com/howto/htaccess.shtml

Prevent flex items from overflowing a container

Your flex items have

flex: 0 0 200px; /* <aside> */
flex: 1 0 auto;  /* <article> */ 

That means:

  • The <aside> will start at 200px wide.

    Then it won't grow nor shrink.

  • The <article> will start at the width given by the content.

    Then, if there is available space, it will grow to cover it.

    Otherwise it won't shrink.

To prevent horizontal overflow, you can:

  • Use flex-basis: 0 and then let them grow with a positive flex-grow.
  • Use a positive flex-shrink to let them shrink if there isn't enough space.

To prevent vertical overflow, you can

  • Use min-height instead of height to allow the flex items grow more if necessary
  • Use overflow different than visible on the flex items
  • Use overflow different than visible on the flex container

For example,

_x000D_
_x000D_
main, aside, article {
  margin: 10px;
  border: solid 1px #000;
  border-bottom: 0;
  min-height: 50px; /* min-height instead of height */
}
main {
  display: flex;
}
aside {
  flex: 0 1 200px; /* Positive flex-shrink */
}
article {
  flex: 1 1 auto; /* Positive flex-shrink */
}
_x000D_
<main>
  <aside>x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x </aside>
  <article>don't let flex item overflow container.... y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y </article>
</main>
_x000D_
_x000D_
_x000D_

How to merge two json string in Python?

What do you mean by merging? JSON objects are key-value data structure. What would be a key and a value in this case? I think you need to create new directory and populate it with old data:

d = {}
d["new_key"] = jsonStringA[<key_that_you_did_not_mention_here>] + \ 
               jsonStringB["timestamp_in_ms"]

Merging method is obviously up to you.

How do I convert speech to text?

Late to the party, so answering more for future reference.

Advances in the field + Mozilla's mindset and agenda led to these two projects towards that end:

The latter has a 12GB data-set for download. The former allows for training a model with your own audio files to my understanding

How do you replace double quotes with a blank space in Java?

You don't need regex for this. Just a character-by-character replace is sufficient. You can use String#replace() for this.

String replaced = original.replace("\"", " ");

Note that you can also use an empty string "" instead to replace with. Else the spaces would double up.

String replaced = original.replace("\"", "");

Obtain form input fields using jQuery?

Late to the party on this question, but this is even easier:

$('#myForm').submit(function() {
    // Get all the forms elements and their values in one step
    var values = $(this).serialize();

});

Select top 10 records for each category

I know this thread is a little bit old but I've just bumped into a similar problem (select the newest article from each category) and this is the solution I came up with :

WITH [TopCategoryArticles] AS (
    SELECT 
        [ArticleID],
        ROW_NUMBER() OVER (
            PARTITION BY [ArticleCategoryID]
            ORDER BY [ArticleDate] DESC
        ) AS [Order]
    FROM [dbo].[Articles]
)
SELECT [Articles].* 
FROM 
    [TopCategoryArticles] LEFT JOIN 
    [dbo].[Articles] ON
        [TopCategoryArticles].[ArticleID] = [Articles].[ArticleID]
WHERE [TopCategoryArticles].[Order] = 1

This is very similar to Darrel's solution but overcomes the RANK problem that might return more rows than intended.

C#: Printing all properties of an object

This is exactly what reflection is for. I don't think there's a simpler solution, but reflection isn't that code intensive anyway.

How to get a unix script to run every 15 seconds?

To avoid possible overlapping of execution, use a locking mechanism as described in that thread.

git push vs git push origin <branchname>

The first push should be a:

git push -u origin branchname

That would make sure:

Any future git push will, with that default policy, only push the current branch, and only if that branch has an upstream branch with the same name.
that avoid pushing all matching branches (previous default policy), where tons of test branches were pushed even though they aren't ready to be visible on the upstream repo.

Malformed String ValueError ast.literal_eval() with String representation of Tuple

From the documentation for ast.literal_eval():

Safely evaluate an expression node or a string containing a Python expression. The string or node provided may only consist of the following Python literal structures: strings, numbers, tuples, lists, dicts, booleans, and None.

Decimal isn't on the list of things allowed by ast.literal_eval().

Update built-in vim on Mac OS X

On Yosemite, install vim using brew and the override-system-vi option. This will automatically install vim with the features of the 'huge' vim install.

brew install vim --with-override-system-vi

The output of this command will show you where brew installed vim. In that folder, go down into /bin/vim to actually run vim. This is your command to run vim from any folder:

/usr/local/Cellar/vim/7.4.873/bin/vim

Then alias this command by adding the following line in your .bashrc:

alias vim="/usr/local/Cellar/vim/7.4.873/bin/vim"

EDIT: Brew flag --override-system-vi has been deprecated. Changed for --with-override-system-vi. Source: https://github.com/Shougo/neocomplete.vim/issues/401

How to deal with SettingWithCopyWarning in Pandas

Followup beginner question / remark

Maybe a clarification for other beginners like me (I come from R which seems to work a bit differently under the hood). The following harmless-looking and functional code kept producing the SettingWithCopy warning, and I couldn't figure out why. I had both read and understood the issued with "chained indexing", but my code doesn't contain any:

def plot(pdb, df, title, **kw):
    df['target'] = (df['ogg'] + df['ugg']) / 2
    # ...

But then, later, much too late, I looked at where the plot() function is called:

    df = data[data['anz_emw'] > 0]
    pixbuf = plot(pdb, df, title)

So "df" isn't a data frame but an object that somehow remembers that it was created by indexing a data frame (so is that a view?) which would make the line in plot()

 df['target'] = ...

equivalent to

 data[data['anz_emw'] > 0]['target'] = ...

which is a chained indexing. Did I get that right?

Anyway,

def plot(pdb, df, title, **kw):
    df.loc[:,'target'] = (df['ogg'] + df['ugg']) / 2

fixed it.

How to upgrade Git to latest version on macOS?

I recently upgraded the Git on my OS X machine to the latest also. I didn't use the same .dmg you used, but when I installed it the binaries were placed in /usr/local/bin. Now, the way my PATH was arranged, the directory /usr/bin appears before /usr/local/bin. So what I did was:

cd /usr/bin
mkdir git.ORIG
mv git* git.ORIG/

This moves the several original programs named git* to a new subdirectory that keeps them out of the way. After that, which git shows that the one in /usr/local/bin is found.

Modify the above procedure as necessary to fit wherever you installed the new binaries.

javascript popup alert on link click

Single line works just fine:

<a href="http://example.com/"
 onclick="return confirm('Please click on OK to continue.');">click me</a>

Adding another line with a different link on the same page works fine too:

<a href="http://stackoverflow.com/"
 onclick="return confirm('Click on another OK to continue.');">another link</a>

Nginx sites-enabled, sites-available: Cannot create soft-link between config files in Ubuntu 12.04

My site configuration file is example.conf in sites-available folder So you can create a symbolic link as

ln -s /etc/nginx/sites-available/example.conf /etc/nginx/sites-enabled/

Getting value from a cell from a gridview on RowDataBound event

use RowDataBound function to bind data with a perticular cell, and to get control use (ASP Control Name like DropDownList) GridView.FindControl("Name of Control")

Reading entire html file to String?

For string operations use StringBuilder or StringBuffer classes for accumulating string data blocks. Do not use += operations for string objects. String class is immutable and you will produce a large amount of string objects upon runtime and it will affect on performance.

Use .append() method of StringBuilder/StringBuffer class instance instead.

Java - Writing strings to a CSV file

I see you already have a answer but here is another answer, maybe even faster A simple class to pass in a List of objects and retrieve either a csv or excel or password protected zip csv or excel. https://github.com/ernst223/spread-sheet-exporter

SpreadSheetExporter spreadSheetExporter = new SpreadSheetExporter(List<Object>, "Filename");
File fileCSV = spreadSheetExporter.getCSV();

Android Bluetooth Example

I have also used following link as others have suggested you for bluetooth communication.

http://developer.android.com/guide/topics/connectivity/bluetooth.html

The thing is all you need is a class BluetoothChatService.java

this class has following threads:

  1. Accept
  2. Connecting
  3. Connected

Now when you call start function of the BluetoothChatService like:

mChatService.start();

It starts accept thread which means it will start looking for connection.

Now when you call

mChatService.connect(<deviceObject>,false/true);

Here first argument is device object that you can get from paired devices list or when you scan for devices you will get all the devices in range you can pass that object to this function and 2nd argument is a boolean to make secure or insecure connection.

connect function will start connecting thread which will look for any device which is running accept thread.

When such a device is found both accept thread and connecting thread will call connected function in BluetoothChatService:

connected(mmSocket, mmDevice, mSocketType);

this method starts connected thread in both the devices: Using this socket object connected thread obtains the input and output stream to the other device. And calls read function on inputstream in a while loop so that it's always trying read from other device so that whenever other device send a message this read function returns that message.

BluetoothChatService also has a write method which takes byte[] as input and calls write method on connected thread.

mChatService.write("your message".getByte());

write method in connected thread just write this byte data to outputsream of the other device.

public void write(byte[] buffer) {
   try {
       mmOutStream.write(buffer);
    // Share the sent message back to the UI Activity
    // mHandler.obtainMessage(
    // BluetoothGameSetupActivity.MESSAGE_WRITE, -1, -1,
    // buffer).sendToTarget();
    } catch (IOException e) {
    Log.e(TAG, "Exception during write", e);
     }
}

Now to communicate between two devices just call write function on mChatService and handle the message that you will receive on the other device.

How to use Comparator in Java to sort

Do not waste time implementing Sorting Algorithm by your own. Instead; use

Collections.sort() to sort data.

NameError: uninitialized constant (rails)

I started having this issue after upgrading from Rails 5.1 to 5.2
It got solved with:

spring stop
spring binstub --all
spring start
rails s

Vim clear last search highlighting

This is what I use (extracted from a lot of different questions/answers):

nnoremap <silent> <Esc><Esc> :let @/=""<CR>

With "double" Esc you remove the highlighting, but as soon as you search again, the highlighting reappears.


Another alternative:

nnoremap <silent> <Esc><Esc> :noh<CR> :call clearmatches()<CR>

According to vim documentation:

clearmatches()

    Clears all matches previously defined by |matchadd()| and the

    |:match| commands.

Datagrid binding in WPF

Without seeing said object list, I believe you should be binding to the DataGrid's ItemsSource property, not its DataContext.

<DataGrid x:Name="Imported" VerticalAlignment="Top" ItemsSource="{Binding Source=list}"  AutoGenerateColumns="False" CanUserResizeColumns="True">
    <DataGrid.Columns>                
        <DataGridTextColumn Header="ID" Binding="{Binding ID}"/>
        <DataGridTextColumn Header="Date" Binding="{Binding Date}"/>
   </DataGrid.Columns>
</DataGrid>

(This assumes that the element [UserControl, etc.] that contains the DataGrid has its DataContext bound to an object that contains the list collection. The DataGrid is derived from ItemsControl, which relies on its ItemsSource property to define the collection it binds its rows to. Hence, if list isn't a property of an object bound to your control's DataContext, you might need to set both DataContext={Binding list} and ItemsSource={Binding list} on the DataGrid...)

Check if date is a valid one

If the date is valid then the getTime() will always be equal to itself.

var date = new Date('2019-12-12');
if(date.getTime() - date.getTime() === 0) {
    console.log('Date is valid');
} else {
    console.log('Date is invalid');
}

MAX() and MAX() OVER PARTITION BY produces error 3504 in Teradata Query

I think this will work even though this was forever ago.

SELECT employee_number, Row_Number()  
   OVER (PARTITION BY course_code ORDER BY course_completion_date DESC ) as rownum
FROM employee_course_completion
WHERE course_code IN ('M910303', 'M91301R', 'M91301P')
   AND rownum = 1

If you want to get the last Id if the date is the same then you can use this assuming your primary key is Id.

SELECT employee_number, Row_Number()  
   OVER (PARTITION BY course_code ORDER BY course_completion_date DESC, Id Desc) as rownum    FROM employee_course_completion
WHERE course_code IN ('M910303', 'M91301R', 'M91301P')
   AND rownum = 1

Storing sex (gender) in database

I'd call the column "gender".

Data Type   Bytes Taken          Number/Range of Values
------------------------------------------------
TinyINT     1                    255 (zero to 255)
INT         4            -       2,147,483,648 to 2,147,483,647
BIT         1 (2 if 9+ columns)  2 (0 and 1)
CHAR(1)     1                    26 if case insensitive, 52 otherwise

The BIT data type can be ruled out because it only supports two possible genders which is inadequate. While INT supports more than two options, it takes 4 bytes -- performance will be better with a smaller/more narrow data type.

CHAR(1) has the edge over TinyINT - both take the same number of bytes, but CHAR provides a more narrow number of values. Using CHAR(1) would make using "m", "f",etc natural keys, vs the use of numeric data which are referred to as surrogate/artificial keys. CHAR(1) is also supported on any database, should there be a need to port.

Conclusion

I would use Option 2: CHAR(1).

Addendum

An index on the gender column likely would not help because there's no value in an index on a low cardinality column. Meaning, there's not enough variety in the values for the index to provide any value.

Invalid date in safari

The same problem facing in Safari and it was solved by inserting this in web page

 <script src="https://cdn.polyfill.io/v2/polyfill.min.js?features=Intl.~locale.en"></script> 

Hope it will work also your case too

Thanks

How do I tell whether my IE is 64-bit? (For that matter, Java too?)

In addition to what TaskManager shows, if you use ProcessExplorer from Sysinternals, you can tell when you right-click on the process name and select Properties. In the Image tab, there is a field toward the bottom that says Image. It says 32-bit for a 32 bit application and 64 bit for the 64 bit application.

How do I convert a String to an int in Java?

Try this code with different inputs of String:

String a = "10";  
String a = "10ssda";  
String a = null; 
String a = "12102";

if(null != a) {
    try {
        int x = Integer.ParseInt(a.trim()); 
        Integer y = Integer.valueOf(a.trim());
        //  It will throw a NumberFormatException in case of invalid string like ("10ssda" or "123 212") so, put this code into try catch
    } catch(NumberFormatException ex) {
        // ex.getMessage();
    }
}

How to install package from github repo in Yarn

For GitHub (or similar) private repository:

yarn add 'ssh://[email protected]:myproject.git#<branch,tag,commit>'
npm install 'ssh://[email protected]:myproject.git#<branch,tag,commit>'

Is it possible to compile a program written in Python?

If you really want, you could always compile with Cython. This will generate C code, which you can then compile with any C compiler such as GCC.

How to access route, post, get etc. parameters in Zend Framework 2

The easisest way to get a posted json string, for example, is to read the contents of 'php://input' and then decode it. For example i had a simple Zend route:

'save-json' => array(
'type' => 'Zend\Mvc\Router\Http\Segment',
            'options' => array(
                'route'    => '/save-json/',
                'defaults' => array(
                    'controller' => 'CDB\Controller\Index',
                    'action'     => 'save-json',
                ),
            ),
        ),

and i wanted to post data to it using Angular's $http.post. The post was fine but the retrive method in Zend

$this->params()->fromPost('paramname'); 

didn't get anything in this case. So my solution was, after trying all kinds of methods like $_POST and the other methods stated above, to read from 'php://':

$content = file_get_contents('php://input');
print_r(json_decode($content));

I got my json array in the end. Hope this helps.

Setting up enviromental variables in Windows 10 to use java and javac

if you have any version problems (javac -version=15.0.1, java -version=1.8.0)
windows search : edit environment variables for your account
then delete these in your windows Environment variable: system variable: Path
C:\Program Files (x86)\Common Files\Oracle\Java\javapath
C:\Program Files\Common Files\Oracle\Java\javapath

then if you're using java 15
environment variable: system variable : Path
add path C:\Program Files\Java\jdk-15.0.1\bin
is enough

if you're using java 8

  • create JAVA_HOME
  • environment variable: system variable : JAVA_HOME
    JAVA_HOME = C:\Program Files\Java\jdk1.8.0_271
  • environment variable: system variable : Path
    add path = %JAVA_HOME%\bin
  • How to get Current Timestamp from Carbon in Laravel 5

    For Laravel 5.5 or above just use the built in helper

    $timestamp = now();
    

    If you want a unix timestamp, you can also try this:

    $unix_timestamp = now()->timestamp;
    

    What is the difference between Left, Right, Outer and Inner Joins?

    Check out Join (SQL) on Wikipedia

    • Inner join - Given two tables an inner join returns all rows that exist in both tables
    • left / right (outer) join - Given two tables returns all rows that exist in either the left or right table of your join, plus the rows from the other side will be returned when the join clause is a match or null will be returned for those columns

    • Full Outer - Given two tables returns all rows, and will return nulls when either the left or right column is not there

    • Cross Joins - Cartesian join and can be dangerous if not used carefully

    How to Query an NTP Server using C#?

    This is a optimized version of the function which removes dependency on BitConverter function and makes it compatible with NETMF (.NET Micro Framework)

    public static DateTime GetNetworkTime()
    {
        const string ntpServer = "pool.ntp.org";
        var ntpData = new byte[48];
        ntpData[0] = 0x1B; //LeapIndicator = 0 (no warning), VersionNum = 3 (IPv4 only), Mode = 3 (Client Mode)
    
        var addresses = Dns.GetHostEntry(ntpServer).AddressList;
        var ipEndPoint = new IPEndPoint(addresses[0], 123);
        var socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
    
        socket.Connect(ipEndPoint);
        socket.Send(ntpData);
        socket.Receive(ntpData);
        socket.Close();
    
        ulong intPart = (ulong)ntpData[40] << 24 | (ulong)ntpData[41] << 16 | (ulong)ntpData[42] << 8 | (ulong)ntpData[43];
        ulong fractPart = (ulong)ntpData[44] << 24 | (ulong)ntpData[45] << 16 | (ulong)ntpData[46] << 8 | (ulong)ntpData[47];
    
        var milliseconds = (intPart * 1000) + ((fractPart * 1000) / 0x100000000L);
        var networkDateTime = (new DateTime(1900, 1, 1)).AddMilliseconds((long)milliseconds);
    
        return networkDateTime;
    }
    

    How do I make UITableViewCell's ImageView a fixed size even when the image is smaller

    UIImage *image = cell.imageView.image;
    
    UIGraphicsBeginImageContext(CGSizeMake(35,35));
    // draw scaled image into thumbnail context
    
    [image drawInRect:CGRectMake(5, 5, 35, 35)]; //
    UIImage *newThumbnail = UIGraphicsGetImageFromCurrentImageContext();
    // pop the context
    UIGraphicsEndImageContext();
    if(newThumbnail == nil)
    {
        NSLog(@"could not scale image");
        cell.imageView.image = image;
    }
    else
    {
        cell.imageView.image = newThumbnail;
    }
    

    What does 'low in coupling and high in cohesion' mean

    I think you have red so many definitions but in the case you still have doubts or In case you are new to programming and want to go deep into this then I will suggest you to watch this video, https://youtu.be/HpJTGW9AwX0 It's just reference to get more info about polymorphism... Hope you get better understanding with this

    Google Maps how to Show city or an Area outline

    I have try twitter geo api, failed.

    Google map api, failed, so far, no way you can get city limit by any api.

    twitter api geo endpoint will NOT give you city boundary,

    what they provide you is ONLY bounding box with 5 point(lat, long)

    this is what I get from twitter api geo for San Francisco enter image description here

    String array initialization in Java

    It is just not a valid Java syntax. You can do

    names = new String[] {"Ankit","Bohra","Xyz"};
    

    Mapping many-to-many association table with extra column(s)

    Since the SERVICE_USER table is not a pure join table, but has additional functional fields (blocked), you must map it as an entity, and decompose the many to many association between User and Service into two OneToMany associations : One User has many UserServices, and one Service has many UserServices.

    You haven't shown us the most important part : the mapping and initialization of the relationships between your entities (i.e. the part you have problems with). So I'll show you how it should look like.

    If you make the relationships bidirectional, you should thus have

    class User {
        @OneToMany(mappedBy = "user")
        private Set<UserService> userServices = new HashSet<UserService>();
    }
    
    class UserService {
        @ManyToOne
        @JoinColumn(name = "user_id")
        private User user;
    
        @ManyToOne
        @JoinColumn(name = "service_code")
        private Service service;
    
        @Column(name = "blocked")
        private boolean blocked;
    }
    
    class Service {
        @OneToMany(mappedBy = "service")
        private Set<UserService> userServices = new HashSet<UserService>();
    }
    

    If you don't put any cascade on your relationships, then you must persist/save all the entities. Although only the owning side of the relationship (here, the UserService side) must be initialized, it's also a good practice to make sure both sides are in coherence.

    User user = new User();
    Service service = new Service();
    UserService userService = new UserService();
    
    user.addUserService(userService);
    userService.setUser(user);
    
    service.addUserService(userService);
    userService.setService(service);
    
    session.save(user);
    session.save(service);
    session.save(userService);
    

    How do I convert a file path to a URL in ASP.NET

    I've accepted Fredriks answer as it appears to solve the problem with the least amount of effort however the Request object doesn't appear to conatin the ResolveUrl method. This can be accessed through the Page object or an Image control object:

    myImage.ImageUrl = Page.ResolveUrl(photoURL);
    myImage.ImageUrl = myImage.ResolveUrl(photoURL);
    

    An alternative, if you are using a static class as I am, is to use the VirtualPathUtility:

    myImage.ImageUrl = VirtualPathUtility.ToAbsolute(photoURL);
    

    What is this spring.jpa.open-in-view=true property in Spring Boot?

    The OSIV Anti-Pattern

    Instead of letting the business layer decide how it’s best to fetch all the associations that are needed by the View layer, OSIV (Open Session in View) forces the Persistence Context to stay open so that the View layer can trigger the Proxy initialization, as illustrated by the following diagram.

    enter image description here

    • The OpenSessionInViewFilter calls the openSession method of the underlying SessionFactory and obtains a new Session.
    • The Session is bound to the TransactionSynchronizationManager.
    • The OpenSessionInViewFilter calls the doFilter of the javax.servlet.FilterChain object reference and the request is further processed
    • The DispatcherServlet is called, and it routes the HTTP request to the underlying PostController.
    • The PostController calls the PostService to get a list of Post entities.
    • The PostService opens a new transaction, and the HibernateTransactionManager reuses the same Session that was opened by the OpenSessionInViewFilter.
    • The PostDAO fetches the list of Post entities without initializing any lazy association.
    • The PostService commits the underlying transaction, but the Session is not closed because it was opened externally.
    • The DispatcherServlet starts rendering the UI, which, in turn, navigates the lazy associations and triggers their initialization.
    • The OpenSessionInViewFilter can close the Session, and the underlying database connection is released as well.

    At first glance, this might not look like a terrible thing to do, but, once you view it from a database perspective, a series of flaws start to become more obvious.

    The service layer opens and closes a database transaction, but afterward, there is no explicit transaction going on. For this reason, every additional statement issued from the UI rendering phase is executed in auto-commit mode. Auto-commit puts pressure on the database server because each transaction issues a commit at end, which can trigger a transaction log flush to disk. One optimization would be to mark the Connection as read-only which would allow the database server to avoid writing to the transaction log.

    There is no separation of concerns anymore because statements are generated both by the service layer and by the UI rendering process. Writing integration tests that assert the number of statements being generated requires going through all layers (web, service, DAO) while having the application deployed on a web container. Even when using an in-memory database (e.g. HSQLDB) and a lightweight webserver (e.g. Jetty), these integration tests are going to be slower to execute than if layers were separated and the back-end integration tests used the database, while the front-end integration tests were mocking the service layer altogether.

    The UI layer is limited to navigating associations which can, in turn, trigger N+1 query problems. Although Hibernate offers @BatchSize for fetching associations in batches, and FetchMode.SUBSELECT to cope with this scenario, the annotations are affecting the default fetch plan, so they get applied to every business use case. For this reason, a data access layer query is much more suitable because it can be tailored to the current use case data fetch requirements.

    Last but not least, the database connection is held throughout the UI rendering phase which increases connection lease time and limits the overall transaction throughput due to congestion on the database connection pool. The more the connection is held, the more other concurrent requests are going to wait to get a connection from the pool.

    Spring Boot and OSIV

    Unfortunately, OSIV (Open Session in View) is enabled by default in Spring Boot, and OSIV is really a bad idea from a performance and scalability perspective.

    So, make sure that in the application.properties configuration file, you have the following entry:

    spring.jpa.open-in-view=false
    

    This will disable OSIV so that you can handle the LazyInitializationException the right way.

    Starting with version 2.0, Spring Boot issues a warning when OSIV is enabled by default, so you can discover this problem long before it affects a production system.

    Comparison of full text search engine - Lucene, Sphinx, Postgresql, MySQL?

    Apache Solr


    Apart from answering OP's queries, Let me throw some insights on Apache Solr from simple introduction to detailed installation and implementation.

    Simple Introduction


    Anyone who has had experience with the search engines above, or other engines not in the list -- I would love to hear your opinions.

    Solr shouldn't be used to solve real-time problems. For search engines, Solr is pretty much game and works flawlessly.

    Solr works fine on High Traffic web-applications (I read somewhere that it is not suited for this, but I am backing up that statement). It utilizes the RAM, not the CPU.

    • result relevance and ranking

    The boost helps you rank your results show up on top. Say, you're trying to search for a name john in the fields firstname and lastname, and you want to give relevancy to the firstname field, then you need to boost up the firstname field as shown.

    http://localhost:8983/solr/collection1/select?q=firstname:john^2&lastname:john
    

    As you can see, firstname field is boosted up with a score of 2.

    More on SolrRelevancy

    • searching and indexing speed

    The speed is unbelievably fast and no compromise on that. The reason I moved to Solr.

    Regarding the indexing speed, Solr can also handle JOINS from your database tables. A higher and complex JOIN do affect the indexing speed. However, an enormous RAM config can easily tackle this situation.

    The higher the RAM, The faster the indexing speed of Solr is.

    • ease of use and ease of integration with Django

    Never attempted to integrate Solr and Django, however you can achieve to do that with Haystack. I found some interesting article on the same and here's the github for it.

    • resource requirements - site will be hosted on a VPS, so ideally the search engine wouldn't require a lot of RAM and CPU

    Solr breeds on RAM, so if the RAM is high, you don't to have to worry about Solr.

    Solr's RAM usage shoots up on full-indexing if you have some billion records, you could smartly make use of Delta imports to tackle this situation. As explained, Solr is only a near real-time solution.

    • scalability

    Solr is highly scalable. Have a look on SolrCloud. Some key features of it.

    • Shards (or sharding is the concept of distributing the index among multiple machines, say if your index has grown too large)
    • Load Balancing (if Solrj is used with Solr cloud it automatically takes care of load-balancing using it's Round-Robin mechanism)
    • Distributed Search
    • High Availability
    • extra features such as "did you mean?", related searches, etc

    For the above scenario, you could use the SpellCheckComponent that is packed up with Solr. There are a lot other features, The SnowballPorterFilterFactory helps to retrieve records say if you typed, books instead of book, you will be presented with results related to book.


    This answer broadly focuses on Apache Solr & MySQL. Django is out of scope.

    Assuming that you are under LINUX environment, you could proceed to this article further. (mine was an Ubuntu 14.04 version)

    Detailed Installation

    Getting Started

    Download Apache Solr from here. That would be version is 4.8.1. You could download new versions, I found this stable.

    After downloading the archive , extract it to a folder of your choice. Say .. Downloads or whatever.. So it will look like Downloads/solr-4.8.1/

    On your prompt.. Navigate inside the directory

    shankar@shankar-lenovo: cd Downloads/solr-4.8.1

    So now you are here ..

    shankar@shankar-lenovo: ~/Downloads/solr-4.8.1$

    Start the Jetty Application Server

    Jetty is available inside the examples folder of the solr-4.8.1 directory , so navigate inside that and start the Jetty Application Server.

    shankar@shankar-lenovo:~/Downloads/solr-4.8.1/example$ java -jar start.jar

    Now , do not close the terminal , minimize it and let it stay aside.

    ( TIP : Use & after start.jar to make the Jetty Server run in the background )

    To check if Apache Solr runs successfully, visit this URL on the browser. http://localhost:8983/solr

    Running Jetty on custom Port

    It runs on the port 8983 as default. You could change the port either here or directly inside the jetty.xml file.

    java -Djetty.port=9091 -jar start.jar

    Download the JConnector

    This JAR file acts as a bridge between MySQL and JDBC , Download the Platform Independent Version here

    After downloading it, extract the folder and copy themysql-connector-java-5.1.31-bin.jar and paste it to the lib directory.

    shankar@shankar-lenovo:~/Downloads/solr-4.8.1/contrib/dataimporthandler/lib

    Creating the MySQL table to be linked to Apache Solr

    To put Solr to use, You need to have some tables and data to search for. For that, we will use MySQL for creating a table and pushing some random names and then we could use Solr to connect to MySQL and index that table and it's entries.

    1.Table Structure

    CREATE TABLE test_solr_mysql
     (
      id INT UNSIGNED NOT NULL AUTO_INCREMENT,
      name VARCHAR(45) NULL,
      created TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP,
      PRIMARY KEY (id)
     );
    

    2.Populate the above table

    INSERT INTO `test_solr_mysql` (`name`) VALUES ('Jean');
    INSERT INTO `test_solr_mysql` (`name`) VALUES ('Jack');
    INSERT INTO `test_solr_mysql` (`name`) VALUES ('Jason');
    INSERT INTO `test_solr_mysql` (`name`) VALUES ('Vego');
    INSERT INTO `test_solr_mysql` (`name`) VALUES ('Grunt');
    INSERT INTO `test_solr_mysql` (`name`) VALUES ('Jasper');
    INSERT INTO `test_solr_mysql` (`name`) VALUES ('Fred');
    INSERT INTO `test_solr_mysql` (`name`) VALUES ('Jenna');
    INSERT INTO `test_solr_mysql` (`name`) VALUES ('Rebecca');
    INSERT INTO `test_solr_mysql` (`name`) VALUES ('Roland');
    

    Getting inside the core and adding the lib directives

    1.Navigate to

    shankar@shankar-lenovo: ~/Downloads/solr-4.8.1/example/solr/collection1/conf
    

    2.Modifying the solrconfig.xml

    Add these two directives to this file..

      <lib dir="../../../contrib/dataimporthandler/lib/" regex=".*\.jar" />
      <lib dir="../../../dist/" regex="solr-dataimporthandler-\d.*\.jar" />
    

    Now add the DIH (Data Import Handler)

    <requestHandler name="/dataimport" 
      class="org.apache.solr.handler.dataimport.DataImportHandler" >
        <lst name="defaults">
          <str name="config">db-data-config.xml</str>
        </lst>
    </requestHandler>
    

    3.Create the db-data-config.xml file

    If the file exists then ignore, add these lines to that file. As you can see the first line, you need to provide the credentials of your MySQL database. The Database name, username and password.

    <dataConfig>
        <dataSource type="JdbcDataSource" driver="com.mysql.jdbc.Driver" url="jdbc:mysql://localhost/yourdbname" user="dbuser" password="dbpass"/>
        <document>
       <entity name="test_solr" query="select CONCAT('test_solr-',id) as rid,name from test_solr_mysql WHERE '${dataimporter.request.clean}' != 'false'
          OR `created` > '${dataimporter.last_index_time}'" >
        <field name="id" column="rid" />
        <field name="solr_name" column="name" />
        </entity>
       </document>
    </dataConfig>
    

    ( TIP : You can have any number of entities but watch out for id field, if they are same then indexing will skipped. )

    4.Modify the schema.xml file

    Add this to your schema.xml as shown..

    <uniqueKey>id</uniqueKey>
    <field name="solr_name" type="string" indexed="true" stored="true" />
    

    Implementation

    Indexing

    This is where the real deal is. You need to do the indexing of data from MySQL to Solr inorder to make use of Solr Queries.

    Step 1: Go to Solr Admin Panel

    Hit the URL http://localhost:8983/solr on your browser. The screen opens like this.

    This is the main Apache Solr Administration Panel

    As the marker indicates, go to Logging inorder to check if any of the above configuration has led to errors.

    Step 2: Check your Logs

    Ok so now you are here, As you can there are a lot of yellow messages (WARNINGS). Make sure you don't have error messages marked in red. Earlier, on our configuration we had added a select query on our db-data-config.xml, say if there were any errors on that query, it would have shown up here.

    This is the logging section of your Apache Solr engine

    Fine, no errors. We are good to go. Let's choose collection1 from the list as depicted and select Dataimport

    Step 3: DIH (Data Import Handler)

    Using the DIH, you will be connecting to MySQL from Solr through the configuration file db-data-config.xml from the Solr interface and retrieve the 10 records from the database which gets indexed onto Solr.

    To do that, Choose full-import , and check the options Clean and Commit. Now click Execute as shown.

    Alternatively, you could use a direct full-import query like this too..

    http://localhost:8983/solr/collection1/dataimport?command=full-import&commit=true
    

    The Data Import Handler

    After you clicked Execute, Solr begins to index the records, if there were any errors, it would say Indexing Failed and you have to go back to the Logging section to see what has gone wrong.

    Assuming there are no errors with this configuration and if the indexing is successfully complete., you would get this notification.

    Indexing Success

    Step 4: Running Solr Queries

    Seems like everything went well, now you could use Solr Queries to query the data that was indexed. Click the Query on the left and then press Execute button on the bottom.

    You will see the indexed records as shown.

    The corresponding Solr query for listing all the records is

    http://localhost:8983/solr/collection1/select?q=*:*&wt=json&indent=true
    

    The indexed data

    Well, there goes all 10 indexed records. Say, we need only names starting with Ja , in this case, you need to target the column name solr_name, Hence your query goes like this.

    http://localhost:8983/solr/collection1/select?q=solr_name:Ja*&wt=json&indent=true
    

    The JSON data starting with Ja*

    That's how you write Solr Queries. To read more about it, Check this beautiful article.

    Round to 2 decimal places

    Try:

    float number mkm = (((((amountdrug/fluidvol)*1000f)/60f)*infrate)/ptwt)*1000f;
    int newNum = (int) mkm;
    mkm = newNum/1000f; // Will return 3 decimal places
    

    Avoid trailing zeroes in printf()

    I would say you should use printf("%.8g",value);

    If you use "%.6g" you will not get desired output for some numbers like.32.230210 it should print 32.23021 but it prints 32.2302

    How do I run Selenium in Xvfb?

    You can use PyVirtualDisplay (a Python wrapper for Xvfb) to run headless WebDriver tests.

    #!/usr/bin/env python
    
    from pyvirtualdisplay import Display
    from selenium import webdriver
    
    display = Display(visible=0, size=(800, 600))
    display.start()
    
    # now Firefox will run in a virtual display. 
    # you will not see the browser.
    browser = webdriver.Firefox()
    browser.get('http://www.google.com')
    print browser.title
    browser.quit()
    
    display.stop()
    

    more info


    You can also use xvfbwrapper, which is a similar module (but has no external dependencies):

    from xvfbwrapper import Xvfb
    
    vdisplay = Xvfb()
    vdisplay.start()
    
    # launch stuff inside virtual display here
    
    vdisplay.stop()
    

    or better yet, use it as a context manager:

    from xvfbwrapper import Xvfb
    
    with Xvfb() as xvfb:
        # launch stuff inside virtual display here.
        # It starts/stops in this code block.
    

    proper way to logout from a session in PHP

    Session_unset(); only destroys the session variables. To end the session there is another function called session_destroy(); which also destroys the session .

    update :

    In order to kill the session altogether, like to log the user out, the session id must also be unset. If a cookie is used to propagate the session id (default behavior), then the session cookie must be deleted. setcookie() may be used for that

    Error java.lang.OutOfMemoryError: GC overhead limit exceeded

    Java heap size descriptions (xms, xmx, xmn)

    -Xms size in bytes
    
    Example : java -Xms32m
    

    Sets the initial size of the Java heap. The default size is 2097152 (2MB). The values must be a multiple of, and greater than, 1024 bytes (1KB). (The -server flag increases the default size to 32M.)

    -Xmn size in bytes
    
    Example : java -Xmx2m
    

    Sets the initial Java heap size for the Eden generation. The default value is 640K. (The -server flag increases the default size to 2M.)

    -Xmx size in bytes
    
    Example : java -Xmx2048m
    

    Sets the maximum size to which the Java heap can grow. The default size is 64M. (The -server flag increases the default size to 128M.) The maximum heap limit is about 2 GB (2048MB).

    Java memory arguments (xms, xmx, xmn) formatting

    When setting the Java heap size, you should specify your memory argument using one of the letters “m” or “M” for MB, or “g” or “G” for GB. Your setting won’t work if you specify “MB” or “GB.” Valid arguments look like this:

    -Xms64m or -Xms64M -Xmx1g or -Xmx1G Can also use 2048MB to specify 2GB Also, make sure you just use whole numbers when specifying your arguments. Using -Xmx512m is a valid option, but -Xmx0.5g will cause an error.

    This reference can be helpful for someone.

    How do I replace text inside a div element?

    In HTML put this

    <div id="field_name">TEXT GOES HERE</div>
    

    In Javascript put this

    var fieldNameElement = document.getElementById('field_name');
            if (fieldNameElement)
            {fieldNameElement.innerHTML = 'some HTML';}
    

    C# - Insert a variable number of spaces into a string? (Formatting an output file)

    I agree with Justin, and the WhiteSpace CHAR can be referenced using ASCII codes here Character number 32 represents a white space, Therefore:

    string.Empty.PadRight(totalLength, (char)32);
    

    An alternative approach: Create all spaces manually within a custom method and call it:

    private static string GetSpaces(int totalLength)
        {
            string result = string.Empty;
            for (int i = 0; i < totalLength; i++)
            {
                result += " ";
            }
            return result;
        }
    

    And call it in your code to create white spaces: GetSpaces(14);

    java.lang.ClassCastException: java.lang.Long cannot be cast to java.lang.Integer in java 1.6

    The number of results can (theoretically) be greater than the range of an integer. I would refactor the code and work with the returned long value instead.

    Generic XSLT Search and Replace template

    Here's one way in XSLT 2

    <?xml version="1.0" encoding="UTF-8"?> <xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">   <xsl:template match="@*|node()">     <xsl:copy>       <xsl:apply-templates select="@*|node()"/>     </xsl:copy>   </xsl:template>   <xsl:template match="text()">     <xsl:value-of select="translate(.,'&quot;','''')"/>   </xsl:template> </xsl:stylesheet> 

    Doing it in XSLT1 is a little more problematic as it's hard to get a literal containing a single apostrophe, so you have to resort to a variable:

    <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">   <xsl:template match="@*|node()">     <xsl:copy>       <xsl:apply-templates select="@*|node()"/>     </xsl:copy>   </xsl:template>   <xsl:variable name="apos">'</xsl:variable>   <xsl:template match="text()">     <xsl:value-of select="translate(.,'&quot;',$apos)"/>   </xsl:template> </xsl:stylesheet> 

    Plotting using a CSV file

    You can also plot to a png file using gnuplot (which is free):

    terminal commands

    gnuplot> set title '<title>'
    gnuplot> set ylabel '<yLabel>'
    gnuplot> set xlabel '<xLabel>'
    gnuplot> set grid
    gnuplot> set term png
    gnuplot> set output '<Output file name>.png'
    gnuplot> plot '<fromfile.csv>'
    

    note: you always need to give the right extension (.png here) at set output

    Then it is also possible that the ouput is not lines, because your data is not continues. To fix this simply change the 'plot' line to:

    plot '<Fromfile.csv>' with line lt -1 lw 2
    

    More line editing options (dashes and line color ect.) at: http://gnuplot.sourceforge.net/demo_canvas/dashcolor.html

    • gnuplot is available in most linux distros via the package manager (e.g. on an apt based distro, run apt-get install gnuplot)
    • gnuplot is available in windows via Cygwin
    • gnuplot is available on macOS via homebrew (run brew install gnuplot)

    How to access your website through LAN in ASP.NET

    You may also need to enable the World Wide Web Service inbound firewall rule.

    On Windows 7: Start -> Control Panel -> Windows Firewall -> Advanced Settings -> Inbound Rules

    Find World Wide Web Services (HTTP Traffic-In) in the list and select to enable the rule. Change is pretty much immediate.

    How to execute .sql script file using JDBC

    You can read the script line per line with a BufferedReader and append every line to a StringBuilder so that the script becomes one large string.

    Then you can create a Statement object using JDBC and call statement.execute(stringBuilder.toString()).

    Drop rows containing empty cells from a pandas DataFrame

    You can use this variation:

    import pandas as pd
    vals = {
        'name' : ['n1', 'n2', 'n3', 'n4', 'n5', 'n6', 'n7'],
        'gender' : ['m', 'f', 'f', 'f',  'f', 'c', 'c'],
        'age' : [39, 12, 27, 13, 36, 29, 10],
        'education' : ['ma', None, 'school', None, 'ba', None, None]
    }
    df_vals = pd.DataFrame(vals) #converting dict to dataframe
    

    This will output(** - highlighting only desired rows):

       age education gender name
    0   39        ma      m   n1 **
    1   12      None      f   n2    
    2   27    school      f   n3 **
    3   13      None      f   n4
    4   36        ba      f   n5 **
    5   29      None      c   n6
    6   10      None      c   n7
    

    So to drop everything that does not have an 'education' value, use the code below:

    df_vals = df_vals[~df_vals['education'].isnull()] 
    

    ('~' indicating NOT)

    Result:

       age education gender name
    0   39        ma      m   n1
    2   27    school      f   n3
    4   36        ba      f   n5
    

    gdb: "No symbol table is loaded"

    First of all, what you have is a fully compiled program, not an object file, so drop the .o extension. Now, pay attention to what the error message says, it tells you exactly how to fix your problem: "No symbol table is loaded. Use the "file" command."

    (gdb) exec-file test
    (gdb) b 2
    No symbol table is loaded.  Use the "file" command.
    (gdb) file test
    Reading symbols from /home/user/test/test...done.
    (gdb) b 2
    Breakpoint 1 at 0x80483ea: file test.c, line 2.
    (gdb) 
    

    Or just pass the program on the command line.

    $ gdb test
    GNU gdb (GDB) 7.4
    Copyright (C) 2012 Free Software Foundation, Inc.
    License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
    [...]
    Reading symbols from /home/user/test/test...done.
    (gdb) b 2
    Breakpoint 1 at 0x80483ea: file test.c, line 2.
    (gdb) 
    

    How can I select checkboxes using the Selenium Java WebDriver?

    Maybe a good starting point:

    isChecked  = driver.findElement((By.id("idOftheElement"))).getAttribute("name");
    if(!isChecked.contains("chkOptions$1"))
    {
        driver.FindElement(By.Id("idOfTheElement")).Click();
    }
    

    How to create JNDI context in Spring Boot with Embedded Tomcat Container

    Please note instead of

    public TomcatEmbeddedServletContainerFactory tomcatFactory()
    

    I had to use the following method signature

    public EmbeddedServletContainerFactory embeddedServletContainerFactory() 
    

    How to update record using Entity Framework Core?

    public async Task<bool> Update(MyObject item)
    {
        Context.Entry(await Context.MyDbSet.FirstOrDefaultAsync(x => x.Id == item.Id)).CurrentValues.SetValues(item);
        return (await Context.SaveChangesAsync()) > 0;
    }
    

    twitter bootstrap autocomplete dropdown / combobox with Knockoutjs

    Can i suggest http://www.jqueryscript.net/form/Twitter-Like-Mentions-Auto-Suggesting-Plugin-with-jQuery-Bootstrap-Suggest.html, works more like the twitter post suggestion where it gives you a list of users or topics based on @ or # tags,

    view demo here: http://www.jqueryscript.net/demo/Twitter-Like-Mentions-Auto-Suggesting-Plugin-with-jQuery-Bootstrap-Suggest/

    in this one you can easily change the @ and # to anything you want

    Table border left and bottom

    You need to use the border property as seen here: jsFiddle

    HTML:

    <table width="770">
        <tr>
            <td class="border-left-bottom">picture (border only to the left and bottom ) </td>
            <td>text</td>
        </tr>
        <tr>
            <td>text</td>
            <td class="border-left-bottom">picture (border only to the left and bottom) </td>
        </tr>
    </table>`
    

    CSS:

    td.border-left-bottom{
        border-left: solid 1px #000;
        border-bottom: solid 1px #000;
    }
    

    findViewByID returns null

    Alongside the classic causes, mentioned elsewhere:

    • Make sure you've called setContentView() before findViewById()
    • Make sure that the id you want is in the view or layout you've given to setContentView()
    • Make sure that the id isn't accidentally duplicated in different layouts

    There is one I have found for custom views in standard layouts, which goes against the documentation:

    In theory you can create a custom view and add it to a layout (see here). However, I have found that in such situations, sometimes the id attribute works for all the views in the layout except the custom ones. The solution I use is:

    1. Replace each custom view with a FrameLayout with the same layout properties as you would like the custom view to have. Give it an appropriate id, say frame_for_custom_view.
    2. In onCreate:

      setContentView(R.layout.my_layout);
      FrameView fv = findViewById(R.id.frame_for_custom_layout);
      MyCustomView cv = new MyCustomView(context);
      fv.addView(cv);
      

      which puts the custom view in the frame.

    Timer Interval 1000 != 1 second?

    The proper interval to get one second is 1000. The Interval property is the time between ticks in milliseconds:

    MSDN: Timer.Interval Property

    So, it's not the interval that you set that is wrong. Check the rest of your code for something like changing the interval of the timer, or binding the Tick event multiple times.

    Handler vs AsyncTask vs Thread

    It depends which one to chose is based on the requirement

    Handler is mostly used to switch from other thread to main thread, Handler is attached to a looper on which it post its runnable task in queue. So If you are already in other thread and switch to main thread then you need handle instead of async task or other thread

    If Handler created in other than main thread which is not a looper is will not give error as handle is created the thread, that thread need to be made a lopper

    AsyncTask is used to execute code for few seconds which run on background thread and gives its result to main thread ** *AsyncTask Limitations 1. Async Task is not attached to life cycle of activity and it keeps run even if its activity destroyed whereas loader doesn't have this limitation 2. All Async Tasks share the same background thread for execution which also impact the app performance

    Thread is used in app for background work also but it doesn't have any call back on main thread. If requirement suits some threads instead of one thread and which need to give task many times then thread pool executor is better option.Eg Requirement of Image loading from multiple url like glide.

    HTTP Status 405 - Request method 'POST' not supported (Spring MVC)

    I found the problem that was causing the HTTP error.

    In the setFalse() function that is triggered by the Save button my code was trying to submit the form that contained the button.

            function setFalse(){
                document.getElementById("hasId").value ="false";
                document.deliveryForm.submit();
                document.submitForm.submit();
    

    when I remove the document.submitForm.submit(); it works:

            function setFalse(){
                document.getElementById("hasId").value ="false";
                document.deliveryForm.submit()
    

    @Roger Lindsjö Thank you for spotting my error where I wasn't passing on the right parameter!

    How to pass a parameter to Vue @click event handler

    I had the same issue and here is how I manage to pass through:

    In your case you have addToCount() which is called. now to pass down a param when user clicks, you can say @click="addToCount(item.contactID)"

    in your function implementation you can receive the params like:

    addToCount(paramContactID){
     // the paramContactID contains the value you passed into the function when you called it
     // you can do what you want to do with the paramContactID in here!
    
    }
    

    Mipmaps vs. drawable folders

    The mipmap folders are for placing your app/launcher icons (which are shown on the homescreen) in only. Any other drawable assets you use should be placed in the relevant drawable folders as before.

    According to this Google blogpost:

    It’s best practice to place your app icons in mipmap- folders (not the drawable- folders) because they are used at resolutions different from the device’s current density.

    When referencing the mipmap- folders ensure you are using the following reference:

    android:icon="@mipmap/ic_launcher"
    

    The reason they use a different density is that some launchers actually display the icons larger than they were intended. Because of this, they use the next size up.

    How to verify an XPath expression in Chrome Developers tool or Firefox's Firebug?

    By using Chrome or Opera

    without any plugins, without writing any single XPath syntax character

    1. right click the required element, then "inspect"
    2. right click on highlighted element tag, choose Copy ? Copy XPath.

    ;)

    Enter image description here

    Best practices for Storyboard login screen, handling clearing of data upon logout

    Doing this from the app delegate is NOT recommended. AppDelegate manages the app life cycle that relate to launching, suspending, terminating and so on. I suggest doing this from your initial view controller in the viewDidAppear. You can self.presentViewController and self.dismissViewController from the login view controller. Store a bool key in NSUserDefaults to see if it's launching for the first time.

    When is it acceptable to call GC.Collect?

    Scott Holden's blog entry on when to (and when not to) call GC.Collect is specific to the .NET Compact Framework, but the rules generally apply to all managed development.

    Visual Studio: How to show Overloads in IntelliSense?

    I know this is an old post, but for the newbies like myself who still hit this page this might be useful. when you hover on a method you get a non clickable info-box whereas if you just write a comma in the method parenthesis the IntelliSense will offer you the beloved info-box with the clickable arrows.

    JPA OneToMany not deleting child

    @Entity 
    class Employee {
         @OneToOne(orphanRemoval=true)
         private Address address;
    }
    

    See here.

    How to set the value of a hidden field from a controller in mvc

    Without a view model you could use a simple HTML hidden input.

    <input type="hidden" name="FullName" id="FullName" value="@ViewBag.FullName" />
    

    The required anti-forgery form field "__RequestVerificationToken" is not present Error in user Registration

    In my case I was getting this error while making an AJAX post, it turned out to be that the __RequestVerificationToken value wasn't being passed across in the call. I had to manually find the value of this field and set this as a property on the data object that's sent to the endpoint.

    i.e.

    data.__RequestVerificationToken = $('input[name="__RequestVerificationToken"]').val();
    

    Example

    HTML

      <form id="myForm">
        @Html.AntiForgeryToken()
    
        <!-- other input fields -->
    
        <input type="submit" class="submitButton" value="Submit" />
      </form>
    

    Javascript

    $(document).on('click', '#myForm .submitButton', function () {
      var myData = { ... };
      myData.__RequestVerificationToken = $('#myForm input[name="__RequestVerificationToken"]').val();
    
      $.ajax({
        type: 'POST',
        url: myUrl,
        data: myData,
        contentType: 'application/x-www-form-urlencoded; charset=utf-8',
        dataType: 'json',
        success: function (response) {
          alert('Form submitted');
        },
        error: function (e) {
          console.error('Error submitting form', e);
          alert('Error submitting form');
        },
      });
      return false; //prevent form reload
    });
    

    Controller

    [HttpPost]
    [Route("myUrl")]
    [ValidateAntiForgeryToken]
    public async Task<ActionResult> MyUrlAsync(MyDto dto)
    {
        ...
    }
    

    How to use RANK() in SQL Server

    You have already grouped by ContenderNum, no need to partition again by it. Use Dense_rank()and order by totals desc. In short,

    SELECT contendernum,totals, **DENSE_RANK()** 
    OVER (ORDER BY totals **DESC**) 
    AS xRank 
    FROM
    (
       SELECT ContenderNum ,SUM(Criteria1+Criteria2+Criteria3+Criteria4) AS totals
       FROM dbo.Cat1GroupImpersonation
       GROUP BY ContenderNum
    ) AS a
    

    How can I display a tooltip on an HTML "option" tag?

    I don't believe that you can achieve this functionality with standard <select> element.

    What i would suggest is to use such way.

    http://filamentgroup.com/lab/jquery_ipod_style_and_flyout_menus/

    The basic version of it won't take too much space and you can easily bind mouseover events to sub items to show a nice tooltip.

    Hope this helps, Sinan.

    JWT (JSON Web Token) automatic prolongation of expiration

    I work at Auth0 and I was involved in the design of the refresh token feature.

    It all depends on the type of application and here is our recommended approach.

    Web applications

    A good pattern is to refresh the token before it expires.

    Set the token expiration to one week and refresh the token every time the user opens the web application and every one hour. If a user doesn't open the application for more than a week, they will have to login again and this is acceptable web application UX.

    To refresh the token, your API needs a new endpoint that receives a valid, not expired JWT and returns the same signed JWT with the new expiration field. Then the web application will store the token somewhere.

    Mobile/Native applications

    Most native applications do login once and only once.

    The idea is that the refresh token never expires and it can be exchanged always for a valid JWT.

    The problem with a token that never expires is that never means never. What do you do if you lose your phone? So, it needs to be identifiable by the user somehow and the application needs to provide a way to revoke access. We decided to use the device's name, e.g. "maryo's iPad". Then the user can go to the application and revoke access to "maryo's iPad".

    Another approach is to revoke the refresh token on specific events. An interesting event is changing the password.

    We believe that JWT is not useful for these use cases, so we use a random generated string and we store it on our side.

    Xml serialization - Hide null values

    I prefer creating my own xml with no auto-generated tags. In this I can ignore creating the nodes with null values:

    public static string ConvertToXML<T>(T objectToConvert)
        {
            XmlDocument doc = new XmlDocument();
            XmlNode root = doc.CreateNode(XmlNodeType.Element, objectToConvert.GetType().Name, string.Empty);
            doc.AppendChild(root);
            XmlNode childNode;
    
            PropertyDescriptorCollection properties = TypeDescriptor.GetProperties(typeof(T));
            foreach (PropertyDescriptor prop in properties)
            {
                if (prop.GetValue(objectToConvert) != null)
                {
                    childNode = doc.CreateNode(XmlNodeType.Element, prop.Name, string.Empty);
                    childNode.InnerText = prop.GetValue(objectToConvert).ToString();
                    root.AppendChild(childNode);
                }
            }            
    
            return doc.OuterXml;
        }
    

    How to push object into an array using AngularJS

    A couple of answers that should work above but this is how i would write it.

    Also, i wouldn't declare controllers inside templates. It's better to declare them on your routes imo.

    add-text.tpl.html

    <div ng-controller="myController">
        <form ng-submit="addText(myText)">
            <input type="text" placeholder="Let's Go" ng-model="myText">
            <button type="submit">Add</button>
        </form>
        <ul>
            <li ng-repeat="text in arrayText">{{ text }}</li>
        </ul>
    </div>
    

    app.js

    (function() {
    
        function myController($scope) {
            $scope.arrayText = ['hello', 'world'];
            $scope.addText = function(myText) {
                 $scope.arrayText.push(myText);     
            };
        }
    
        angular.module('app', [])
            .controller('myController', myController);
    
    })();
    

    For each row in an R dataframe

    I was curious about the time performance of the non-vectorised options. For this purpose, I have used the function f defined by knguyen

    f <- function(x, output) {
      wellName <- x[1]
      plateName <- x[2]
      wellID <- 1
      print(paste(wellID, x[3], x[4], sep=","))
      cat(paste(wellID, x[3], x[4], sep=","), file= output, append = T, fill = T)
    }
    

    and a dataframe like the one in his example:

    n = 100; #number of rows for the data frame
    d <- data.frame( name = LETTERS[ sample.int( 25, n, replace=T ) ],
                      plate = paste0( "P", 1:n ),
                      value1 = 1:n,
                      value2 = (1:n)*10 )
    

    I included two vectorised functions (for sure quicker than the others) in order to compare the cat() approach with a write.table() one...

    library("ggplot2")
    library( "microbenchmark" )
    library( foreach )
    library( iterators )
    
    tm <- microbenchmark(S1 =
                           apply(d, 1, f, output = 'outputfile1'),
                         S2 = 
                           for(i in 1:nrow(d)) {
                             row <- d[i,]
                             # do stuff with row
                             f(row, 'outputfile2')
                           },
                         S3 = 
                           foreach(d1=iter(d, by='row'), .combine=rbind) %dopar% f(d1,"outputfile3"),
                         S4= {
                           print( paste(wellID=rep(1,n), d[,3], d[,4], sep=",") )
                           cat( paste(wellID=rep(1,n), d[,3], d[,4], sep=","), file= 'outputfile4', sep='\n',append=T, fill = F)                           
                         },
                         S5 = {
                           print( (paste(wellID=rep(1,n), d[,3], d[,4], sep=",")) )
                           write.table(data.frame(rep(1,n), d[,3], d[,4]), file='outputfile5', row.names=F, col.names=F, sep=",", append=T )
                         },
                         times=100L)
    autoplot(tm)
    

    The resulting image shows that apply gives the best performance for a non-vectorised version, whereas write.table() seems to outperform cat(). ForEachRunningTime

    How do I find out what version of WordPress is running?

    Look in wp-includes/version.php

    /**
     * The WordPress version string
     *
     * @global string $wp_version
     */
    $wp_version = '2.8.4';
    

    What is the difference between supervised learning and unsupervised learning?

    Machine learning: It explores the study and construction of algorithms that can learn from and make predictions on data.Such algorithms operate by building a model from example inputs in order to make data-driven predictions or decisions expressed as outputs,rather than following strictly static program instructions.

    Supervised learning: It is the machine learning task of inferring a function from labeled training data.The training data consist of a set of training examples. In supervised learning, each example is a pair consisting of an input object (typically a vector) and a desired output value (also called the supervisory signal). A supervised learning algorithm analyzes the training data and produces an inferred function, which can be used for mapping new examples.

    The computer is presented with example inputs and their desired outputs, given by a "teacher", and the goal is to learn a general rule that maps inputs to outputs.Specifically, a supervised learning algorithm takes a known set of input data and known responses to the data (output), and trains a model to generate reasonable predictions for the response to new data.

    Unsupervised learning: It is learning without a teacher. One basic thing that you might want to do with data is to visualize it. It is the machine learning task of inferring a function to describe hidden structure from unlabeled data. Since the examples given to the learner are unlabeled, there is no error or reward signal to evaluate a potential solution. This distinguishes unsupervised learning from supervised learning. Unsupervised learning uses procedures that attempt to find natural partitions of patterns.

    With unsupervised learning there is no feedback based on the prediction results, i.e., there is no teacher to correct you.Under the Unsupervised learning methods no labeled examples are provided and there is no notion of the output during the learning process. As a result, it is up to the learning scheme/model to find patterns or discover the groups of the input data

    You should use unsupervised learning methods when you need a large amount of data to train your models, and the willingness and ability to experiment and explore, and of course a challenge that isn’t well solved via more-established methods.With unsupervised learning it is possible to learn larger and more complex models than with supervised learning.Here is a good example on it

    .

    vagrant login as root by default

    Note: Only use this method for local development, it's not secure. You can setup password and ssh config while provisioning the box. For example with debian/stretch64 box this is my provision script:

    config.vm.provision "shell", inline: <<-SHELL
        echo -e "vagrant\nvagrant" | passwd root
        echo "PermitRootLogin yes" >> /etc/ssh/sshd_config
        sed -in 's/PasswordAuthentication no/PasswordAuthentication yes/g' /etc/ssh/sshd_config
        service ssh restart
    SHELL
    

    This will set root password to vagrant and permit root login with password. If you are using private_network say with ip address 192.168.10.37 then you can ssh with ssh [email protected]

    You may need to change that echo and sed commands depending on the default sshd_config file.

    How to send 100,000 emails weekly?

    Here is what I did recently in PHP on one of my bigger systems:

    1. User inputs newsletter text and selects the recipients (which generates a query to retrieve the email addresses for later).

    2. Add the newsletter text and recipients query to a row in mysql table called *email_queue*

      • (The table email_queue has the columns "to" "subject" "body" "priority")
    3. I created another script, which runs every minute as a cron job. It uses the SwiftMailer class. This script simply:

      • during business hours, sends all email with priority == 0

      • after hours, send other emails by priority

    Depending on the hosts settings, I can now have it throttle using standard swiftmailers plugins like antiflood and throttle...

    $mailer->registerPlugin(new Swift_Plugins_AntiFloodPlugin(50, 30));
    

    and

    $mailer->registerPlugin(new Swift_Plugins_ThrottlerPlugin( 100, Swift_Plugins_ThrottlerPlugin::MESSAGES_PER_MINUTE ));
    

    etc, etc..

    I have expanded it way beyond this pseudocode, with attachments, and many other configurable settings, but it works very well as long as your server is setup correctly to send email. (Probably wont work on shared hosting, but in theory it should...) Swiftmailer even has a setting

    $message->setReturnPath
    

    Which I now use to track bounces...

    Happy Trails! (Happy Emails?)

    A JOIN With Additional Conditions Using Query Builder or Eloquent

    You can replicate those brackets in the left join:

    LEFT JOIN bookings  
                   ON rooms.id = bookings.room_type_id
                  AND (  bookings.arrival between ? and ?
                      OR bookings.departure between ? and ? )
    

    is

    ->leftJoin('bookings', function($join){
        $join->on('rooms.id', '=', 'bookings.room_type_id');
        $join->on(DB::raw('(  bookings.arrival between ? and ? OR bookings.departure between ? and ? )'), DB::raw(''), DB::raw(''));
    })
    

    You'll then have to set the bindings later using "setBindings" as described in this SO post: How to bind parameters to a raw DB query in Laravel that's used on a model?

    It's not pretty but it works.

    Function to calculate distance between two coordinates

    I have written a similar equation before - tested it and also got 1.6 km.

    Your google maps was showing the DRIVING distance.

    Your function is calculating as the crow flies (straight line distance).

    alert(calcCrow(59.3293371,13.4877472,59.3225525,13.4619422).toFixed(1));
    
    
    
        //This function takes in latitude and longitude of two location and returns the distance between them as the crow flies (in km)
        function calcCrow(lat1, lon1, lat2, lon2) 
        {
          var R = 6371; // km
          var dLat = toRad(lat2-lat1);
          var dLon = toRad(lon2-lon1);
          var lat1 = toRad(lat1);
          var lat2 = toRad(lat2);
    
          var a = Math.sin(dLat/2) * Math.sin(dLat/2) +
            Math.sin(dLon/2) * Math.sin(dLon/2) * Math.cos(lat1) * Math.cos(lat2); 
          var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a)); 
          var d = R * c;
          return d;
        }
    
        // Converts numeric degrees to radians
        function toRad(Value) 
        {
            return Value * Math.PI / 180;
        }
    

    How to print to console using swift playground?

    for displaying variables only in playground, just mention the variable name without anything

    let stat = 100

    stat // this outputs the value of stat on playground right window

    Adding a 'share by email' link to website

    <a target="_blank" title="Share this page" href="http://www.sharethis.com/share?url=[INSERT URL]&title=[INSERT TITLE]&summary=[INSERT SUMMARY]&img=[INSERT IMAGE URL]&pageInfo=%7B%22hostname%22%3A%22[INSERT DOMAIN NAME]%22%2C%22publisher%22%3A%22[INSERT PUBLISHERID]%22%7D"><img width="86" height="25" alt="Share this page" src="http://w.sharethis.com/images/share-classic.gif"></a>
    

    Instructions

    First, insert these lines wherever you want within your newsletter code. Then:

    1. Change "INSERT URL" to whatever website holds the shared content.
    2. Change "INSERT TITLE" to the title of the article.
    3. Change "INSERT SUMMARY" to a short summary of the article.
    4. Change "INSERT IMAGE URL" to an image that will be shared with the rest of the content.
    5. Change "INSERT DOMAIN NAME" to your domain name.
    6. Change "INSERT PUBLISHERID" to your publisher ID (if you have an account, if not, remove "[INSERT PUBLISHERID]" or sign up!)

    If you are using this on an email newsletter, make sure you add our sharing buttons to the destination page. This will ensure that you get complete sharing analytics for your page. Make sure you replace "INSERT PUBLISHERID" with your own.

    Access to the path is denied

    I had the same problem but I fixed it by saving the file in a different location and then copying the file and pasting it in the location where I wanted it to be. I used the option to replace the the existing file and that did the trick for me. I know this is not the most efficient way but it works and takes less than 15 seconds.

    Are HTTPS headers encrypted?

    HTTP version 1.1 added a special HTTP method, CONNECT - intended to create the SSL tunnel, including the necessary protocol handshake and cryptographic setup.
    The regular requests thereafter all get sent wrapped in the SSL tunnel, headers and body inclusive.

    Reading from memory stream to string

    string result = Encoding.UTF8.GetString((stream as MemoryStream).ToArray());
    

    Python's most efficient way to choose longest string in list?

    What should happen if there are more than 1 longest string (think '12', and '01')?

    Try that to get the longest element

    max_length,longest_element = max([(len(x),x) for x in ('a','b','aa')])
    

    And then regular foreach

    for st in mylist:
        if len(st)==max_length:...
    

    cat, grep and cut - translated to python

    You need a loop over the lines of a file, you need to learn about string methods

    with open(filename,'r') as f:
        for line in f.readlines():
            # python can do regexes, but this is for s fixed string only
            if "something" in line:
                idx1 = line.find('"')
                idx2 = line.find('"', idx1+1)
                field = line[idx1+1:idx2-1]
                print(field)
    

    and you need a method to pass the filename to your python program and while you are at it, maybe also the string to search for...

    For the future, try to ask more focused questions if you can,

    could not extract ResultSet in hibernate

    I faced the same problem after migrating a database from online server to localhost. The schema changed so I had to define the schema manually for each table:

    @Entity
    @Table(name = "ESBCORE_DOMAIN", schema = "SYS")
    

    How do I attach events to dynamic HTML elements with jQuery?

    If your on jQuery 1.3+ then use .live()

    Binds a handler to an event (like click) for all current - and future - matched element. Can also bind custom events.

    Heap space out of memory

    There is no way to dynamically increase the heap programatically since the heap is allocated when the Java Virtual Machine is started.

    However, you can use this command

    java -Xmx1024M YourClass
    

    to set the memory to 1024

    or, you can set a min max

    java -Xms256m -Xmx1024m YourClassNameHere
    

    Creating composite primary key in SQL Server

    How about something like

    CREATE TABLE testRequest (
            wardNo nchar(5),
            BHTNo nchar(5),
            testID nchar(5),
            reqDateTime datetime,
            PRIMARY KEY (wardNo, BHTNo, testID)
    );
    

    Have a look at this example

    SQL Fiddle DEMO

    sudo in php exec()

    The best secure method is to use the crontab. ie Save all your commands in a database say, mysql table and create a cronjob to read these mysql entreis and execute via exec() or shell_exec(). Please read this link for more detailed information.

            • killProcess.php

    How to remove elements from a generic list while iterating over it?

     foreach (var item in list.ToList()) {
         list.Remove(item);
     }
    

    If you add ".ToList()" to your list (or the results of a LINQ query), you can remove "item" directly from "list" without the dreaded "Collection was modified; enumeration operation may not execute." error. The compiler makes a copy of "list", so that you can safely do the remove on the array.

    While this pattern is not super efficient, it has a natural feel and is flexible enough for almost any situation. Such as when you want to save each "item" to a DB and remove it from the list only when the DB save succeeds.

    No value accessor for form control

    For UnitTest angular 2 with angular material you have to add MatSelectModule module in imports section.

    import { MatSelectModule } from '@angular/material';
    
    beforeEach(async(() => {
        TestBed.configureTestingModule({
          declarations: [ CreateUserComponent ],
          imports : [ReactiveFormsModule,        
            MatSelectModule,
            MatAutocompleteModule,......
    
          ],
          providers: [.........]
        })
        .compileComponents();
      }));
    

    How to run a C# console application with the console hidden

    Simple answer is that: Go to your console app's properties(project's properties).In the "Application" tab, just change the "Output type" to "Windows Application". That's all.

    Run PowerShell scripts on remote PC

    Can you try the following?

    psexec \\server cmd /c "echo . | powershell script.ps1"
    

    How can I remove a specific item from an array?

    To find and remove a particular string from an array of strings:

    var colors = ["red","blue","car","green"];
    var carIndex = colors.indexOf("car"); // Get "car" index
    // Remove car from the colors array
    colors.splice(carIndex, 1); // colors = ["red", "blue", "green"]
    

    Source: https://www.codegrepper.com/?search_term=remove+a+particular+element+from+array

    Can an AWS Lambda function call another

    I was working with the answer provided by blueskin but I could not read the Payload response because the InvocationType='Event' is async, so I changed as InvocationType='RequestResponse' and now all works good.

    Git stash pop- needs merge, unable to refresh index

    Its much simpler than the accepted answer. You need to:

    1. Check git status and unmerged paths under it. Fix the conflicts. You can skip this step if you'd rather do it later.

    2. Add all these files under unmerged paths to index using git add <filename>.

    3. Now do git stash pop. If you get any conflicts these will again need to be resolved.

    Graph visualization library in JavaScript

    In a commercial scenario, a serious contestant for sure is yFiles for HTML:

    It offers:

    • Easy import of custom data (this interactive online demo seems to pretty much do exactly what the OP was looking for)
    • Interactive editing for creating and manipulating the diagrams through user gestures (see the complete editor)
    • A huge programming API for customizing each and every aspect of the library
    • Support for grouping and nesting (both interactive, as well as through the layout algorithms)
    • Does not depend on a specfic UI toolkit but supports integration into almost any existing Javascript toolkit (see the "integration" demos)
    • Automatic layout (various styles, like "hierarchic", "organic", "orthogonal", "tree", "circular", "radial", and more)
    • Automatic sophisticated edge routing (orthogonal and organic edge routing with obstacle avoidance)
    • Incremental and partial layout (adding and removing elements and only slightly or not at all changing the rest of the diagram)
    • Support for grouping and nesting (both interactive, as well as through the layout algorithms)
    • Implementations of graph analysis algorithms (paths, centralities, network flows, etc.)
    • Uses HTML 5 technologies like SVG+CSS and Canvas and modern Javascript leveraging properties and other more ES5 and ES6 features (but for the same reason will not run in IE versions 8 and lower).
    • Uses a modular API that can be loaded on-demand using UMD loaders

    Here is a sample rendering that shows most of the requested features:

    Screenshot of a sample rendering created by the BPMN demo.

    Full disclosure: I work for yWorks, but on Stackoverflow I do not represent my employer.

    MySQL Update Inner Join tables query

    Try this:

    UPDATE business AS b
    INNER JOIN business_geocode AS g ON b.business_id = g.business_id
    SET b.mapx = g.latitude,
      b.mapy = g.longitude
    WHERE  (b.mapx = '' or b.mapx = 0) and
      g.latitude > 0
    

    Update:

    Since you said the query yielded a syntax error, I created some tables that I could test it against and confirmed that there is no syntax error in my query:

    mysql> create table business (business_id int unsigned primary key auto_increment, mapx varchar(255), mapy varchar(255)) engine=innodb;
    Query OK, 0 rows affected (0.01 sec)
    
    mysql> create table business_geocode (business_geocode_id int unsigned primary key auto_increment, business_id int unsigned not null, latitude varchar(255) not null, longitude varchar(255) not null, foreign key (business_id) references business(business_id)) engine=innodb;
    Query OK, 0 rows affected (0.01 sec)
    
    mysql> UPDATE business AS b
        -> INNER JOIN business_geocode AS g ON b.business_id = g.business_id
        -> SET b.mapx = g.latitude,
        ->   b.mapy = g.longitude
        -> WHERE  (b.mapx = '' or b.mapx = 0) and
        ->   g.latitude > 0;
    Query OK, 0 rows affected (0.00 sec)
    Rows matched: 0  Changed: 0  Warnings: 0
    

    See? No syntax error. I tested against MySQL 5.5.8.

    Angularjs loading screen on ajax request

    Include this in your "app.config":

     $httpProvider.interceptors.push('myHttpInterceptor');
    

    And add this code:

    app.factory('myHttpInterceptor', function ($q, $window,$rootScope) {
        $rootScope.ActiveAjaxConectionsWithouthNotifications = 0;
        var checker = function(parameters,status){
                //YOU CAN USE parameters.url TO IGNORE SOME URL
                if(status == "request"){
                    $rootScope.ActiveAjaxConectionsWithouthNotifications+=1;
                    $('#loading_view').show();
                }
                if(status == "response"){
                    $rootScope.ActiveAjaxConectionsWithouthNotifications-=1;
    
                }
                if($rootScope.ActiveAjaxConectionsWithouthNotifications<=0){
                    $rootScope.ActiveAjaxConectionsWithouthNotifications=0;
                    $('#loading_view').hide();
    
                }
    
    
        };
    return {
        'request': function(config) {
            checker(config,"request");
            return config;
        },
       'requestError': function(rejection) {
           checker(rejection.config,"request");
          return $q.reject(rejection);
        },
        'response': function(response) {
             checker(response.config,"response");
          return response;
        },
       'responseError': function(rejection) {
            checker(rejection.config,"response");
          return $q.reject(rejection);
        }
      };
    });
    

    How can I install a CPAN module into a local directory?

    I had a similar problem, where I couldn't even install local::lib

    I created an installer that installed the module somewhere relative to the .pl files

    The install goes like:

    perl Makefile.PL PREFIX=./modulos
    make
    make install
    

    Then, in the .pl file that requires the module, which is in ./

    use lib qw(./modulos/share/perl/5.8.8/); # You may need to change this path
    use module::name;
    

    The rest of the files (makefile.pl, module.pm, etc) require no changes.

    You can call the .pl file with just

    perl file.pl
    

    Google Spreadsheet, Count IF contains a string

    It will likely have been solved by now, but I ran accross this and figured to give my input

    =COUNTIF(a2:a51;"*iPad*")
    

    The important thing is that separating parameters in google docs is using a ; and not a ,

    AngularJS does not send hidden field value

    Below Code will work for this IFF it in the same order as its mentionened make sure you order is type then name, ng-model ng-init, value. thats It.

    What does random.sample() method in python do?

    According to documentation:

    random.sample(population, k)

    Return a k length list of unique elements chosen from the population sequence. Used for random sampling without replacement.

    Basically, it picks k unique random elements, a sample, from a sequence:

    >>> import random
    >>> c = list(range(0, 15))
    >>> c
    [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14]
    >>> random.sample(c, 5)
    [9, 2, 3, 14, 11]
    

    random.sample works also directly from a range:

    >>> c = range(0, 15)
    >>> c
    range(0, 15)
    >>> random.sample(c, 5)
    [12, 3, 6, 14, 10]
    

    In addition to sequences, random.sample works with sets too:

    >>> c = {1, 2, 4}
    >>> random.sample(c, 2)
    [4, 1]
    

    However, random.sample doesn't work with arbitrary iterators:

    >>> c = [1, 3]
    >>> random.sample(iter(c), 5)
    TypeError: Population must be a sequence or set.  For dicts, use list(d).
    

    XML to CSV Using XSLT

    Here is a version with configurable parameters that you can set programmatically:

    <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
      <xsl:output method="text" encoding="utf-8" />
    
      <xsl:param name="delim" select="','" />
      <xsl:param name="quote" select="'&quot;'" />
      <xsl:param name="break" select="'&#xA;'" />
    
      <xsl:template match="/">
        <xsl:apply-templates select="projects/project" />
      </xsl:template>
    
      <xsl:template match="project">
        <xsl:apply-templates />
        <xsl:if test="following-sibling::*">
          <xsl:value-of select="$break" />
        </xsl:if>
      </xsl:template>
    
      <xsl:template match="*">
        <!-- remove normalize-space() if you want keep white-space at it is --> 
        <xsl:value-of select="concat($quote, normalize-space(), $quote)" />
        <xsl:if test="following-sibling::*">
          <xsl:value-of select="$delim" />
        </xsl:if>
      </xsl:template>
    
      <xsl:template match="text()" />
    </xsl:stylesheet>
    

    How to download and save a file from Internet using Java?

    It's possible to download the file with with Apache's HttpComponents instead of Commons-IO. This code allows you to download a file in Java according to its URL and save it at the specific destination.

    public static boolean saveFile(URL fileURL, String fileSavePath) {
    
        boolean isSucceed = true;
    
        CloseableHttpClient httpClient = HttpClients.createDefault();
    
        HttpGet httpGet = new HttpGet(fileURL.toString());
        httpGet.addHeader("User-Agent", "Mozilla/5.0 (Windows NT 6.3; WOW64; rv:34.0) Gecko/20100101 Firefox/34.0");
        httpGet.addHeader("Referer", "https://www.google.com");
    
        try {
            CloseableHttpResponse httpResponse = httpClient.execute(httpGet);
            HttpEntity fileEntity = httpResponse.getEntity();
    
            if (fileEntity != null) {
                FileUtils.copyInputStreamToFile(fileEntity.getContent(), new File(fileSavePath));
            }
    
        } catch (IOException e) {
            isSucceed = false;
        }
    
        httpGet.releaseConnection();
    
        return isSucceed;
    }
    

    In contrast to the single line of code:

    FileUtils.copyURLToFile(fileURL, new File(fileSavePath),
                            URLS_FETCH_TIMEOUT, URLS_FETCH_TIMEOUT);
    

    this code will give you more control over a process and let you specify not only time outs but User-Agent and Referer values, which are critical for many web-sites.

    Angular2 dynamic change CSS property

    I did this plunker to explore one way to do what you want.

    Here I get mystyle from the parent component but you can get it from a service.

    import {Component, View} from 'angular2/angular2'
    
    @Component({
      selector: '[my-person]',
      inputs: [
        'name',
        'mystyle: customstyle'
      ],
      host: {
        '[style.backgroundColor]': 'mystyle.backgroundColor'
      }
    })
    @View({
      template: `My Person Component: {{ name }}`
    })
    export class Person {}
    

    changing minDate option in JQuery DatePicker not working

    Month start from 0. 0 = January, 1 = February, 2 = March, ..., 11 = December.

    "Unicode Error "unicodeescape" codec can't decode bytes... Cannot open text files in Python 3

    The problem is with the string

    "C:\Users\Eric\Desktop\beeline.txt"
    

    Here, \U in "C:\Users... starts an eight-character Unicode escape, such as \U00014321. In your code, the escape is followed by the character 's', which is invalid.

    You either need to duplicate all backslashes:

    "C:\\Users\\Eric\\Desktop\\beeline.txt"
    

    Or prefix the string with r (to produce a raw string):

    r"C:\Users\Eric\Desktop\beeline.txt"
    

    How to delete and update a record in Hive

    The CLI told you where is your mistake : delete WHAT? from student ...

    Delete : How to delete/truncate tables from Hadoop-Hive?

    Update : Update , SET option in Hive

    Entity Framework Core add unique constraint code-first

    Also if you want to create Unique constrains on multiple columns you can simply do this (following @Sampath's link)

    class MyContext : DbContext
    {
        public DbSet<Person> People { get; set; }
    
        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            modelBuilder.Entity<Person>()
                .HasIndex(p => new { p.FirstName, p.LastName })
                .IsUnique(true);
        }
    }
    
    public class Person
    {
        public int PersonId { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
    }
    

    How to repair COMException error 80040154?

    WORKAROUND:

    The possible workaround is modify your project's platform from 'Any CPU' to 'X86' (in Project's Properties, Build/Platform's Target)

    ROOTCAUSE

    The VSS Interop is a managed assembly using 32-bit Framework and the dll contains a 32-bit COM object. If you run this COM dll in 64 bit environment, you will get the error message.

    Java converting Image to BufferedImage

    From a Java Game Engine:

    /**
     * Converts a given Image into a BufferedImage
     *
     * @param img The Image to be converted
     * @return The converted BufferedImage
     */
    public static BufferedImage toBufferedImage(Image img)
    {
        if (img instanceof BufferedImage)
        {
            return (BufferedImage) img;
        }
    
        // Create a buffered image with transparency
        BufferedImage bimage = new BufferedImage(img.getWidth(null), img.getHeight(null), BufferedImage.TYPE_INT_ARGB);
    
        // Draw the image on to the buffered image
        Graphics2D bGr = bimage.createGraphics();
        bGr.drawImage(img, 0, 0, null);
        bGr.dispose();
    
        // Return the buffered image
        return bimage;
    }
    

    How to find all tables that have foreign keys that reference particular table.column and have values for those foreign keys?

    I wrote a little bash onliner that you can write to a script to get a friendly output:

    mysql_references_to:

    mysql -uUSER -pPASS -A DB_NAME -se "USE information_schema; SELECT * FROM KEY_COLUMN_USAGE WHERE REFERENCED_TABLE_NAME = '$1' AND REFERENCED_COLUMN_NAME = 'id'\G" | sed 's/^[ \t]*//;s/[ \t]*$//' |egrep "\<TABLE_NAME|\<COLUMN_NAME" |sed 's/TABLE_NAME: /./g' |sed 's/COLUMN_NAME: //g' | paste -sd "," -| tr '.' '\n' |sed 's/,$//' |sed 's/,/./'
    

    So the execution: mysql_references_to transaccion (where transaccion is a random table name) gives an output like this:

    carrito_transaccion.transaccion_id
    comanda_detalle.transaccion_id
    comanda_detalle_devolucion.transaccion_positiva_id
    comanda_detalle_devolucion.transaccion_negativa_id
    comanda_transaccion.transaccion_id
    cuenta_operacion.transaccion_id
    ...
    

    Converting an int to a binary string representation in Java?

    public static string intToBinary(int n)
    {
        String s = "";
        while (n > 0)
        {
            s =  ( (n % 2 ) == 0 ? "0" : "1") +s;
            n = n / 2;
        }
        return s;
    }
    

    Constants in Kotlin -- what's a recommended way to create them?

    In Kotlin, if you want to create the local constants which are supposed to be used with in the class then you can create it like below

    val MY_CONSTANT = "Constants"
    

    And if you want to create a public constant in kotlin like public static final in java, you can create it as follow.

    companion object{
    
         const val MY_CONSTANT = "Constants"
    
    }
    

    Check if a temporary table exists and delete if it exists before creating a temporary table

    I think the problem is you need to add GO statement in between to separate the execution into batches. As the second drop script i.e. IF OBJECT_ID('tempdb..#Results') IS NOT NULL DROP TABLE #Results did not drop the temp table being part of single batch. Can you please try the below script.

    IF OBJECT_ID('tempdb..#Results') IS NOT NULL
        DROP TABLE #Results
    
    CREATE TABLE #Results
    (
        Company                CHAR(3),
        StepId                TINYINT,
        FieldId                TINYINT,
    )
    
    GO
    
    select company, stepid, fieldid from #Results
    
    IF OBJECT_ID('tempdb..#Results') IS NOT NULL
    DROP TABLE #Results
    
    CREATE TABLE #Results
    (
        Company                CHAR(3),
        StepId                TINYINT,
        FieldId                TINYINT,
        NewColumn            NVARCHAR(50)
    )
    
    GO
    
    select company, stepid, fieldid, NewColumn from #Results
    

    List the queries running on SQL Server

    SELECT
        p.spid, p.status, p.hostname, p.loginame, p.cpu, r.start_time, r.command,
        p.program_name, text 
    FROM
        sys.dm_exec_requests AS r,
        master.dbo.sysprocesses AS p 
        CROSS APPLY sys.dm_exec_sql_text(p.sql_handle)
    WHERE
        p.status NOT IN ('sleeping', 'background') 
    AND r.session_id = p.spid
    

    Microsoft.ACE.OLEDB.12.0 is not registered

    Summarized: INSTALL 32 bit version of Microsoft Access Database Engine 2010 Redistributable. Uninstall 64 bit version if previously installed. http://www.microsoft.com/en-us/download/details.aspx?id=13255

    The Excel connection manager is trying to use the ACE OLE DB provider in order to access the Excel file when the version is above 2007 (xlsx). Although your box is 64-bit, you’re using SQL Server Data Tools, which is a 32-bit application. There is no 64-bit version for SSDT. When you design your package within SSDT, you’re using a 32-bit process, which can only use 32-bit providers. When you try to choose the table in the Excel file, the connection manager needs to access the 32-bit version of the ACE OLE DB provider, but this provider is not registered on your machine, only the 64-bit version is installed.

    You should download the 32-bit version of the “Microsoft Access Database Engine 2010 Redistributable”. When you try to install it, you might get an error message. You should first uninstall only the 64-bit version of the “Microsoft Access Database Engine 2010 Redistributable”, which you probably installed previously. The 64-bit version and the 32-bit version can’t live together on the same host, so you’ll have to uninstall (through “Program and Features”) and install the other one if you wish to switch between them.

    Once you finish uninstalling the 64-bit version and installing the 32-bit version of the provider, the problem is solved, and you can finally choose the table within the Excel file. The Excel connection manager is now able to use the ACE OLE DB provider (32-bit version) in order to access the Excel file.

    How to read the value of a private field from a different class in Java?

    Use the Soot Java Optimization framework to directly modify the bytecode. http://www.sable.mcgill.ca/soot/

    Soot is completely written in Java and works with new Java versions.

    Request redirect to /Account/Login?ReturnUrl=%2f since MVC 3 install on server

    I fixed it this way

    1. Go to IIS
    2. Select your Project
    3. Click on "Authentication"
    4. Click on "Anonymous Authentication" > Edit > select "Application pool identity" instead of "Specific User".
    5. Done.

    HTTP status code for update and delete?

    Since the question delves into if DELETE "should" return 200 vs 204 it is worth considering that some people recommend returning an entity with links so the preference is for 200.

    "Instead of returning 204 (No Content), the API should be helpful and suggest places to go. In this example I think one obvious link to provide is to" 'somewhere.com/container/' (minus 'resource') "- the container from which the client just deleted a resource. Perhaps the client wishes to delete more resources, so that would be a helpful link."

    http://blog.ploeh.dk/2013/04/30/rest-lesson-learned-avoid-204-responses/

    If a client encounters a 204 response, it can either give up, go to the entry point of the API, or go back to the previous resource it visited. Neither option is particularly good.

    Personally I would not say 204 is wrong (neither does the author; he says "annoying") because good caching at the client side has many benefits. Best is to be consistent either way.