Programs & Examples On #Custom backend

getSupportActionBar() The method getSupportActionBar() is undefined for the type TaskActivity. Why?

You have to change the extends Activity to extends AppCompactActivity then try set and getSupportActionBar()

rand() returns the same number each time the program is run

You need to "seed" the generator. Check out this short video, it will clear things up.

https://www.thenewboston.com/videos.php?cat=16&video=17503

Using Enum values as String literals

For my enums I don't really like to think of them being allocated with 1 String each. This is how I implement a toString() method on enums.

enum Animal
{
    DOG, CAT, BIRD;
    public String toString(){
        switch (this) {
            case DOG: return "Dog";
            case CAT: return "Cat";
            case BIRD: return "Bird";
        }
        return null;
    }
}

Test if number is odd or even

You were right in thinking mod was a good place to start. Here is an expression which will return true if $number is even, false if odd:

$number % 2 == 0

Works for every integerPHP value, see as well Arithmetic OperatorsPHP.

Example:

$number = 20;
if ($number % 2 == 0) {
  print "It's even";
}

Output:

It's even

How do I restart nginx only after the configuration test was successful on Ubuntu?

As of nginx 1.8.0, the correct solution is

sudo nginx -t && sudo service nginx reload

Note that due to a bug, configtest always returns a zero exit code even if the config file has an error.

Call Stored Procedure within Create Trigger in SQL Server

I think you will have to loop over the "inserted" table, which contains all rows that were updated. You can use a WHERE loop, or a WITH statement if your primary key is a GUID. This is the simpler (for me) to write, so here is my example. We use this approach, so I know for a fact it works fine.

ALTER TRIGGER [dbo].[RA2Newsletter] ON [dbo].[Reiseagent]
    AFTER INSERT
AS
        -- This is your primary key.  I assume INT, but initialize
        -- to minimum value for the type you are using.
        DECLARE @rAgent_ID INT = 0

        -- Looping variable.
        DECLARE @i INT = 0

        -- Count of rows affected for looping over
        DECLARE @count INT

        -- These are your old variables.
        DECLARE @rAgent_Name NVARCHAR(50)
        DECLARE @rAgent_Email NVARCHAR(50)
        DECLARE @rAgent_IP NVARCHAR(50)
        DECLARE @hotelID INT
        DECLARE @retval INT

    BEGIN 
        SET NOCOUNT ON ;

        -- Get count of affected rows
        SELECT  @Count = Count(rAgent_ID)
        FROM    inserted

        -- Loop over rows affected
        WHILE @i < @count
            BEGIN
                -- Get the next rAgent_ID
                SELECT TOP 1
                        @rAgent_ID = rAgent_ID
                FROM    inserted
                WHERE   rAgent_ID > @rAgent_ID
                ORDER BY rAgent_ID ASC

                -- Populate values for the current row
                SELECT  @rAgent_Name = rAgent_Name,
                        @rAgent_Email = rAgent_Email,
                        @rAgent_IP = rAgent_IP,
                        @hotelID = hotelID
                FROM    Inserted
                WHERE   rAgent_ID = @rAgent_ID

                -- Run your stored procedure
                EXEC insert2Newsletter '', '', @rAgent_Name, @rAgent_Email,
                    @rAgent_IP, @hotelID, 'RA', @retval 

                -- Set up next iteration
                SET @i = @i + 1
            END
    END 
GO

I sure hope this helps you out. Cheers!

how to run a command at terminal from java program?

You don't actually need to run a command from an xterm session, you can run it directly:

String[] arguments = new String[] {"/path/to/executable", "arg0", "arg1", "etc"};
Process proc = new ProcessBuilder(arguments).start();

If the process responds interactively to the input stream, and you want to inject values, then do what you did before:

OutputStream out = proc.getOutputStream();  
out.write("command\n");  
out.flush();

Don't forget the '\n' at the end though as most apps will use it to identify the end of a single command's input.

Python variables as keys to dict

This question has practically been answered, but I just wanted to say it was funny that you said

This isn't anything fancy, like putting all local variables into a dictionary.

Because it is actually "fancier"

what you want is:

apple = 1
banana = 'f'
carrot = 3
fruitdict = {}

# I want to set the key equal to variable name, and value equal to variable value
# is there a more Pythonic way to get {'apple': 1, 'banana': 'f', 'carrot': 3}?

names= 'apple banana carrot'.split() # I'm just being lazy for this post
items = globals()                    # or locals()

for name in names:
    fruitdict[name] = items[name]

Honestly, what you are doing is just copying items from one dictionary to another.

(Greg Hewgill practically gave the whole answer, I just made it complete)

...and like people suggested, you should probably be putting these in the dictionary in the first place, but I'll assume that for some reason you can't

how to display excel sheet in html page

Upload your file to Skydrive and then right click and select "Embed". They will provide iframe snippet which you can paste in your html. This works flawlessly.

Source: Office.com

Convert UTC date time to local date time

A JSON date string (serialized in C#) looks like "2015-10-13T18:58:17".

In angular, (following Hulvej) make a localdate filter:

myFilters.filter('localdate', function () {
    return function(input) {
        var date = new Date(input + '.000Z');
        return date;
    };
})

Then, display local time like:

{{order.createDate | localdate | date : 'MMM d, y h:mm a' }}

Creating/writing into a new file in Qt

It can happen that the cause is not that you don't find the right directory. For example, you can read from the file (even without absolute path) but it seems you cannot write into it.

In that case, it might be that you program exits before the writing can be finished.

If your program uses an event loop (like with a GUI application, e.g. QMainWindow) it's not a problem. However, if your program exits immediately after writing to the file, you should flush the text stream, closing the file is not always enough (and it's unnecessary, as it is closed in the destructor).

stream << "something" << endl;
stream.flush();

This guarantees that the changes are committed to the file before the program continues from this instruction.

The problem seems to be that the QFile is destructed before the QTextStream. So, even if the stream is flushed in the QTextStream destructor, it's too late, as the file is already closed.

Prevent form redirect OR refresh on submit?

An alternative solution would be to not use form tag and handle click event on submit button through jquery. This way there wont be any page refresh but at the same time there is a downside that "enter" button for submission wont work and also on mobiles you wont get a go button( a style in some mobiles). So stick to use of form tag and use the accepted answer.

How to get item's position in a list?

Try the below:

testlist = [1,2,3,5,3,1,2,1,6]    
position=0
for i in testlist:
   if i == 1:
      print(position)
   position=position+1

JS Client-Side Exif Orientation: Rotate and Mirror JPEG Images

The github project JavaScript-Load-Image provides a complete solution to the EXIF orientation problem, correctly rotating/mirroring images for all 8 exif orientations. See the online demo of javascript exif orientation

The image is drawn onto an HTML5 canvas. Its correct rendering is implemented in js/load-image-orientation.js through canvas operations.

Hope this saves somebody else some time, and teaches the search engines about this open source gem :)

Javascript Date Validation ( DD/MM/YYYY) & Age Checking

If you're using moment then that's the single line code:

moment(date).format("DD/MM/YYYY").isValid()

Convert DataSet to List

Use the code below:

using Newtonsoft.Json;
string JSONString = string.Empty;
JSONString = JsonConvert.SerializeObject(ds.Tables[0]);

Vue.js—Difference between v-model and v-bind

In simple words v-model is for two way bindings means: if you change input value, the bound data will be changed and vice versa.

but v-bind:value is called one way binding that means: you can change input value by changing bound data but you can't change bound data by changing input value through the element.

check out this simple example: https://jsfiddle.net/gs0kphvc/

WordPress query single post by slug

As wordpress api has changed, you can´t use get_posts with param 'post_name'. I´ve modified Maartens function a bit:

function get_post_id_by_slug( $slug, $post_type = "post" ) {
    $query = new WP_Query(
        array(
            'name'   => $slug,
            'post_type'   => $post_type,
            'numberposts' => 1,
            'fields'      => 'ids',
        ) );
    $posts = $query->get_posts();
    return array_shift( $posts );
}

jQuery move to anchor location on page load

Put this right before the closing Body tag at the bottom of the page.

<script>
    if (location.hash) {
        location.href = location.hash;
    }
</script>

jQuery is actually not required.

SVN (Subversion) Problem "File is scheduled for addition, but is missing" - Using Versions

This solved my similar problem. I used it to revert the changes, then I added everything and commited changes in the terminal with

svn add folder_path/*
svn commit -m "message"

Angular 2: import external js file into component

Instead of including your js file extension in index.html, you can include it in .angular-cli-json file.

These are the steps I followed to get this working:

  1. First include your external js file in assets/js
  2. In .angular-cli.json - add the file path under scripts: [../app/assets/js/test.js]
  3. In the component where you want to use the functions of the js file.

Declare at the top where you want to import the files as

declare const Test:any;

After this you can access its functions as for example Test.add()

Enable remote MySQL connection: ERROR 1045 (28000): Access denied for user

New location for mysql config file is

/etc/mysql/mysql.conf.d/mysqld.cnf

How does jQuery work when there are multiple elements with the same ID value?

jQuery's id selector only returns one result. The descendant and multiple selectors in the second and third statements are designed to select multiple elements. It's similar to:

Statement 1

var length = document.getElementById('a').length;

...Yields one result.

Statement 2

var length = 0;
for (i=0; i<document.body.childNodes.length; i++) {
    if (document.body.childNodes.item(i).id == 'a') {
        length++;
    }
}

...Yields two results.

Statement 3

var length = document.getElementById('a').length + document.getElementsByTagName('div').length;

...Also yields two results.

How to Correctly Check if a Process is running and Stop it

Thanks @Joey. It's what I am looking for.

I just bring some improvements:

  • to take into account multiple processes
  • to avoid reaching the timeout when all processes have terminated
  • to package the whole in a function

function Stop-Processes {
    param(
        [parameter(Mandatory=$true)] $processName,
                                     $timeout = 5
    )
    $processList = Get-Process $processName -ErrorAction SilentlyContinue
    if ($processList) {
        # Try gracefully first
        $processList.CloseMainWindow() | Out-Null

        # Wait until all processes have terminated or until timeout
        for ($i = 0 ; $i -le $timeout; $i ++){
            $AllHaveExited = $True
            $processList | % {
                $process = $_
                If (!$process.HasExited){
                    $AllHaveExited = $False
                }                    
            }
            If ($AllHaveExited){
                Return
            }
            sleep 1
        }
        # Else: kill
        $processList | Stop-Process -Force        
    }
}

findViewByID returns null

Ways to debug and find the issue:

  • Comment out all findViewById in your activity.
  • Comment out everything except onCreate and setContentView
  • Run the project and see if any layout is set

In my case, I was using activity_main.xml in both my app module and also my library module. So when I performed the above steps, instead of the layout which I designed in the library, the layout inside app module was inflated.

So I changed the activity_main.xml file name to activity_main_lib.xml.

So make sure you do not have any duplicate layout names in your whole project.

Reversing an Array in Java

In case you don't want to use a temporary variable, you can also do like this:

final int len = arr.length;
for (int i=0; i < (len/2); i++) {
    arr[i] += arr[len - 1 - i]; //  a = a+b
    arr[len - 1 - i] = arr[i] - arr[len - 1 - i];   //  b = a-b
    arr[i] -= arr[len - 1 - i]; //  a = a-b
}

C/C++ NaN constant (literal)?

As others have pointed out you are looking for std::numeric_limits<double>::quiet_NaN() although I have to say I prefer the cppreference.com documents. Especially because this statement is a little vague:

Only meaningful if std::numeric_limits::has_quiet_NaN == true.

and it was simple to figure out what this means on this site, if you check their section on std::numeric_limits::has_quiet_NaN it says:

This constant is meaningful for all floating-point types and is guaranteed to be true if std::numeric_limits::is_iec559 == true.

which as explained here if true means your platform supports IEEE 754 standard. This previous thread explains this should be true for most situations.

Rails: Address already in use - bind(2) (Errno::EADDRINUSE)

It might be old but in my case, it was because of docker. Hope it will help others.

Getting Error - ORA-01858: a non-numeric character was found where a numeric was expected

I added TO_DATE and it resolved issue.

Before modification - due to below condition i got this error

record_update_dt>='05-May-2017'

After modification - after adding to_date, issue got resolved.

record_update_dt>=to_date('05-May-2017','DD-Mon-YYYY')

accessing a variable from another class

I hope I'm understanding the problem correctly, but it looks like you don't have a reference back to your DrawFrame object from DrawCircle.

Try this:

Change your constructor signature for DrawCircle to take in a DrawFrame object. Within the constructor, set the class variable "d" to the DrawFrame object you just took in. Now add the getWidth/getHeight methods to DrawFrame as mentioned in previous answers. See if that allows you to get what you're looking for.

Your DrawCircle constructor should be changed to something like:

public DrawCircle(DrawFrame frame)
{
    d = frame;
    w = 400;
    h = 400;
    diBig = 300;
    diSmall = 10;
    maxRad = (diBig/2) - diSmall;
    xSq = 50;
    ySq = 50;
    xPoint = 200;
    yPoint = 200;
}

The last line of code in DrawFrame should look something like:

contentPane.add(new DrawCircle(this));

Then, try using d.getheight(), d.getWidth() and so on within DrawCircle. This assumes you still have those methods available on DrawFrame to access them, of course.

How to unload a package without restarting R

Note also that you can only use unload() once. If you use it a second time without rerunning library(), y'll get the not very informative error message invalid 'name' argument:

library(vegan)
#> Loading required package: permute
#> Loading required package: lattice
#> This is vegan 2.5-6
detach("package:vegan",  unload=TRUE)
detach("package:vegan",  unload=TRUE)
#> Error in detach("package:vegan", unload = TRUE): invalid 'name' argument

Created on 2020-05-09 by the reprex package (v0.3.0)

AngularJS dynamic routing

In the $routeProvider URI patters, you can specify variable parameters, like so: $routeProvider.when('/page/:pageNumber' ... , and access it in your controller via $routeParams.

There is a good example at the end of the $route page: http://docs.angularjs.org/api/ng.$route

EDIT (for the edited question):

The routing system is unfortunately very limited - there is a lot of discussion on this topic, and some solutions have been proposed, namely via creating multiple named views, etc.. But right now, the ngView directive serves only ONE view per route, on a one-to-one basis. You can go about this in multiple ways - the simpler one would be to use the view's template as a loader, with a <ng-include src="myTemplateUrl"></ng-include> tag in it ($scope.myTemplateUrl would be created in the controller).

I use a more complex (but cleaner, for larger and more complicated problems) solution, basically skipping the $route service altogether, that is detailed here:

http://www.bennadel.com/blog/2420-Mapping-AngularJS-Routes-Onto-URL-Parameters-And-Client-Side-Events.htm

Get my phone number in android

From the documentation:

Returns the phone number string for line 1, for example, the MSISDN for a GSM phone. Return null if it is unavailable.

So you have done everything right, but there is no phone number stored.

If you get null, you could display something to get the user to input the phone number on his/her own.

Exercises to improve my Java programming skills

Once you are quite good in Java SE (lets say you are able to pass SCJP), I'd suggest you get junior Java programmer job and improve yourself on real world problems

Email Address Validation for ASP.NET

In our code we have a specific validator inherited from the BaseValidator class.

This class does the following:

  1. Validates the e-mail address against a regular expression.
  2. Does a lookup on the MX record for the domain to make sure there is at least a server to deliver to.

This is the closest you can get to validation without actually sending the person an e-mail confirmation link.

How to display raw html code in PRE or something like it but without escaping it

xmp is the way to go, i.e.:

<xmp>
  # your code...
</xmp>

Visual Studio 2008 Product Key in Registry?

For 32 bit Windows:


Visual Studio 2003:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\VisualStudio\7.0\Registration\PIDKEY

Visual Studio 2005:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\VisualStudio\8.0\Registration\PIDKEY

Visual Studio 2008:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\VisualStudio\9.0\Registration\PIDKEY


For 64 bit Windows:


Visual Studio 2003:

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\VisualStudio\7.0\Registration\PIDKEY

Visual Studio 2005:

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\VisualStudio\8.0\Registration\PIDKEY

Visual Studio 2008:

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\VisualStudio\9.0\Registration\PIDKEY


Notes:

  • Data is a GUID without dashes. Put a dash ( – ) after every 5 characters to convert to product key.
  • If PIDKEY value is empty try to look at the subfolders e.g.

    ...\Registration\1000.0x0000\PIDKEY

    or

    ...\Registration\2000.0x0000\PIDKEY

Xcode 6 Bug: Unknown class in Interface Builder file

For me, I'm using Xcode7 + Swift2

Solved this problem by checking my code, I have this line in my viewController:

 self?.navigationController?.pushViewController(vc, animated: true)

Then I realized that I haven't get navigationController connected to the detail page. So if you're pushing a new ViewController with customized ID, better to check that.

How can I convert a stack trace to a string?

public static String getStackTrace(Throwable t) {
    StringWriter sw = new StringWriter();
    t.printStackTrace(new PrintWriter(sw));
    return sw.toString();
}

Android Studio: Gradle - build fails -- Execution failed for task ':dexDebug'

Many of the answers here are trial and error to find duplicate dependencies but if you scroll up just a little bit from the Execution failed for task ':app:dexDebug'. line it will give you a hint at the duplications

error with a hint.

In my case I had the following error:

UNEXPECTED TOP-LEVEL EXCEPTION:
com.android.dex.DexException: Multiple dex files define L/com/parse/AbstractQueryController$1;
...
...
...
Execution failed for task ':app:dexDebug'.

So I knew that in order to fix this bug I needed to find the duplicate dependencies that define parse.AbstractQueryController

In my case I had two imported modules that were loading in two different Parse libraries. Making my project only load one fixed my issue.

how to refresh Select2 dropdown menu after ajax loading different content?

Select 3.*

Please see Update select2 data without rebuilding the control as this may be a duplicate. Another way is to destroy and then recreate the select2 element.

$("#dropdown").select2("destroy");

$("#dropdown").select2();

If you are having problems with resetting the state/region on country change try clearing the current value with

$("#dropdown").select2("val", "");

You can view the documentation here http://ivaynberg.github.io/select2/ that outlines nearly/all features. Select2 supports events such as change that can be used to update the subsequent dropdowns.

$("#dropdown").on("change", function(e) {});

Select 4.* Update

You can now update the data/list without rebuilding the control using:

fooBarDropdown.select2({
    data: fromAccountData
});

Why is this error, 'Sequence contains no elements', happening?

In the following line.

temp.Response = db.Responses.Where(y => y.ResponseId.Equals(item.ResponseId)).First();

You are calling First but the collection returned from db.Responses.Where is empty.

Finding non-numeric rows in dataframe in pandas?

In case you are working with a column with string values, you can use THE VERY USEFUL function series.str.isnumeric() like:

a = pd.Series(['hi','hola','2.31','288','312','1312', '0,21', '0.23'])

What i do is to copy that column to new column, and do a str.replace('.','') and str.replace(',','') then i select the numeric values. and:

a = a.str.replace('.','')
a = a.str.replace(',','') 
a.str.isnumeric()

Out[15]: 0 False 1 False 2 True 3 True 4 True 5 True 6 True 7 True dtype: bool

Good luck all!

Check if table exists without using "select from"

show tables like 'table_name'

if this returns rows > 0 the table exists

End-line characters from lines read from text file, using Python

What's wrong with your code? I find it to be quite elegant and simple. The only problem is that if the file doesn't end in a newline, the last line returned won't have a '\n' as the last character, and therefore doing line = line[:-1] would incorrectly strip off the last character of the line.

The most elegant way to solve this problem would be to define a generator which took the lines of the file and removed the last character from each line only if that character is a newline:

def strip_trailing_newlines(file):
    for line in file:
        if line[-1] == '\n':
            yield line[:-1]
        else:
            yield line

f = open("myFile.txt", "r")
for line in strip_trailing_newlines(f):
    # do something with line

Passing arguments to AsyncTask, and returning results

You can receive returning results like that: AsyncTask class

@Override
protected Boolean doInBackground(Void... params) {
    if (host.isEmpty() || dbName.isEmpty() || user.isEmpty() || pass.isEmpty() || port.isEmpty()) {
        try {
            throw new SQLException("Database credentials missing");
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    try {
        Class.forName("org.postgresql.Driver");
    } catch (ClassNotFoundException e) {
        e.printStackTrace();
    }

    try {
        this.conn = DriverManager.getConnection(this.host + ':' + this.port + '/' + this.dbName, this.user, this.pass);
    } catch (SQLException e) {
        e.printStackTrace();
    }

    return true;
}

receiving class:

_store.execute();
boolean result =_store.get();

Hoping it will help.

How to set up a cron job to run an executable every hour?

Since I could not run the C executable that way, I wrote a simple shell script that does the following

cd /..path_to_shell_script
./c_executable_name

In the cron jobs list, I call the shell script.

Call two functions from same onclick

Just to offer some variety, the comma operator can be used too but some might say "noooooo!", but it works:

<input type="button" onclick="one(), two(), three(), four()"/>

http://jsbin.com/oqizir/1/edit

getResources().getColor() is deprecated

It looks like the best approach is to use:

ContextCompat.getColor(context, R.color.color_name)

eg:

yourView.setBackgroundColor(ContextCompat.getColor(applicationContext,
                            R.color.colorAccent))

This will choose the Marshmallow two parameter method or the pre-Marshmallow method appropriately.

Setting the selected value on a Django forms.ChoiceField

To be sure I need to see how you're rendering the form. The initial value is only used in a unbound form, if it's bound and a value for that field is not included nothing will be selected.

C++, What does the colon after a constructor mean?

It's called an initialization list. It initializes members before the body of the constructor executes.

How do I escape ampersands in batch files?

& is used to separate commands. Therefore you can use ^ to escape the &.

What is {this.props.children} and when you should use it?

props.children represents the content between the opening and the closing tags when invoking/rendering a component:

const Foo = props => (
  <div>
    <p>I'm {Foo.name}</p>
    <p>abc is: {props.abc}</p>

    <p>I have {props.children.length} children.</p>
    <p>They are: {props.children}.</p>
    <p>{Array.isArray(props.children) ? 'My kids are an array.' : ''}</p>
  </div>
);

const Baz = () => <span>{Baz.name} and</span>;
const Bar = () => <span> {Bar.name}</span>;

invoke/call/render Foo:

<Foo abc={123}>
  <Baz />
  <Bar />
</Foo>

props and props.children

Proper way to empty a C-String

needs name of string and its length will zero all characters other methods might stop at the first zero they encounter

    void strClear(char p[],u8 len){u8 i=0; 
        if(len){while(i<len){p[i]=0;i++;}}
    }

Fast way to get the min/max values among properties of object

// Sorted
let Sorted = Object.entries({ "a":4, "b":0.5 , "c":0.35, "d":5 }).sort((prev, next) => prev[1] - next[1])
>> [ [ 'c', 0.35 ], [ 'b', 0.5 ], [ 'a', 4 ], [ 'd', 5 ] ]


//Min:
Sorted.shift()
>> [ 'c', 0.35 ]

// Max:
Sorted.pop()
>> [ 'd', 5 ]

How to check if a file exists in Ansible?

This can be achieved with the stat module to skip the task when file exists.

- hosts: servers
  tasks:
  - name: Ansible check file exists.
    stat:
      path: /etc/issue
    register: p
  - debug:
      msg: "File exists..."
    when: p.stat.exists
  - debug:
      msg: "File not found"
    when: p.stat.exists == False

Do you have to put Task.Run in a method to make it async?

One of the most important thing to remember when decorating a method with async is that at least there is one await operator inside the method. In your example, I would translate it as shown below using TaskCompletionSource.

private Task<int> DoWorkAsync()
{
    //create a task completion source
    //the type of the result value must be the same
    //as the type in the returning Task
    TaskCompletionSource<int> tcs = new TaskCompletionSource<int>();
    Task.Run(() =>
    {
        int result = 1 + 2;
        //set the result to TaskCompletionSource
        tcs.SetResult(result);
    });
    //return the Task
    return tcs.Task;
}

private async void DoWork()
{
    int result = await DoWorkAsync();
}

How to fill a Javascript object literal with many static key/value pairs efficiently?

The syntax you wrote as first is not valid. You can achieve something using the follow:

var map =  {"aaa": "rrr", "bbb": "ppp" /* etc */ };

Xcode is not currently available from the Software Update server

Command + Space

Search for Xcode

Open it and accept license

Then run again from terminal xcode-select --install

How do I convert from int to String?

The expression

"" + i

leads to string conversion of i at runtime. The overall type of the expression is String. i is first converted to an Integer object (new Integer(i)), then String.valueOf(Object obj) is called. So it is equivalent to

"" + String.valueOf(new Integer(i));

Obviously, this is slightly less performant than just calling String.valueOf(new Integer(i)) which will produce the very same result.

The advantage of ""+i is that typing is easier/faster and some people might think, that it's easier to read. It is not a code smell as it does not indicate any deeper problem.

(Reference: JLS 15.8.1)

The given key was not present in the dictionary. Which key?

This exception is thrown when you try to index to something that isn't there, for example:

Dictionary<String, String> test = new Dictionary<String,String>();
test.Add("Key1","Value1");
string error = test["Key2"];

Often times, something like an object will be the key, which undoubtedly makes it harder to get. However, you can always write the following (or even wrap it up in an extension method):

if (test.ContainsKey(myKey))
   return test[myKey];
else
   throw new Exception(String.Format("Key {0} was not found", myKey));

Or more efficient (thanks to @ScottChamberlain)

T retValue;
if (test.TryGetValue(myKey, out retValue))
    return retValue;
else
   throw new Exception(String.Format("Key {0} was not found", myKey));

Microsoft chose not to do this, probably because it would be useless when used on most objects. Its simple enough to do yourself, so just roll your own!

Error: getaddrinfo ENOTFOUND in nodejs for get call

When I tried to install a new ionic app, I got the same error as follows, I tried many sources and found the mistake made in User Environment and System Environment unnecessarily included the PROXY value. I removed the ```user variables http://host:port PROXY

system Variables http_proxy http://username:password@host:port ```` and now it is working fine without trouble.

[ERROR] Network connectivity error occurred, are you offline?

        If you are behind a firewall and need to configure proxy settings, see: https://ion.link/cli-proxy-docs

        Error: getaddrinfo ENOTFOUND host host:80

How do I use T-SQL's Case/When?

If logical test is against a single column then you could use something like

USE AdventureWorks2012;  
GO  
SELECT   ProductNumber, Category =  
      CASE ProductLine  
         WHEN 'R' THEN 'Road'  
         WHEN 'M' THEN 'Mountain'  
         WHEN 'T' THEN 'Touring'  
         WHEN 'S' THEN 'Other sale items'  
         ELSE 'Not for sale'  
      END,  
   Name  
FROM Production.Product  
ORDER BY ProductNumber;  
GO  

More information - https://docs.microsoft.com/en-us/sql/t-sql/language-elements/case-transact-sql?view=sql-server-2017

A Space between Inline-Block List Items

I have seen this and answered on it before:

After further research I have discovered that inline-block is a whitespace dependent method and is dependent on the font setting. In this case 4px is rendered.

To avoid this you could run all your lis together in one line, or block the end tags and begin tags together like this:

<ul>
        <li>
            <div>first</div>
        </li><li>
            <div>first</div>
        </li><li>
            <div>first</div>
        </li><li>
            <div>first</div>
        </li>
</ul>

Example here.


As mentioned by other answers and comments, the best practice for solving this is to add font-size: 0; to the parent element:

ul {
    font-size: 0;
}

ul li {
    font-size: 14px;
    display: inline-block;
}

This is better for HTML readability (avoiding running the tags together etc). The spacing effect is because of the font's spacing setting, so you must reset it for the inlined elements and set it again for the content within.

jQuery using append with effects

In my case:

$("div.which-stores-content").append("<div class="content">Content</div>);
$("div.content").hide().show("fast");

you can adjust your css with visibility:hidden -> visibility:visible and adjust the transitions etc transition: visibility 1.0s;

How to configure logging to syslog in Python?

Is your syslog.conf set up to handle facility=user?

You can set the facility used by the python logger with the facility argument, something like this:

handler = logging.handlers.SysLogHandler(facility=SysLogHandler.LOG_DAEMON)

vba pass a group of cells as range to function

As I'm beginner for vba, I'm willing to get a deep knowledge of vba of how all excel in-built functions work form there back.

So as on the above question I have putted my basic efforts.

Function multi_add(a As Range, ParamArray b() As Variant) As Double

    Dim ele As Variant

    Dim i As Long

    For Each ele In a
        multi_add = a + ele.Value **- a**
    Next ele

    For i = LBound(b) To UBound(b)
        For Each ele In b(i)
            multi_add = multi_add + ele.Value
        Next ele
    Next i

End Function

- a: This is subtracted for above code cause a count doubles itself so what values you adds it will add first value twice.

Append an int to a std::string

You cannot cast an int to a char* to get a string. Try this:

std::ostringstream sstream;
sstream << "select logged from login where id = " << ClientID;
std::string query = sstream.str();

stringstream reference

How to use the DropDownList's SelectedIndexChanged event

You should add AutoPostBack="true" to DropDownList1

                <asp:DropDownList ID="ddmanu" runat="server" AutoPostBack="true"
                    DataSourceID="Sql_fur_model_manu"    
                    DataTextField="manufacturer" DataValueField="manufacturer" 
                    onselectedindexchanged="ddmanu_SelectedIndexChanged">
                </asp:DropDownList>

How do I use tools:overrideLibrary in a build.gradle file?

Use overrideLibrary when the minSdk is declared in build.gradle instead of in AndroidManifest.xml

If you are using Android Studio:

add <uses-sdk tools:overrideLibrary="android.support.v17.leanback"/> to your manifest, don't forget to include xmlns:tools="http://schemas.android.com/tools" too.

How to get the current date and time

Just construct a new Date object without any arguments; this will assign the current date and time to the new object.

import java.util.Date;

Date d = new Date();

In the words of the Javadocs for the zero-argument constructor:

Allocates a Date object and initializes it so that it represents the time at which it was allocated, measured to the nearest millisecond.

Make sure you're using java.util.Date and not java.sql.Date -- the latter doesn't have a zero-arg constructor, and has somewhat different semantics that are the topic of an entirely different conversation. :)

SecurityException during executing jnlp file (Missing required Permissions manifest attribute in main jar)

If you'd like to set this globally for all users of a machine, you can create the following directory and file structures:

mkdir %windir%\Sun\Java\Deployment

Create a file deployment.config with the content:

deployment.system.config=file:///c:/windows/Sun/Java/Deployment/deployment.properties
deployment.system.config.mandatory=TRUE

Create a file deployment.properties

deployment.user.security.exception.sites=C\:/WINDOWS/Sun/Java/Deployment/exception.sites

Create a file exception.sites

http://example1.com
http://example2.com/path/to/specific/directory/

Reference https://blogs.oracle.com/java-platform-group/entry/upcoming_exception_site_list_in

Failed to resolve: com.android.support:appcompat-v7:28.0

Add the following code on build.gragle (project) for adding Google maven repository

allprojects {
    repositories {
    ...
        maven {
            url 'https://maven.google.com/'
            name 'Google'
        }
    ...
    }
}

How do I convert from int to Long in Java?

We shall get the long value by using Number reference.

public static long toLong(Number number){
    return number.longValue();
}

It works for all number types, here is a test:

public static void testToLong() throws Exception {
    assertEquals(0l, toLong(0));   // an int
    assertEquals(0l, toLong((short)0)); // a short
    assertEquals(0l, toLong(0l)); // a long
    assertEquals(0l, toLong((long) 0)); // another long
    assertEquals(0l, toLong(0.0f));  // a float
    assertEquals(0l, toLong(0.0));  // a double

}

Execute Python script via crontab

Just use crontab -e and follow the tutorial here.

Look at point 3 for a guide on how to specify the frequency.

Based on your requirement, it should effectively be:

*/10 * * * * /usr/bin/python script.py

Struct memory layout in C

In C, the compiler is allowed to dictate some alignment for every primitive type. Typically the alignment is the size of the type. But it's entirely implementation-specific.

Padding bytes are introduced so every object is properly aligned. Reordering is not allowed.

Possibly every remotely modern compiler implements #pragma pack which allows control over padding and leaves it to the programmer to comply with the ABI. (It is strictly nonstandard, though.)

From C99 §6.7.2.1:

12 Each non-bit-field member of a structure or union object is aligned in an implementation- defined manner appropriate to its type.

13 Within a structure object, the non-bit-field members and the units in which bit-fields reside have addresses that increase in the order in which they are declared. A pointer to a structure object, suitably converted, points to its initial member (or if that member is a bit-field, then to the unit in which it resides), and vice versa. There may be unnamed padding within a structure object, but not at its beginning.

How to find out which processes are using swap space in Linux?

Yet two more variants:

Because top or htop could be not installed on small systems, browsing /proc stay always possible.

Even on small systems, you will found a shell...

A variant! (Not bash only)

This is exactly same than lolotux script, but without any fork to grep, awk or ps. This is a lot quicker!

And as is one of the poorest regarding performance, a little work was done to ensure this script will run well under , and some other. Then, (thanks to Stéphane Chazelas,) become a lot quicker again!

#!/bin/sh 
# Get current swap usage for all running processes
# Felix Hauri 2016-08-05
# Rewritted without fork. Inspired by first stuff from
# Erik Ljungstrom 27/05/2011
# Modified by Mikko Rantalainen 2012-08-09
# Pipe the output to "sort -nk3" to get sorted output
# Modified by Marc Methot 2014-09-18
# removed the need for sudo

OVERALL=0
rifs=`printf ': \t'`
for FILE in /proc/[0-9]*/status ;do
    SUM=0
    while IFS="$rifs" read FIELD VALUE ;do
        case $FIELD in
            Pid )    PID=$VALUE      ;;
            Name )   PROGNAME="$VALUE" ;;
            VmSwap ) SUM=$((SUM=${VALUE% *}))  ;;
        esac
    done <$FILE
    [ $SUM -gt 0 ] &&
        printf "PID: %9d  swapped: %11d KB (%s)\n" $PID $SUM "$PROGNAME"
    OVERALL=$((OVERALL+SUM))
done
printf "Total swapped memory: %14u KB\n" $OVERALL

Don't forgot to double quote "$PROGNAME" ! See Stéphane Chazelas's comment:

read FIELD PROGNAME < <(
    perl -ne 'BEGIN{$0="/*/*/../../*/*"} print if /^Name/' /proc/self/status
)
echo $FIELD "$PROGNAME"

Don't try echo $PROGNAME without double quote on sensible system, and be ready to kill current shell before!

And a version

As this become a not so simple script, time is comming to write a dedicated tool by using more efficient language.

#!/usr/bin/perl -w

use strict;
use Getopt::Std;
my ($tot,$mtot)=(0,0);
my %procs;

my %opts;
getopt('', \%opts);

sub sortres {
    return $a <=> $b                                          if $opts{'p'};
    return $procs{$a}->{'cmd'} cmp $procs{$b}->{'cmd'}        if $opts{'c'};
    return $procs{$a}->{'mswap'} <=> $procs{$b}->{'mswap'}    if $opts{'m'};
    return $procs{$a}->{'swap'} <=> $procs{$b}->{'swap'};
};

opendir my $dh,"/proc";

for my $pid (grep {/^\d+$/} readdir $dh) {
    if (open my $fh,"</proc/$pid/status") {
        my ($sum,$nam)=(0,"");
        while (<$fh>) {
            $sum+=$1 if /^VmSwap:\s+(\d+)\s/;
            $nam=$1 if /^Name:\s+(\S+)/;
        }
        if ($sum) {
            $tot+=$sum;
            $procs{$pid}->{'swap'}=$sum;
            $procs{$pid}->{'cmd'}=$nam;
            close $fh;
            if (open my $fh,"</proc/$pid/smaps") {
                $sum=0;
                while (<$fh>) {
                    $sum+=$1 if /^Swap:\s+(\d+)\s/;
                };
            };
            $mtot+=$sum;
            $procs{$pid}->{'mswap'}=$sum;
        } else { close $fh; };
    };
};
map {
    printf "PID: %9d  swapped: %11d (%11d) KB (%s)\n",
        $_, $procs{$_}->{'swap'}, $procs{$_}->{'mswap'}, $procs{$_}->{'cmd'};
} sort sortres keys %procs;
printf "Total swapped memory: %14u (%11u) KB\n", $tot,$mtot;

could by run with one of

-c  sort by command name
-p  sort by pid
-m  sort by swap values
by default, output is sorted by status's vmsize

List<Map<String, String>> vs List<? extends Map<String, String>>

What I'm missing in the other answers is a reference to how this relates to co- and contravariance and sub- and supertypes (that is, polymorphism) in general and to Java in particular. This may be well understood by the OP, but just in case, here it goes:

Covariance

If you have a class Automobile, then Car and Truck are their subtypes. Any Car can be assigned to a variable of type Automobile, this is well-known in OO and is called polymorphism. Covariance refers to using this same principle in scenarios with generics or delegates. Java doesn't have delegates (yet), so the term applies only to generics.

I tend to think of covariance as standard polymorphism what you would expect to work without thinking, because:

List<Car> cars;
List<Automobile> automobiles = cars;
// You'd expect this to work because Car is-a Automobile, but
// throws inconvertible types compile error.

The reason of the error is, however, correct: List<Car> does not inherit from List<Automobile> and thus cannot be assigned to each other. Only the generic type parameters have an inherit relationship. One might think that the Java compiler simply isn't smart enough to properly understand your scenario there. However, you can help the compiler by giving him a hint:

List<Car> cars;
List<? extends Automobile> automobiles = cars;   // no error

Contravariance

The reverse of co-variance is contravariance. Where in covariance the parameter types must have a subtype relationship, in contravariance they must have a supertype relationship. This can be considered as an inheritance upper-bound: any supertype is allowed up and including the specified type:

class AutoColorComparer implements Comparator<Automobile>
    public int compare(Automobile a, Automobile b) {
        // Return comparison of colors
    }

This can be used with Collections.sort:

public static <T> void sort(List<T> list, Comparator<? super T> c)

// Which you can call like this, without errors:
List<Car> cars = getListFromSomewhere();
Collections.sort(cars, new AutoColorComparer());

You could even call it with a comparer that compares objects and use it with any type.

When to use contra or co-variance?

A bit OT perhaps, you didn't ask, but it helps understanding answering your question. In general, when you get something, use covariance and when you put something, use contravariance. This is best explained in an answer to Stack Overflow question How would contravariance be used in Java generics?.

So what is it then with List<? extends Map<String, String>>

You use extends, so the rules for covariance applies. Here you have a list of maps and each item you store in the list must be a Map<string, string> or derive from it. The statement List<Map<String, String>> cannot derive from Map, but must be a Map.

Hence, the following will work, because TreeMap inherits from Map:

List<Map<String, String>> mapList = new ArrayList<Map<String, String>>();
mapList.add(new TreeMap<String, String>());

but this will not:

List<? extends Map<String, String>> mapList = new ArrayList<? extends Map<String, String>>();
mapList.add(new TreeMap<String, String>());

and this will not work either, because it does not satisfy the covariance constraint:

List<? extends Map<String, String>> mapList = new ArrayList<? extends Map<String, String>>();
mapList.add(new ArrayList<String>());   // This is NOT allowed, List does not implement Map

What else?

This is probably obvious, but you may have already noted that using the extends keyword only applies to that parameter and not to the rest. I.e., the following will not compile:

List<? extends Map<String, String>> mapList = new List<? extends Map<String, String>>();
mapList.add(new TreeMap<String, Element>())  // This is NOT allowed

Suppose you want to allow any type in the map, with a key as string, you can use extend on each type parameter. I.e., suppose you process XML and you want to store AttrNode, Element etc in a map, you can do something like:

List<? extends Map<String, ? extends Node>> listOfMapsOfNodes = new...;

// Now you can do:
listOfMapsOfNodes.add(new TreeMap<Sting, Element>());
listOfMapsOfNodes.add(new TreeMap<Sting, CDATASection>());

How to implement zoom effect for image view in android?

Here is a great example on how to implement zoom affect on touch with a imageview

Zoom effect on imageview

EDIT:

Also here is another great one.

Pinch to zoom tutorial

How to rename HTML "browse" button of an input type=file?

The button isn't called the "browse button" — that's just the name your browser gives for it. Browsers are free to implement the file upload control however they like. In Safari, for example, it's called "Choose File" and it's on the opposite side of whatever you're probably using.

You can implement a custom look for the upload control using the technique outlined on QuirksMode, but that goes beyond just changing the button's text.

Logical Operators, || or OR?

I know it's an old topic but still. I've just met the problem in the code I am debugging at work and maybe somebody may have similar issue...

Let's say the code looks like this:

$positions = $this->positions() || [];

You would expect (as you are used to from e.g. javascript) that when $this->positions() returns false or null, $positions is empty array. But it isn't. The value is TRUE or FALSE depends on what $this->positions() returns.

If you need to get value of $this->positions() or empty array, you have to use:

$positions = $this->positions() or [];

EDIT:

The above example doesn't work as intended but the truth is that || and or is not the same... Try this:

<?php

function returnEmpty()
{
  //return "string";
  //return [1];
  return null;
}

$first = returnEmpty() || [];
$second = returnEmpty() or [];
$third = returnEmpty() ?: [];

var_dump($first);
var_dump($second);
var_dump($third);
echo "\n";

This is the result:

bool(false)
NULL
array(0) {
}

So, actually the third option ?: is the correct solution when you want to set returned value or empty array.

$positions = $this->positions() ?: [];

Tested with PHP 7.2.1

How to use ng-if to test if a variable is defined

Try this:

item.shipping!==undefined

Android error while retrieving information from server 'RPC:s-5:AEC-0' in Google Play?

I've been having this problem too and I'm not sure why. Some people suggest removing your Google account and re-adding it and/or deleting the Play Store cache. I'm looking for more solutions, but it happens for all apps free, paid, whatever.

EDIT: just found this http://www.droid-life.com/2012/11/14/after-4-2-update-is-your-nexus-7-having-troubles-updating-apps-in-google-play/

AngularJS 1.2 $injector:modulerr

my error disappeared by adding this '()' at the end

(function(){
    var home = angular.module('home',[]);

    home.controller('QuestionsController',function(){
        console.log("controller initialized");
        this.addPoll = function(){
            console.log("inside function");
        };
    });
})();

Javascript Iframe innerHTML

You can get the source from another domain if you install the ForceCORS filter on Firefox. When you turn on this filter, it will bypass the security feature in the browser and your script will work even if you try to read another webpage. For example, you could open FoxNews.com in an iframe and then read its source. The reason modern web brwosers deny this ability by default is because if the other domain includes a piece of JavaScript and you're reading that and displaying it on your page, it could contain malicious code and pose a security threat. So, whenever you're displaying data from another domain on your page, you must beware of this real threat and implement a way to filter out all JavaScript code from your text before you're going to display it. Remember, when a supposed piece of raw text contains some code enclosed within script tags, they won't show up when you display it on your page, nevertheless they will run! So, realize this is a threat.

http://www-jo.se/f.pfleger/forcecors

What is the command for cut copy paste a file from one directory to other directory

use the xclip which is command line interface to X selections

install

apt-get install xclip

usage

echo "test xclip " > /tmp/test.xclip
xclip -i < /tmp/test.xclip
xclip -o > /tmp/test.xclip.out

cat /tmp/test.xclip.out   # "test xclip"

enjoy.

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 ;)

Standardize data columns in R

Realizing that the question is old and one answer is accepted, I'll provide another answer for reference.

scale is limited by the fact that it scales all variables. The solution below allows to scale only specific variable names while preserving other variables unchanged (and the variable names could be dynamically generated):

library(dplyr)

set.seed(1234)
dat <- data.frame(x = rnorm(10, 30, .2), 
                  y = runif(10, 3, 5),
                  z = runif(10, 10, 20))
dat

dat2 <- dat %>% mutate_at(c("y", "z"), ~(scale(.) %>% as.vector))
dat2

which gives me this:

> dat
          x        y        z
1  29.75859 3.633225 14.56091
2  30.05549 3.605387 12.65187
3  30.21689 3.318092 13.04672
4  29.53086 3.079992 15.07307
5  30.08582 3.437599 11.81096
6  30.10121 4.621197 17.59671
7  29.88505 4.051395 12.01248
8  29.89067 4.829316 12.58810
9  29.88711 4.662690 19.92150
10 29.82199 3.091541 18.07352

and

> dat2 <- dat %>% mutate_at(c("y", "z"), ~(scale(.) %>% as.vector))
> dat2
          x          y           z
1  29.75859 -0.3004815 -0.06016029
2  30.05549 -0.3423437 -0.72529604
3  30.21689 -0.7743696 -0.58772361
4  29.53086 -1.1324181  0.11828039
5  30.08582 -0.5946582 -1.01827752
6  30.10121  1.1852038  0.99754666
7  29.88505  0.3283513 -0.94806607
8  29.89067  1.4981677 -0.74751378
9  29.88711  1.2475998  1.80753470
10 29.82199 -1.1150515  1.16367556

EDIT 1 (2016): Addressed Julian's comment: the output of scale is Nx1 matrix so ideally we should add an as.vector to convert the matrix type back into a vector type. Thanks Julian!

EDIT 2 (2019): Quoting Duccio A.'s comment: For the latest dplyr (version 0.8) you need to change dplyr::funcs with list, like dat %>% mutate_each_(list(~scale(.) %>% as.vector), vars=c("y","z"))

EDIT 3 (2020): Thanks to @mj_whales: the old solution is deprecated and now we need to use mutate_at.

Concatenate string with field value in MySQL

Have you tried using the concat() function?

ON tableTwo.query = concat('category_id=',tableOne.category_id)

Iterating over Numpy matrix rows to apply a function each?

Use numpy.apply_along_axis(). Assuming your matrix is 2D, you can use like:

import numpy as np
mymatrix = np.matrix([[11,12,13],
                      [21,22,23],
                      [31,32,33]])
def myfunction( x ):
    return sum(x)

print np.apply_along_axis( myfunction, axis=1, arr=mymatrix )
#[36 66 96]

C pass int array pointer as parameter into a function

main()
{
    int *arr[5];
    int i=31, j=5, k=19, l=71, m;

    arr[0]=&i;
    arr[1]=&j;
    arr[2]=&k;
    arr[3]=&l;
    arr[4]=&m;

    for(m=0; m<=4; m++)
    {
        printf("%d",*(arr[m]));
    }
    return 0;
}

how to create a window with two buttons that will open a new window

You add your ActionListener twice to button. So correct your code for button2 to

  JButton button2 = new JButton("hello agin2");
  panel.add(button2);
  button2.addActionListener (new Action2());//note the button2 here instead of button

Furthermore, perform your Swing operations on the correct thread by using EventQueue.invokeLater

Routing with multiple Get methods in ASP.NET Web API

From here Routing in Asp.net Mvc 4 and Web Api

Darin Dimitrov has posted a very good answer which is working for me.

It says...

You could have a couple of routes:

public static class WebApiConfig
{
    public static void Register(HttpConfiguration config)
    {
        config.Routes.MapHttpRoute(
            name: "ApiById",
            routeTemplate: "api/{controller}/{id}",
            defaults: new { id = RouteParameter.Optional },
            constraints: new { id = @"^[0-9]+$" }
        );

        config.Routes.MapHttpRoute(
            name: "ApiByName",
            routeTemplate: "api/{controller}/{action}/{name}",
            defaults: null,
            constraints: new { name = @"^[a-z]+$" }
        );

        config.Routes.MapHttpRoute(
            name: "ApiByAction",
            routeTemplate: "api/{controller}/{action}",
            defaults: new { action = "Get" }
        );
    }
}

Python popen command. Wait until the command is finished

What you are looking for is the wait method.

Extract column values of Dataframe as List in Apache Spark

This should return the collection containing single list:

dataFrame.select("YOUR_COLUMN_NAME").rdd.map(r => r(0)).collect()

Without the mapping, you just get a Row object, which contains every column from the database.

Keep in mind that this will probably get you a list of Any type. Ïf you want to specify the result type, you can use .asInstanceOf[YOUR_TYPE] in r => r(0).asInstanceOf[YOUR_TYPE] mapping

P.S. due to automatic conversion you can skip the .rdd part.

CSS rotation cross browser with jquery.animate()

Another answer, because jQuery.transit is not compatible with jQuery.easing. This solution comes as an jQuery extension. Is more generic, rotation is a specific case:

$.fn.extend({
    animateStep: function(options) {
        return this.each(function() {
            var elementOptions = $.extend({}, options, {step: options.step.bind($(this))});
            $({x: options.from}).animate({x: options.to}, elementOptions);
        });
    },
    rotate: function(value) {
        return this.css("transform", "rotate(" + value + "deg)");
    }
});

The usage is as simple as:

$(element).animateStep({from: 0, to: 90, step: $.fn.rotate});

Python IndentationError: unexpected indent

Check if you mixed tabs and spaces, that is a frequent source of indentation errors.

Can I have onScrollListener for a ScrollView?

Here's a derived HorizontalScrollView I wrote to handle notifications about scrolling and scroll ending. It properly handles when a user has stopped actively scrolling and when it fully decelerates after a user lets go:

public class ObservableHorizontalScrollView extends HorizontalScrollView {
    public interface OnScrollListener {
        public void onScrollChanged(ObservableHorizontalScrollView scrollView, int x, int y, int oldX, int oldY);
        public void onEndScroll(ObservableHorizontalScrollView scrollView);
    }

    private boolean mIsScrolling;
    private boolean mIsTouching;
    private Runnable mScrollingRunnable;
    private OnScrollListener mOnScrollListener;

    public ObservableHorizontalScrollView(Context context) {
        this(context, null, 0);
    }

    public ObservableHorizontalScrollView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

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

    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        int action = ev.getAction();

        if (action == MotionEvent.ACTION_MOVE) {
            mIsTouching = true;
            mIsScrolling = true;
        } else if (action == MotionEvent.ACTION_UP || action == MotionEvent.ACTION_CANCEL) {
            if (mIsTouching && !mIsScrolling) {
                if (mOnScrollListener != null) {
                    mOnScrollListener.onEndScroll(this);
                }
            }

            mIsTouching = false;
        }

        return super.onTouchEvent(ev);
    }

    @Override
    protected void onScrollChanged(int x, int y, int oldX, int oldY) {
        super.onScrollChanged(x, y, oldX, oldY);

        if (Math.abs(oldX - x) > 0) {
            if (mScrollingRunnable != null) {
                removeCallbacks(mScrollingRunnable);
            }

            mScrollingRunnable = new Runnable() {
                public void run() {
                    if (mIsScrolling && !mIsTouching) {
                        if (mOnScrollListener != null) {
                            mOnScrollListener.onEndScroll(ObservableHorizontalScrollView.this);
                        }
                    }

                    mIsScrolling = false;
                    mScrollingRunnable = null;
                }
            };

            postDelayed(mScrollingRunnable, 200);
        }

        if (mOnScrollListener != null) {
            mOnScrollListener.onScrollChanged(this, x, y, oldX, oldY);
        }
    }

    public OnScrollListener getOnScrollListener() {
        return mOnScrollListener;
    }

    public void setOnScrollListener(OnScrollListener mOnEndScrollListener) {
        this.mOnScrollListener = mOnEndScrollListener;
    }

}

Uses of content-disposition in an HTTP response header

For asp.net users, the .NET framework provides a class to create a content disposition header: System.Net.Mime.ContentDisposition

Basic usage:

var cd = new System.Net.Mime.ContentDisposition();
cd.FileName = "myFile.txt";
cd.ModificationDate = DateTime.UtcNow;
cd.Size = 100;
Response.AppendHeader("content-disposition", cd.ToString());

Removing a model in rails (reverse of "rails g model Title...")

  1. To remove migration (if you already migrated the migration)

    rake db:migrate:down VERSION="20130417185845" #Your migration version
    
  2. To remove Model

    rails d model name  #name => Your model name
    

How to convert .pem into .key?

If you're looking for a file to use in httpd-ssl.conf as a value for SSLCertificateKeyFile, a PEM file should work just fine.

See this SO question/answer for more details on the SSL options in that file.

Why is SSLCertificateKeyFile needed for Apache?

How to run Rake tasks from within Rake tasks?

for example:

Rake::Task["db:migrate"].invoke

Select unique values with 'select' function in 'dplyr' library

Just to add to the other answers, if you would prefer to return a vector rather than a dataframe, you have the following options:

dplyr < 0.7.0

Enclose the dplyr functions in a parentheses and combine it with $ syntax:

(mtcars %>% distinct(cyl))$cyl

dplyr >= 0.7.0

Use the pull verb:

mtcars %>% distinct(cyl) %>% pull()

Page loaded over HTTPS but requested an insecure XMLHttpRequest endpoint

this is easy,
if you use .htaccess , check http: for https: ,
if you use codeigniter, check config : url_base -> you url http change for https.....
I solved my problem.

MySQL stored procedure vs function, which would I use when?

One significant difference is that you can include a function in your SQL queries, but stored procedures can only be invoked with the CALL statement:

UDF Example:

CREATE FUNCTION hello (s CHAR(20))
   RETURNS CHAR(50) DETERMINISTIC
   RETURN CONCAT('Hello, ',s,'!');
Query OK, 0 rows affected (0.00 sec)

CREATE TABLE names (id int, name varchar(20));
INSERT INTO names VALUES (1, 'Bob');
INSERT INTO names VALUES (2, 'John');
INSERT INTO names VALUES (3, 'Paul');

SELECT hello(name) FROM names;
+--------------+
| hello(name)  |
+--------------+
| Hello, Bob!  |
| Hello, John! |
| Hello, Paul! |
+--------------+
3 rows in set (0.00 sec)

Sproc Example:

delimiter //

CREATE PROCEDURE simpleproc (IN s CHAR(100))
BEGIN
   SELECT CONCAT('Hello, ', s, '!');
END//
Query OK, 0 rows affected (0.00 sec)

delimiter ;

CALL simpleproc('World');
+---------------------------+
| CONCAT('Hello, ', s, '!') |
+---------------------------+
| Hello, World!             |
+---------------------------+
1 row in set (0.00 sec)

Create a directly-executable cross-platform GUI app using Python

For the GUI itself:

PyQT is pretty much the reference.

Another way to develop a rapid user interface is to write a web app, have it run locally and display the app in the browser.

Plus, if you go for the Tkinter option suggested by lubos hasko you may want to try portablepy to have your app run on Windows environment without Python.

How to set lifetime of session

The sessions on PHP works with a Cookie type session, while on server-side the session information is constantly deleted.

For set the time life in php, you can use the function session_set_cookie_params, before the session_start:

session_set_cookie_params(3600,"/");
session_start();

For ex, 3600 seconds is one hour, for 2 hours 3600*2 = 7200.

But it is session cookie, the browser can expire it by itself, if you want to save large time sessions (like remember login), you need to save the data in the server and a standard cookie in the client side.

You can have a Table "Sessions":

  • session_id int
  • session_hash varchar(20)
  • session_data text

And validating a Cookie, you save the "session id" and the "hash" (for security) on client side, and you can save the session's data on the server side, ex:

On login:

setcookie('sessid', $sessionid, 604800);      // One week or seven days
setcookie('sesshash', $sessionhash, 604800);  // One week or seven days
// And save the session data:
saveSessionData($sessionid, $sessionhash, serialize($_SESSION)); // saveSessionData is your function

If the user return:

if (isset($_COOKIE['sessid'])) {
    if (valide_session($_COOKIE['sessid'], $_COOKIE['sesshash'])) {
        $_SESSION = unserialize(get_session_data($_COOKIE['sessid']));
    } else {
        // Dont validate the hash, possible session falsification
    }
}

Obviously, save all session/cookies calls, before sending data.

How to check if two words are anagrams

A similar answer may have been posted in C++, here it is again in Java. Note that the most elegant way would be to use a Trie to store the characters in sorted order, however, that's a more complex solution. One way is to use a hashset to store all the words we are comparing and then compare them one by one. To compare them, make an array of characters with the index representing the ANCII value of the characters (using a normalizer since ie. ANCII value of 'a' is 97) and the value representing the occurrence count of that character. This will run in O(n) time and use O(m*z) space where m is the size of the currentWord and z the size for the storedWord, both for which we create a Char[].

public static boolean makeAnagram(String currentWord, String storedWord){
    if(currentWord.length() != storedWord.length()) return false;//words must be same length
    Integer[] currentWordChars = new Integer[totalAlphabets];
    Integer[] storedWordChars = new Integer[totalAlphabets];
    //create a temp Arrays to compare the words
    storeWordCharacterInArray(currentWordChars, currentWord);
    storeWordCharacterInArray(storedWordChars, storedWord);
    for(int i = 0; i < totalAlphabets; i++){
        //compare the new word to the current charList to see if anagram is possible
        if(currentWordChars[i] != storedWordChars[i]) return false;
    }
    return true;//and store this word in the HashSet of word in the Heap
}
//for each word store its characters
public static void storeWordCharacterInArray(Integer[] characterList, String word){
    char[] charCheck = word.toCharArray();
    for(char c: charCheck){
        Character cc = c;
        int index = cc.charValue()-indexNormalizer;
        characterList[index] += 1;
    }
}

"You have mail" message in terminal, os X

If you don't want the hassle of using mail, you can read the mail with

cat /var/mail/<username>

and delete the mail with

sudo rm /var/mail/<username>

Adding timestamp to a filename with mv in BASH

I use this command for simple rotate a file:

mv output.log `date +%F`-output.log

In local folder I have 2019-09-25-output.log

Capture Video of Android's Screen

If you are on a PC then you can run My Phone Explorer on the PC, the MyPhoneExplorer Client on the phone, set the screen capture to refresh continuously, and use Wink to capture a custom rectangular area of your screen over the My Phone Explorer window with your own capture rate. Then convert to a FLV in Wink, then convert from Flash video to MPG with WinFF.

jQuery same click event for multiple elements

Add a comma separated list of classes like this :

jQuery(document).ready(function($) {

$('.class, .id').click(function() { 

//  Your code

    }

});

Calling an executable program using awk

A much more robust way would be to use the getline() function of GNU awk to use a variable from a pipe. In form cmd | getline result, cmd is run, then its output is piped to getline. It returns 1 if got output, 0 if EOF, -1 on failure.

First construct the command to run in a variable in the BEGIN clause if the command is not dependant on the contents of the file, e.g. a simple date or an ls.

A simple example of the above would be

awk 'BEGIN {
    cmd = "ls -lrth"
    while ( ( cmd | getline result ) > 0 ) {
        print result
    }
    close(cmd);
}'

When the command to run is part of the columnar content of a file, you generate the cmd string in the main {..} as below. E.g. consider a file whose $2 contains the name of the file and you want it to be replaced with the md5sum hash content of the file. You can do

awk '{ cmd = "md5sum "$2
       while ( ( cmd | getline md5result ) > 0 ) { 
           $2 = md5result
       }
       close(cmd);
 }1'

Another frequent usage involving external commands in awk is during date processing when your awk does not support time functions out of the box with mktime(), strftime() functions.

Consider a case when you have Unix EPOCH timestamp stored in a column and you want to convert that to a human readable date format. Assuming GNU date is available

awk '{ cmd = "date -d @" $1 " +\"%d-%m-%Y %H:%M:%S\"" 
       while ( ( cmd | getline fmtDate) > 0 ) { 
           $1 = fmtDate
       }
       close(cmd);
}1' 

for an input string as

1572608319 foo bar zoo

the above command produces an output as

01-11-2019 07:38:39 foo bar zoo

The command can be tailored to modify the date fields on any of the columns in a given line. Note that -d is a GNU specific extension, the *BSD variants support -f ( though not exactly similar to -d).

More information about getline can be referred to from this AllAboutGetline article at awk.freeshell.org page.

How do I delete everything in Redis?

Use FLUSHALL ASYNC if using (Redis 4.0.0 or greater) else FLUSHALL.

https://redis.io/commands/flushall

Note: Everything before executing FLUSHALL ASYNC will be evicted. The changes made during executing FLUSHALL ASYNC will remain unaffected.

Preventing HTML and Script injections in Javascript

Try this method to convert a 'string that could potentially contain html code' to 'text format':

$msg = "<div></div>";
$safe_msg = htmlspecialchars($msg, ENT_QUOTES);
echo $safe_msg;

Hope this helps!

String parsing in Java with delimiter tab "\t" using split

You can use yourstring.split("\x09"); I tested it, and it works.

.htaccess not working apache

For Ubuntu,
First, run this command :-

sudo a2enmod rewrite

Then, edit the file /etc/apache2/sites-available/000-default.conf using nano or vim using this command :-

sudo nano /etc/apache2/sites-available/000-default.conf

Then in the 000-default.conf file, add this after the line DocumentRoot /var/www/html. If your root html directory is something other, then write that :-

<Directory "/var/www/html">
  AllowOverride All
</Directory>

After doing everything, restart apache using the command sudo service apache2 restart

Store boolean value in SQLite

There is no native boolean data type for SQLite. Per the Datatypes doc:

SQLite does not have a separate Boolean storage class. Instead, Boolean values are stored as integers 0 (false) and 1 (true).

Are members of a C++ struct initialized to 0 by default?

I believe the correct answer is that their values are undefined. Often, they are initialized to 0 when running debug versions of the code. This is usually not the case when running release versions.

Comparison of Android Web Service and Networking libraries: OKHTTP, Retrofit and Volley

Retrofit 1.9.0 vs. RoboSpice

I am using both in my app.

Robospice works faster than Retrofit whenever I parse the nested JSON class. Because Spice Manger will do everything for you. In Retrofit you need to create GsonConverter and deserialize it.

I created two fragments in the same activity and called the same time with two same kind of URLs.

09-23 20:12:32.830  16002-16002/com.urbanpro.seeker E/RETROFIT?   RestAdapter Init
09-23 20:12:32.833  16002-16002/com.urbanpro.seeker E/RETROFIT? calling the method
09-23 20:12:32.837  16002-16002/com.urbanpro.seeker E/ROBOSPICE? initialzig spice manager
09-23 20:12:32.860  16002-16002/com.urbanpro.seeker E/ROBOSPICE? Executing the method
09-23 20:12:33.537  16002-16002/com.urbanpro.seeker E/ROBOSPICE? on SUcceess
09-23 20:12:33.553  16002-16002/com.urbanpro.seeker E/ROBOSPICE? gettting the all contents
09-23 20:12:33.601  16002-21819/com.urbanpro.seeker E/RETROFIT? deseriazation starts
09-23 20:12:33.603  16002-21819/com.urbanpro.seeker E/RETROFIT? deseriazation ends

How do I get interactive plots again in Spyder/IPython/matplotlib?

As said in the comments, the problem lies in your script. Actually, there are 2 problems:

  • There is a matplotlib error, I guess that you're passing an argument as None somewhere. Maybe due to the defaultdict ?
  • You call show() after each subplot. show() should be called once at the end of your script. The alternative is to use interactive mode, look for ion in matplotlib's documentation.

How to initialize a List<T> to a given size (as opposed to capacity)?

If I understand correctly, you want the List<T> version of new T[size], without the overhead of adding values to it.

If you are not afraid the implementation of List<T> will change dramatically in the future (and in this case I believe the probability is close to 0), you can use reflection:

    public static List<T> NewOfSize<T>(int size) {
        var list = new List<T>(size);
        var sizeField = list.GetType().GetField("_size",BindingFlags.Instance|BindingFlags.NonPublic);
        sizeField.SetValue(list, size);
        return list;
    }

Note that this takes into account the default functionality of the underlying array to prefill with the default value of the item type. All int arrays will have values of 0 and all reference type arrays will have values of null. Also note that for a list of reference types, only the space for the pointer to each item is created.

If you, for some reason, decide on not using reflection, I would have liked to offer an option of AddRange with a generator method, but underneath List<T> just calls Insert a zillion times, which doesn't serve.

I would also like to point out that the Array class has a static method called ResizeArray, if you want to go the other way around and start from Array.

To end, I really hate when I ask a question and everybody points out that it's the wrong question. Maybe it is, and thanks for the info, but I would still like an answer, because you have no idea why I am asking it. That being said, if you want to create a framework that has an optimal use of resources, List<T> is a pretty inefficient class for anything than holding and adding stuff to the end of a collection.

How to define dimens.xml for every different screen size in android?

There are nice libraries which will handle everything and reduce your pain. For using it, just add two dependencies in gradle:

 implementation 'com.intuit.ssp:ssp-android:1.0.5'
 implementation 'com.intuit.sdp:sdp-android:1.0.5'

After that, use dimens like this:

        android:layout_marginTop="@dimen/_80sdp"

How can I wait for a thread to finish with .NET?

The previous two answers are great and will work for simple scenarios. There are other ways to synchronize threads, however. The following will also work:

public void StartTheActions()
{
    ManualResetEvent syncEvent = new ManualResetEvent(false);

    Thread t1 = new Thread(
        () =>
        {
            // Do some work...
            syncEvent.Set();
        }
    );
    t1.Start();

    Thread t2 = new Thread(
        () =>
        {
            syncEvent.WaitOne();

            // Do some work...
        }
    );
    t2.Start();
}

ManualResetEvent is one of the various WaitHandle's that the .NET framework has to offer. They can provide much richer thread synchronization capabilities than the simple, but very common tools like lock()/Monitor, Thread.Join, etc.

They can also be used to synchronize more than two threads, allowing complex scenarios such as a 'master' thread that coordinates multiple 'child' threads, multiple concurrent processes that are dependent upon several stages of each other to be synchronized, etc.

How can I get column names from a table in SQL Server?

select *
from INFORMATION_SCHEMA.COLUMNS
where TABLE_NAME='tableName'

This is better than getting from sys.columns because it shows DATA_TYPE directly.

make a phone call click on a button

check permissions before (for android 6 and above):

if (ActivityCompat.checkSelfPermission(context, Manifest.permission.CALL_PHONE) ==
                            PackageManager.PERMISSION_GRANTED) 
   {

     context.startActivity(new Intent(Intent.ACTION_CALL, Uri.parse("tel:09130000000")));
   }

How can I trigger the click event of another element in ng-click using angularjs?

One more directive

html

<btn-file-selector/>

code

.directive('btnFileSelector',[function(){
  return {
    restrict: 'AE', 
    template: '<div></div>', 
    link: function(s,e,a){

      var el = angular.element(e);
      var button = angular.element('<button type="button" class="btn btn-default btn-upload">Add File</button>'); 
      var fileForm = angular.element('<input type="file" style="display:none;"/>'); 

      fileForm.on('change', function(){
         // Actions after the file is selected
         console.log( fileForm[0].files[0].name );
      });

      button.bind('click',function(){
        fileForm.click();
      });     


     el.append(fileForm);
     el.append(button);
    }
  }  
}]); 

Spring .properties file: get element as an Array

With a Spring Boot one can do the following:

application.properties

values[0]=abc
values[1]=def

Configuration class

import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;

import java.util.ArrayList;
import java.util.List;

@Component
@ConfigurationProperties
public class Configuration {

    List<String> values = new ArrayList<>();

    public List<String> getValues() {
        return values;
    }

}

This is needed, without this class or without the values in class it is not working.

Spring Boot Application class

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

import java.util.List;

@SpringBootApplication
public class SpringBootConsoleApplication implements CommandLineRunner {

    private static Logger LOG = LoggerFactory.getLogger(SpringBootConsoleApplication.class);

    // notice #{} is used instead of ${}
    @Value("#{configuration.values}")
    List<String> values;

    public static void main(String[] args) {
        SpringApplication.run(SpringBootConsoleApplication.class, args);
    }

    @Override
    public void run(String... args) {
        LOG.info("values: {}", values);
    }

}

Python: Remove division decimal

When a number as a decimal it is usually a float in Python.

If you want to remove the decimal and keep it an integer (int). You can call the int() method on it like so...

>>> int(2.0)
2

However, int rounds down so...

>>> int(2.9)
2

If you want to round to the nearest integer you can use round:

>>> round(2.9)
3.0
>>> round(2.4)
2.0

And then call int() on that:

>>> int(round(2.9))
3
>>> int(round(2.4))
2

Determine number of pages in a PDF file

I have good success using CeTe Dynamic PDF products. They're not free, but are well documented. They did the job for me.

http://www.dynamicpdf.com/

Setting up Eclipse with JRE Path

Java version used : 1.8 IDE : Eclipse Neon

Adding like the below didn't work for me

-vm [relative java home]/jdk1.8.0_21/bin/javaw.exe

and then when i removed

javaw.exe

it worked, so it will be like

-vm [relative java home]/jdk1.8.0_21/bin/

What does "TypeError 'xxx' object is not callable" means?

I came across this error message through a silly mistake. A classic example of Python giving you plenty of room to make a fool of yourself. Observe:

class DOH(object):
def __init__(self, property=None):
    self.property=property

def property():
    return property

x = DOH(1)
print(x.property())

Results

$ python3 t.py
Traceback (most recent call last):
  File "t.py", line 9, in <module>
    print(x.property())
TypeError: 'int' object is not callable

The problem here of course is that the function is overwritten with a property.

Radio/checkbox alignment in HTML/CSS

@sfjedi

I've created a class and assigned the css values to it.

.radioA{
   vertical-align: middle;
}

It is working and you can check it in the below link. http://jsfiddle.net/gNVsC/ Hope it was useful.

How to use OKHTTP to make a post request?

Here is my method to do post request first pass in method map and data like

HashMap<String, String> param = new HashMap<String, String>();

param.put("Name", name);
param.put("Email", email);
param.put("Password", password);
param.put("Img_Name", "");

final JSONObject result = doPostRequest(map,Url);

public static JSONObject doPostRequest(HashMap<String, String> data, String url) {

    try {
        RequestBody requestBody;
        MultipartBuilder mBuilder = new MultipartBuilder().type(MultipartBuilder.FORM);

        if (data != null) {


            for (String key : data.keySet()) {
                String value = data.get(key);
                Utility.printLog("Key Values", key + "-----------------" + value);

                mBuilder.addFormDataPart(key, value);

            }
        } else {
            mBuilder.addFormDataPart("temp", "temp");
        }
        requestBody = mBuilder.build();


        Request request = new Request.Builder()
                .url(url)
                .post(requestBody)
                .build();

        OkHttpClient client = new OkHttpClient();
        Response response = client.newCall(request).execute();
        String responseBody = response.body().string();
        Utility.printLog("URL", url);
        Utility.printLog("Response", responseBody);
        return new JSONObject(responseBody);

    } catch (UnknownHostException | UnsupportedEncodingException e) {

        JSONObject jsonObject=new JSONObject();

        try {
            jsonObject.put("status","false");
            jsonObject.put("message",e.getLocalizedMessage());
        } catch (JSONException e1) {
            e1.printStackTrace();
        }
        Log.e(TAG, "Error: " + e.getLocalizedMessage());
    } catch (Exception e) {
        e.printStackTrace();
        JSONObject jsonObject=new JSONObject();

        try {
            jsonObject.put("status","false");
            jsonObject.put("message",e.getLocalizedMessage());
        } catch (JSONException e1) {
            e1.printStackTrace();
        }
        Log.e(TAG, "Other Error: " + e.getLocalizedMessage());
    }
    return null;
}

Delete empty lines using sed

I am missing the awk solution:

awk 'NF' file

Which would return:

xxxxxx
yyyyyy
zzzzzz

How does this work? Since NF stands for "number of fields", those lines being empty have 0 fiedls, so that awk evaluates 0 to False and no line is printed; however, if there is at least one field, the evaluation is True and makes awk perform its default action: print the current line.

Ansible - Save registered variable to file

A local action will run once for each remote host (in parallel). If you want a unique file per host, make sure to put the inventory_hostname as part of the file name.

- local_action: copy content={{ foo_result }} dest=/path/to/destination/{{ inventory_hostname }}file

If you instead want a single file with all host's information, one way is to have a serial task (don't want to append in parallel) and then append to the file with a module (lineinfile is capable, or could pipe with a shell command)

- hosts: web_servers
  serial: 1
  tasks:
  - local_action: lineinfile line={{ foo_result }} path=/path/to/destination/file

Alternatively, you can add a second play/role/task to the playbook which runs against only local host. Then access the variable from each of the hosts where the registration command ran inside a template Access Other Hosts Variables Docs Template Module Docs

Executing Shell Scripts from the OS X Dock?

As joe mentioned, creating the shell script and then creating an applescript script to call the shell script, will accomplish this, and is quite handy.

Shell Script

  1. Create your shell script in your favorite text editor, for example:

    mono "/Volumes/Media/~Users/me/Software/keepass/keepass.exe"

    (this runs the w32 executable, using the mono framework)

  2. Save shell script, for my example "StartKeepass.sh"

Apple Script

  1. Open AppleScript Editor, and call the shell script

    do shell script "sh /Volumes/Media/~Users/me/Software/StartKeepass.sh" user name "<enter username here>" password "<Enter password here>" with administrator privileges

    • do shell script - applescript command to call external shell commands
    • "sh ...." - this is your shell script (full path) created in step one (you can also run direct commands, I could omit the shell script and just run my mono command here)
    • user name - declares to applescript you want to run the command as a specific user
    • "<enter username here> - replace with your username (keeping quotes) ex "josh"
    • password - declares to applescript your password
    • "<enter password here>" - replace with your password (keeping quotes) ex "mypass"
    • with administrative privileges - declares you want to run as an admin

Create Your .APP

  1. save your applescript as filename.scpt, in my case RunKeepass.scpt

  2. save as... your applescript and change the file format to application, resulting in RunKeepass.app in my case

  3. Copy your app file to your apps folder

How do I get the path of the Python script I am running in?

7.2 of Dive Into Python: Finding the Path.

import sys, os

print('sys.argv[0] =', sys.argv[0])             
pathname = os.path.dirname(sys.argv[0])        
print('path =', pathname)
print('full path =', os.path.abspath(pathname)) 

ng-if, not equal to?

Try this:

ng-if="details.Payment[0].Status != '6'".

Sorry about that, but I think you can use ng-show or ng-hide.

How do I write good/correct package __init__.py files

Your __init__.py should have a docstring.

Although all the functionality is implemented in modules and subpackages, your package docstring is the place to document where to start. For example, consider the python email package. The package documentation is an introduction describing the purpose, background, and how the various components within the package work together. If you automatically generate documentation from docstrings using sphinx or another package, the package docstring is exactly the right place to describe such an introduction.

For any other content, see the excellent answers by firecrow and Alex Martelli.

How can I create a blank/hardcoded column in a sql query?

This should work on most databases. You can also select a blank string as your extra column like so:

Select
  Hat, Show, Boat, '' as SomeValue
From
  Objects

Bound method error

The syntax problem is shadowing method and variable names. In the current version sort_word_list() is a method, and sorted_word_list is a variable, whereas num_words is both. Also, list.sort() modifies the list and replaces it with a sorted version; the sorted(list) function actually returns a new list.

But I suspect this indicates a design problem. What's the point of calls like

test.parser()
test.sort_word_list()
test.num_words()

which don't do anything? You should probably just have the methods figure out whether the appropriate counting and/or sorting has been done, and, if appropriate, do the count or sort and otherwise just return something.

E.G.,

def sort_word_list(self):
   if self.sorted_word_list is not None:
      self.sorted_word_list = sorted(self.word_list)
   return self.sorted_word_list

(Alternately, you could use properties.)

html select option SELECTED

foreach ($array as $value => $name) {
     echo '<option value="' . htmlentities($value) . '"' . (($_GET['sel'] === $value) ? ' selected="selected"') . '>' . htmlentities($name) . '</option>';
}

This is fairly neat, and, I think, self-explanatory.

Using Spring RestTemplate in generic method with generic parameter

Actually, you can do this, but with additional code.

There is Guava equivalent of ParameterizedTypeReference and it's called TypeToken.

Guava's class is much more powerful then Spring's equivalent. You can compose the TypeTokens as you wish. For example:

static <K, V> TypeToken<Map<K, V>> mapToken(TypeToken<K> keyToken, TypeToken<V> valueToken) {
  return new TypeToken<Map<K, V>>() {}
    .where(new TypeParameter<K>() {}, keyToken)
    .where(new TypeParameter<V>() {}, valueToken);
}

If you call mapToken(TypeToken.of(String.class), TypeToken.of(BigInteger.class)); you will create TypeToken<Map<String, BigInteger>>!

The only disadvantage here is that many Spring APIs require ParameterizedTypeReference and not TypeToken. But we can create ParameterizedTypeReference implementation which is adapter to TypeToken itself.

import com.google.common.reflect.TypeToken;
import org.springframework.core.ParameterizedTypeReference;

import java.lang.reflect.Type;

public class ParameterizedTypeReferenceBuilder {

    public static <T> ParameterizedTypeReference<T> fromTypeToken(TypeToken<T> typeToken) {
        return new TypeTokenParameterizedTypeReference<>(typeToken);
    }

    private static class TypeTokenParameterizedTypeReference<T> extends ParameterizedTypeReference<T> {

        private final Type type;

        private TypeTokenParameterizedTypeReference(TypeToken<T> typeToken) {
            this.type = typeToken.getType();
        }

        @Override
        public Type getType() {
            return type;
        }

        @Override
        public boolean equals(Object obj) {
            return (this == obj || (obj instanceof ParameterizedTypeReference &&
                    this.type.equals(((ParameterizedTypeReference<?>) obj).getType())));
        }

        @Override
        public int hashCode() {
            return this.type.hashCode();
        }

        @Override
        public String toString() {
            return "ParameterizedTypeReference<" + this.type + ">";
        }

    }

}

Then you can use it like this:

public <T> ResponseWrapper<T> makeRequest(URI uri, Class<T> clazz) {
   ParameterizedTypeReference<ResponseWrapper<T>> responseTypeRef =
           ParameterizedTypeReferenceBuilder.fromTypeToken(
               new TypeToken<ResponseWrapper<T>>() {}
                   .where(new TypeParameter<T>() {}, clazz));
   ResponseEntity<ResponseWrapper<T>> response = template.exchange(
        uri,
        HttpMethod.POST,
        null,
        responseTypeRef);
    return response;
}

And call it like:

ResponseWrapper<MyClass> result = makeRequest(uri, MyClass.class);

And the response body will be correctly deserialized as ResponseWrapper<MyClass>!

You can even use more complex types if you rewrite your generic request method (or overload it) like this:

public <T> ResponseWrapper<T> makeRequest(URI uri, TypeToken<T> resultTypeToken) {
   ParameterizedTypeReference<ResponseWrapper<T>> responseTypeRef =
           ParameterizedTypeReferenceBuilder.fromTypeToken(
               new TypeToken<ResponseWrapper<T>>() {}
                   .where(new TypeParameter<T>() {}, resultTypeToken));
   ResponseEntity<ResponseWrapper<T>> response = template.exchange(
        uri,
        HttpMethod.POST,
        null,
        responseTypeRef);
    return response;
}

This way T can be complex type, like List<MyClass>.

And call it like:

ResponseWrapper<List<MyClass>> result = makeRequest(uri, new TypeToken<List<MyClass>>() {});

Program to find prime numbers

Here is a solution with unit test:

The solution:

public class PrimeNumbersKata
    {
        public int CountPrimeNumbers(int n)
        {
            if (n < 0) throw new ArgumentException("Not valide numbre");
            if (n == 0 || n == 1) return 0;
            int cpt = 0;
            for (int i = 2; i <= n; i++)
            {
                if (IsPrimaire(i)) cpt++;
            }
            return cpt;
        }

        private bool IsPrimaire(int number)
        {

            for (int i = 2; i <= number / 2; i++)
            {
                if (number % i == 0) return false;
            }
            return true;
        }
    }

The tests:

[TestFixture]
    class PrimeNumbersKataTest
    {
        private PrimeNumbersKata primeNumbersKata;
        [SetUp]
        public void Init()
        {
            primeNumbersKata = new PrimeNumbersKata();
        }
        [TestCase(1,0)]
        [TestCase(0,0)]
        [TestCase(2,1)]
        [TestCase(3,2)]
        [TestCase(5,3)]
        [TestCase(7,4)]
        [TestCase(9,4)]
        [TestCase(11,5)]
        [TestCase(13,6)]
        public void CountPrimeNumbers_N_AsArgument_returnCountPrimes(int n, int expected)
        {
            //arrange
            //act
            var actual = primeNumbersKata.CountPrimeNumbers(n);
            //assert
            Assert.AreEqual(expected,actual);
        }

        [Test]
        public void CountPrimairs_N_IsNegative_RaiseAnException()
        {
            var ex = Assert.Throws<ArgumentException>(()=> { primeNumbersKata.CountPrimeNumbers(-1); });
            //Assert.That(ex.Message == "Not valide numbre");
             Assert.That(ex.Message, Is.EqualTo("Not valide numbre"));

        }
    }

Mock a constructor with parameter

Starting with version 3.5.0 of Mockito and using the InlineMockMaker, you can now mock object constructions:

 try (MockedConstruction mocked = mockConstruction(A.class)) {
   A a = new A();
   when(a.check()).thenReturn("bar");
 }

Inside the try-with-resources construct all object constructions are returning a mock.

How do I implement a callback in PHP?

I cringe every time I use create_function() in php.

Parameters are a coma separated string, the whole function body in a string... Argh... I think they could not have made it uglier even if they tried.

Unfortunately, it is the only choice when creating a named function is not worth the trouble.

How to restore PostgreSQL dump file into Postgres databases?

By using pg_restore command you can restore postgres database

First open terminal type

sudo su postgres

Create new database

createdb [database name] -O [owner]

createdb test_db [-O openerp]

pg_restore -d [Database Name] [path of dump file]

pg_restore -d test_db /home/sagar/Download/sample_dbump

Wait for completion of database restoring.

Remember that dump file should have read, write, execute access, so for that you can apply chmod command

Difference between natural join and inner join

One significant difference between INNER JOIN and NATURAL JOIN is the number of columns returned.

Consider:

TableA                           TableB
+------------+----------+        +--------------------+    
|Column1     | Column2  |        |Column1  |  Column3 |
+-----------------------+        +--------------------+
| 1          |  2       |        | 1       |   3      |
+------------+----------+        +---------+----------+

The INNER JOIN of TableA and TableB on Column1 will return

SELECT * FROM TableA AS a INNER JOIN TableB AS b USING (Column1);
SELECT * FROM TableA AS a INNER JOIN TableB AS b ON a.Column1 = b.Column1;
+------------+-----------+---------------------+    
| a.Column1  | a.Column2 | b.Column1| b.Column3|
+------------------------+---------------------+
| 1          |  2        | 1        |   3      |
+------------+-----------+----------+----------+

The NATURAL JOIN of TableA and TableB on Column1 will return:

SELECT * FROM TableA NATURAL JOIN TableB
+------------+----------+----------+    
|Column1     | Column2  | Column3  |
+-----------------------+----------+
| 1          |  2       |   3      |
+------------+----------+----------+

The repeated column is avoided.

(AFAICT from the standard grammar, you can't specify the joining columns in a natural join; the join is strictly name-based. See also Wikipedia.)

(There's a cheat in the inner join output; the a. and b. parts would not be in the column names; you'd just have column1, column2, column1, column3 as the headings.)

UIView bottom border?

Implemented in a category as below:

UIButton+Border.h:

@interface UIButton (Border)

- (void)addBottomBorderWithColor: (UIColor *) color andWidth:(CGFloat) borderWidth;

- (void)addLeftBorderWithColor: (UIColor *) color andWidth:(CGFloat) borderWidth;

- (void)addRightBorderWithColor: (UIColor *) color andWidth:(CGFloat) borderWidth;

- (void)addTopBorderWithColor: (UIColor *) color andWidth:(CGFloat) borderWidth;

@end

UIButton+Border.m:

@implementation UIButton (Border)

- (void)addTopBorderWithColor:(UIColor *)color andWidth:(CGFloat) borderWidth {
    CALayer *border = [CALayer layer];
    border.backgroundColor = color.CGColor;

    border.frame = CGRectMake(0, 0, self.frame.size.width, borderWidth);
    [self.layer addSublayer:border];
}

- (void)addBottomBorderWithColor:(UIColor *)color andWidth:(CGFloat) borderWidth {
    CALayer *border = [CALayer layer];
    border.backgroundColor = color.CGColor;

    border.frame = CGRectMake(0, self.frame.size.height - borderWidth, self.frame.size.width, borderWidth);
    [self.layer addSublayer:border];
}

- (void)addLeftBorderWithColor:(UIColor *)color andWidth:(CGFloat) borderWidth {
    CALayer *border = [CALayer layer];
    border.backgroundColor = color.CGColor;

    border.frame = CGRectMake(0, 0, borderWidth, self.frame.size.height);
    [self.layer addSublayer:border];
}

- (void)addRightBorderWithColor:(UIColor *)color andWidth:(CGFloat) borderWidth {
    CALayer *border = [CALayer layer];
    border.backgroundColor = color.CGColor;

    border.frame = CGRectMake(self.frame.size.width - borderWidth, 0, borderWidth, self.frame.size.height);
    [self.layer addSublayer:border];
}

@end

Android Gradle Apache HttpClient does not exist?

I cloned the following: https://github.com/google/play-licensing

Then I imported that into my project.

Add Expires headers

<IfModule mod_expires.c>
    # Enable expirations
    ExpiresActive On 

    # Default directive
    ExpiresDefault "access plus 1 month"

    # My favicon
    ExpiresByType image/x-icon "access plus 1 year"

    # Images
    ExpiresByType image/gif "access plus 1 month"
    ExpiresByType image/png "access plus 1 month"
    ExpiresByType image/jpg "access plus 1 month"
    ExpiresByType image/jpeg "access plus 1 month"

    # CSS
    ExpiresByType text/css "access plus 1 month"

    # Javascript
    ExpiresByType application/javascript "access plus 1 year"
</IfModule>

default select option as blank

Solution that works by only using CSS:

A: Inline CSS

_x000D_
_x000D_
<select>_x000D_
    <option style="display:none;"></option>_x000D_
    <option>Option 1</option>_x000D_
    <option>Option 2</option>_x000D_
    <option>Option 3</option>_x000D_
</select>
_x000D_
_x000D_
_x000D_

B: CSS Style Sheet

If you have a CSS file at hand, you can target the first option using:

_x000D_
_x000D_
select.first-opt-hidden option:first-of-type {_x000D_
  display:none;_x000D_
}
_x000D_
<select class="first-opt-hidden">_x000D_
    <option></option>_x000D_
    <option>Option 1</option>_x000D_
    <option>Option 2</option>_x000D_
    <option>Option 3</option>_x000D_
</select>
_x000D_
_x000D_
_x000D_

installing urllib in Python3.6

urllib is a standard python library (built-in) so you don't have to install it. just import it if you need to use request by:

import urllib.request

if it's not work maybe you compiled python in wrong way, so be kind and give us more details.

JQuery - how to select dropdown item based on value

You can use this jQuery code which I find it eaiser to use:

_x000D_
_x000D_
$('#your_id [value=3]').attr('selected', 'true');
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
_x000D_
<select id="your_id" name="name" class="form-control input-md">_x000D_
  <option value="1">Option #1</option>_x000D_
  <option value="2">Option #2</option>_x000D_
  <option value="3">Option #3</option>_x000D_
  <option value="4">Option #4</option>_x000D_
  <option value="5">Option #5</option>_x000D_
  <option value="6">Option #6</option>_x000D_
  <option value="7">Option #7</option>_x000D_
</select>
_x000D_
_x000D_
_x000D_

Where can I find jenkins restful api reference?

Additional Solution: use Restul api wrapper libraries written in Java / python / Ruby - An object oriented wrappers which aim to provide a more conventionally way of controlling a Jenkins server.

For documentation and links: Remote Access API

Get value of a merged cell of an excel from its cell address in vba

Even if it is really discouraged to use merge cells in Excel (use Center Across Selection for instance if needed), the cell that "contains" the value is the one on the top left (at least, that's a way to express it).

Hence, you can get the value of merged cells in range B4:B11 in several ways:

  • Range("B4").Value
  • Range("B4:B11").Cells(1).Value
  • Range("B4:B11").Cells(1,1).Value

You can also note that all the other cells have no value in them. While debugging, you can see that the value is empty.

Also note that Range("B4:B11").Value won't work (raises an execution error number 13 if you try to Debug.Print it) because it returns an array.

Keylistener in Javascript

JSFIDDLE DEMO

If you don't want the event to be continuous (if you want the user to have to release the key each time), change onkeydown to onkeyup

window.onkeydown = function (e) {
    var code = e.keyCode ? e.keyCode : e.which;
    if (code === 38) { //up key
        alert('up');
    } else if (code === 40) { //down key
        alert('down');
    }
};

How do you align left / right a div without using float?

You could just use a margin-left with a percentage.

HTML

<div class="goleft">Left Div</div>
<div class="goright">Right Div</div>

CSS

.goright{
    margin-left:20%;
}
.goleft{
    margin-right:20%;
}

(goleft would be the same as default, but can reverse if needed)

text-align doesn't always work as intended for layout options, it's mainly just for text. (But is often used for form elements too).

The end result of doing this will have a similar effect to a div with float:right; and width:80% set. Except, it won't clump together like a float will. (Saving the default display properties for the elements that come after).

How to add message box with 'OK' button?

I think there may be problem that you haven't added click listener for ok positive button.

dlgAlert.setPositiveButton("Ok",
    new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog, int which) {
          //dismiss the dialog  
        }
    });

Load text file as strings using numpy.loadtxt()

Is it essential that you need a NumPy array? Otherwise you could speed things up by loading the data as a nested list.

def load(fname):
    ''' Load the file using std open'''
    f = open(fname,'r')

    data = []
    for line in f.readlines():
        data.append(line.replace('\n','').split(' '))

    f.close()

    return data

For a text file with 4000x4000 words this is about 10 times faster than loadtxt.

Rotating and spacing axis labels in ggplot2

Use coord_flip()

data(diamonds)
diamonds$cut <- paste("Super Dee-Duper",as.character(diamonds$cut))

qplot(cut, carat, data = diamonds, geom = "boxplot") +
  coord_flip()

enter image description here


Add str_wrap()

# wrap text to no more than 15 spaces
library(stringr)
diamonds$cut2 <- str_wrap(diamonds$cut, width = 15)
qplot(cut2, carat, data = diamonds, geom = "boxplot") +
  coord_flip()

enter image description here


In Ch 3.9 of R for Data Science, Wickham and Grolemund speak to this exact question:

coord_flip() switches the x and y axes. This is useful (for example), if you want horizontal boxplots. It’s also useful for long labels: it’s hard to get them to fit without overlapping on the x-axis.

How to click a link whose href has a certain substring in Selenium?

I need to click the link who's href has substring "long" in it. How can I do this?

With the beauty of CSS selectors.

your statement would be...

driver.findElement(By.cssSelector("a[href*='long']")).click();

This means, in english,

Find me any 'a' elements, that have the href attribute, and that attribute contains 'long'

You can find a useful article about formulating your own selectors for automation effectively, as well as a list of all the other equality operators. contains, starts with, etc... You can find that at: http://ddavison.io/css/2014/02/18/effective-css-selectors.html

How to use Greek symbols in ggplot2?

You do not need the latex2exp package to do what you wanted to do. The following code would do the trick.

ggplot(smr, aes(Fuel.Rate, Eng.Speed.Ave., color=Eng.Speed.Max.)) + 
  geom_point() + 
  labs(title=expression("Fuel Efficiency"~(alpha*Omega)), 
color=expression(alpha*Omega), x=expression(Delta~price))

enter image description here

Also, some comments (unanswered as of this point) asked about putting an asterisk (*) after a Greek letter. expression(alpha~"*") works, so I suggest giving it a try.

More comments asked about getting ? Price and I find the most straightforward way to achieve that is expression(Delta~price)). If you need to add something before the Greek letter, you can also do this: expression(Indicative~Delta~price) which gets you:

enter image description here

SQL Server - transactions roll back on error?

From MDSN article, Controlling Transactions (Database Engine).

If a run-time statement error (such as a constraint violation) occurs in a batch, the default behavior in the Database Engine is to roll back only the statement that generated the error. You can change this behavior using the SET XACT_ABORT statement. After SET XACT_ABORT ON is executed, any run-time statement error causes an automatic rollback of the current transaction. Compile errors, such as syntax errors, are not affected by SET XACT_ABORT. For more information, see SET XACT_ABORT (Transact-SQL).

In your case it will rollback the complete transaction when any of inserts fail.

How can I create a simple index.html file which lists all files/directories?

For me PHP is the easiest way to do it:

<?php
echo "Here are our files";
$path = ".";
$dh = opendir($path);
$i=1;
while (($file = readdir($dh)) !== false) {
    if($file != "." && $file != ".." && $file != "index.php" && $file != ".htaccess" && $file != "error_log" && $file != "cgi-bin") {
        echo "<a href='$path/$file'>$file</a><br /><br />";
        $i++;
    }
}
closedir($dh);
?> 

Place this in your directory and set where you want it to search on the $path. The first if statement will hide your php file and .htaccess and the error log. It will then display the output with a link. This is very simple code and easy to edit.

How to fix corrupt HDFS FIles

the solution here worked for me : https://community.hortonworks.com/articles/4427/fix-under-replicated-blocks-in-hdfs-manually.html

su - <$hdfs_user>

bash-4.1$ hdfs fsck / | grep 'Under replicated' | awk -F':' '{print $1}' >> /tmp/under_replicated_files 

-bash-4.1$ for hdfsfile in `cat /tmp/under_replicated_files`; do echo "Fixing $hdfsfile :" ;  hadoop fs -setrep 3 $hdfsfile; done

Oracle Date TO_CHAR('Month DD, YYYY') has extra spaces in it

if you use 'Month' in to_char it right pads to 9 characters; you have to use the abbreviated 'MON', or to_char then trim and concatenate it to avoid this. See, http://www.techonthenet.com/oracle/functions/to_char.php

select trim(to_char(date_field, 'month')) || ' ' || to_char(date_field,'dd, yyyy')
  from ...

or

select to_char(date_field,'mon dd, yyyy')
  from ...  

Cannot find module '@angular/compiler'

Uninstall the Angular CLI and install the latest version of it.

npm uninstall angular-cli

npm install --save-dev @angular/cli@latest

Format Float to n decimal places

public static double roundToDouble(float d, int decimalPlace) {
        BigDecimal bd = new BigDecimal(Float.toString(d));
        bd = bd.setScale(decimalPlace, BigDecimal.ROUND_HALF_UP);
        return bd.doubleValue();
    }

How to change RGB color to HSV?

There's a C implementation here:

http://www.cs.rit.edu/~ncs/color/t_convert.html

Should be very straightforward to convert to C#, as almost no functions are called - just calculations.

found via Google

How to get page content using cURL?

I suppose that have you noticed that your link is actually an HTTPS link.... It seems that CURL parameters do not include any kind of SSH handling... maybe this could be your problem. Why don't you try with a non-HTTPS link to see what happens (i.e Google Custom Search Engine)...?

How can I map "insert='false' update='false'" on a composite-id key-property which is also used in a one-to-many FK?

I think the annotation you are looking for is:

public class CompanyName implements Serializable {
//...
@JoinColumn(name = "COMPANY_ID", referencedColumnName = "COMPANY_ID", insertable = false, updatable = false)
private Company company;

And you should be able to use similar mappings in a hbm.xml as shown here (in 23.4.2):

http://docs.jboss.org/hibernate/core/3.3/reference/en/html/example-mappings.html

how to convert rgb color to int in java

You may declare a value in color.xml, and thus you can get integer value by calling the code below.

context.getColor(int resId);

SQLSTATE[HY093]: Invalid parameter number: number of bound variables does not match number of tokens on line 102

You didn't bind all your bindings here

$sql = "SELECT SQL_CALC_FOUND_ROWS *, UNIX_TIMESTAMP(publicationDate) AS publicationDate     FROM comments WHERE articleid = :art 
ORDER BY " . mysqli_escape_string($order) . " LIMIT :numRows";

$st = $conn->prepare( $sql );
$st->bindValue( ":art", $art, PDO::PARAM_INT );

You've declared a binding called :numRows but you never actually bind anything to it.

UPDATE 2019: I keep getting upvotes on this and that reminded me of another suggestion

Double quotes are string interpolation in PHP, so if you're going to use variables in a double quotes string, it's pointless to use the concat operator. On the flip side, single quotes are not string interpolation, so if you've only got like one variable at the end of a string it can make sense, or just use it for the whole string.

In fact, there's a micro op available here since the interpreter doesn't care about parsing the string for variables. The boost is nearly unnoticable and totally ignorable on a small scale. However, in a very large application, especially good old legacy monoliths, there can be a noticeable performance increase if strings are used like this. (and IMO, it's easier to read anyway)

Maven: mvn command not found

If you are on windows, what i suppose you need to do set the PATH like this:

SET PATH=%M2%

furthermore i assume you need to set your path to something like C:...\apache-maven-3.0.3\ cause this is the default folder for the windows archive. On the other i assume you need to add the path of maven to your and not set it to only maven so you setting should look like this:

SET PATH=%PATH%;%M2%

How to get current user, and how to use User class in MVC5?

In .Net MVC5 core 2.2, I use HttpContext.User.Identity.Name . It worked for me.

Django return redirect() with parameters

urls.py:

#...    
url(r'element/update/(?P<pk>\d+)/$', 'element.views.element_update', name='element_update'),

views.py:

from django.shortcuts import redirect
from .models import Element


def element_info(request):
    # ...
    element = Element.object.get(pk=1)
    return redirect('element_update', pk=element.id)

def element_update(request, pk)
    # ...

Display curl output in readable JSON format in Unix shell script

I am guessing that you want to prettify the JSON output. That could be achieved using python:

curl http://localhost:8880/test.json | python -mjson.tool > out.json

Skip certain tables with mysqldump

To exclude some table data, but not the table structure. Here is how I do it:

Dump the database structure of all tables, without any data:

mysqldump -u user -p --no-data database > database_structure.sql

Then dump the database with data, except the excluded tables, and do not dump the structure:

mysqldump -u user -p --no-create-info \
    --ignore-table=database.table1 \
    --ignore-table=database.table2 database > database_data.sql

Then, to load it into a new database:

mysql -u user -p newdatabase < database_structure.sql
mysql -u user -p newdatabase < database_data.sql

GIT: Checkout to a specific folder

Use git archive branch-index | tar -x -C your-folder-on-PC to clone a branch to another folder. I think, then you can copy any file that you need

Update using LINQ to SQL

LINQ is a query tool (Q = Query) - so there is no magic LINQ way to update just the single row, except through the (object-oriented) data-context (in the case of LINQ-to-SQL). To update data, you need to fetch it out, update the record, and submit the changes:

using(var ctx = new FooContext()) {
    var obj = ctx.Bars.Single(x=>x.Id == id);
    obj.SomeProp = 123;
    ctx.SubmitChanges();
}

Or write an SP that does the same in TSQL, and expose the SP through the data-context:

using(var ctx = new FooContext()) {
    ctx.UpdateBar(id, 123);
}

Get absolute path to workspace directory in Jenkins Pipeline plugin

Since version 2.5 of the Pipeline Nodes and Processes Plugin (a component of the Pipeline plugin, installed by default), the WORKSPACE environment variable is available again. This version was released on 2016-09-23, so it should be available on all up-to-date Jenkins instances.

Example

node('label'){
    // now you are on slave labeled with 'label'
    def workspace = WORKSPACE
    // ${workspace} will now contain an absolute path to job workspace on slave

    workspace = env.WORKSPACE
    // ${workspace} will still contain an absolute path to job workspace on slave

    // When using a GString at least later Jenkins versions could only handle the env.WORKSPACE variant:
    echo "Current workspace is ${env.WORKSPACE}"

    // the current Jenkins instances will support the short syntax, too:
    echo "Current workspace is $WORKSPACE"

}

Error: Java: invalid target release: 11 - IntelliJ IDEA

Just had same error. Problem was that I had empty package-info.java file. As soon as I added package name inside it worked...

What is the best way to determine a session variable is null or empty in C#?

That is pretty much how you do it. However, there is a shorter syntax you can use.

sSession = (string)Session["variable"] ?? "set this";

This is saying if the session variables is null, set sSession to "set this"

HTML select drop-down with an input field

You can use input text with "list" attribute, which refers to the datalist of values.

_x000D_
_x000D_
<input type="text" name="city" list="cityname">_x000D_
    <datalist id="cityname">_x000D_
      <option value="Boston">_x000D_
      <option value="Cambridge">_x000D_
    </datalist>
_x000D_
_x000D_
_x000D_

This creates a free text input field that also has a drop-down to select predefined choices. Attribution for example and more information: https://www.w3.org/wiki/HTML/Elements/datalist

Capture keyboardinterrupt in Python without try-except

If all you want is to not show the traceback, make your code like this:

## all your app logic here
def main():
   ## whatever your app does.


if __name__ == "__main__":
   try:
      main()
   except KeyboardInterrupt:
      # do nothing here
      pass

(Yes, I know that this doesn't directly answer the question, but it's not really clear why needing a try/except block is objectionable -- maybe this makes it less annoying to the OP)

javascript Unable to get property 'value' of undefined or null reference

The issue is how you're attempting to get the value. Things like...

if ( document.frm_new_user_request.u_isid.value == '' )

won't work. You need to find the element you want to get the value of first. It's not quite like a server side language where you can type in an object's reference name and a period to get or assign values.

document.getElementById('[id goes here]').value;

will work. Note: JavaScript is case-sensitive

I would recommend using:

var variablename = document.getElementById('[id goes here]');

or

var variablename = document.getElementById('[id goes here]').value;

Real world use of JMS/message queues?

I've had so many amazing uses for JMS:

  • Web chat communication for customer service.

  • Debug logging on the backend. All app servers broadcasted debug messages at various levels. A JMS client could then be launched to watch for debug messages. Sure I could've used something like syslog, but this gave me all sorts of ways to filter the output based on contextual information (e.q. by app server name, api call, log level, userid, message type, etc...). I also colorized the output.

  • Debug logging to file. Same as above, only specific pieces were pulled out using filters, and logged to file for general logging.

  • Alerting. Again, a similar setup to the above logging, watching for specific errors, and alerting people via various means (email, text message, IM, Growl pop-up...)

  • Dynamically configuring and controlling software clusters. Each app server would broadcast a "configure me" message, then a configuration daemon that would respond with a message containing all kinds of config info. Later, if all the app servers needed their configurations changed at once, it could be done from the config daemon.

  • And the usual - queued transactions for delayed activity such as billing, order processing, provisioning, email generation...

It's great anywhere you want to guarantee delivery of messages asynchronously.

What is syntax for selector in CSS for next element?

This is called the adjacent sibling selector, and it is represented by a plus sign...

h1.hc-reform + p {
  clear:both;
}

Note: this is not supported in IE6 or older.

Multiple REPLACE function in Oracle

Even if this thread is old is the first on Google, so I'll post an Oracle equivalent to the function implemented here, using regular expressions.

Is fairly faster than nested replace(), and much cleaner.

To replace strings 'a','b','c' with 'd' in a string column from a given table

select regexp_replace(string_col,'a|b|c','d') from given_table

It is nothing else than a regular expression for several static patterns with 'or' operator.

Beware of regexp special characters!

static const vs #define

Defining constants by using preprocessor directive #define is not recommended to apply not only in C++, but also in C. These constants will not have the type. Even in C was proposed to use const for constants.

Fastest check if row exists in PostgreSQL

Use the EXISTS key word for TRUE / FALSE return:

select exists(select 1 from contact where id=12)

notifyDataSetChanged not working on RecyclerView

Try this method:

List<Business> mBusinesses2 = mBusinesses;
mBusinesses.clear();
mBusinesses.addAll(mBusinesses2);
//and do the notification

a little time consuming, but it should work.