Programs & Examples On #Form helpers

How to use Simple Ajax Beginform in Asp.net MVC 4?

Simple example: Form with textbox and Search button.

If you write "name" into the textbox and submit form, it will brings you patients with "name" in table.

View:

@using (Ajax.BeginForm("GetPatients", "Patient", new AjaxOptions {//GetPatients is name of method in PatientController
    InsertionMode = InsertionMode.Replace, //target element(#patientList) will be replaced
    UpdateTargetId = "patientList",
    LoadingElementId = "loader" // div with .gif loader - that is shown when data are loading   
}))
{
    string patient_Name = "";
    @Html.EditorFor(x=>patient_Name) //text box with name and id, that it will pass to controller
    <input  type="submit" value="Search" />
}

@* ... *@
<div id="loader" class=" aletr" style="display:none">
    Loading...<img src="~/Images/ajax-loader.gif" />
</div>
@Html.Partial("_patientList") @* this is view with patient table. Same view you will return from controller *@

_patientList.cshtml:

@model IEnumerable<YourApp.Models.Patient>

<table id="patientList" >
<tr>
    <th>
        @Html.DisplayNameFor(model => model.Name)
    </th>
    <th>
        @Html.DisplayNameFor(model => model.Number)
    </th>       
</tr>
@foreach (var patient in Model) {
<tr>
    <td>
        @Html.DisplayFor(modelItem => patient.Name)
    </td>
    <td>
        @Html.DisplayFor(modelItem => patient.Number)
    </td>
</tr>
}
</table>

Patient.cs

public class Patient
{
   public string Name { get; set; }
   public int Number{ get; set; }
}

PatientController.cs

public PartialViewResult GetPatients(string patient_Name="")
{
   var patients = yourDBcontext.Patients.Where(x=>x.Name.Contains(patient_Name))
   return PartialView("_patientList", patients);
}

And also as TSmith said in comments, don´t forget to install jQuery Unobtrusive Ajax library through NuGet.

Extract regression coefficient values

The package broom comes in handy here (it uses the "tidy" format).

tidy(mg) will give a nicely formated data.frame with coefficients, t statistics etc. Works also for other models (e.g. plm, ...).

Example from broom's github repo:

lmfit <- lm(mpg ~ wt, mtcars)
require(broom)    
tidy(lmfit)

      term estimate std.error statistic   p.value
1 (Intercept)   37.285   1.8776    19.858 8.242e-19
2          wt   -5.344   0.5591    -9.559 1.294e-10

is.data.frame(tidy(lmfit))
[1] TRUE

How change List<T> data to IQueryable<T> data

var list = new List<string>();
var queryable = list.AsQueryable();

Add a reference to: System.Linq

How to run a cron job on every Monday, Wednesday and Friday?

Here's my example crontab I always use as a template:

    # Use the hash sign to prefix a comment
    # +---------------- minute (0 - 59)
    # |  +------------- hour (0 - 23)
    # |  |  +---------- day of month (1 - 31)
    # |  |  |  +------- month (1 - 12)
    # |  |  |  |  +---- day of week (0 - 7) (Sunday=0 or 7)
    # |  |  |  |  |
    # *  *  *  *  *  command to be executed
    #--------------------------------------------------------------------------

To run my cron job every Monday, Wednesady and Friday at 7:00PM, the result will be:

      0 19 * * 1,3,5 nohup /home/lathonez/script.sh > /tmp/script.log 2>&1

source

How to Turn Off Showing Whitespace Characters in Visual Studio IDE

CTRL+SHIFT+* is the de-facto standard key combination for showing/hiding whitespace characters in all Microsoft products that support this feature.

P.S: * refers to 8- * key, not to numeric keypad * key.

Multi-dimensional arrays in Bash

Bash does not supports multidimensional array, but we can implement using Associate array. Here the indexes are the key to retrieve the value. Associate array is available in bash version 4.

#!/bin/bash

declare -A arr2d
rows=3
columns=2

for ((i=0;i<rows;i++)) do
    for ((j=0;j<columns;j++)) do
        arr2d[$i,$j]=$i
    done
done


for ((i=0;i<rows;i++)) do
    for ((j=0;j<columns;j++)) do
        echo ${arr2d[$i,$j]}
    done
done

How do I disable the resizable property of a textarea?

You simply use: resize: none; in your CSS.

The resize property specifies whether or not an element is resizable by the user.

Note: The resize property applies to elements whose computed overflow value is something other than "visible".

Also resize not supported in Internet Explorer at the moment.

Here are different properties for resize:

No Resize:

textarea {
  resize: none;
}

Resize both ways (vertically & horizontally):

textarea {
  resize: both;
}

Resize vertically:

textarea {
  resize: vertical;
}

Resize horizontally:

textarea {
  resize: horizontal;
}

Also if you have width and height in your CSS or HTML, it will prevent your textarea be resized, with a broader browsers support.

iPhone and WireShark

I like to use Pirni (availble for free in Cydia on a jailbroken device), or there's also Pirni Pro now for a few bucks (http://en.wikipedia.org/wiki/Pirni). I've been using the pirni-derv script available for free on Google Code (http://code.google.com/p/pirni-derv/) mixed with Pirni and it's been working very well. I recommend it.

Stop floating divs from wrapping

For me (using bootstrap), only thing that worked was setting display:absolute;z-index:1 on the last cell.

Cannot use object of type stdClass as array?

To get an array as result from a json string you should set second param as boolean true.

$result = json_decode($json_string, true);
$context = $result['context'];

Otherwise $result will be an std object. but you can access values as object.

  $result = json_decode($json_string);
 $context = $result->context;

Reading/Writing a MS Word file in PHP

I don't know what you are going to use it for, but I needed .doc support for search indexing; What I did was use a little commandline tool called "catdoc"; This transfers the contents of the Word document to plain text so it can be indexed. If you need to keep formatting and stuff this is not your tool.

Are there constants in JavaScript?

in Javascript already exists constants. You define a constant like this:

const name1 = value;

This cannot change through reassignment.

jQuery Mobile how to check if button is disabled?

Faced with the same issue when trying to check if a button is disabled. I've tried a variety of approaches, such as btn.disabled, .is(':disabled'), .attr('disabled'), .prop('disabled'). But no one works for me.

Some, for example .disabled or .is(':disabled') returned undefined and other like .attr('disabled') returned the wrong result - false when the button was actually disabled.

But only one technique works for me: .is('[disabled]') (with square brackets).

So to determine if a button is disabled try this:

$("#myButton").is('[disabled]');

How do I format a date in Jinja2?

You can use it like this in jinja template {{ row.session_start_date_time.strftime('%d-%m-%Y %H:%M:%S')}}

In this code the field name is row.session_start_date_time.

Filtering by Multiple Specific Model Properties in AngularJS (in OR relationship)

You can pass an Object as the parameter to your filter expression, as described in the API Reference. This object can selectively apply the properties you're interested in, like so:

<input ng-model="search.name">
<input ng-model="search.phone">
<input ng-model="search.secret">
<tr ng-repeat="user in users | filter:{name: search.name, phone: search.phone}">

Here's a Plunker

Heads up...this example works great with AngularJS 1.1.5, but not always as well in 1.0.7. In this example 1.0.7 will initialize with everything filtered out, then work when you start using the inputs. It behaves like the inputs have non-matching values in them, even though they start out blank. If you want to stay on stable releases, go ahead and try this out for your situation, but some scenarios may want to use @maxisam's solution until 1.2.0 is released.

How do I enable logging for Spring Security?

Assuming you're using Spring Boot, another option is to put the following in your application.properties:

logging.level.org.springframework.security=DEBUG

This is the same for most other Spring modules as well.

If you're not using Spring Boot, try setting the property in your logging configuration, e.g. logback.

Here is the application.yml version as well:

logging:
  level:
    org:
      springframework:
        security: DEBUG

Writing a dictionary to a csv file with one line for every 'key: value'

Just to give an option, writing a dictionary to csv file could also be done with the pandas package. With the given example it could be something like this:

mydict = {'key1': 'a', 'key2': 'b', 'key3': 'c'}

import pandas as pd

(pd.DataFrame.from_dict(data=mydict, orient='index')
   .to_csv('dict_file.csv', header=False))

The main thing to take into account is to set the 'orient' parameter to 'index' inside the from_dict method. This lets you choose if you want to write each dictionary key in a new row.

Additionaly, inside the to_csv method the header parameter is set to False just to have only the dictionary elements without annoying rows. You can always set column and index names inside the to_csv method.

Your output would look like this:

key1,a
key2,b
key3,c

If instead you want the keys to be the column's names, just use the default 'orient' parameter that is 'columns', as you could check in the documentation links.

Avoid line break between html elements

If you need this for several words or elements, but can't apply it to a whole TD or similar, the Span tag can be used.

<span style="white-space: nowrap">Text to break together</span>
    or 
<span class=nobr>Text to break together</span>

If you use the class version, remember to set up the CSS as detailed in the accepted answer.

Ruby/Rails: converting a Date to a UNIX timestamp

I get the following when I try it:

>> Date.today.to_time.to_i
=> 1259244000
>> Time.now.to_i
=> 1259275709

The difference between these two numbers is due to the fact that Date does not store the hours, minutes or seconds of the current time. Converting a Date to a Time will result in that day, midnight.

How to: "Separate table rows with a line"

You have to use CSS.

In my opinion when you have a table often it is good with a separate line each side of the line.

Try this code:

HTML:

<table>
    <tr class="row"><td>row 1</td></tr>
    <tr class="row"><td>row 2</td></tr>
</table>

CSS:

.row {
    border:1px solid black; 
}

Bye

Andrea

How to set ChartJS Y axis title?

For me it works like this:

    options : {
      scales: {
        yAxes: [{
          scaleLabel: {
            display: true,
            labelString: 'probability'
          }
        }]
      }
    }

Choosing line type and color in Gnuplot 4.0

I've ran into this topic, because i was struggling with dashed lines too (gnuplot 4.6 patchlevel 0)

If you use:

set termoption dashed

Your posted code will work accordingly.

Related question:
However, if I want to export a png with: set terminal png, this isn't working anymore. Anyone got a clue why?

Turns out, out, gnuplots png export library doesnt support this.
Possbile solutions:

  • one can simply export to ps, then convert it with pstopng
  • according to @christoph, if you use pngcairo as your terminal (set terminal pngcairo) it will work

Angular2 router (@angular/router), how to set default route?

I faced same issue apply all possible solution but finally this solve my problem

export class AppRoutingModule {
constructor(private router: Router) {
    this.router.errorHandler = (error: any) => {
        this.router.navigate(['404']); // or redirect to default route
    }
  }
}

Hope this will help you.

Express.js Response Timeout

Before you set your routes, add the code:

app.all('*', function(req, res, next) {
    setTimeout(function() {
        next();
    }, 120000); // 120 seconds
});

Laravel Update Query

Try doing it like this.

User::where('email', $userEmail)
       ->update([
           'member_type' => $plan
        ]);

Concatenate String in String Objective-c

Variations on a theme:

NSString *varying = @"whatever it is";
NSString *final = [NSString stringWithFormat:@"first part %@ third part", varying];

NSString *varying = @"whatever it is";
NSString *final = [[@"first part" stringByAppendingString:varying] stringByAppendingString:@"second part"];

NSMutableString *final = [NSMutableString stringWithString:@"first part"];
[final appendFormat:@"%@ third part", varying];

NSMutableString *final = [NSMutableString stringWithString:@"first part"];
[final appendString:varying];
[final appendString:@"third part"];

MySQL compare now() (only date, not time) with a datetime field

Use DATE(NOW()) to compare dates

DATE(NOW()) will give you the date part of current date and DATE(duedate) will give you the date part of the due date. then you can easily compare the dates

So you can compare it like

DATE(NOW()) = DATE(duedate)

OR

DATE(duedate) = CURDATE() 

See here

Initializing a struct to 0

If the data is a static or global variable, it is zero-filled by default, so just declare it myStruct _m;

If the data is a local variable or a heap-allocated zone, clear it with memset like:

memset(&m, 0, sizeof(myStruct));

Current compilers (e.g. recent versions of gcc) optimize that quite well in practice. This works only if all zero values (include null pointers and floating point zero) are represented as all zero bits, which is true on all platforms I know about (but the C standard permits implementations where this is false; I know no such implementation).

You could perhaps code myStruct m = {}; or myStruct m = {0}; (even if the first member of myStruct is not a scalar).

My feeling is that using memset for local structures is the best, and it conveys better the fact that at runtime, something has to be done (while usually, global and static data can be understood as initialized at compile time, without any cost at runtime).

Explicitly select items from a list or tuple

>>> map(myList.__getitem__, (2,2,1,3))
('baz', 'baz', 'bar', 'quux')

You can also create your own List class which supports tuples as arguments to __getitem__ if you want to be able to do myList[(2,2,1,3)].

Unable to find velocity template resources

I have put this working code snippet for future references. The code sample was written with Apache velocity version 1.7 with embedded Jetty.

Velocity template path is located at the resource folder email_templates subfolder.

enter image description here

Code Snippet in Java (Snippets are worked both running on eclipse and inside a Jar)

    templateName = "/email_templates/byoa.tpl.vm"
    VelocityEngine ve = new VelocityEngine();
    ve.setProperty(RuntimeConstants.RESOURCE_LOADER, "classpath");
    ve.setProperty("classpath.resource.loader.class", ClasspathResourceLoader.class.getName());
    ve.init();
    Template t = ve.getTemplate(this.templateName);
    VelocityContext velocityContext = new VelocityContext();
    velocityContext.put("","") // put your template values here
    StringWriter writer = new StringWriter();
    t.merge(this.velocityContext, writer);

System.out.println(writer.toString()); // print the updated template as string

For OSGI plugging code snippets.

final String TEMPLATE = "resources/template.vm" // located in the resources folder
Thread current = Thread.currentThread();
       ClassLoader oldLoader = current.getContextClassLoader();
       try {
          current.setContextClassLoader(TemplateHelper.class.getClassLoader()); // TemplateHelper is a class inside your jar file
          Properties p = new Properties();
          p.setProperty("resource.loader", "class");
          p.setProperty("class.resource.loader.class", "org.apache.velocity.runtime.resource.loader.ClasspathResourceLoader");
          Velocity.init( p );       
          VelocityEngine ve = new VelocityEngine();
          Template template = Velocity.getTemplate( TEMPLATE );
          VelocityContext context = new VelocityContext();
          context.put("tc", obj);
          StringWriter writer = new StringWriter();
          template.merge( context, writer );
          return writer.toString() ;  
       }  catch(Exception e){
          e.printStackTrace();
       } finally {
          current.setContextClassLoader(oldLoader);
       }

How to gettext() of an element in Selenium Webdriver

You need to store it in a String variable first before displaying it like so:

String Txt = TxtBoxContent.getText();
System.out.println(Txt);

Delete a row in Excel VBA

Better yet, use union to grab all the rows you want to delete, then delete them all at once. The rows need not be continuous.

dim rng as range
dim rDel as range

for each rng in {the range you're searching}
   if {Conditions to be met} = true then
      if not rDel is nothing then
         set rDel = union(rng,rDel)
      else
         set rDel = rng
      end if
   end if
 next
 
 rDel.entirerow.delete

That way you don't have to worry about sorting or things being at the bottom.

VBA Go to last empty row

This does it:

Do
   c = c + 1
Loop While Cells(c, "A").Value <> ""

'prints the last empty row
Debug.Print c

Oracle TNS names not showing when adding new connection to SQL Developer

You can always find out the location of the tnsnames.ora file being used by running TNSPING to check connectivity (9i or later):

C:\>tnsping dev

TNS Ping Utility for 32-bit Windows: Version 10.2.0.1.0 - Production on 08-JAN-2009 12:48:38

Copyright (c) 1997, 2005, Oracle.  All rights reserved.

Used parameter files:
C:\oracle\product\10.2.0\client_1\NETWORK\ADMIN\sqlnet.ora


Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = XXX)(PORT = 1521)) (CONNECT_DATA = (SERVICE_NAME = DEV)))
OK (30 msec)

C:\>

Sometimes, the problem is with the entry you made in tnsnames.ora, not that the system can't find it. That said, I agree that having a tns_admin environment variable set is a Good Thing, since it avoids the inevitable issues that arise with determining exactly which tnsnames file is being used in systems with multiple oracle homes.

How do I change Eclipse to use spaces instead of tabs?

  • Click Window » Preferences
  • Expand Java » Code Style
  • Click Formatter
  • click new
  • Select the profile name
  • Click ok
  • Click the Edit button
  • Click the Indentation tab
  • Under General Settings, set Tab policy to: Spaces only
  • Click OK.

"date(): It is not safe to rely on the system's timezone settings..."

This answer above from CtrlX is the correct answer, but it may not work completely. I added this line to my php.ini file:

date.timezone = "America/Los_Angeles"

but it did not remove the PHP error for all my files because some of my PHP scripts are in subfolders. So I had to edit .htaccess file to setup php.ini to be used recursively (in subfolders):

suphp_configpath /home/account_name/public_html

where account_name is your cpanel account name and public_html is the folder your php.ini file is in.

Max size of an iOS application

As of June 2019, if your user's are on iOS 13 the cellular download limit has been lifted. User's just get a warning now. Read here

In case the article is removed here are screen shots of it below

enter image description here

enter image description here

enter image description here

How do you run a single test/spec file in RSpec?

The raw invocation:

rake spec SPEC=spec/controllers/sessions_controller_spec.rb \
          SPEC_OPTS="-e \"should log in with cookie\""

Now figure out how to embed this into your editor.

GitHub - List commits by author

Just add ?author=<emailaddress> or ?author=<githubUserName> to the url when viewing the "commits" section of a repo.

What is WEB-INF used for in a Java EE web application?

There is a convention (not necessary) of placing jsp pages under WEB-INF directory so that they cannot be deep linked or bookmarked to. This way all requests to jsp page must be directed through our application, so that user experience is guaranteed.

Maximum filename length in NTFS (Windows XP and Windows Vista)?

The length in NTFS is 255. The NameLength field in the NTFS $Filename attribute is a byte with no offset; this yields a range of 0-255.

The file name iself can be in different "namespaces". So far there are: POSIX, WIN32, DOS and (WIN32DOS - when a filename can be natively a DOS name). (Since the string has a length, it could contain \0 but that would yield to problems and is not in the namespaces above.)

Thus the name of a file or directory can be up to 255 characters. When specifying the full path under Windows, you need to prefix the path with \\?\ (or use \\?\UNC\server\share for UNC paths) to mark this path as an extended-length one (~32k characters). If your path is longer, you will have to set your working directory along the way (ugh - side effects due to the process-wide setting).

Change Timezone in Lumen or Laravel 5

Use php time zones from php manual Php time zones

For example mine i changed from the UTC value in config/app.php with

'timezone' => 'Africa/Nairobi',

What does functools.wraps do?

I very often use classes, rather than functions, for my decorators. I was having some trouble with this because an object won't have all the same attributes that are expected of a function. For example, an object won't have the attribute __name__. I had a specific issue with this that was pretty hard to trace where Django was reporting the error "object has no attribute '__name__'". Unfortunately, for class-style decorators, I don't believe that @wrap will do the job. I have instead created a base decorator class like so:

class DecBase(object):
    func = None

    def __init__(self, func):
        self.__func = func

    def __getattribute__(self, name):
        if name == "func":
            return super(DecBase, self).__getattribute__(name)

        return self.func.__getattribute__(name)

    def __setattr__(self, name, value):
        if name == "func":
            return super(DecBase, self).__setattr__(name, value)

        return self.func.__setattr__(name, value)

This class proxies all the attribute calls over to the function that is being decorated. So, you can now create a simple decorator that checks that 2 arguments are specified like so:

class process_login(DecBase):
    def __call__(self, *args):
        if len(args) != 2:
            raise Exception("You can only specify two arguments")

        return self.func(*args)

Copy a git repo without history

Deleting the .git folder is probably the easiest path since you don't want/need the history (as Stephan said).

So you can create a new repo from your latest commit: (How to clone seed/kick-start project without the whole history?)

git clone <git_url>

then delete .git, and afterwards run

git init

Or if you want to reuse your current repo: Make the current commit the only (initial) commit in a Git repository?

Follow the above steps then:

git add .
git commit -m "Initial commit"

Push to your repo.

git remote add origin <github-uri>
git push -u --force origin master

How can I read comma separated values from a text file in Java?

You can also use the java.util.Scanner class.

private static void readFileWithScanner() {
    File file = new File("path/to/your/file/file.txt");

    Scanner scan = null;

    try {
        scan = new Scanner(file);

        while (scan.hasNextLine()) {
            String line = scan.nextLine();
            String[] lineArray = line.split(",");
            // do something with lineArray, such as instantiate an object
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } finally {
        scan.close();
    }
}

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

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

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

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

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

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

.NET Format a string with fixed spaces

This will give you exactly the strings that you asked for:

string s = "String goes here";
string lineAlignedRight  = String.Format("{0,27}", s);
string lineAlignedCenter = String.Format("{0,-27}",
    String.Format("{0," + ((27 + s.Length) / 2).ToString() +  "}", s));
string lineAlignedLeft   = String.Format("{0,-27}", s);

How to get certain commit from GitHub project

Try the following command sequence:

$ git fetch origin <copy/past commit sha1 here>
$ git checkout FETCH_HEAD
$ git push origin master

Error ITMS-90717: "Invalid App Store Icon"

changed the icon from .png format to .jpg and everything went well.

How to embed a YouTube channel into a webpage

Seems like the accepted answer does not work anymore. I found the correct method from another post: https://stackoverflow.com/a/46811403/6368026

Now you should use:

http://www.youtube.com/embed/videoseries?list=USERID And the USERID is your youtube user id with 'UU' appended.

For example, if your user id is TlQ5niAIDsLdEHpQKQsupg then you should put UUTlQ5niAIDsLdEHpQKQsupg. If you only have the channel id (which you can find in your channel URL) then just replace the first two characters (UC) with UU.

So in the end you would have an URL like this:

http://www.youtube.com/embed/videoseries?list=UUTlQ5niAIDsLdEHpQKQsupg

Is this the right way to clean-up Fragment back stack when leaving a deeply nested stack?

I'm using a similar code as those that use the while loop but I call the entry count in every loop... so I suppose it's somewhat slower

FragmentManager manager = getFragmentManager();
while (manager.getBackStackEntryCount() > 0){
        manager.popBackStackImmediate();
    }

C#: How to make pressing enter in a text box trigger a button, yet still allow shortcuts such as "Ctrl+A" to get through?

If you want the return to trigger an action only when the user is in the textbox, you can assign the desired button the AcceptButton control, like this.

    private void textBox_Enter(object sender, EventArgs e)
    {
        ActiveForm.AcceptButton = Button1; // Button1 will be 'clicked' when user presses return
    }

    private void textBox_Leave(object sender, EventArgs e)
    {
        ActiveForm.AcceptButton = null; // remove "return" button behavior
    }

How do I prevent the padding property from changing width or height in CSS?

when I add the padding-left property, the width of the DIV changes to 220px

Yes, that is exactly according to the standards. That's how it's supposed to work.

Let's say I create another DIV named anotherdiv exactly the same as newdiv, and put it inside of newdiv but newdiv has no padding and anotherdiv has padding-left: 20px. I get the same thing, newdiv's width will be 220px;

No, newdiv will remain 200px wide.

textarea character limit

Try using jQuery to avoid cross browser compatibility problems...

$("textarea").keyup(function(){
    if($(this).text().length > 500){
        var text = $(this).text();
        $(this).text(text.substr(0, 500));   
    }
});

How to modify existing XML file with XmlDocument and XmlNode in C#

You need to do something like this:

// instantiate XmlDocument and load XML from file
XmlDocument doc = new XmlDocument();
doc.Load(@"D:\test.xml");

// get a list of nodes - in this case, I'm selecting all <AID> nodes under
// the <GroupAIDs> node - change to suit your needs
XmlNodeList aNodes = doc.SelectNodes("/Equipment/DataCollections/GroupAIDs/AID");

// loop through all AID nodes
foreach (XmlNode aNode in aNodes)
{
   // grab the "id" attribute
   XmlAttribute idAttribute = aNode.Attributes["id"];

   // check if that attribute even exists...
   if (idAttribute != null)
   {
      // if yes - read its current value
      string currentValue = idAttribute.Value;

      // here, you can now decide what to do - for demo purposes,
      // I just set the ID value to a fixed value if it was empty before
      if (string.IsNullOrEmpty(currentValue))
      {
         idAttribute.Value = "515";
      }
   }
}

// save the XmlDocument back to disk
doc.Save(@"D:\test2.xml");

How can I convert a string to a float in mysql?

This will convert to a numeric value without the need to cast or specify length or digits:

STRING_COL+0.0

If your column is an INT, can leave off the .0 to avoid decimals:

STRING_COL+0

In c# is there a method to find the max of 3 numbers?

Well, you can just call it twice:

int max3 = Math.Max(x, Math.Max(y, z));

If you find yourself doing this a lot, you could always write your own helper method... I would be happy enough seeing this in my code base once, but not regularly.

(Note that this is likely to be more efficient than Andrew's LINQ-based answer - but obviously the more elements you have the more appealing the LINQ approach is.)

EDIT: A "best of both worlds" approach might be to have a custom set of methods either way:

public static class MoreMath
{
    // This method only exists for consistency, so you can *always* call
    // MoreMath.Max instead of alternating between MoreMath.Max and Math.Max
    // depending on your argument count.
    public static int Max(int x, int y)
    {
        return Math.Max(x, y);
    }

    public static int Max(int x, int y, int z)
    {
        // Or inline it as x < y ? (y < z ? z : y) : (x < z ? z : x);
        // Time it before micro-optimizing though!
        return Math.Max(x, Math.Max(y, z));
    }

    public static int Max(int w, int x, int y, int z)
    {
        return Math.Max(w, Math.Max(x, Math.Max(y, z)));
    }

    public static int Max(params int[] values)
    {
        return Enumerable.Max(values);
    }
}

That way you can write MoreMath.Max(1, 2, 3) or MoreMath.Max(1, 2, 3, 4) without the overhead of array creation, but still write MoreMath.Max(1, 2, 3, 4, 5, 6) for nice readable and consistent code when you don't mind the overhead.

I personally find that more readable than the explicit array creation of the LINQ approach.

C++ catching all exceptions

try {
   // ...
} catch (...) {
   // ...
}

Note that the ... inside the catch is a real ellipsis, ie. three dots.

However, because C++ exceptions are not necessarily subclasses of a base Exception class, there isn't any way to actually see the exception variable that is thrown when using this construct.

How to call an async method from a getter or setter?

When I ran into this problem, trying to run an async method synchronicity from either a setter or a constructor got me into a deadlock on the UI thread, and using an event handler required too many changes in the general design.
The solution was, as often is, to just write explicitly what I wanted to happen implicitly, which was to have another thread handle the operation and to get the main thread to wait for it to finish:

string someValue=null;
var t = new Thread(() =>someValue = SomeAsyncMethod().Result);
t.Start();
t.Join();

You could argue that I abuse the framework, but it works.

How to generate a Dockerfile from an image?

This is derived from @fallino's answer, with some adjustments and simplifications by using the output format option for docker history. Since macOS and Gnu/Linux have different command-line utilities, a different version is necessary for Mac. If you only need one or the other, you can just use those lines.

#!/bin/bash
case "$OSTYPE" in
    linux*)
        docker history --no-trunc --format "{{.CreatedBy}}" $1 | # extract information from layers
        tac                                                    | # reverse the file
        sed 's,^\(|3.*\)\?/bin/\(ba\)\?sh -c,RUN,'             | # change /bin/(ba)?sh calls to RUN
        sed 's,^RUN #(nop) *,,'                                | # remove RUN #(nop) calls for ENV,LABEL...
        sed 's,  *&&  *, \\\n \&\& ,g'                           # pretty print multi command lines following Docker best practices
    ;;
    darwin*)
        docker history --no-trunc --format "{{.CreatedBy}}" $1 | # extract information from layers
        tail -r                                                | # reverse the file
        sed -E 's,^(\|3.*)?/bin/(ba)?sh -c,RUN,'               | # change /bin/(ba)?sh calls to RUN
        sed 's,^RUN #(nop) *,,'                                | # remove RUN #(nop) calls for ENV,LABEL...
        sed $'s,  *&&  *, \\\ \\\n \&\& ,g'                      # pretty print multi command lines following Docker best practices
    ;;
    *)
        echo "unknown OSTYPE: $OSTYPE"
    ;;
esac

What's the best way to get the current URL in Spring MVC?

If you need the URL till hostname and not the path use Apache's Common Lib StringUtil, and from URL extract the substring till third indexOf /.

public static String getURL(HttpServletRequest request){
   String fullURL = request.getRequestURL().toString();
   return fullURL.substring(0,StringUtils.ordinalIndexOf(fullURL, "/", 3)); 
}

Example: If fullURL is https://example.com/path/after/url/ then Output will be https://example.com

TypeError: window.initMap is not a function

turns out it has to do with ng-Route and the order of loading script wrote a directive and put the API script on top of everything works.

How do I divide so I get a decimal value?

Don't worry about it. In your code, just do the separate / and % operations as you mention, even though it might seem like it's inefficient. Let the JIT compiler worry about combining these operations to get both quotient and remainder in a single machine instruction (as far as I recall, it generally does).

Running an executable in Mac Terminal

To run an executable in mac

1). Move to the path of the file:

cd/PATH_OF_THE_FILE

2). Run the following command to set the file's executable bit using the chmod command:

chmod +x ./NAME_OF_THE_FILE

3). Run the following command to execute the file:

./NAME_OF_THE_FILE

Once you have run these commands, going ahead you just have to run command 3, while in the files path.

Accessing elements by type in javascript

In plain-old JavaScript you can do this:

var inputs = document.getElementsByTagName('input');

for(var i = 0; i < inputs.length; i++) {
    if(inputs[i].type.toLowerCase() == 'text') {
        alert(inputs[i].value);
    }
}

In jQuery, you would just do:

// select all inputs of type 'text' on the page
$("input:text")

// hide all text inputs which are descendants of div class="foo"
$("div.foo input:text").hide();

Execute command on all files in a directory

i think the simple solution is:

sh /dir/* > ./result.txt

remove double quotes from Json return data using Jquery

I dont think there is a need to replace any quotes, this is a perfectly formed JSON string, you just need to convert JSON string into object.This article perfectly explains the situation : Link

Example :

success: function (data) {

        // assuming that everything is correct and there is no exception being thrown
        // output string {"d":"{"username":"hi","email":"[email protected]","password":"123"}"}
        // now we need to remove the double quotes (as it will create problem and 
        // if double quotes aren't removed then this JSON string is useless)
        // The output string : {"d":"{"username":"hi","email":"[email protected]","password":"123"}"}
        // The required string : {"d":{username:"hi",email:"[email protected]",password:"123"}"}
        // For security reasons the d is added (indicating the return "data")
        // so actually we need to convert data.d into series of objects
        // Inbuilt function "JSON.Parse" will return streams of objects
        // JSON String : "{"username":"hi","email":"[email protected]","password":"123"}"
        console.log(data);                     // output  : Object {d="{"username":"hi","email":"[email protected]","password":"123"}"}
        console.log(data.d);                   // output : {"username":"hi","email":"[email protected]","password":"123"} (accessing what's stored in "d")
        console.log(data.d[0]);                // output : {  (just accessing the first element of array of "strings")
        var content = JSON.parse(data.d);      // output : Object {username:"hi",email:"[email protected]",password:"123"}" (correct)
        console.log(content.username);         // output : hi 
        var _name = content.username;
        alert(_name);                         // hi

}

How do you get the logical xor of two variables in Python?

  • Python logical or: A or B: returns A if bool(A) is True, otherwise returns B
  • Python logical and: A and B: returns A if bool(A) is False, otherwise returns B

To keep most of that way of thinking, my logical xor definintion would be:

def logical_xor(a, b):
    if bool(a) == bool(b):
        return False
    else:
        return a or b

That way it can return a, b, or False:

>>> logical_xor('this', 'that')
False
>>> logical_xor('', '')
False
>>> logical_xor('this', '')
'this'
>>> logical_xor('', 'that')
'that'

How to read a text file?

It depends on what you are trying to do.

file, err := os.Open("file.txt")
fmt.print(file)

The reason it outputs &{0xc082016240}, is because you are printing the pointer value of a file-descriptor (*os.File), not file-content. To obtain file-content, you may READ from a file-descriptor.


To read all file content(in bytes) to memory, ioutil.ReadAll

package main

import (
    "fmt"
    "io/ioutil"
    "os"
    "log"
)

func main() {
    file, err := os.Open("file.txt")
    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        if err = f.Close(); err != nil {
            log.Fatal(err)
        }
    }()


  b, err := ioutil.ReadAll(file)
  fmt.Print(b)
}

But sometimes, if the file size is big, it might be more memory-efficient to just read in chunks: buffer-size, hence you could use the implementation of io.Reader.Read from *os.File

func main() {
    file, err := os.Open("file.txt")
    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        if err = f.Close(); err != nil {
            log.Fatal(err)
        }
    }()


    buf := make([]byte, 32*1024) // define your buffer size here.

    for {
        n, err := file.Read(buf)

        if n > 0 {
            fmt.Print(buf[:n]) // your read buffer.
        }

        if err == io.EOF {
            break
        }
        if err != nil {
            log.Printf("read %d bytes: %v", n, err)
            break
        }
    }

}

Otherwise, you could also use the standard util package: bufio, try Scanner. A Scanner reads your file in tokens: separator.

By default, scanner advances the token by newline (of course you can customise how scanner should tokenise your file, learn from here the bufio test).

package main

import (
    "fmt"
    "os"
    "log"
    "bufio"
)

func main() {
    file, err := os.Open("file.txt")
    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        if err = f.Close(); err != nil {
            log.Fatal(err)
        }
    }()

    scanner := bufio.NewScanner(file)

    for scanner.Scan() {             // internally, it advances token based on sperator
        fmt.Println(scanner.Text())  // token in unicode-char
        fmt.Println(scanner.Bytes()) // token in bytes

    }
}

Lastly, I would also like to reference you to this awesome site: go-lang file cheatsheet. It encompassed pretty much everything related to working with files in go-lang, hope you'll find it useful.

What is the difference between "SMS Push" and "WAP Push"?

SMS Push uses SMS as a carrier, WAP uses download via WAP.

How to add items into a numpy array

np.insert can also be used for the purpose

import numpy as np
a = np.array([[1, 3, 4],
              [1, 2, 3],
              [1, 2, 1]])
x = 5
index = 3 # the position for x to be inserted before
np.insert(a, index, x, axis=1)
array([[1, 3, 4, 5],
       [1, 2, 3, 5],
       [1, 2, 1, 5]])

index can also be a list/tuple

>>> index = [1, 1, 3] # equivalently (1, 1, 3)
>>> np.insert(a, index, x, axis=1)
array([[1, 5, 5, 3, 4, 5],
       [1, 5, 5, 2, 3, 5],
       [1, 5, 5, 2, 1, 5]])

or a slice

>>> index = slice(0, 3)
>>> np.insert(a, index, x, axis=1)
array([[5, 1, 5, 3, 5, 4],
       [5, 1, 5, 2, 5, 3],
       [5, 1, 5, 2, 5, 1]])

How do I add a submodule to a sub-directory?

Note that starting git1.8.4 (July 2013), you wouldn't have to go back to the root directory anymore.

 cd ~/.janus/snipmate-snippets
 git submodule add <git@github ...> snippets

(Bouke Versteegh comments that you don't have to use /., as in snippets/.: snippets is enough)

See commit 091a6eb0feed820a43663ca63dc2bc0bb247bbae:

submodule: drop the top-level requirement

Use the new rev-parse --prefix option to process all paths given to the submodule command, dropping the requirement that it be run from the top-level of the repository.

Since the interpretation of a relative submodule URL depends on whether or not "remote.origin.url" is configured, explicitly block relative URLs in "git submodule add" when not at the top level of the working tree.

Signed-off-by: John Keeping

Depends on commit 12b9d32790b40bf3ea49134095619700191abf1f

This makes 'git rev-parse' behave as if it were invoked from the specified subdirectory of a repository, with the difference that any file paths which it prints are prefixed with the full path from the top of the working tree.

This is useful for shell scripts where we may want to cd to the top of the working tree but need to handle relative paths given by the user on the command line.

"if not exist" command in batch file

if not exist "%USERPROFILE%\.qgis-custom\" (
    mkdir "%USERPROFILE%\.qgis-custom" 2>nul
    if not errorlevel 1 (
        xcopy "%OSGEO4W_ROOT%\qgisconfig" "%USERPROFILE%\.qgis-custom" /s /v /e
    )
)

You have it almost done. The logic is correct, just some little changes.

This code checks for the existence of the folder (see the ending backslash, just to differentiate a folder from a file with the same name).

If it does not exist then it is created and creation status is checked. If a file with the same name exists or you have no rights to create the folder, it will fail.

If everyting is ok, files are copied.

All paths are quoted to avoid problems with spaces.

It can be simplified (just less code, it does not mean it is better). Another option is to always try to create the folder. If there are no errors, then copy the files

mkdir "%USERPROFILE%\.qgis-custom" 2>nul 
if not errorlevel 1 (
    xcopy "%OSGEO4W_ROOT%\qgisconfig" "%USERPROFILE%\.qgis-custom" /s /v /e
)

In both code samples, files are not copied if the folder is not being created during the script execution.

EDITED - As dbenham comments, the same code can be written as a single line

md "%USERPROFILE%\.qgis-custom" 2>nul && xcopy "%OSGEO4W_ROOT%\qgisconfig" "%USERPROFILE%\.qgis-custom" /s /v /e

The code after the && will only be executed if the previous command does not set errorlevel. If mkdir fails, xcopy is not executed.

Fixing the order of facets in ggplot

Make your size a factor in your dataframe by:

temp$size_f = factor(temp$size, levels=c('50%','100%','150%','200%'))

Then change the facet_grid(.~size) to facet_grid(.~size_f)

Then plot: enter image description here

The graphs are now in the correct order.

Forcing to download a file using PHP

Or you can do this using HTML5. Simply with

<a href="example.csv" download>download not open it</a>

vbscript output to console

You only need to force cscript instead wscript. I always use this template. The function ForceConsole() will execute your vbs into cscript, also you have nice alias to print and scan text.

 Set oWSH = CreateObject("WScript.Shell")
 vbsInterpreter = "cscript.exe"

 Call ForceConsole()

 Function printf(txt)
    WScript.StdOut.WriteLine txt
 End Function

 Function printl(txt)
    WScript.StdOut.Write txt
 End Function

 Function scanf()
    scanf = LCase(WScript.StdIn.ReadLine)
 End Function

 Function wait(n)
    WScript.Sleep Int(n * 1000)
 End Function

 Function ForceConsole()
    If InStr(LCase(WScript.FullName), vbsInterpreter) = 0 Then
        oWSH.Run vbsInterpreter & " //NoLogo " & Chr(34) & WScript.ScriptFullName & Chr(34)
        WScript.Quit
    End If
 End Function

 Function cls()
    For i = 1 To 50
        printf ""
    Next
 End Function

 printf " _____ _ _           _____         _    _____         _     _   "
 printf "|  _  |_| |_ ___ ___|     |_ _ _ _| |  |   __|___ ___|_|___| |_ "
 printf "|     | | '_| . |   |   --| | | | . |  |__   |  _|  _| | . |  _|"
 printf "|__|__|_|_,_|___|_|_|_____|_____|___|  |_____|___|_| |_|  _|_|  "
 printf "                                                       |_|     v1.0"
 printl " Enter your name:"
 MyVar = scanf
 cls
 printf "Your name is: " & MyVar
 wait(5)

How to get Spinner value?

If you already know the item is a String, I prefer:

String itemText = (String) mySpinner.getSelectedItem();

Calling toString() on an Object that you know is a String seems like a more roundabout path than just casting the Object to String.

Create a directory if it doesn't exist

Use CreateDirectory (char *DirName, SECURITY_ATTRIBUTES Attribs);

If the function succeeds it returns non-zero otherwise NULL.

How do I close a single buffer (out of many) in Vim?

Rather than browse the ouput of the :ls command and delete (unload, wipe..) a buffer by specifying its number, I find that using file names is often more effective.

For instance, after I opened a couple of .txt file to refresh my memories of some fine point.. copy and paste a few lines of text to use as a template of sorts.. etc. I would type the following:

:bd txt <Tab>

Note that the matching string does not have to be at the start of the file name.

The above displays the list of file names that match 'txt' at the bottom of the screen and keeps the :bd command I initially typed untouched, ready to be completed.

Here's an example:

doc1.txt doc2.txt
:bd txt 

I could backspace over the 'txt' bit and type in the file name I wish to delete, but where this becomes really convenient is that I don't have to: if I hit the Tab key a second time, Vim automatically completes my command with the first match:

:bd doc1.txt

If I want to get rid of this particular buffer I just need to hit Enter.

And if the buffer I want to delete happens to be the second (third.. etc.) match, I only need to keep hitting the Tab key to make my :bd command cycle through the list of matches.

Naturally, this method can also be used to switch to a given buffer via such commands as :b.. :sb.. etc.

This approach is particularly useful when the 'hidden' Vim option is set, because the buffer list can quickly become quite large, covering several screens, and making it difficult to spot the particular buffer I am looking for.

To make the most of this feature, it's probably best to read the following Vim help file and tweak the behavior of Tab command-line completion accordingly so that it best suits your workflow:

:help wildmode

The behavior I described above results from the following setting, which I chose for consistency's sake in order to emulate bash completion:

:set wildmode=list:longest,full

As opposed to using buffer numbers, the merit of this approach is that I usually remember at least part of a given file name letting me target the buffer directly rather than having to first look up its number via the :ls command.

Ant if else condition?

The quirky syntax using conditions on the target (described by Mads) is the only supported way to perform conditional execution in core ANT.

ANT is not a programming language and when things get complicated I choose to embed a script within my build as follows:

<target name="prepare-copy" description="copy file based on condition">
    <groovy>
        if (properties["some.condition"] == "true") {
            ant.copy(file:"${properties["some.dir"]}/true", todir:".")
        }
    </groovy>
</target>

ANT supports several languages (See script task), my preference is Groovy because of it's terse syntax and because it plays so well with the build.

Apologies, David I am not a fan of ant-contrib.

Can I call a base class's virtual function if I'm overriding it?

Just in case you do this for a lot of functions in your class:

class Foo {
public:
  virtual void f1() {
    // ...
  }
  virtual void f2() {
    // ...
  }
  //...
};

class Bar : public Foo {
private:
  typedef Foo super;
public:
  void f1() {
    super::f1();
  }
};

This might save a bit of writing if you want to rename Foo.

Passing vector by reference

You can pass vector by reference just like this:

void do_something(int el, std::vector<int> &arr){
    arr.push_back(el);
}

However, note that this function would always add a new element at the back of the vector, whereas your array function actually modifies the first element (or initializes it value).

In order to achieve exactly the same result you should write:

void do_something(int el, std::vector<int> &arr){
    if (arr.size() == 0) { // can't modify value of non-existent element
        arr.push_back(el);
    } else {
        arr[0] = el;
    }
}

In this way you either add the first element (if the vector is empty) or modify its value (if there first element already exists).

Remove spaces from a string in VB.NET

What about Regex.Replace solution?

myStr = Regex.Replace(myStr, "\s", "")

What Process is using all of my disk IO

You're looking for iotop (assuming you've got kernel >2.6.20 and Python 2.5). Failing that, you're looking into hooking into the filesystem. I recommend the former.

java.lang.ClassNotFoundException: com.sun.jersey.spi.container.servlet.ServletContainer

It basically depends on which version jersey you are using. If you are using Jersey ver.1.X.X you need to add

Jersey 1 uses "com.sun.jersey", and Jersey 2 uses org.glassfish. on servlet class tag. Also, note that also init-param starting with com.sun.jersey won't be recognized by Jersey 2.

And Add all the jar file into WEB-INF lib folder

Elasticsearch error: cluster_block_exception [FORBIDDEN/12/index read-only / allow delete (api)], flood stage disk watermark exceeded

Only changing the settings with the following command did not work in my environment:

curl -XPUT -H "Content-Type: application/json" http://localhost:9200/_all/_settings -d '{"index.blocks.read_only_allow_delete": null}'

I had to also ran the Force Merge API command:

curl -X POST "localhost:9200/my-index-000001/_forcemerge?pretty"

ref: Force Merge API

TypeScript for ... of with index / key?

"Old school javascript" to the rescue (for those who aren't familiar/in love of functional programming)

for (let i = 0; i < someArray.length ; i++) {
  let item = someArray[i];
}

jQuery using append with effects

Why don't you simply hide, append, then show, like this:

<div id="parent1" style="  width: 300px; height: 300px; background-color: yellow;">
    <div id="child" style=" width: 100px; height: 100px; background-color: red;"></div>
</div>


<div id="parent2" style="  width: 300px; height: 300px; background-color: green;">
</div>

<input id="mybutton" type="button" value="move">

<script>
    $("#mybutton").click(function(){
        $('#child').hide(1000, function(){
            $('#parent2').append($('#child'));
            $('#child').show(1000);
        });

    });
</script>

How to convert <font size="10"> to px?

Using the data points from the accepted answer you can use polynomial interpolation to obtain a formula.

WolframAlpha Input: interpolating polynomial {{1,.63},{2,.82}, {3,1}, {4,1.13}, {5,1.5}, {6, 2}, {7,3}}

Formula: 0.00223611x^6 - 0.0530417x^5 + 0.496319x^4 - 2.30479x^3 + 5.51644x^2 - 6.16717x + 3.14

And use in Groovy code:

import java.math.*
def convert = {x -> (0.00223611*x**6 - 0.053042*x**5 + 0.49632*x**4 - 2.30479*x**3 + 5.5164*x**2 - 6.167*x + 3.14).setScale(2, RoundingMode.HALF_UP) }
(1..7).each { i -> println(convert(i)) }

Markdown open a new window link

It is very dependent of the engine that you use for generating html files. If you are using Hugo for generating htmls you have to write down like this:

<a href="https://example.com" target="_blank" rel="noopener"><span>Example Text</span> </a>.

If/else else if in Jquery for a condition

If statement for images in jquery:
#html

<button id="chain">Chain</button>
<img src="bulb_on.jpg" alt="img" id="img"/>

#script
    <script>
        $(document).ready(function(){
            $("#chain").click(function(){
            if($("#img").attr('src')!='bulb_on.jpg'){
                $("#img").attr('src', 'bulb_on.jpg');
            }
            else
            {
                $("#img").attr('src', 'bulb_onn.jpg');
            }
            });
        });
    </script>

Plotting in a non-blocking way with Matplotlib

The Python package drawnow allows to update a plot in real time in a non blocking way.
It also works with a webcam and OpenCV for example to plot measures for each frame.
See the original post.

Conditionally ignoring tests in JUnit 4

A quick note: Assume.assumeTrue(condition) ignores rest of the steps but passes the test. To fail the test, use org.junit.Assert.fail() inside the conditional statement. Works same like Assume.assumeTrue() but fails the test.

Get selected item value from Bootstrap DropDown with specific ID

$('#demolist li').on('click', function(){
    $('#datebox').val($(this).text());
});

http://jsfiddle.net/kcpma/18/

What is stdClass in PHP?

Likewise,

$myNewObj->setNewVar = 'newVal'; 

yields a stdClass object - auto casted

I found this out today by misspelling:

$GLOBASLS['myObj']->myPropertyObj->myProperty = 'myVal';

Cool!

What is the difference between git pull and git fetch + git rebase?

It should be pretty obvious from your question that you're actually just asking about the difference between git merge and git rebase.

So let's suppose you're in the common case - you've done some work on your master branch, and you pull from origin's, which also has done some work. After the fetch, things look like this:

- o - o - o - H - A - B - C (master)
               \
                P - Q - R (origin/master)

If you merge at this point (the default behavior of git pull), assuming there aren't any conflicts, you end up with this:

- o - o - o - H - A - B - C - X (master)
               \             /
                P - Q - R --- (origin/master)

If on the other hand you did the appropriate rebase, you'd end up with this:

- o - o - o - H - P - Q - R - A' - B' - C' (master)
                          |
                          (origin/master)

The content of your work tree should end up the same in both cases; you've just created a different history leading up to it. The rebase rewrites your history, making it look as if you had committed on top of origin's new master branch (R), instead of where you originally committed (H). You should never use the rebase approach if someone else has already pulled from your master branch.

Finally, note that you can actually set up git pull for a given branch to use rebase instead of merge by setting the config parameter branch.<name>.rebase to true. You can also do this for a single pull using git pull --rebase.

How to tell if homebrew is installed on Mac OS X

brew -v or brew --version does the trick!

How to clear browsing history using JavaScript?

You cannot clear the browser history. It belongs to the user, not the developer. Also have a look at the MDN documentation.

Update: The link you were posting all over does not actually clear your browser history. It just prevents using the back button.

How do you reset the stored credentials in 'git credential-osxkeychain'?

On Mac, use the command git credential-osxkeychain erase.

OR remove manually from keychain from Applications ? Utilities ? Keychain Access. Then remove the github.com keychain. Then use push; it will ask for the keychain access; then deny.

It will ask for the new username and password, add it then pushes a file for that.

After git push I found this error. Then I use the upper case- issue:

remote: Permission to user1/file.git denied to user2(previously exist user ). fatal: unable to access 'https://github.com/xxxxxxxxxxxx/': The requested URL returned error: 403

How to set the font style to bold, italic and underlined in an Android TextView?

Without quotes works for me:

<item name="android:textStyle">bold|italic</item>

print spaces with String.format()

int numberOfSpaces = 3;
String space = String.format("%"+ numberOfSpaces +"s", " ");

Use of #pragma in C

All answers above make nice explanations for #pragma but I wanted to a add small example

I just want to explain a simple OpenMP example that demonstrate some uses of #pragma to doing its work

OpenMp briefly is an implementation for multi-platform shared-memory parallel programming (then we can say it's machine-specific or operating-system-specific)

let's go to the example

#include <stdio.h>
#include <omp.h>// compile with: /openmp

int main() {
   #pragma omp parallel num_threads(4)
   {
      int i = omp_get_thread_num();
      printf_s("Hello from thread %d\n", i);
   }
}

the output is

Hello from thread 0
Hello from thread 1
Hello from thread 2
Hello from thread 3

Note that the order of output can vary on different machines.

now let me tell you what #pragma did...

it tells the OS to run the some block of code on 4 threads

this is just one of many many applications you can do with the little #pragma

sorry for the outside sample OpenMP

Convert a python UTC datetime to a local datetime using only python standard library?

A simple (but maybe flawed) way that works in Python 2 and 3:

import time
import datetime

def utc_to_local(dt):
    return dt - datetime.timedelta(seconds = time.timezone)

Its advantage is that it's trivial to write an inverse function

Get a DataTable Columns DataType

dt.Columns[0].DataType.Name.ToString()

Run / Open VSCode from Mac Terminal

add below snipped in your bash profile -

PATH="/Library/Frameworks/Python.framework/Versions/3.6/bin:${PATH}"
code () { VSCODE_CWD="$PWD" open -n -b "com.microsoft.VSCode" --args $* ;}

Algorithm to find all Latitude Longitude locations within a certain distance from a given Lat Lng location

PostgreSQL GIS extensions might be helpful - as in, it may already implement much of the functionality you are thinking of implementing.

Can JavaScript connect with MySQL?

I think you would need to add something like PHP into the equation. PHP to interact with the database and then you could make AJAX calls with Javascript.

Can you Run Xcode in Linux?

If you cannot shell out thousands of dollars for a decent Mac then there is an option to run OSX and XCode in the cloud:

http://www.macincloud.com/

How to Parse JSON Array with Gson

Type listType = new TypeToken<List<Post>>() {}.getType();
List<Post> posts = new Gson().fromJson(jsonOutput.toString(), listType);

Maven – Always download sources and javadocs

In my case the "settings.xml" solution didn't work so I use this command in order to download all the sources:

mvn dependency:sources

You also can use it with other maven commands, for example:

mvn clean install dependency:sources -Dmaven.test.skip=true

To download all documentation, use the following command:

mvn dependency:resolve -Dclassifier=javadoc

jQuery - Getting form values for ajax POST

$("#registerSubmit").serialize() // returns all the data in your form
$.ajax({
     type: "POST",
     url: 'your url',
     data: $("#registerSubmit").serialize(),
     success: function() {
          //success message mybe...
     }
});

Node.js quick file server (static files over HTTP)

If you do not want to use ready tool, you can use the code below, as demonstrated by me at https://developer.mozilla.org/en-US/docs/Node_server_without_framework:

var http = require('http');
var fs = require('fs');
var path = require('path');

http.createServer(function (request, response) {
    console.log('request starting...');

    var filePath = '.' + request.url;
    if (filePath == './')
        filePath = './index.html';

    var extname = path.extname(filePath);
    var contentType = 'text/html';
    switch (extname) {
        case '.js':
            contentType = 'text/javascript';
            break;
        case '.css':
            contentType = 'text/css';
            break;
        case '.json':
            contentType = 'application/json';
            break;
        case '.png':
            contentType = 'image/png';
            break;      
        case '.jpg':
            contentType = 'image/jpg';
            break;
        case '.wav':
            contentType = 'audio/wav';
            break;
    }

    fs.readFile(filePath, function(error, content) {
        if (error) {
            if(error.code == 'ENOENT'){
                fs.readFile('./404.html', function(error, content) {
                    response.writeHead(200, { 'Content-Type': contentType });
                    response.end(content, 'utf-8');
                });
            }
            else {
                response.writeHead(500);
                response.end('Sorry, check with the site admin for error: '+error.code+' ..\n');
                response.end(); 
            }
        }
        else {
            response.writeHead(200, { 'Content-Type': contentType });
            response.end(content, 'utf-8');
        }
    });

}).listen(8125);
console.log('Server running at http://127.0.0.1:8125/');

UPDATE If you need to access your server from external demand/file, you need to overcome the CORS, in your node.js file by writing the below, as I mentioned in a previous answer here

// Website you wish to allow to connect
response.setHeader('Access-Control-Allow-Origin', '*');

// Request methods you wish to allow
response.setHeader('Access-Control-Allow-Methods', 'GET, POST, OPTIONS, PUT, PATCH, DELETE');

// Request headers you wish to allow
response.setHeader('Access-Control-Allow-Headers', 'X-Requested-With,content-type');

// Set to true if you need the website to include cookies in the requests sent
// to the API (e.g. in case you use sessions)
response.setHeader('Access-Control-Allow-Credentials', true);

UPDATE

As Adrian mentioned, in the comments, he wrote an ES6 code with full explanation here, I just re-posting his code below, in case the code gone from the original site for any reason:

const http = require('http');
const url = require('url');
const fs = require('fs');
const path = require('path');
const port = process.argv[2] || 9000;

http.createServer(function (req, res) {
  console.log(`${req.method} ${req.url}`);

  // parse URL
  const parsedUrl = url.parse(req.url);
  // extract URL path
  let pathname = `.${parsedUrl.pathname}`;
  // based on the URL path, extract the file extention. e.g. .js, .doc, ...
  const ext = path.parse(pathname).ext;
  // maps file extention to MIME typere
  const map = {
    '.ico': 'image/x-icon',
    '.html': 'text/html',
    '.js': 'text/javascript',
    '.json': 'application/json',
    '.css': 'text/css',
    '.png': 'image/png',
    '.jpg': 'image/jpeg',
    '.wav': 'audio/wav',
    '.mp3': 'audio/mpeg',
    '.svg': 'image/svg+xml',
    '.pdf': 'application/pdf',
    '.doc': 'application/msword'
  };

  fs.exists(pathname, function (exist) {
    if(!exist) {
      // if the file is not found, return 404
      res.statusCode = 404;
      res.end(`File ${pathname} not found!`);
      return;
    }

    // if is a directory search for index file matching the extention
    if (fs.statSync(pathname).isDirectory()) pathname += '/index' + ext;

    // read file from file system
    fs.readFile(pathname, function(err, data){
      if(err){
        res.statusCode = 500;
        res.end(`Error getting the file: ${err}.`);
      } else {
        // if the file is found, set Content-type and send data
        res.setHeader('Content-type', map[ext] || 'text/plain' );
        res.end(data);
      }
    });
  });


}).listen(parseInt(port));

console.log(`Server listening on port ${port}`);

Convert a string to integer with decimal in Python

What sort of rounding behavior do you want? Do you 2.67 to turn into 3, or 2. If you want to use rounding, try this:

s = '234.67'
i = int(round(float(s)))

Otherwise, just do:

s = '234.67'
i = int(float(s))

Conditionally formatting cells if their value equals any value of another column

Here is the formula

create a new rule in conditional formating based on a formula. Use the following formula and apply it to $A:$A

=NOT(ISERROR(MATCH(A1,$B$1:$B$1000,0)))


enter image description here

here is the example sheet to download if you encounter problems


UPDATE
here is @pnuts's suggestion which works perfect as well:

=MATCH(A1,B:B,0)>0


Cannot find runtime 'node' on PATH - Visual Studio Code and Node.js

This is the solution according to the VS code debugging page. This worked for my setup on Windows 10.

"version": "0.2.0",
"configurations": [
{
    "type": "node",
    "request": "launch",
    "name": "Launch Program",
    "program": "${file}"
}

The solution is here:

https://code.visualstudio.com/docs/editor/debugging

Here is the launch configuration generated for Node.js debugging

$(document).ready shorthand

These specific lines are the usual wrapper for jQuery plugins:

"...to make sure that your plugin doesn't collide with other libraries that might use the dollar sign, it's a best practice to pass jQuery to a self executing function (closure) that maps it to the dollar sign so it can't be overwritten by another library in the scope of its execution."

(function( $ ){
  $.fn.myPlugin = function() {
    // Do your awesome plugin stuff here
  };
})( jQuery );

From http://docs.jquery.com/Plugins/Authoring

jquery json to string?

I use

$.param(jsonObj)

which gets me the string.

Make div 100% Width of Browser Window

If width:100% works in any cases, just use that, otherwise you can use vw in this case which is relative to 1% of the width of the viewport.

That means if you want to cover off the width, just use 100vw.

Look at the image I draw for you here:

enter image description here

Try the snippet I created for you as below:

_x000D_
_x000D_
.full-width {_x000D_
  width: 100vw;_x000D_
  height: 100px;_x000D_
  margin-bottom: 40px;_x000D_
  background-color: red;_x000D_
}_x000D_
_x000D_
.one-vw-width {_x000D_
  width: 1vw;_x000D_
  height: 100px;_x000D_
  background-color: red;_x000D_
}
_x000D_
<div class="full-width"></div>_x000D_
<div class="one-vw-width"></div>
_x000D_
_x000D_
_x000D_

SOAP request in PHP with CURL

Tested and working!

  • with https, user & password

     <?php 
     //Data, connection, auth
     $dataFromTheForm = $_POST['fieldName']; // request data from the form
     $soapUrl = "https://connecting.website.com/soap.asmx?op=DoSomething"; // asmx URL of WSDL
     $soapUser = "username";  //  username
     $soapPassword = "password"; // password
    
     // xml post structure
    
     $xml_post_string = '<?xml version="1.0" encoding="utf-8"?>
                         <soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
                           <soap:Body>
                             <GetItemPrice xmlns="http://connecting.website.com/WSDL_Service"> // xmlns value to be set to your WSDL URL
                               <PRICE>'.$dataFromTheForm.'</PRICE> 
                             </GetItemPrice >
                           </soap:Body>
                         </soap:Envelope>';   // data from the form, e.g. some ID number
    
        $headers = array(
                     "Content-type: text/xml;charset=\"utf-8\"",
                     "Accept: text/xml",
                     "Cache-Control: no-cache",
                     "Pragma: no-cache",
                     "SOAPAction: http://connecting.website.com/WSDL_Service/GetPrice", 
                     "Content-length: ".strlen($xml_post_string),
                 ); //SOAPAction: your op URL
    
         $url = $soapUrl;
    
         // PHP cURL  for https connection with auth
         $ch = curl_init();
         curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 1);
         curl_setopt($ch, CURLOPT_URL, $url);
         curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
         curl_setopt($ch, CURLOPT_USERPWD, $soapUser.":".$soapPassword); // username and password - declared at the top of the doc
         curl_setopt($ch, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
         curl_setopt($ch, CURLOPT_TIMEOUT, 10);
         curl_setopt($ch, CURLOPT_POST, true);
         curl_setopt($ch, CURLOPT_POSTFIELDS, $xml_post_string); // the SOAP request
         curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
    
         // converting
         $response = curl_exec($ch); 
         curl_close($ch);
    
         // converting
         $response1 = str_replace("<soap:Body>","",$response);
         $response2 = str_replace("</soap:Body>","",$response1);
    
         // convertingc to XML
         $parser = simplexml_load_string($response2);
         // user $parser to get your data out of XML response and to display it. 
     ?>
    

Swift's guard keyword

One benefit is elimination a lot of nested if let statements. See the WWDC "What's New in Swift" video around 15:30, the section titled "Pyramid of Doom".

How can I stop float left?

You could modify .adm and add

.adm{
 clear:both;
}

That should make it move to a new line

Error - is not marked as serializable

You need to add a Serializable attribute to the class which you want to serialize.

[Serializable]
public class OrgPermission

mongoError: Topology was destroyed

In my case, this error was caused by an identical server instance already running background.

The weird thing is when I started my server without notice there's one running already, the console didn't show anything like 'something is using port xxx'. I could even upload something to the server. So, it took me quite long to locate this problem.

What's more, after closing all the applications I can imagine, I still could not find the process which is using this port in my Mac's activity monitor. I have to use lsof to trace. The culprit was not surprising - it's a node process. However, with the PID shown in the terminal, I found the port number in the monitor is different from the one used by my server.

All in all, kill all the node processes may solve this problem directly.

SFTP Libraries for .NET

Check this out: http://www.tamirgal.com/home/dev.aspx?Item=sharpSsh

SharpSSH is a pure .NET implementation of the SSH2 client protocol suite. It provides an API for communication with SSH servers and can be integrated into any .NET application.

The library is a C# port of the JSch project from JCraft Inc. and is released under BSD style license.

SharpSSH allows you to read/write data and transfer files over SSH channels using an API similar to JSch's API. In addition, it provides some additional wrapper classes which offer even simpler abstraction for SSH communication.

SharpSSH project page at source forge: http://sourceforge.net/projects/sharpssh

Decode JSON with unknown structure

package main

import "encoding/json"

func main() {
    in := []byte(`{ "votes": { "option_A": "3" } }`)
    var raw map[string]interface{}
    if err := json.Unmarshal(in, &raw); err != nil {
        panic(err)
    }
    raw["count"] = 1
    out, err := json.Marshal(raw)
    if err != nil {
        panic(err)
    }
    println(string(out))
}

https://play.golang.org/p/o8ZwvgsQmoO

Using Javascript's atob to decode base64 doesn't properly decode utf-8 strings

including above solution if still facing issue try as below, Considerign the case where escape is not supported for TS.

blob = new Blob(["\ufeff", csv_content]); // this will make symbols to appears in excel 

for csv_content you can try like below.

function b64DecodeUnicode(str: any) {        
        return decodeURIComponent(atob(str).split('').map((c: any) => {
            return '%' + ('00' + c.charCodeAt(0).toString(16)).slice(-2);
        }).join(''));
    }

Protecting cells in Excel but allow these to be modified by VBA script

You can modify a sheet via code by taking these actions

  • Unprotect
  • Modify
  • Protect

In code this would be:

Sub UnProtect_Modify_Protect()

  ThisWorkbook.Worksheets("Sheet1").Unprotect Password:="Password"
'Unprotect

  ThisWorkbook.ActiveSheet.Range("A1").FormulaR1C1 = "Changed"
'Modify

  ThisWorkbook.Worksheets("Sheet1").Protect Password:="Password"
'Protect

End Sub

The weakness of this method is that if the code is interrupted and error handling does not capture it, the worksheet could be left in an unprotected state.

The code could be improved by taking these actions

  • Re-protect
  • Modify

The code to do this would be:

Sub Re-Protect_Modify()

ThisWorkbook.Worksheets("Sheet1").Protect Password:="Password", _
 UserInterfaceOnly:=True
'Protect, even if already protected

  ThisWorkbook.ActiveSheet.Range("A1").FormulaR1C1 = "Changed"
'Modify

End Sub

This code renews the protection on the worksheet, but with the ‘UserInterfaceOnly’ set to true. This allows VBA code to modify the worksheet, while keeping the worksheet protected from user input via the UI, even if execution is interrupted.

This setting is lost when the workbook is closed and re-opened. The worksheet protection is still maintained.

So the 'Re-protection' code needs to be included at the start of any procedure that attempts to modify the worksheet or can just be run once when the workbook is opened.

Can you have multiline HTML5 placeholder text in a <textarea>?

There is actual a hack which makes it possible to add multiline placeholders in Webkit browsers, Chrome used to work but in more recent versions they removed it:


First add the first line of your placeholder to the html5 as usual

<textarea id="text1" placeholder="Line 1" rows="10"></textarea>

then add the rest of the line by css:

#text1::-webkit-input-placeholder::after {
    display:block;
    content:"Line 2\A Line 3";
}

If you want to keep your lines at one place you can try the following. The downside of this is that other browsers than chrome, safari, webkit-etc. don't even show the first line:

<textarea id="text2" placeholder="." rows="10"></textarea>?

then add the rest of the line by css:

#text2::-webkit-input-placeholder{
    color:transparent;
}

#text2::-webkit-input-placeholder::before {
    color:#666;
    content:"Line 1\A Line 2\A Line 3\A";
}

Demo Fiddle

It would be very great, if s.o. could get a similar demo working on Firefox.

Extracting text from HTML file using Python

The LibreOffice writer comment has merit since the application can employ python macros. It seems to offer multiple benefits both for answering this question and furthering the macro base of LibreOffice. If this resolution is a one-off implementation, rather than to be used as part of a greater production program, opening the HTML in writer and saving the page as text would seem to resolve the issues discussed here.

BigDecimal setScale and round

One important point that is alluded to but not directly addressed is the difference between "precision" and "scale" and how they are used in the two statements. "precision" is the total number of significant digits in a number. "scale" is the number of digits to the right of the decimal point.

The MathContext constructor only accepts precision and RoundingMode as arguments, and therefore scale is never specified in the first statement.

setScale() obviously accepts scale as an argument, as well as RoundingMode, however precision is never specified in the second statement.

If you move the decimal point one place to the right, the difference will become clear:

// 1.
new BigDecimal("35.3456").round(new MathContext(4, RoundingMode.HALF_UP));
//result = 35.35
// 2.
new BigDecimal("35.3456").setScale(4, RoundingMode.HALF_UP);
// result = 35.3456

How to use SQL LIKE condition with multiple values in PostgreSQL?

You might be able to use IN, if you don't actually need wildcards.

SELECT * from table WHERE column IN ('AAA', 'BBB', 'CCC')

Freeing up a TCP/IP port?

To a kill a specific port in Linux use below command

sudo fuser -k Port_Number/tcp

replace Port_Number with your occupied port.

jquery: animate scrollLeft

First off I should point out that css animations would probably work best if you are doing this a lot but I ended getting the desired effect by wrapping .scrollLeft inside .animate

$('.swipeRight').click(function()
{

    $('.swipeBox').animate( { scrollLeft: '+=460' }, 1000);
});

$('.swipeLeft').click(function()
{
    $('.swipeBox').animate( { scrollLeft: '-=460' }, 1000);
});

The second parameter is speed, and you can also add a third parameter if you are using smooth scrolling of some sort.

When is a language considered a scripting language?

A scripting language is typically:

  1. Dynamically typed
  2. Interpreted, with very little emphasis on performance, but good portability
  3. Requires a lot less boilerplate code, leading to very fast prototyping
  4. Is used for small tasks, suitable for writing one single file to run some useful "script".

While a non-scripting language is usually: 1. Statically typed 2. Compiled, with emphasis on performance 3. Requires more boilerplate code, leading to slower prototyping but more readability and long-term maintainability 4. Used for large projects, adapts to many design patterns

But it's more of a historical difference nowadays, in my opinion. Javascript and Perl were written with small, simple scripts in mind, while C++ was written with complex applications in mind; but both can be used either way. And many programming languages, modern and old alike, blur the line anyway (and it was fuzzy in the first place!).

The sad thing is, I've known a few developers who loathes what they perceived as "scripting languages", thinking them to be simpler and not as powerful. My opinion is that old cliche - use the right tool for the job.

Select elements by attribute

JQuery will return the attribute as a string. Therefore you can check the length of that string to determine if is set:

if ($("input#A").attr("myattr").length == 0)
 return null;
else
 return $("input#A").attr("myattr");

How do I reset a sequence in Oracle?

This stored procedure restarts my sequence:

Create or Replace Procedure Reset_Sequence  
  is
  SeqNbr Number;
begin
   /*  Reset Sequence 'seqXRef_RowID' to 0    */
   Execute Immediate 'Select seqXRef.nextval from dual ' Into SeqNbr;
   Execute Immediate 'Alter sequence  seqXRef increment by - ' || TO_CHAR(SeqNbr) ;
   Execute Immediate 'Select seqXRef.nextval from dual ' Into SeqNbr;
   Execute Immediate 'Alter sequence  seqXRef increment by 1';
END;

/

VBA Subscript out of range - error 9

Suggest the following simplification: capture return value from Workbooks.Add instead of subscripting Windows() afterward, as follows:

Set wkb = Workbooks.Add
wkb.SaveAs ...

wkb.Activate ' instead of Windows(expression).Activate


General Philosophy Advice:

Avoid use Excel's built-ins: ActiveWorkbook, ActiveSheet, and Selection: capture return values, and, favor qualified expressions instead.

Use the built-ins only once and only in outermost macros(subs) and capture at macro start, e.g.

Set wkb = ActiveWorkbook
Set wks = ActiveSheet
Set sel = Selection

During and within macros do not rely on these built-in names, instead capture return values, e.g.

Set wkb = Workbooks.Add 'instead of Workbooks.Add without return value capture
wkb.Activate 'instead of Activeworkbook.Activate

Also, try to use qualified expressions, e.g.

wkb.Sheets("Sheet3").Name = "foo" ' instead of Sheets("Sheet3").Name = "foo"

or

Set newWks = wkb.Sheets.Add
newWks.Name = "bar" 'instead of ActiveSheet.Name = "bar"

Use qualified expressions, e.g.

newWks.Name = "bar" 'instead of `xyz.Select` followed by Selection.Name = "bar" 

These methods will work better in general, give less confusing results, will be more robust when refactoring (e.g. moving lines of code around within and between methods) and, will work better across versions of Excel. Selection, for example, changes differently during macro execution from one version of Excel to another.

Also please note that you'll likely find that you don't need to .Activate nearly as much when using more qualified expressions. (This can mean the for the user the screen will flicker less.) Thus the whole line Windows(expression).Activate could simply be eliminated instead of even being replaced by wkb.Activate.

(Also note: I think the .Select statements you show are not contributing and can be omitted.)

(I think that Excel's macro recorder is responsible for promoting this more fragile style of programming using ActiveSheet, ActiveWorkbook, Selection, and Select so much; this style leaves a lot of room for improvement.)

How can I find non-ASCII characters in MySQL?

@zende's answer was the only one that covered columns with a mix of ascii and non ascii characters, but it also had that problematic hex thing. I used this:

SELECT * FROM `table` WHERE NOT `column` REGEXP '^[ -~]+$' AND `column` !=''

How to easily initialize a list of Tuples?

Why do like tuples? It's like anonymous types: no names. Can not understand structure of data.

I like classic classes

class FoodItem
{
     public int Position { get; set; }
     public string Name { get; set; }
}

List<FoodItem> list = new List<FoodItem>
{
     new FoodItem { Position = 1, Name = "apple" },
     new FoodItem { Position = 2, Name = "kiwi" }
};

How to open the Google Play Store directly from my Android application?

Some of the answers to this question are outdated.

What worked for me (in 2020) was to explicitly tell the intent to skip the chooser and directly open the play store app, according to this link:

"If you want to link to your products from an Android app, create an Intent that opens a URL. As you configure this intent, pass "com.android.vending" into Intent.setPackage() so that users see your app's details in the Google Play Store app instead of a chooser."

This is the Kotlin code I used to direct users to viewing the app containing the package name com.google.android.apps.maps in Google Play:

val intent = Intent(Intent.ACTION_VIEW).apply {
               data = Uri.parse("http://play.google.com/store/apps/details?id=com.google.android.apps.maps")
               setPackage("com.android.vending")
            }
            startActivity(intent)

I hope that helps someone!

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

I would go with Lev, but it's worth pointing out that if you end up with more complex searches that using re.finditer may be worth bearing in mind (but re's often cause more trouble than worth - but sometimes handy to know)

test = "ooottat"
[ (i.start(), i.end()) for i in re.finditer('o', test)]
# [(0, 1), (1, 2), (2, 3)]

[ (i.start(), i.end()) for i in re.finditer('o+', test)]
# [(0, 3)]

How do I execute a string containing Python code in Python?

In the example a string is executed as code using the exec function.

import sys
import StringIO

# create file-like string to capture output
codeOut = StringIO.StringIO()
codeErr = StringIO.StringIO()

code = """
def f(x):
    x = x + 1
    return x

print 'This is my output.'
"""

# capture output and errors
sys.stdout = codeOut
sys.stderr = codeErr

exec code

# restore stdout and stderr
sys.stdout = sys.__stdout__
sys.stderr = sys.__stderr__

print f(4)

s = codeErr.getvalue()

print "error:\n%s\n" % s

s = codeOut.getvalue()

print "output:\n%s" % s

codeOut.close()
codeErr.close()

SSRS expression to format two decimal places does not show zeros

If you want to always display some value after decimal for example "12.00" or "12.23" Then use just like below , it worked for me

FormatNumber("145.231000",2) Which will display 145.23

FormatNumber("145",2) Which will display 145.00

Cleanest Way to Invoke Cross-Thread Events

I have some code for this online. It's much nicer than the other suggestions; definitely check it out.

Sample usage:

private void mCoolObject_CoolEvent(object sender, CoolObjectEventArgs args)
{
    // You could use "() =>" in place of "delegate"; it's a style choice.
    this.Invoke(delegate
    {
        // Do the dirty work of my method here.
    });
}

Tensorflow image reading & display

After speaking with you in the comments, I believe that you can just do this using numpy/scipy. The ideas is to read the image in the numpy 3d-array and feed it into the variable.

from scipy import misc
import tensorflow as tf

img = misc.imread('01.png')
print img.shape    # (32, 32, 3)

img_tf = tf.Variable(img)
print img_tf.get_shape().as_list()  # [32, 32, 3]

Then you can run your graph:

init = tf.initialize_all_variables()
sess = tf.Session()
sess.run(init)
im = sess.run(img_tf)

and verify that it is the same:

import matplotlib.pyplot as plt
fig = plt.figure()
fig.add_subplot(1,2,1)
plt.imshow(im)
fig.add_subplot(1,2,2)
plt.imshow(img)
plt.show()

enter image description here

P.S. you mentioned: Since it's supposed to parallelize reading, it seems useful to know.. To which I can say that rarely in data-analysis reading of the data is the bottleneck. Most of your time you will spend training your model.

Binding arrow keys in JS/jQuery

This is a bit late, but HotKeys has a very major bug which causes events to get executed multiple times if you attach more than one hotkey to an element. Just use plain jQuery.

$(element).keydown(function(ev) {
    if(ev.which == $.ui.keyCode.DOWN) {
        // your code
        ev.preventDefault();
    }
});

select unique rows based on single distinct column

I'm assuming you mean that you don't care which row is used to obtain the title, id, and commentname values (you have "rob" for all of the rows, but I don't know if that is actually something that would be enforced or not in your data model). If so, then you can use windowing functions to return the first row for a given email address:

select
    id,
    title,
    email,
    commentname

from
(
select 
    *, 
    row_number() over (partition by email order by id) as RowNbr 

from YourTable
) source

where RowNbr = 1

Adding a favicon to a static HTML page

Most browsers will pick up favicon.ico from the root directory of the site without needing to be told; but they don't always update it with a new one right away.

However, I usually go for the second of your examples:

<link rel='shortcut icon' type='image/x-icon' href='/favicon.ico' />

What is the difference between JSF, Servlet and JSP?

Servlet - it's java server side layer.

  • JSP - it's Servlet with html
  • JSF - it's components base on tag libs
  • JSP - it's converted into servlet once when server got request.

How to draw interactive Polyline on route google maps v2 android

Instead of creating too many short Polylines just create one like here:

PolylineOptions options = new PolylineOptions().width(5).color(Color.BLUE).geodesic(true);
for (int z = 0; z < list.size(); z++) {
    LatLng point = list.get(z);
    options.add(point);
}
line = myMap.addPolyline(options);

I'm also not sure you should use geodesic when your points are so close to each other.

Split a large dataframe into a list of data frames based on common value in column

From version 0.8.0, dplyr offers a handy function called group_split():

# On sample data from @Aus_10

df %>%
  group_split(g)

[[1]]
# A tibble: 25 x 3
   ran_data1 ran_data2 g    
       <dbl>     <dbl> <fct>
 1     2.04      0.627 A    
 2     0.530    -0.703 A    
 3    -0.475     0.541 A    
 4     1.20     -0.565 A    
 5    -0.380    -0.126 A    
 6     1.25     -1.69  A    
 7    -0.153    -1.02  A    
 8     1.52     -0.520 A    
 9     0.905    -0.976 A    
10     0.517    -0.535 A    
# … with 15 more rows

[[2]]
# A tibble: 25 x 3
   ran_data1 ran_data2 g    
       <dbl>     <dbl> <fct>
 1     1.61      0.858 B    
 2     1.05     -1.25  B    
 3    -0.440    -0.506 B    
 4    -1.17      1.81  B    
 5     1.47     -1.60  B    
 6    -0.682    -0.726 B    
 7    -2.21      0.282 B    
 8    -0.499     0.591 B    
 9     0.711    -1.21  B    
10     0.705     0.960 B    
# … with 15 more rows

To not include the grouping column:

df %>%
 group_split(g, keep = FALSE)

How to upload a project to Github

Create a new repository on GitHub. To avoid errors, do not initialize the new repository with README, license, or gitignore files. You can add these files after your project has been pushed to GitHub. Open Terminal (for Mac users) or the command prompt (for Windows and Linux users).

Change the current working directory to your local project.

Initialize the local directory as a Git repository.

git init
#Add the files in your new local repository. This stages them for the first commit.

git add
# Adds the files in the local repository and stages them for commit. To unstage a file, use 'git reset HEAD YOUR-FILE'. Commit the files that you've staged in your local repository.

git commit -m 'First commit'
#Commits the tracked changes and prepares them to be pushed to a remote repository. To remove this commit and modify the file, use 'git reset --soft HEAD~1' and commit and add the file again.

  1. At the top of your GitHub repository's Quick Setup page, click enter image description here to copy the remote repository URL. At the top of your GitHub repository's Quick Setup page, click to copy the remote repository URL.
  2. In the Command prompt, add the URL for the remote repository where your local repository will be pushed.

$ git remote add origin remote repository URL # Sets the new remote git remote -v # Verifies the new remote URL Note: GitHub for Windows users should use the command git remote set-url origin instead of git remote add origin here. Push the changes in your local repository to GitHub.

$ git push origin master
# Pushes the changes in your local repository up to the remote repository you specified as the origin.

Source Attribution: https://help.github.com/articles/adding-an-existing-project-to-github-using-the-command-line/

Java String encoding (UTF-8)

This could be complicated way of doing

String newString = new String(oldString);

This shortens the String is the underlying char[] used is much longer.

However more specifically it will be checking that every character can be UTF-8 encoded.

There are some "characters" you can have in a String which cannot be encoded and these would be turned into ?

Any character between \uD800 and \uDFFF cannot be encoded and will be turned into '?'

String oldString = "\uD800";
String newString = new String(oldString.getBytes("UTF-8"), "UTF-8");
System.out.println(newString.equals(oldString));

prints

false

jQuery - passing value from one input to another

It's simpler if you modify your HTML a little bit:

<label for="first_name">First Name</label>
<input type="text" id="name" name="name" />

<label for="surname">Surname</label>
<input type="text" id="surname" name="surname" />

<label for="firstname">Firstname</label>
<input type="text" id="firstname" name="firstname" disabled="disabled" />

then it's relatively simple

$(document).ready(function() { 
    $('#name').change(function() {
      $('#firstname').val($('#name').val());
    });
});

How can I change the user on Git Bash?

If you want to change the user at git Bash .You just need to configure particular user and email(globally) at the git bash.

$ git config --global user.name "abhi"
$ git config --global user.email "[email protected]"

Note: No need to delete the user from Keychain .

How to check if datetime happens to be Saturday or Sunday in SQL Server 2008

This expression

SELECT (((DATEPART(DW, @my_date_var) - 1 ) + @@DATEFIRST ) % 7)

will always return a number between 0 and 6 where

0 -> Sunday
1 -> Monday
2 -> Tuesday
3 -> Wednesday
4 -> Thursday
5 -> Friday
6 -> Saturday

Independently from @@DATEFIRST

So a weekend day is tested like this

SELECT (CASE
           WHEN (((DATEPART(DW, @my_date_var) - 1 ) + @@DATEFIRST ) % 7) IN (0,6)
           THEN 1
           ELSE 0
       END) AS is_weekend_day

What is the use of static constructors?

No you can't overload it; a static constructor is useful for initializing any static fields associated with a type (or any other per-type operations) - useful in particular for reading required configuration data into readonly fields, etc.

It is run automatically by the runtime the first time it is needed (the exact rules there are complicated (see "beforefieldinit"), and changed subtly between CLR2 and CLR4). Unless you abuse reflection, it is guaranteed to run at most once (even if two threads arrive at the same time).

HTML Upload MAX_FILE_SIZE does not appear to work

Before I start, please let me emphasize that the size of the file must be checked on the server side. If not checked on server side, malicious users can override your client side limits, and upload huge files to your server. DO NOT TRUST THE USERS.

I played a bit with PHP's MAX_FILE_SIZE, it seemed to work only after the file was uploaded, which makes it irrelevant (again, malicious user can override it quite easily).

The javascript code below (tested in Firefox and Chrome), based on Matthew's post, will warn the user (the good, innocent one) a priori to uploading a large file, saving both traffic and the user's time:

<form method="post" enctype="multipart/form-data" 
onsubmit="return checkSize(2097152)">    
<input type="file" id="upload" />
<input type="submit" />

<script type="text/javascript">
function checkSize(max_img_size)
{
    var input = document.getElementById("upload");
    // check for browser support (may need to be modified)
    if(input.files && input.files.length == 1)
    {           
        if (input.files[0].size > max_img_size) 
        {
            alert("The file must be less than " + (max_img_size/1024/1024) + "MB");
            return false;
        }
    }

    return true;
}
</script>

Checking for an empty file in C++

How about (not elegant way though )

int main( int argc, char* argv[] )
{
    std::ifstream file;
    file.open("example.txt");

    bool isEmpty(true);
    std::string line;

    while( file >> line ) 
        isEmpty = false;

        std::cout << isEmpty << std::endl;
}

Define make variable at rule execution time

I dislike "Don't" answers, but... don't.

make's variables are global and are supposed to be evaluated during makefile's "parsing" stage, not during execution stage.

In this case, as long as the variable local to a single target, follow @nobar's answer and make it a shell variable.

Target-specific variables, too, are considered harmful by other make implementations: kati, Mozilla pymake. Because of them, a target can be built differently depending on if it's built standalone, or as a dependency of a parent target with a target-specific variable. And you won't know which way it was, because you don't know what is already built.

Make new column in Panda dataframe by adding values from other columns

You could use sum function to achieve that as @EdChum mentioned in the comment:

df['C'] =  df[['A', 'B']].sum(axis=1)

In [245]: df
Out[245]: 
   A  B   C
0  1  4   5
1  2  6   8
2  3  9  12

Angular ui-grid dynamically calculate height of the grid

UPDATE:

The HTML was requested so I've pasted it below.

<div ui-grid="gridOptions" class="my-grid"></div>

ORIGINAL:

We were able to adequately solve this problem by using responsive CSS (@media) that sets the height and width based on screen real estate. Something like (and clearly you can add more based on your needs):

@media (min-width: 1024px) {
  .my-grid {
    width: 772px;
  }
}

@media (min-width: 1280px) {
  .my-grid {
    width: 972px;
  }
}

@media (min-height: 768px) {
  .my-grid {
    height: 480px;
  }
}

@media (min-height: 900px) {
  .my-grid {
    height: 615px;
  }
}

The best part about this solution is that we need no resize event handling to monitor for grid size changes. It just works.

Round a double to 2 decimal places

value = (int)(value * 100 + 0.5) / 100.0;

How to get the month name in C#?

If you just want to use MonthName then reference Microsoft.VisualBasic and it's in Microsoft.VisualBasic.DateAndTime

//eg. Get January
String monthName = Microsoft.VisualBasic.DateAndTime.MonthName(1);

How to navigate to a directory in C:\ with Cygwin?

You can just use

cd C:/Users/../..

How to calculate modulus of large numbers?

What you're looking for is modular exponentiation, specifically modular binary exponentiation. This wikipedia link has pseudocode.

Finding the number of non-blank columns in an Excel sheet using VBA

Result is shown in the following code as column number (8,9 etc.):

Dim lastColumn As Long
lastColumn = Sheet1.Cells(1, Columns.Count).End(xlToLeft).Column
MsgBox lastColumn

Result is shown in the following code as letter (H,I etc.):

Dim lastColumn As Long
lastColumn = Sheet1.Cells(1, Columns.Count).End(xlToLeft).Column
MsgBox Split(Sheet1.Cells(1, lastColumn).Address, "$")(1)

What in layman's terms is a Recursive Function using PHP

It work a simple example recursive (Y)

<?php 


function factorial($y,$x) { 

    if ($y < $x) { 
        echo $y; 
    } else { 
        echo $x; 
        factorial($y,$x+1);
    } 
}

$y=10;

$x=0;
factorial($y,$x);

 ?>

Python math module

You can also import as

from math import *

Then you can use any mathematical function without prefixing math. e.g.

sqrt(4)

Convert date to datetime in Python

Do I really have to manually call datetime(d.year, d.month, d.day)

No, you'd rather like to call

date_to_datetime(dt)

which you can implement once in some utils/time.py in your project:

from typing import Optional
from datetime import date, datetime

def date_to_datetime(
    dt: date,
    hour: Optional[int] = 0,
    minute: Optional[int] = 0, 
    second: Optional[int] = 0) -> datetime:

    return datetime(dt.year, dt.month, dt.day, hour, minute, second)

How do I edit an incorrect commit message in git ( that I've pushed )?

(From http://git.or.cz/gitwiki/GitTips#head-9f87cd21bcdf081a61c29985604ff4be35a5e6c0)

How to change commits deeper in history

Since history in Git is immutable, fixing anything but the most recent commit (commit which is not branch head) requires that the history is rewritten from the changed commit and forward.

You can use StGIT for that, initialize branch if necessary, uncommitting up to the commit you want to change, pop to it if necessary, make a change then refresh patch (with -e option if you want to correct commit message), then push everything and stg commit.

Or you can use rebase to do that. Create new temporary branch, rewind it to the commit you want to change using git reset --hard, change that commit (it would be top of current head), then rebase branch on top of changed commit, using git rebase --onto .

Or you can use git rebase --interactive, which allows various modifications like patch re-ordering, collapsing, ...

I think that should answer your question. However, note that if you have pushed code to a remote repository and people have pulled from it, then this is going to mess up their code histories, as well as the work they've done. So do it carefully.

How to get last month/year in java?

java.time

Using java.time framework built into Java 8:

import java.time.LocalDate;

LocalDate now = LocalDate.now(); // 2015-11-24
LocalDate earlier = now.minusMonths(1); // 2015-10-24

earlier.getMonth(); // java.time.Month = OCTOBER
earlier.getMonth.getValue(); // 10
earlier.getYear(); // 2015

Can't install Scipy through pip

Try downloading the scipy file from the below link

https://sourceforge.net/projects/scipy/?source=typ_redirect

It will be a .exe file and you just need to run it. But be sure to chose the scipy version corresponding to your python version.

When the scipy.exe file is run it will locate the python directory and will be installed .

System.Threading.Timer in C# it seems to be not working. It runs very fast every 3 second

 var span = TimeSpan.FromMinutes(2);
 var t = Task.Factory.StartNew(async delegate / () =>
   {
        this.SomeAsync();
        await Task.Delay(span, source.Token);
  }, source.Token, TaskCreationOptions.LongRunning, TaskScheduler.Default);

source.Cancel(true/or not);

// or use ThreadPool(whit defaul options thread) like this
Task.Start(()=>{...}), source.Token)

if u like use some loop thread inside ...

public async void RunForestRun(CancellationToken token)
{
  var t = await Task.Factory.StartNew(async delegate
   {
       while (true)
       {
           await Task.Delay(TimeSpan.FromSeconds(1), token)
                 .ContinueWith(task => { Console.WriteLine("End delay"); });
           this.PrintConsole(1);
        }
    }, token) // drop thread options to default values;
}

// And somewhere there
source.Cancel();
//or
token.ThrowIfCancellationRequested(); // try/ catch block requred.

How to unmount, unrender or remove a component, from itself in a React/Redux/Typescript notification message

instead of using

ReactDOM.unmountComponentAtNode(ReactDOM.findDOMNode(this).parentNode);

try using

ReactDOM.unmountComponentAtNode(document.getElementById('root'));

Expected block end YAML error

In my case, the error occured when I tried to pass a variable which was looking like a bytes-object (b"xxxx") but was actually a string.

You can convert the string to a real bytes object like this:

foo.strip('b"').replace("\\n", "\n").encode()

Python datetime strptime() and strftime(): how to preserve the timezone information

Here is my answer in Python 2.7

Print current time with timezone

from datetime import datetime
import tzlocal  # pip install tzlocal

print datetime.now(tzlocal.get_localzone()).strftime("%Y-%m-%d %H:%M:%S %z")

Print current time with specific timezone

from datetime import datetime
import pytz # pip install pytz

print datetime.now(pytz.timezone('Asia/Taipei')).strftime("%Y-%m-%d %H:%M:%S %z")

It will print something like

2017-08-10 20:46:24 +0800

Why can't Python find shared objects that are in directories in sys.path?

You can also set LD_RUN_PATH to /usr/local/lib in your user environment when you compile pycurl in the first place. This will embed /usr/local/lib in the RPATH attribute of the C extension module .so so that it automatically knows where to find the library at run time without having to have LD_LIBRARY_PATH set at run time.

React.js: Set innerHTML vs dangerouslySetInnerHTML

According to Dangerously Set innerHTML,

Improper use of the innerHTML can open you up to a cross-site scripting (XSS) attack. Sanitizing user input for display is notoriously error-prone, and failure to properly sanitize is one of the leading causes of web vulnerabilities on the internet.

Our design philosophy is that it should be "easy" to make things safe, and developers should explicitly state their intent when performing “unsafe” operations. The prop name dangerouslySetInnerHTML is intentionally chosen to be frightening, and the prop value (an object instead of a string) can be used to indicate sanitized data.

After fully understanding the security ramifications and properly sanitizing the data, create a new object containing only the key __html and your sanitized data as the value. Here is an example using the JSX syntax:

function createMarkup() {
    return {
       __html: 'First &middot; Second'    };
 }; 

<div dangerouslySetInnerHTML={createMarkup()} /> 

Read more about it using below link:

documentation: React DOM Elements - dangerouslySetInnerHTML.

How to loop backwards in python?

for x in reversed(whatever):
    do_something()

This works on basically everything that has a defined order, including xrange objects and lists.

Android emulator failed to allocate memory 8

Go to edit Android Virtual Devices and change the 1024 Under Memory Options to 768. If it still doesn't work, keep going lower and lower.

Changing project port number in Visual Studio 2013

This has proved to be elusive for me (WebSite Project) until I figured out the following procedure, which combines the solution provided by @Jimmy, with the added step of checking out the solution from Source Control

Steps: (if using VS2013+ with website project and SourceControl)

  1. Check out the Solution file only (from sourceControl) (this can be tricky. the easiest way to do this is to make a small change in the Solution file properties/settings and then undo if necessary)
  2. Locate the solution file (e.g. solution.sln) in exploer, and open in text editor.
  3. Locate the entry: VWDPort = ...... and change to desired port: (example: "60000" - depends on your IISExpress Settings)
  4. save the change (will prompt to reload solution)

Is a URL allowed to contain a space?

To answer your question. I would say it's fairly common for applications to replace spaces in values that will be used in URLs. The reason for this is ussually to avoid the more difficult to read percent (URI) encoding that occurs.

Check out this wikipedia article about Percent-encoding.

Synchronizing a local Git repository with a remote one

git fetch --prune

-p, --prune
After fetching, remove any remote-tracking branches which no longer exist on the remote. prune options

Spring RestTemplate - how to enable full debugging/logging of requests/responses?

Besides the HttpClient logging described in the other answer, you can also introduce a ClientHttpRequestInterceptor that reads the body of the request and the response and logs it. You might want to do this if other stuff also uses the HttpClient, or if you want a custom logging format. Caution: you will want to give the RestTemplate a BufferingClientHttpRequestFactory such that you can read the response twice.

Is there a RegExp.escape function in JavaScript?

The function linked above is insufficient. It fails to escape ^ or $ (start and end of string), or -, which in a character group is used for ranges.

Use this function:

function escapeRegex(string) {
    return string.replace(/[-\/\\^$*+?.()|[\]{}]/g, '\\$&');
}

While it may seem unnecessary at first glance, escaping - (as well as ^) makes the function suitable for escaping characters to be inserted into a character class as well as the body of the regex.

Escaping / makes the function suitable for escaping characters to be used in a JavaScript regex literal for later evaluation.

As there is no downside to escaping either of them, it makes sense to escape to cover wider use cases.

And yes, it is a disappointing failing that this is not part of standard JavaScript.

How to enable cURL in PHP / XAMPP

PHP 7^ version:

sudo apt-get install php-curl
sudo service apache2 restart

Viewing local storage contents on IE

Since localStorage is a global object, you can add a watch in the dev tools. Just enter the dev tools, goto "watch", click on "Click to add..." and type in "localStorage".

Could not load file or assembly Microsoft.SqlServer.management.sdk.sfc version 11.0.0.0

I am running VS 2012, and SQL Server 2008 R2 SP2, Developer Edition. I ended up having to install items from the Microsoft® SQL Server® 2012 Feature Pack. I think that the install instructions noted that these items work for SQL Server 2005 through 2012. I don't know what the exact requirements are to fix this error, but I installed the three items, and the error stopped appearing.

Microsoft® SQL Server® 2012 Feature Pack Items

  • Microsoft® SQL Server® 2012 Shared Management Objects : x86 , x64
  • Microsoft® System CLR Types for Microsoft® SQL Server® 2012 : x86 , x64
  • Microsoft® SQL Server® 2012 Native Client : x86 , x64

Based on threads elsewhere, you may not end up needing the last item or two. Good luck!

jQuery replace one class with another

jQuery.fn.replaceClass = function(sSearch, sReplace) {
    return this.each(function() {
        var s = (' ' + this.className + ' ').replace(
            ' ' + sSearch.trim() + ' ',
            ' ' + sReplace.trim() + ' '
        );
        this.className = s.substr(1, s.length - 2);
    });
};

EDIT

This is my solution to replace one class with another (the jQuery way). Actually the other answers don't replace one class with another but add one class and remove another which technically is not the same at all.

Here is an example:

Markup before: <br class="el search-replace"><br class="el dont-search-replace">
js: jQuery('.el').remove('search-replace').add('replaced')
Markup after: <br class="el replaced"><br class="el dont-search-replace replaced">


With my solution

js: jQuery('.el').replaceClass('search-replace', 'replaced')
Markup after: <br class="el replaced"><br class="el dont-search-replace">


Imagine a string replace function in whatever language:

Search: "search-replace"
Replace: "replaced"
Subject: "dont-search-replace"
Result: "dont-search-replace"
Result (wrong but actually what the other solutions produce): "dont-search-replace replaced"


PS If it's for sure that the class to add is not present and the class to remove is present for sure the most simple jQuery solution would be:
jQuery('el').toggleClass('is-present-will-be-removed is-not-present-will-be-added')

PPS I'm totally aware that if your selector equals the class to remove the other solutions would work just fine jQuery('.search-replace').removeClass('search-replace').addClass('whatever').
But sometimes you work with more arbitrary collections.

How do multiple clients connect simultaneously to one port, say 80, on a server?

Multiple clients can connect to the same port (say 80) on the server because on the server side, after creating a socket and binding (setting local IP and port) listen is called on the socket which tells the OS to accept incoming connections.

When a client tries to connect to server on port 80, the accept call is invoked on the server socket. This creates a new socket for the client trying to connect and similarly new sockets will be created for subsequent clients using same port 80.

Words in italics are system calls.

Ref

http://www.scs.stanford.edu/07wi-cs244b/refs/net2.pdf

How do I convert an integer to binary in JavaScript?

A solution i'd go with that's fine for 32-bits, is the code the end of this answer, which is from developer.mozilla.org(MDN), but with some lines added for A)formatting and B)checking that the number is in range.

Some suggested x.toString(2) which doesn't work for negatives, it just sticks a minus sign in there for them, which is no good.

Fernando mentioned a simple solution of (x>>>0).toString(2); which is fine for negatives, but has a slight issue when x is positive. It has the output starting with 1, which for positive numbers isn't proper 2s complement.

Anybody that doesn't understand the fact of positive numbers starting with 0 and negative numbers with 1, in 2s complement, could check this SO QnA on 2s complement. What is “2's Complement”?

A solution could involve prepending a 0 for positive numbers, which I did in an earlier revision of this answer. And one could accept sometimes having a 33bit number, or one could make sure that the number to convert is within range -(2^31)<=x<2^31-1. So the number is always 32bits. But rather than do that, you can go with this solution on mozilla.org

Patrick's answer and code is long and apparently works for 64-bit, but had a bug that a commenter found, and the commenter fixed patrick's bug, but patrick has some "magic number" in his code that he didn't comment about and has forgotten about and patrick no longer fully understands his own code / why it works.

Annan had some incorrect and unclear terminology but mentioned a solution by developer.mozilla.org https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Bitwise_Operators This works for 32-bit numbers.

The code is pretty compact, a function of three lines.

But I have added a regex to format the output in groups of 8 bits. Based on How to print a number with commas as thousands separators in JavaScript (I just amended it from grouping it in 3s right to left and adding commas, to grouping in 8s right to left, and adding spaces)

And, while mozilla made a comment about the size of nMask(the number fed in)..that it has to be in range, they didn't test for or throw an error when the number is out of range, so i've added that.

I'm not sure why they named their parameter 'nMask' but i'll leave that as is.

Reference: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Bitwise_Operators

_x000D_
_x000D_
function createBinaryString(nMask) {_x000D_
  // nMask must be between -2147483648 and 2147483647_x000D_
  if (nMask > 2**31-1) _x000D_
     throw "number too large. number shouldn't be > 2**31-1"; //added_x000D_
  if (nMask < -1*(2**31))_x000D_
     throw "number too far negative, number shouldn't be < 2**31" //added_x000D_
  for (var nFlag = 0, nShifted = nMask, sMask = ''; nFlag < 32;_x000D_
       nFlag++, sMask += String(nShifted >>> 31), nShifted <<= 1);_x000D_
  sMask=sMask.replace(/\B(?=(.{8})+(?!.))/g, " ") // added_x000D_
  return sMask;_x000D_
}_x000D_
_x000D_
_x000D_
console.log(createBinaryString(-1))    // "11111111 11111111 11111111 11111111"_x000D_
console.log(createBinaryString(1024))  // "00000000 00000000 00000100 00000000"_x000D_
console.log(createBinaryString(-2))    // "11111111 11111111 11111111 11111110"_x000D_
console.log(createBinaryString(-1024)) // "11111111 11111111 11111100 00000000"
_x000D_
_x000D_
_x000D_

How do I accomplish an if/else in mustache.js?

Your else statement should look like this (note the ^):

{{^avatar}}
 ...
{{/avatar}}

In mustache this is called 'Inverted sections'.

What's the point of the X-Requested-With header?

Some frameworks are using this header to detect xhr requests e.g. grails spring security is using this header to identify xhr request and give either a json response or html response as response.

Most Ajax libraries (Prototype, JQuery, and Dojo as of v2.1) include an X-Requested-With header that indicates that the request was made by XMLHttpRequest instead of being triggered by clicking a regular hyperlink or form submit button.

Source: http://grails-plugins.github.io/grails-spring-security-core/guide/helperClasses.html

How to select a record and update it, with a single queryset in Django?

This answer compares the above two approaches. If you want to update many objects in a single line, go for:

# Approach 1
MyModel.objects.filter(field1='Computer').update(field2='cool')

Otherwise you would have to iterate over the query set and update individual objects:

#Approach 2    
objects = MyModel.objects.filter(field1='Computer')
for obj in objects:
    obj.field2 = 'cool'
    obj.save()
  1. Approach 1 is faster because, it makes only one database query, compared to approach 2 which makes 'n+1' database queries. (For n items in the query set)

  2. Fist approach makes one db query ie UPDATE, the second one makes two: SELECT and then UPDATE.

  3. The tradeoff is that, suppose you have any triggers, like updating updated_on or any such related fields, it will not be triggered on direct update ie approach 1.

  4. Approach 1 is used on a queryset, so it is possible to update multiple objects at once, not in the case of approach 2.

Hex-encoded String to Byte Array

That should do the trick :

byte[] bytes = toByteArray(Str.toCharArray());

public static byte[] toByteArray(char[] array) {
    return toByteArray(array, Charset.defaultCharset());
}

public static byte[] toByteArray(char[] array, Charset charset) {
    CharBuffer cbuf = CharBuffer.wrap(array);
    ByteBuffer bbuf = charset.encode(cbuf);
    return bbuf.array();
}

Set default value of javascript object attributes

var obj = {
  a: 2,
  b: 4
};

console.log(obj);

--> {a: 2, b: 4}

function applyDefaults(obj) {
  obj.a ||= 10;
  obj.b ||= 10;
  obj.c ||= 10;
}

// do some magic
applyDefaults(obj);

console.log(obj);

--> {a: 2, b: 4, c: 10}

This works because

undefined || "1111111" --> "1111111"
"0000000" || "1111111" --> "0000000"

as null, undefined, NaN, 0, "" (Empty String), false itself, are all considered to be equivalent to false (falsy). Anything else is true (truthy).

Note that this is not uniformly supported across browsers and nodejs versions (confirm for yourself).

So two troublesome cases are the empty String "" and 0 (zero). If it is important not to override those, you might need to rewrite this as:

if (typeof obj.d == "undefined") obj.d = "default"

This will be better supported across browsers also.

Alternatively you could write this as:

obj.d ??= "default"

This is the nullish assignment which applies only to values that are null or undefined (nullish) - of which the empty string is not part. However, this has again a diminished cross-browser support.

See also on the official Mozilla Website - Assigning a default value to a variable.