Programs & Examples On #Image.createimage

git stash changes apply to new branch?

Since you've already stashed your changes, all you need is this one-liner:

  • git stash branch <branchname> [<stash>]

From the docs (https://www.kernel.org/pub/software/scm/git/docs/git-stash.html):

Creates and checks out a new branch named <branchname> starting from the commit at which the <stash> was originally created, applies the changes recorded in <stash> to the new working tree and index. If that succeeds, and <stash> is a reference of the form stash@{<revision>}, it then drops the <stash>. When no <stash> is given, applies the latest one.

This is useful if the branch on which you ran git stash save has changed enough that git stash apply fails due to conflicts. Since the stash is applied on top of the commit that was HEAD at the time git stash was run, it restores the originally stashed state with no conflicts.

What's the difference between Git Revert, Checkout and Reset?

Let's say you had commits:

C
B
A

git revert B, will create a commit that undoes changes in B.

git revert A, will create a commit that undoes changes in A, but will not touch changes in B

Note that if changes in B are dependent on changes in A, the revert of A is not possible.

git reset --soft A, will change the commit history and repository; staging and working directory will still be at state of C.

git reset --mixed A, will change the commit history, repository, and staging; working directory will still be at state of C.

git reset --hard A, will change the commit history, repository, staging and working directory; you will go back to the state of A completely.

Inline SVG in CSS

My solution was https://yoksel.github.io/url-encoder/ You just simply insert your svg and getting back background-image code

How to access parent scope from within a custom directive *with own scope* in AngularJS?

 scope: false
 transclude: false

and you will have the same scope(with parent element)

$scope.$watch(...

There are a lot of ways how to access parent scope depending on this two options scope& transclude.

Set initially selected item in Select list in Angular2

You can achieve the same using

<select [ngModel]="object">
  <option *ngFor="let object of objects;let i= index;" [value]="object.value" selected="i==0">{{object.name}}</option>
</select>

Angular 4: How to include Bootstrap?

Angular 4 - Bootstrap / @ng-bootstrap setup

First install bootstrap into your project using below command:

npm install --save bootstrap

Then add this line "../node_modules/bootstrap/dist/css/bootstrap.min.css" to angular-cli.json file (root folder) in styles

"styles": [
   "../node_modules/bootstrap/dist/css/bootstrap.min.css",
   "styles.css"
],

After installing the above dependencies, install ng-bootstrap via:

npm install --save @ng-bootstrap/ng-bootstrap

Once installed you need to import main module.

import {NgbModule} from '@ng-bootstrap/ng-bootstrap';

After this, you can use All the Bootstrap widgets (ex. carousel, modal, popovers, tooltips, tabs etc.) and several additional goodies ( datepicker, rating, timepicker, typeahead).

Casting objects in Java

Have a look at this sample:

public class A {
  //statements
}

public class B extends A {
  public void foo() { }
}

A a=new B();

//To execute **foo()** method.

((B)a).foo();

Detect click inside/outside of element with single event handler

Rather than using the jQuery .parents function (as suggested in the accepted answer), it's better to use .closest for this purpose. As explained in the jQuery api docs, .closest checks the element passed and all its parents, whereas .parents just checks the parents. Consequently, this works:

$(function() {
    $("body").click(function(e) {
        if ($(e.target).closest("#myDiv").length) {
            alert("Clicked inside #myDiv");
        } else { 
            alert("Clicked outside #myDiv");
        }
    });
})

How do I reverse a commit in git?

Unable to comment on others answers, I'll provide a bit of extra information.

If you want to revert the last commit, you can use git revert head. head refers to the most recent commit in your branch.

The reason you use head~1 when using reset is that you are telling Git to "remove all changes in the commits after" (reset --hard) "the commit one before head" (head~1).

reset is to a commit, revert is on a commit.

As AmpT pointed out, you can also use the commit SHA to identify it, rather than counting how far away from head it is. The SHA can be found in the logs (git log) and a variety of other ways.

You can also always use any other pointers in Git. e.g. a tag or branch. And can also use all of these fun other ways to reference commits https://www.kernel.org/pub/software/scm/git/docs/git-rev-parse.html#_specifying_revisions

How to safely upgrade an Amazon EC2 instance from t1.micro to large?

From my experience, the way I do it is create a snapshot of your current image, then once its done you'll see it as an option when launching new instances. Simply launch it as a large instance at that point.

This is my approach if I do not want any downtime(i.e. production server) because this solution only takes a server offline only after the new one is up and running(I also use it to add new machines to my clusters by using this approach to only add new machines). If Downtime is acceptable then see Marcel Castilho's answer.

Installing Node.js (and npm) on Windows 10

I had the same problem, what helped we was turning of my anti virus protection for like 10 minutes while node installed and it worked like a charm.

Getting time difference between two times in PHP

You can also use DateTime class:

$time1 = new DateTime('09:00:59');
$time2 = new DateTime('09:01:00');
$interval = $time1->diff($time2);
echo $interval->format('%s second(s)');

Result:

1 second(s)

Can't connect to MySQL server on 'localhost' (10061)

  1. Make sure that your windows host file (located at c://windows/system32/drivers/etc.host) has following line. If not, add it at the end

    127.0.0.1 localhost
    ::1 localhost
    
  2. Sometimes mysql can not trigger Windows to force start host services if firewall blocks it, so start it manually

win+run>>services.msc, select the "MySQL_xx" where "xx" is the name you have assigned to MySQL host services during setup. Click on 'start' to start from hyperlink appeared on left side.

Python to print out status bar and percentage

based on the above answers and other similar questions about CLI progress bar, I think I got a general common answer to all of them. Check it at https://stackoverflow.com/a/15860757/2254146

Here is a copy of the function, but modified to fit your style:

import time, sys

# update_progress() : Displays or updates a console progress bar
## Accepts a float between 0 and 1. Any int will be converted to a float.
## A value under 0 represents a 'halt'.
## A value at 1 or bigger represents 100%
def update_progress(progress):
    barLength = 20 # Modify this to change the length of the progress bar
    status = ""
    if isinstance(progress, int):
        progress = float(progress)
    if not isinstance(progress, float):
        progress = 0
        status = "error: progress var must be float\r\n"
    if progress < 0:
        progress = 0
        status = "Halt...\r\n"
    if progress >= 1:
        progress = 1
        status = "Done...\r\n"
    block = int(round(barLength*progress))
    text = "\rPercent: [{0}] {1}% {2}".format( "="*block + " "*(barLength-block), progress*100, status)
    sys.stdout.write(text)
    sys.stdout.flush()

Looks like

Percent: [====================] 99.0%

C - function inside struct

How about this?

#include <stdio.h>

typedef struct hello {
    int (*someFunction)();
} hello;

int foo() {
    return 0;
}

hello Hello() {
    struct hello aHello;
    aHello.someFunction = &foo;
    return aHello;
}

int main()
{
    struct hello aHello = Hello();
    printf("Print hello: %d\n", aHello.someFunction());

    return 0;
} 

java.lang.ClassNotFoundException: org.springframework.web.context.ContextLoaderListener

In my case the problem was that the class was located in test package. Moving it to main package has solved the problem.

Send POST request using NSURLSession

    use like this.....

    Create file

    #import <Foundation/Foundation.h>`    
    #import "SharedManager.h"
    #import "Constant.h"
    #import "UserDetails.h"

    @interface APISession : NSURLSession<NSURLSessionDelegate>
    @property (nonatomic, retain) NSMutableData *responseData;
    +(void)postRequetsWithParam:(NSMutableDictionary* )objDic withAPIName:(NSString* 
    )strAPIURL completionHandler:(void (^)(id result, BOOL status))completionHandler;
    @end

****************.m*************************
    #import "APISession.h"
    #import <UIKit/UIKit.h>
    @implementation APISession

    +(void)postRequetsWithParam:(NSMutableDictionary *)objDic withAPIName:(NSString 
    *)strAPIURL completionHandler:(void (^)(id, BOOL))completionHandler
    {
    NSURL *url=[NSURL URLWithString:strAPIURL];
    NSMutableURLRequest *request=[[NSMutableURLRequest alloc]initWithURL:url];
    [request setHTTPMethod:@"POST"];
    [request addValue:@"application/json" forHTTPHeaderField:@"Content-Type"];
    NSError *err = nil;

    NSData *data=[NSJSONSerialization dataWithJSONObject:objDic options:NSJSONWritingPrettyPrinted error:&err];
    [request setHTTPBody:data];

    NSString *strJsonFormat = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
    NSLog(@"API URL: %@ \t  Api Request Parameter ::::::::::::::%@",url,strJsonFormat);
    //    NSLog(@"Request data===%@",objDic);
    NSURLSessionConfiguration *defaultConfigObject = [NSURLSessionConfiguration defaultSessionConfiguration];
    NSURLSession *session = [NSURLSession sessionWithConfiguration: defaultConfigObject delegate: nil delegateQueue: [NSOperationQueue mainQueue]];

    //  NSURLSession *session=[NSURLSession sharedSession];

    NSURLSessionTask *task=[session dataTaskWithRequest:request completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error)
                            {
                                if (error==nil) {
                                    NSDictionary *dicData=[NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingAllowFragments error:&error];\
                                    NSLog(@"Response Data=============%@",dicData);
                                    if([[dicData valueForKey:@"tokenExpired"]integerValue] == 1)
                                    {

                                        NSLog(@"hello");
                                        NSDictionary *dict = [NSDictionary dictionaryWithObject:@"Access Token Expire." forKey:@"message"];
                                        [[NSNotificationCenter defaultCenter] postNotificationName:@"UserLogOut" object:self userInfo:dict];
                                    }
                                    dispatch_async(dispatch_get_main_queue(), ^{
                                        completionHandler(dicData,(error == nil));
                                    });
                                    NSLog(@"%@",dicData);
                                }
                                else{
                                    dispatch_async(dispatch_get_main_queue(), ^{
                                        completionHandler(error.localizedDescription,NO);
                                    });
                                }
                            }];
    //    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(2.0 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
    [task resume];
    //    });
    }
    @end

    *****************************in .your view controller***********
    #import "file"
    txtEmail.text = [txtEmail.text stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];

    {
            [SVProgressHUD showWithStatus:@"Loading..."];
            [SVProgressHUD setDefaultMaskType:SVProgressHUDMaskTypeGradient];

            NSMutableDictionary *objLoginDic=[[NSMutableDictionary alloc] init];
            [objLoginDic setValue:txtEmail.text forKey:@"email"];
            [objLoginDic setValue:@0            forKey:kDeviceType];
            [objLoginDic setValue:txtPassword.text forKey:kPassword];
            [objLoginDic setValue:@"376545432"  forKey:kDeviceTokan];
            [objLoginDic setValue:@""           forKey:kcountryId];
            [objLoginDic setValue:@""           forKey:kfbAccessToken];
            [objLoginDic setValue:@0            forKey:kloginType];

            [APISession postRequetsWithParam:objLoginDic withAPIName:KLOGIN_URL completionHandler:^(id result, BOOL status) {

                [SVProgressHUD dismiss];

                NSInteger statusResponse=[[result valueForKey:kStatus] integerValue];
                NSString *strMessage=[result valueForKey:KMessage];
                if (status) {
                    if (statusResponse == 1)
                {
                        UserDetails *objLoginUserDetail=[[UserDetails alloc] 
                        initWithObject:[result valueForKey:@"userDetails"]];
                          [[NSUserDefaults standardUserDefaults] 
                        setObject:@(objLoginUserDetail.userId) forKey:@"user_id"];
                        [[NSUserDefaults standardUserDefaults] synchronize];
                        [self clearTextfeilds];
                        HomeScreen *obj=[Kiran_Storyboard instantiateViewControllerWithIdentifier:@"HomeScreen"];
                        [self.navigationController pushViewController:obj animated:YES];
                    }
                    else{
                        [strMessage showAsAlert:self];
                    }
                }
            }];
        }
**********use model class for represnt data*************

    #import <Foundation/Foundation.h>
    #import "Constant.h"
    #import <objc/runtime.h>


    @interface UserDetails : NSObject
    @property(strong,nonatomic) NSString *emailId,
    *deviceToken,
    *countryId,
    *fbAccessToken,
    *accessToken,
    *countryName,
    *isProfileSetup,
    *profilePic,
    *firstName,
    *lastName,
    *password;

    @property (assign) NSInteger userId,deviceType,loginType;

    -(id)initWithObject :(NSDictionary *)dicUserData;
    -(void)saveLoginUserDetail;
    +(UserDetails *)getLoginUserDetail;
    -(UserDetails *)getEmptyModel;
    - (NSArray *)allPropertyNames;
    -(void)printDescription;
       -(NSMutableDictionary *)getDictionary;

    @end

    ******************model.m*************

    #import "UserDetails.h"
    #import "SharedManager.h"

    @implementation UserDetails



      -(id)initWithObject :(NSDictionary *)dicUserData
       {
       self = [[UserDetails alloc] init];
       if (self)
       {
           @try {
               [self setFirstName:([dicUserData valueForKey:@"firstName"] != [NSNull null])? 
               [dicUserData valueForKey:@"firstName"]:@""];


               [self setUserId:([dicUserData valueForKey:kUserId] != [NSNull null])? 
               [[dicUserData valueForKey:kUserId] integerValue]:0];


               }
        @catch (NSException *exception) {
            NSLog(@"Exception: %@",exception.description);
        }
        @finally {
        }
    }
    return self;
}

    -(UserDetails *)getEmptyModel{
    [self setFirstName:@""];
    [self setLastName:@""];



    [self setDeviceType:0];


    return self;
       }

     -  (void)encodeWithCoder:(NSCoder *)encoder {
    //    Encode properties, other class variables, etc
    [encoder encodeObject:_firstName forKey:kFirstName];


    [encoder encodeObject:[NSNumber numberWithInteger:_deviceType] forKey:kDeviceType];

    }

    - (id)initWithCoder:(NSCoder *)decoder {
    if((self = [super init])) {
        _firstName = [decoder decodeObjectForKey:kEmailId];

        _deviceType= [[decoder decodeObjectForKey:kDeviceType] integerValue];

    }
    return self;
    }
    - (NSArray *)allPropertyNames
    {
    unsigned count;
    objc_property_t *properties = class_copyPropertyList([self class], &count);

    NSMutableArray *rv = [NSMutableArray array];

    unsigned i;
    for (i = 0; i < count; i++)
    {
        objc_property_t property = properties[i];
        NSString *name = [NSString stringWithUTF8String:property_getName(property)];
        [rv addObject:name];
    }

    free(properties);

    return rv; 
    } 

    -(void)printDescription{
    NSMutableDictionary *dic = [[NSMutableDictionary alloc] init];

    for(NSString *key in [self allPropertyNames])
    {
        [dic setValue:[self valueForKey:key] forKey:key];
    }
    NSLog(@"\n========================= User Detail ==============================\n");
    NSLog(@"%@",[dic description]);
    NSLog(@"\n=============================================================\n");
    }
    -(NSMutableDictionary *)getDictionary{
    NSMutableDictionary *dic = [[NSMutableDictionary alloc] init];
    for(NSString *key in [self allPropertyNames])
    {
        [dic setValue:[self valueForKey:key] forKey:key];
    }
    return dic;
    }
    #pragma mark
    #pragma mark - Save and get User details
    -(void)saveLoginUserDetail{
    NSData *encodedObject = [NSKeyedArchiver archivedDataWithRootObject:self];
    [Shared_UserDefault setObject:encodedObject forKey:kUserDefault_SavedUserDetail];
    [Shared_UserDefault synchronize];
    }
      +(UserDetails *)getLoginUserDetail{
      NSData *encodedObject = [Shared_UserDefault objectForKey:kUserDefault_SavedUserDetail];
    UserDetails *object = [NSKeyedUnarchiver unarchiveObjectWithData:encodedObject];
    return object;
   }
    @end


     ************************usefull code while add data into model and get data********

                   NSLog(@"Response %@",result);
                  NSString *strMessg = [result objectForKey:kMessage];
                 NSString *status = [NSString stringWithFormat:@"%@",[result 
                objectForKey:kStatus]];

            if([status isEqualToString:@"1"])
            {
                arryBankList =[[NSMutableArray alloc]init];

                NSMutableArray *arrEvents=[result valueForKey:kbankList];
                ShareOBJ.isDefaultBank = [result valueForKey:kisDefaultBank];
                if ([arrEvents count]>0)
                {

                for (NSMutableArray *dic in arrEvents)
                    {
                        BankList *objBankListDetail =[[BankList alloc]initWithObject:[dic 
                         mutableCopy]];
                        [arryBankList addObject:objBankListDetail];
                    }
           //display data using model...
           BankList *objBankListing  =[arryBankList objectAtIndex:indexPath.row];

How to provide shadow to Button

Android now provides ExtendedFloatingActionButton which does the same thing for you.

vim line numbers - how to have them on by default?

If you don't want to add/edit .vimrc, you can start with

vi "+set number" /path/to/file

Flask SQLAlchemy query, specify column names

As session.query(SomeModel.col1) returns an array of tuples like this [('value_1',),('value_2',)] if you want t cast the result to a plain array you can do it by using one of the following statements:

values = [value[0] for value in session.query(SomeModel.col1)]
values = [model.col1 for model in session.query(SomeModel).options(load_only('col1'))]

Result:

 ['value_1', 'value_2']

R: += (plus equals) and ++ (plus plus) equivalent from c++/c#/java, etc.?

We can also use inplace

library(inplace)
x <- 1
x %+<-% 2

Pandas: Creating DataFrame from Series

No need to initialize an empty DataFrame (you weren't even doing that, you'd need pd.DataFrame() with the parens).

Instead, to create a DataFrame where each series is a column,

  1. make a list of Series, series, and
  2. concatenate them horizontally with df = pd.concat(series, axis=1)

Something like:

series = [pd.Series(mat[name][:, 1]) for name in Variables]
df = pd.concat(series, axis=1)

What is the maximum possible length of a query string?

RFC 2616 (Hypertext Transfer Protocol — HTTP/1.1) states there is no limit to the length of a query string (section 3.2.1). RFC 3986 (Uniform Resource Identifier — URI) also states there is no limit, but indicates the hostname is limited to 255 characters because of DNS limitations (section 2.3.3).

While the specifications do not specify any maximum length, practical limits are imposed by web browser and server software. Based on research which is unfortunately no longer available on its original site (it leads to a shady seeming loan site) but which can still be found at Internet Archive Of Boutell.com:

  • Microsoft Internet Explorer (Browser)
    Microsoft states that the maximum length of a URL in Internet Explorer is 2,083 characters, with no more than 2,048 characters in the path portion of the URL. Attempts to use URLs longer than this produced a clear error message in Internet Explorer.

  • Microsoft Edge (Browser)
    The limit appears to be around 81578 characters. See URL Length limitation of Microsoft Edge

  • Chrome
    It stops displaying the URL after 64k characters, but can serve more than 100k characters. No further testing was done beyond that.

  • Firefox (Browser)
    After 65,536 characters, the location bar no longer displays the URL in Windows Firefox 1.5.x. However, longer URLs will work. No further testing was done after 100,000 characters.

  • Safari (Browser)
    At least 80,000 characters will work. Testing was not tried beyond that.

  • Opera (Browser)
    At least 190,000 characters will work. Stopped testing after 190,000 characters. Opera 9 for Windows continued to display a fully editable, copyable and pasteable URL in the location bar even at 190,000 characters.

  • Apache (Server)
    Early attempts to measure the maximum URL length in web browsers bumped into a server URL length limit of approximately 4,000 characters, after which Apache produces a "413 Entity Too Large" error. The current up to date Apache build found in Red Hat Enterprise Linux 4 was used. The official Apache documentation only mentions an 8,192-byte limit on an individual field in a request.

  • Microsoft Internet Information Server (Server)
    The default limit is 16,384 characters (yes, Microsoft's web server accepts longer URLs than Microsoft's web browser). This is configurable.

  • Perl HTTP::Daemon (Server)
    Up to 8,000 bytes will work. Those constructing web application servers with Perl's HTTP::Daemon module will encounter a 16,384 byte limit on the combined size of all HTTP request headers. This does not include POST-method form data, file uploads, etc., but it does include the URL. In practice this resulted in a 413 error when a URL was significantly longer than 8,000 characters. This limitation can be easily removed. Look for all occurrences of 16x1024 in Daemon.pm and replace them with a larger value. Of course, this does increase your exposure to denial of service attacks.

How to set up subdomains on IIS 7

As DotNetMensch said but you DO NOT need to add another site in IIS as this can also cause further problems and make things more complicated because you then have a website within a website so the file paths, masterpage paths and web.config paths may need changing. You just need to edit teh bindings of the existing site and add the new subdomain there.

So:

  1. Add sub-domain to DNS records. My host (RackSpace) uses a web portal to do this so you just log in and go to Network->Domains(DNS)->Actions->Create Zone, and enter your subdomain as mysubdomain.domain.com etc, leave the other settings as default

  2. Go to your domain in IIS, right-click->Edit Bindings->Add, and add your new subdomain leaving everything else the same e.g. mysubdomain.domain.com

You may need to wait 5-10 mins for the DNS records to update but that's all you need.

PHP MySQL Query Where x = $variable

$result = mysqli_query($con,"SELECT `note` FROM `glogin_users` WHERE email = '".$email."'");
while($row = mysqli_fetch_array($result))
echo $row['note'];

Upload files with FTP using PowerShell

I am not sure you can 100% bullet proof the script from not hanging or crashing, as there are things outside your control (what if the server loses power mid-upload?) - but this should provide a solid foundation for getting you started:

# create the FtpWebRequest and configure it
$ftp = [System.Net.FtpWebRequest]::Create("ftp://localhost/me.png")
$ftp = [System.Net.FtpWebRequest]$ftp
$ftp.Method = [System.Net.WebRequestMethods+Ftp]::UploadFile
$ftp.Credentials = new-object System.Net.NetworkCredential("anonymous","anonymous@localhost")
$ftp.UseBinary = $true
$ftp.UsePassive = $true
# read in the file to upload as a byte array
$content = [System.IO.File]::ReadAllBytes("C:\me.png")
$ftp.ContentLength = $content.Length
# get the request stream, and write the bytes into it
$rs = $ftp.GetRequestStream()
$rs.Write($content, 0, $content.Length)
# be sure to clean up after ourselves
$rs.Close()
$rs.Dispose()

How to use Google Translate API in my Java application?

Generate your own API key here. Check out the documentation here.

You may need to set up a billing account when you try to enable the Google Cloud Translation API in your account.

Below is a quick start example which translates two English strings to Spanish:

import java.io.IOException;
import java.security.GeneralSecurityException;
import java.util.Arrays;

import com.google.api.client.googleapis.javanet.GoogleNetHttpTransport;
import com.google.api.client.json.gson.GsonFactory;
import com.google.api.services.translate.Translate;
import com.google.api.services.translate.model.TranslationsListResponse;
import com.google.api.services.translate.model.TranslationsResource;

public class QuickstartSample
{
    public static void main(String[] arguments) throws IOException, GeneralSecurityException
    {
        Translate t = new Translate.Builder(
                GoogleNetHttpTransport.newTrustedTransport()
                , GsonFactory.getDefaultInstance(), null)
                // Set your application name
                .setApplicationName("Stackoverflow-Example")
                .build();
        Translate.Translations.List list = t.new Translations().list(
                Arrays.asList(
                        // Pass in list of strings to be translated
                        "Hello World",
                        "How to use Google Translate from Java"),
                // Target language
                "ES");

        // TODO: Set your API-Key from https://console.developers.google.com/
        list.setKey("your-api-key");
        TranslationsListResponse response = list.execute();
        for (TranslationsResource translationsResource : response.getTranslations())
        {
            System.out.println(translationsResource.getTranslatedText());
        }
    }
}

Required maven dependencies for the code snippet:

<dependency>
    <groupId>com.google.cloud</groupId>
    <artifactId>google-cloud-translate</artifactId>
    <version>LATEST</version>
</dependency>

<dependency>
    <groupId>com.google.http-client</groupId>
    <artifactId>google-http-client-gson</artifactId>
    <version>LATEST</version>
</dependency>

Grouping functions (tapply, by, aggregate) and the *apply family

On the side note, here is how the various plyr functions correspond to the base *apply functions (from the intro to plyr document from the plyr webpage http://had.co.nz/plyr/)

Base function   Input   Output   plyr function 
---------------------------------------
aggregate        d       d       ddply + colwise 
apply            a       a/l     aaply / alply 
by               d       l       dlply 
lapply           l       l       llply  
mapply           a       a/l     maply / mlply 
replicate        r       a/l     raply / rlply 
sapply           l       a       laply 

One of the goals of plyr is to provide consistent naming conventions for each of the functions, encoding the input and output data types in the function name. It also provides consistency in output, in that output from dlply() is easily passable to ldply() to produce useful output, etc.

Conceptually, learning plyr is no more difficult than understanding the base *apply functions.

plyr and reshape functions have replaced almost all of these functions in my every day use. But, also from the Intro to Plyr document:

Related functions tapply and sweep have no corresponding function in plyr, and remain useful. merge is useful for combining summaries with the original data.

Putty: Getting Server refused our key Error

Oh my God I spent days trying to fix this. So here is what worked for me. I went back to the root fold like this: cd /root/ mkdir .ssh cd .ssh chmod 700 .ssh nano -w authorized_keys service ssh restart So I used root to logging via Putty and it worked. so try to do the same with the user you want to use in putty.

How to remove the default link color of the html hyperlink 'a' tag?

Simply add this in CSS,

a {
    color: inherit;
    text-decoration: none;
}

that's it, done.

android adb turn on wifi via adb

You can turn on wifi : - connect usb on pc; - will show alert dialog "connect UMS mode or KIES" - do not click, do not cancel - pull notification bar and turn on wifi.

How to install sshpass on mac?

Please follow the steps below to install sshpass in mac.

curl -O -L https://fossies.org/linux/privat/sshpass-1.06.tar.gz && tar xvzf sshpass-1.06.tar.gz

cd sshpass-1.06

./configure

sudo make install

SQL Server Script to create a new user

Full admin rights for the whole server, or a specific database? I think the others answered for a database, but for the server:

USE [master];
GO
CREATE LOGIN MyNewAdminUser 
    WITH PASSWORD    = N'abcd',
    CHECK_POLICY     = OFF,
    CHECK_EXPIRATION = OFF;
GO
EXEC sp_addsrvrolemember 
    @loginame = N'MyNewAdminUser', 
    @rolename = N'sysadmin';

You may need to leave off the CHECK_ parameters depending on what version of SQL Server Express you are using (it is almost always useful to include this information in your question).

Warning: Cannot modify header information - headers already sent by ERROR

Those blank lines between your ?> and <?php tags are being sent to the client.

When the first one of those is sent, it causes your headers to be sent first.

Once that happens, you can't modify the headers any more.

Remove those unnecessary tags, have it all in one big <?php block.

Setting up SSL on a local xampp/apache server

It turns out that OpenSSL is compiled and enabled in php 5.3 of XAMPP 1.7.2 and so no longer requires a separate extension dll.

However, you STILL need to enable it in your PHP.ini file the line extension=php_openssl.dll

SQLSTATE[HY000] [2002] php_network_getaddresses: getaddrinfo failed: Name or service not known

In my case, when laravel generated the .env configuration file, laravel also generated two uncommented "DB_HOST" lines at line 11 and 12, delete the one that says "mysql" and uncomment (if yours it's commented) the other one (the one with the localhost ip 127.0.0.1) and it worked. (In my case).

Have a great day

Delimiters in MySQL

When you create a stored routine that has a BEGIN...END block, statements within the block are terminated by semicolon (;). But the CREATE PROCEDURE statement also needs a terminator. So it becomes ambiguous whether the semicolon within the body of the routine terminates CREATE PROCEDURE, or terminates one of the statements within the body of the procedure.

The way to resolve the ambiguity is to declare a distinct string (which must not occur within the body of the procedure) that the MySQL client recognizes as the true terminator for the CREATE PROCEDURE statement.

Should I use encodeURI or encodeURIComponent for encoding URLs?

encodeURIComponent() : assumes that its argument is a portion (such as the protocol, hostname, path, or query string) of a URI. Therefore it escapes the punctuation characters that are used to separate the portionsof a URI.

encodeURI(): is used for encoding existing url

Python: Select subset from list based on index set

Matlab and Scilab languages offer a simpler and more elegant syntax than Python for the question you're asking, so I think the best you can do is to mimic Matlab/Scilab by using the Numpy package in Python. By doing this the solution to your problem is very concise and elegant:

from numpy import *
property_a = array([545., 656., 5.4, 33.])
property_b = array([ 1.2,  1.3, 2.3, 0.3])
good_objects = [True, False, False, True]
good_indices = [0, 3]
property_asel = property_a[good_objects]
property_bsel = property_b[good_indices]

Numpy tries to mimic Matlab/Scilab but it comes at a cost: you need to declare every list with the keyword "array", something which will overload your script (this problem doesn't exist with Matlab/Scilab). Note that this solution is restricted to arrays of number, which is the case in your example.

Looking for a short & simple example of getters/setters in C#

C# introduces properties which do most of the heavy lifting for you...

ie

public string Name { get; set; }

is a C# shortcut to writing...

private string _name;

public string getName { return _name; }
public void setName(string value) { _name = value; }

Basically getters and setters are just means of helping encapsulation. When you make a class you have several class variables that perhaps you want to expose to other classes to allow them to get a glimpse of some of the data you store. While just making the variables public to begin with may seem like an acceptable alternative, in the long run you will regret letting other classes manipulate your classes member variables directly. If you force them to do it through a setter, you can add logic to ensure no strange values ever occur, and you can always change that logic in the future without effecting things already manipulating this class.

ie

private string _name;

public string getName { return _name; }
public void setName(string value) 
{ 
    //Don't want things setting my Name to null
    if (value == null) 
    {
        throw new InvalidInputException(); 
    }
    _name = value; 
}

apache and httpd running but I can't see my website

Did you restart the server after you changed the config file?

Can you telnet to the server from a different machine?

Can you telnet to the server from the server itself?

telnet <ip address> 80

telnet localhost 80

struct in class

Your E class doesn't have a member of type struct X, you've just defined a nested struct X in there (i.e. you've defined a new type).

Try:

#include <iostream>

class E
{
    public: 
    struct X { int v; };
    X x; // an instance of `struct X`
};

int main(){

    E object;
    object.x.v = 1;

    return 0;
}

Replace tabs with spaces in vim

Try

set expandtab

for soft tabs.

To fix pre-existing tabs:

:%s/\t/  /g

I used two spaces since you already set your tabstop to 2 spaces.

How to change value for innodb_buffer_pool_size in MySQL on Mac OS?

add this to your my.cnf

innodb_buffer_pool_size=1G

restart your mysql to make it effect

Postgresql : syntax error at or near "-"

i was trying trying to GRANT read-only privileges to a particular table to a user called walters-ro. So when i ran the sql command # GRANT SELECT ON table_name TO walters-ro; --- i got the following error..`syntax error at or near “-”

The solution to this was basically putting the user_name into double quotes since there is a dash(-) between the name.

# GRANT SELECT ON table_name TO "walters-ro";

That solved the problem.

show icon in actionbar/toolbar with AppCompat-v7 21

For Actionbar:

getActionBar().setDisplayHomeAsUpEnabled(true);
getActionBar().setHomeAsUpIndicator(R.drawable.ic_action_back);

For Toolbar:

getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setHomeAsUpIndicator(R.drawable.ic_action_back);

Defining static const integer members in class definition

Another way to do this, for integer types anyway, is to define constants as enums in the class:

class test
{
public:
    enum { N = 10 };
};

Spring cron expression for every after 30 minutes

Graphically, the cron syntax for Quarz is (source):

+-------------------- second (0 - 59)
|  +----------------- minute (0 - 59)
|  |  +-------------- hour (0 - 23)
|  |  |  +----------- day of month (1 - 31)
|  |  |  |  +-------- month (1 - 12)
|  |  |  |  |  +----- day of week (0 - 6) (Sunday=0 or 7)
|  |  |  |  |  |  +-- year [optional]
|  |  |  |  |  |  |
*  *  *  *  *  *  * command to be executed 

So if you want to run a command every 30 minutes you can say either of these:

0 0/30 * * * * ?
0 0,30 * * * * ?

You can check crontab expressions using either of these:

  • crontab.guru — (disclaimer: I am not related to that page at all, only that I find it very useful). This page uses UNIX style of cron that does not have seconds in it, while Spring does as the first field.
  • Cron Expression Generator & Explainer - Quartz — cron formatter, allowing seconds also.

Change image source in code behind - Wpf

None of the methods worked for me as i needed to pull the image from a folder instead of adding it to the application. The below code worked:

TestImage.Source = GetImage("/Content/Images/test.png")

private static BitmapImage GetImage(string imageUri)
{
    var bitmapImage = new BitmapImage();
    
    bitmapImage.BeginInit();
    bitmapImage.UriSource = new Uri("pack://siteoforigin:,,,/" + imageUri,             UriKind.RelativeOrAbsolute);
    bitmapImage.EndInit();
    
    return bitmapImage;
} 

Turn off warnings and errors on PHP and MySQL

When you are sure your script is perfectly working, you can get rid of warning and notices like this: Put this line at the beginning of your PHP script:

error_reporting(E_ERROR);

Before that, when working on your script, I would advise you to properly debug your script so that all notice or warning disappear one by one.

So you should first set it as verbose as possible with:

error_reporting(E_ERROR | E_WARNING | E_PARSE | E_NOTICE);

UPDATE: how to log errors instead of displaying them

As suggested in the comments, the better solution is to log errors into a file so only the PHP developer sees the error messages, not the users.

A possible implementation is via the .htaccess file, useful if you don't have access to the php.ini file (source).

# Suppress PHP errors
php_flag display_startup_errors off
php_flag display_errors off
php_flag html_errors off
php_value docref_root 0
php_value docref_ext 0

# Enable PHP error logging
php_flag  log_errors on
php_value error_log  /home/path/public_html/domain/PHP_errors.log

# Prevent access to PHP error log
<Files PHP_errors.log>
 Order allow,deny
 Deny from all
 Satisfy All
</Files>

RecyclerView - Get view at particular position

You can simply use "findViewHolderForAdapterPosition" method of recycler view and you will get a viewHolder object from that then typecast that viewholder into your adapter viewholder so you can directly access your viewholder's views

following is the sample code for kotlin

 val viewHolder = recyclerView.findViewHolderForAdapterPosition(position)
 val textview=(viewHolder as YourViewHolder).yourTextView

How do I update Ruby Gems from behind a Proxy (ISA-NTLM)

If you are having problems getting authenticated through your proxy, be sure to set the environment variables in exactly the format below:

set HTTP_PROXY=some.proxy.com
set HTTP_PROXY_USER=user
set HTTP_PROXY_PASS=password

The user:password@ syntax doesn't seem to work and there are also some badly named environment variables floating around on Stack Overflow and various forum posts.

Also be aware that it can take a while for your gems to start downloading. At first I thought it wasn't working but with a bit of patience they started downloading as expected.

chai test array equality doesn't work as expected

For expect, .equal will compare objects rather than their data, and in your case it is two different arrays.

Use .eql in order to deeply compare values. Check out this link.
Or you could use .deep.equal in order to simulate same as .eql.
Or in your case you might want to check .members.

For asserts you can use .deepEqual, link.

Razor Views not seeing System.Web.Mvc.HtmlHelper

I used the following article on MSDN to solve this issue (in this case from MVC 4 to MVC 5)

https://docs.microsoft.com/en-us/aspnet/mvc/overview/releases/how-to-upgrade-an-aspnet-mvc-4-and-web-api-project-to-aspnet-mvc-5-and-web-api-2

Main extracts from the article are:

Main Web.config (Not the one in the Views folder)

In the runtime block update System.Web.Mvc to 5.0.0.0 ,System.Web.Helpers to 3.0.0.0 and System.Web.WebPages to 3.0.0.0

<dependentAssembly>
  <assemblyIdentity name="System.Web.Helpers" publicKeyToken="31bf3856ad364e35" />
  <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0" />
</dependentAssembly>

<dependentAssembly>
  <assemblyIdentity name="System.Web.Mvc" publicKeyToken="31bf3856ad364e35" />
  <bindingRedirect oldVersion="1.0.0.0-5.0.0.0" newVersion="5.0.0.0" />
</dependentAssembly>

<dependentAssembly>
  <assemblyIdentity name="System.Web.WebPages" publicKeyToken="31bf3856ad364e35" />
  <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0" />
</dependentAssembly>

Then look for the appsettings block and update the webpages:Version value to 3.0.0.0

<appSettings>
    <add key="webpages:Version" value="3.0.0.0" />
</appSettings>

Views Web.config

Update the host factoryType block to System.Web.Mvc to 5.0.0.0

<system.web.webPages.razor>
   <host factoryType="System.Web.Mvc.MvcWebRazorHostFactory, System.Web.Mvc, Version=5.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
   <pages pageBaseType="System.Web.Mvc.WebViewPage">
      <namespaces>
         <add namespace="System.Web.Mvc" />
      </namespaces>
   </pages>
</system.web.webPages.razor>

Then under the pages block update any references to System.Web.Mvc to 5.0.0.0

    <pages
      validateRequest="false"
      pageParserFilterType="System.Web.Mvc.ViewTypeParserFilter, System.Web.Mvc, Version=5.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"
      pageBaseType="System.Web.Mvc.ViewPage, System.Web.Mvc, Version=5.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"
      userControlBaseType="System.Web.Mvc.ViewUserControl, System.Web.Mvc, Version=5.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
    <controls>
      <add assembly="System.Web.Mvc, Version=5.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" namespace="System.Web.Mvc" tagPrefix="mvc" />
    </controls>
  </pages>

And finally under the configuration block update the System.Web references to 3.0.0.0

<configuration>
  <configSections>
    <sectionGroup name="system.web.webPages.razor" type="System.Web.WebPages.Razor.Configuration.RazorWebSectionGroup, System.Web.WebPages.Razor, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
      <section name="host" type="System.Web.WebPages.Razor.Configuration.HostSection, System.Web.WebPages.Razor, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" />
      <section name="pages" type="System.Web.WebPages.Razor.Configuration.RazorPagesSection, System.Web.WebPages.Razor, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" />
    </sectionGroup>
  </configSections>

How to return a table from a Stored Procedure?

In SQL Server 2008 you can use

http://www.sommarskog.se/share_data.html#tableparam

or else simple and same as common execution

CREATE PROCEDURE OrderSummary @MaxQuantity INT OUTPUT AS

SELECT Ord.EmployeeID, SummSales = SUM(OrDet.UnitPrice * OrDet.Quantity)
FROM Orders AS Ord
     JOIN [Order Details] AS OrDet ON (Ord.OrderID = OrDet.OrderID)
GROUP BY Ord.EmployeeID
ORDER BY Ord.EmployeeID

SELECT @MaxQuantity = MAX(Quantity) FROM [Order Details]

RETURN (SELECT SUM(Quantity) FROM [Order Details])
GO

I hopes its help to you

How to use setArguments() and getArguments() methods in Fragments?

If you are using navigation components and navigation graph create a bundle like this

val bundle = bundleOf(KEY to VALUE) // or whatever you would like to create the bundle

then when navigating to the other fragment use this:

findNavController().navigate(
        R.id.action_navigate_from_frag1_to_frag2,
        bundle
    )

and when you land the destination fragment u can access that bundle using

Bundle b = getArguments()// in Java

or

val b = arguments// in kotlin

Declare a constant array

As others have mentioned, there is no official Go construct for this. The closest I can imagine would be a function that returns a slice. In this way, you can guarantee that no one will manipulate the elements of the original slice (as it is "hard-coded" into the array).

I have shortened your slice to make it...shorter...:

func GetLetterGoodness() []float32 {
    return []float32 { .0817,.0149,.0278,.0425,.1270,.0223 }
}

How to overcome "datetime.datetime not JSON serializable"?

This Q repeats time and time again - a simple way to patch the json module such that serialization would support datetime.

import json
import datetime

json.JSONEncoder.default = lambda self,obj: (obj.isoformat() if isinstance(obj, datetime.datetime) else None)

Than use json serialization as you always do - this time with datetime being serialized as isoformat.

json.dumps({'created':datetime.datetime.now()})

Resulting in: '{"created": "2015-08-26T14:21:31.853855"}'

See more details and some words of caution at: StackOverflow: JSON datetime between Python and JavaScript

How do I use Assert.Throws to assert the type of the exception?

A solution that actually works:

public void Test() {
    throw new MyCustomException("You can't do that!");
}

[TestMethod]
public void ThisWillPassIfExceptionThrown()
{
    var exception = Assert.ThrowsException<MyCustomException>(
        () => Test(),
        "This should have thrown!");
    Assert.AreEqual("You can't do that!", exception.Message);
}

This works with using Microsoft.VisualStudio.TestTools.UnitTesting;.

Postgres: How to convert a json string to text?

There is no way in PostgreSQL to deconstruct a scalar JSON object. Thus, as you point out,

select  length(to_json('Some "text"'::TEXT) ::TEXT);

is 15,

The trick is to convert the JSON into an array of one JSON element, then extract that element using ->>.

select length( array_to_json(array[to_json('Some "text"'::TEXT)])->>0 );

will return 11.

Virtual/pure virtual explained

From Wikipedia's Virtual function ...

In object-oriented programming, in languages such as C++, and Object Pascal, a virtual function or virtual method is an inheritable and overridable function or method for which dynamic dispatch is facilitated. This concept is an important part of the (runtime) polymorphism portion of object-oriented programming (OOP). In short, a virtual function defines a target function to be executed, but the target might not be known at compile time.

Unlike a non-virtual function, when a virtual function is overridden the most-derived version is used at all levels of the class hierarchy, rather than just the level at which it was created. Therefore if one method of the base class calls a virtual method, the version defined in the derived class will be used instead of the version defined in the base class.

This is in contrast to non-virtual functions, which can still be overridden in a derived class, but the "new" version will only be used by the derived class and below, but will not change the functionality of the base class at all.

whereas..

A pure virtual function or pure virtual method is a virtual function that is required to be implemented by a derived class if the derived class is not abstract.

When a pure virtual method exists, the class is "abstract" and can not be instantiated on its own. Instead, a derived class that implements the pure-virtual method(s) must be used. A pure-virtual isn't defined in the base-class at all, so a derived class must define it, or that derived class is also abstract, and can not be instantiated. Only a class that has no abstract methods can be instantiated.

A virtual provides a way to override the functionality of the base class, and a pure-virtual requires it.

Checking whether a String contains a number value in Java

You could use a regex to find out if the String contains a number. Take a look at the matches() method.

MVC Razor view nested foreach's model

The quick answer is to use a for() loop in place of your foreach() loops. Something like:

@for(var themeIndex = 0; themeIndex < Model.Theme.Count(); themeIndex++)
{
   @Html.LabelFor(model => model.Theme[themeIndex])

   @for(var productIndex=0; productIndex < Model.Theme[themeIndex].Products.Count(); productIndex++)
   {
      @Html.LabelFor(model=>model.Theme[themeIndex].Products[productIndex].name)
      @for(var orderIndex=0; orderIndex < Model.Theme[themeIndex].Products[productIndex].Orders; orderIndex++)
      {
          @Html.TextBoxFor(model => model.Theme[themeIndex].Products[productIndex].Orders[orderIndex].Quantity)
          @Html.TextAreaFor(model => model.Theme[themeIndex].Products[productIndex].Orders[orderIndex].Note)
          @Html.EditorFor(model => model.Theme[themeIndex].Products[productIndex].Orders[orderIndex].DateRequestedDeliveryFor)
      }
   }
}

But this glosses over why this fixes the problem.

There are three things that you have at least a cursory understanding before you can resolve this issue. I have to admit that I cargo-culted this for a long time when I started working with the framework. And it took me quite a while to really get what was going on.

Those three things are:

  • How do the LabelFor and other ...For helpers work in MVC?
  • What is an Expression Tree?
  • How does the Model Binder work?

All three of these concepts link together to get an answer.

How do the LabelFor and other ...For helpers work in MVC?

So, you've used the HtmlHelper<T> extensions for LabelFor and TextBoxFor and others, and you probably noticed that when you invoke them, you pass them a lambda and it magically generates some html. But how?

So the first thing to notice is the signature for these helpers. Lets look at the simplest overload for TextBoxFor

public static MvcHtmlString TextBoxFor<TModel, TProperty>(
    this HtmlHelper<TModel> htmlHelper,
    Expression<Func<TModel, TProperty>> expression
) 

First, this is an extension method for a strongly typed HtmlHelper, of type <TModel>. So, to simply state what happens behind the scenes, when razor renders this view it generates a class. Inside of this class is an instance of HtmlHelper<TModel> (as the property Html, which is why you can use @Html...), where TModel is the type defined in your @model statement. So in your case, when you are looking at this view TModel will always be of the type ViewModels.MyViewModels.Theme.

Now, the next argument is a bit tricky. So lets look at an invocation

@Html.TextBoxFor(model=>model.SomeProperty);

It looks like we have a little lambda, And if one were to guess the signature, one might think that the type for this argument would simply be a Func<TModel, TProperty>, where TModel is the type of the view model and TProperty is inferred as the type of the property.

But thats not quite right, if you look at the actual type of the argument its Expression<Func<TModel, TProperty>>.

So when you normally generate a lambda, the compiler takes the lambda and compiles it down into MSIL, just like any other function (which is why you can use delegates, method groups, and lambdas more or less interchangeably, because they are just code references.)

However, when the compiler sees that the type is an Expression<>, it doesn't immediately compile the lambda down to MSIL, instead it generates an Expression Tree!

What is an Expression Tree?

So, what the heck is an expression tree. Well, it's not complicated but its not a walk in the park either. To quote ms:

| Expression trees represent code in a tree-like data structure, where each node is an expression, for example, a method call or a binary operation such as x < y.

Simply put, an expression tree is a representation of a function as a collection of "actions".

In the case of model=>model.SomeProperty, the expression tree would have a node in it that says: "Get 'Some Property' from a 'model'"

This expression tree can be compiled into a function that can be invoked, but as long as it's an expression tree, it's just a collection of nodes.

So what is that good for?

So Func<> or Action<>, once you have them, they are pretty much atomic. All you can really do is Invoke() them, aka tell them to do the work they are supposed to do.

Expression<Func<>> on the other hand, represents a collection of actions, which can be appended, manipulated, visited, or compiled and invoked.

So why are you telling me all this?

So with that understanding of what an Expression<> is, we can go back to Html.TextBoxFor. When it renders a textbox, it needs to generate a few things about the property that you are giving it. Things like attributes on the property for validation, and specifically in this case it needs to figure out what to name the <input> tag.

It does this by "walking" the expression tree and building a name. So for an expression like model=>model.SomeProperty, it walks the expression gathering the properties that you are asking for and builds <input name='SomeProperty'>.

For a more complicated example, like model=>model.Foo.Bar.Baz.FooBar, it might generate <input name="Foo.Bar.Baz.FooBar" value="[whatever FooBar is]" />

Make sense? It is not just the work that the Func<> does, but how it does its work is important here.

(Note other frameworks like LINQ to SQL do similar things by walking an expression tree and building a different grammar, that this case a SQL query)

How does the Model Binder work?

So once you get that, we have to briefly talk about the model binder. When the form gets posted, it's simply like a flat Dictionary<string, string>, we have lost the hierarchical structure our nested view model may have had. It's the model binder's job to take this key-value pair combo and attempt to rehydrate an object with some properties. How does it do this? You guessed it, by using the "key" or name of the input that got posted.

So if the form post looks like

Foo.Bar.Baz.FooBar = Hello

And you are posting to a model called SomeViewModel, then it does the reverse of what the helper did in the first place. It looks for a property called "Foo". Then it looks for a property called "Bar" off of "Foo", then it looks for "Baz"... and so on...

Finally it tries to parse the value into the type of "FooBar" and assign it to "FooBar".

PHEW!!!

And voila, you have your model. The instance the Model Binder just constructed gets handed into requested Action.


So your solution doesn't work because the Html.[Type]For() helpers need an expression. And you are just giving them a value. It has no idea what the context is for that value, and it doesn't know what to do with it.

Now some people suggested using partials to render. Now this in theory will work, but probably not the way that you expect. When you render a partial, you are changing the type of TModel, because you are in a different view context. This means that you can describe your property with a shorter expression. It also means when the helper generates the name for your expression, it will be shallow. It will only generate based on the expression it's given (not the entire context).

So lets say you had a partial that just rendered "Baz" (from our example before). Inside that partial you could just say:

@Html.TextBoxFor(model=>model.FooBar)

Rather than

@Html.TextBoxFor(model=>model.Foo.Bar.Baz.FooBar)

That means that it will generate an input tag like this:

<input name="FooBar" />

Which, if you are posting this form to an action that is expecting a large deeply nested ViewModel, then it will try to hydrate a property called FooBar off of TModel. Which at best isn't there, and at worst is something else entirely. If you were posting to a specific action that was accepting a Baz, rather than the root model, then this would work great! In fact, partials are a good way to change your view context, for example if you had a page with multiple forms that all post to different actions, then rendering a partial for each one would be a great idea.


Now once you get all of this, you can start to do really interesting things with Expression<>, by programatically extending them and doing other neat things with them. I won't get into any of that. But, hopefully, this will give you a better understanding of what is going on behind the scenes and why things are acting the way that they are.

Convert txt to csv python script

import pandas as pd
df = pd.read_fwf('log.txt')
df.to_csv('log.csv')

IF... OR IF... in a windows batch file

I realize this question is old, but I wanted to post an alternate solution in case anyone else (like myself) found this thread while having the same question. I was able to work around the lack of an OR operator by echoing the variable and using findstr to validate.

for /f %%v in ('echo %var% ^| findstr /x /c:"1" /c:"2"') do (
    if %errorlevel% equ 0 echo true
)

String comparison in Objective-C

Use the -isEqualToString: method to compare the value of two strings. Using the C == operator will simply compare the addresses of the objects.

if ([category isEqualToString:@"Some String"])
{
    // Do stuff...
}

SQL-Server: Error - Exclusive access could not be obtained because the database is in use

I got this error when unbeknownst to me, someone else was connected to the database in another SSMS session. After I signed them out the restore completed successfully.

When is a language considered a scripting language?

I think Mr Roberto Ierusalimschy has a very good answer or the question in 'Programming in Lua':

However, the distinguishing feature of interpreted languages is not that they are not compiled, but that any compiler is part of the language runtime and that, therefore, it is possible (and easy) to execute code generated on the fly

Firebase cloud messaging notification not received by device

In my case, I just turn on WIFI and mobile data in the emulator and it works like a charm. cause I can't send comments, post a reply. Good luck

How to copy file from HDFS to the local file system

you can accomplish in both these ways.

1.hadoop fs -get <HDFS file path> <Local system directory path>
2.hadoop fs -copyToLocal <HDFS file path> <Local system directory path>

Ex:

My files are located in /sourcedata/mydata.txt I want to copy file to Local file system in this path /user/ravi/mydata

hadoop fs -get /sourcedata/mydata.txt /user/ravi/mydata/

HTML5 phone number validation with pattern

This code will accept all country code with + sign

<input type="text" pattern="[0-9]{5}[-][0-9]{7}[-][0-9]{1}"/>

Some countries allow a single "0" character instead of "+" and others a double "0" character instead of the "+". Neither are standard.

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

This trick worked for me, although I admit that this is probably not the best way to solve this problem. Instead of trying this, you should see why the javascripts aren't loading. Try keeping a local copy of the script in your server, etc. or check with the third party vendor from where you are trying to download the script.

Anyways, so here's the workaround: 1) Initialize a variable to false 2) Set it to true when the javascript loads (using the onload attribute) 3) check if the variable is true or false once the HTML body has loaded

<html>
  <head>
    <script>
      var scriptLoaded = false;

      function checkScriptLoaded() {
        if (scriptLoaded) {
          // do something here
        } else {
          // do something else here!
        }
      }
    </script>
    <script src="http://some-external-script.js" onload="scriptLoaded=true;" />
  </head>
  <body onload="checkScriptLoaded()">
    <p>My Test Page!</p>
  </body>
</html>

javascript remove "disabled" attribute from html input

Best answer is just removeAttribute

element.removeAttribute("disabled");

NSDate get year/month/day

New In iOS 8

ObjC

NSDate *date = [NSDate date];
NSInteger era, year, month, day;
[[NSCalendar currentCalendar] getEra:&era year:&year month:&month day:&day fromDate:date];

Swift

let date = NSDate.init()
var era = 0, year = 0, month = 0, day = 0
NSCalendar.currentCalendar().getEra(&era, year:&year, month:&month, day:&day, fromDate: date)

What is the default boolean value in C#?

The default value is indeed false.

However you can't use a local variable is it's not been assigned first.

You can use the default keyword to verify:

bool foo = default(bool);
if (!foo) { Console.WriteLine("Default is false"); }

Getting the client IP address: REMOTE_ADDR, HTTP_X_FORWARDED_FOR, what else could be useful?

It depends on the nature of your site.

I happen to work on a bit of software where IP tracking is important, and within a field consumed by parter sites I'd guess some 20% - 40% of requests are either detectably spoofed IPs or headers blanked out, depending on the time of day and where they came from. For a site which gets organic traffic (i.e. not through partners) I'd expect a much higher ratio of good IPs.

As Kosi said, be careful what you're doing with this - IPs are in no way a reliable way to identify unique visitors.

Getting distance between two points based on latitude/longitude

Update: 04/2018: Note that Vincenty distance is deprecated since GeoPy version 1.13 - you should use geopy.distance.distance() instead!


The answers above are based on the Haversine formula, which assumes the earth is a sphere, which results in errors of up to about 0.5% (according to help(geopy.distance)). Vincenty distance uses more accurate ellipsoidal models such as WGS-84, and is implemented in geopy. For example,

import geopy.distance

coords_1 = (52.2296756, 21.0122287)
coords_2 = (52.406374, 16.9251681)

print geopy.distance.vincenty(coords_1, coords_2).km

will print the distance of 279.352901604 kilometers using the default ellipsoid WGS-84. (You can also choose .miles or one of several other distance units).

permission denied - php unlink

// Path relative to where the php file is or absolute server path
chdir($FilePath); // Comment this out if you are on the same folder
chown($FileName,465); //Insert an Invalid UserId to set to Nobody Owner; for instance 465
$do = unlink($FileName);

if($do=="1"){ 
    echo "The file was deleted successfully."; 
} else { echo "There was an error trying to delete the file."; } 

Try this. Hope it helps.

PHP - Notice: Undefined index:

You're getting errors because you're attempting to read post variables that haven't been set, they only get set on form submission. Wrap your php code at the bottom in an

if ($_SERVER['REQUEST_METHOD'] === 'POST') { ... }

Also, your code is ripe for SQL injection. At the very least use mysql_real_escape_string on the post vars before using them in SQL queries. mysql_real_escape_string is not good enough for a production site, but should score you extra points in class.

How to map to multiple elements with Java 8 streams?

It's an interesting question, because it shows that there are a lot of different approaches to achieve the same result. Below I show three different implementations.


Default methods in Collection Framework: Java 8 added some methods to the collections classes, that are not directly related to the Stream API. Using these methods, you can significantly simplify the implementation of the non-stream implementation:

Collection<DataSet> convert(List<MultiDataPoint> multiDataPoints) {
    Map<String, DataSet> result = new HashMap<>();
    multiDataPoints.forEach(pt ->
        pt.keyToData.forEach((key, value) ->
            result.computeIfAbsent(
                key, k -> new DataSet(k, new ArrayList<>()))
            .dataPoints.add(new DataPoint(pt.timestamp, value))));
    return result.values();
}

Stream API with flatten and intermediate data structure: The following implementation is almost identical to the solution provided by Stuart Marks. In contrast to his solution, the following implementation uses an anonymous inner class as intermediate data structure.

Collection<DataSet> convert(List<MultiDataPoint> multiDataPoints) {
    return multiDataPoints.stream()
        .flatMap(mdp -> mdp.keyToData.entrySet().stream().map(e ->
            new Object() {
                String key = e.getKey();
                DataPoint dataPoint = new DataPoint(mdp.timestamp, e.getValue());
            }))
        .collect(
            collectingAndThen(
                groupingBy(t -> t.key, mapping(t -> t.dataPoint, toList())),
                m -> m.entrySet().stream().map(e -> new DataSet(e.getKey(), e.getValue())).collect(toList())));
}

Stream API with map merging: Instead of flattening the original data structures, you can also create a Map for each MultiDataPoint, and then merge all maps into a single map with a reduce operation. The code is a bit simpler than the above solution:

Collection<DataSet> convert(List<MultiDataPoint> multiDataPoints) {
    return multiDataPoints.stream()
        .map(mdp -> mdp.keyToData.entrySet().stream()
            .collect(toMap(e -> e.getKey(), e -> asList(new DataPoint(mdp.timestamp, e.getValue())))))
        .reduce(new HashMap<>(), mapMerger())
        .entrySet().stream()
        .map(e -> new DataSet(e.getKey(), e.getValue()))
        .collect(toList());
}

You can find an implementation of the map merger within the Collectors class. Unfortunately, it is a bit tricky to access it from the outside. Following is an alternative implementation of the map merger:

<K, V> BinaryOperator<Map<K, List<V>>> mapMerger() {
    return (lhs, rhs) -> {
        Map<K, List<V>> result = new HashMap<>();
        lhs.forEach((key, value) -> result.computeIfAbsent(key, k -> new ArrayList<>()).addAll(value));
        rhs.forEach((key, value) -> result.computeIfAbsent(key, k -> new ArrayList<>()).addAll(value));
        return result;
    };
}

Regex to match 2 digits, optional decimal, two digits

You mentioned that you want the regex to match each of those strings, yet you previously mention that the is 1-2 digits before the decimal?

This will match 1-2 digits followed by a possible decimal, followed by another 1-2 digits but FAIL on your example of .33

\d{1,2}\.?\d{1,2}

This will match 0-2 digits followed by a possible deciaml, followed by another 1-2 digits and match on your example of .33

\d{0,2}\.?\d{1,2}

Not sure exactly which one you're looking for.

How to generate random number with the specific length in python

Does 0 count as a possible first digit? If so, then you need random.randint(0,10**n-1). If not, random.randint(10**(n-1),10**n-1). And if zero is never allowed, then you'll have to explicitly reject numbers with a zero in them, or draw n random.randint(1,9) numbers.

Aside: it is interesting that randint(a,b) uses somewhat non-pythonic "indexing" to get a random number a <= n <= b. One might have expected it to work like range, and produce a random number a <= n < b. (Note the closed upper interval.)

Given the responses in the comments about randrange, note that these can be replaced with the cleaner random.randrange(0,10**n), random.randrange(10**(n-1),10**n) and random.randrange(1,10).

How can I get the current date and time in the terminal and set a custom command in the terminal for it?

You can use date to get time and date of a day:

[pengyu@GLaDOS ~]$date
Tue Aug 27 15:01:27 CST 2013

Also hwclock would do:

[pengyu@GLaDOS ~]$hwclock
Tue 27 Aug 2013 03:01:29 PM CST  -0.516080 seconds

For customized output, you can either redirect the output of date to something like awk, or write your own program to do that.

Remember to put your own executable scripts/binary into your PATH (e.g. /usr/bin) to make it invokable anywhere.

CMake is not able to find BOOST libraries

I just want to point out that the FindBoost macro might be looking for an earlier version, for instance, 1.58.0 when you might have 1.60.0 installed. I suggest popping open the FindBoost macro from whatever it is you are attempting to build, and checking if that's the case. You can simply edit it to include your particular version. (This was my problem.)

How to assign a select result to a variable?

In order to assign a variable safely you have to use the SET-SELECT statement:

SET @PrimaryContactKey = (SELECT c.PrimaryCntctKey
    FROM tarcustomer c, tarinvoice i
    WHERE i.custkey = c.custkey 
    AND i.invckey = @tmp_key)

Make sure you have both a starting and an ending parenthesis!

The reason the SET-SELECT version is the safest way to set a variable is twofold.

1. The SELECT returns several posts

What happens if the following select results in several posts?

SELECT @PrimaryContactKey = c.PrimaryCntctKey
FROM tarcustomer c, tarinvoice i
WHERE i.custkey = c.custkey 
    AND i.invckey = @tmp_key

@PrimaryContactKey will be assigned the value from the last post in the result.

In fact @PrimaryContactKey will be assigned one value per post in the result, so it will consequently contain the value of the last post the SELECT-command was processing.

Which post is "last" is determined by any clustered indexes or, if no clustered index is used or the primary key is clustered, the "last" post will be the most recently added post. This behavior could, in a worst case scenario, be altered every time the indexing of the table is changed.

With a SET-SELECT statement your variable will be set to null.

2. The SELECT returns no posts

What happens, when using the second version of the code, if your select does not return a result at all?

In a contrary to what you may believe the value of the variable will not be null - it will retain it's previous value!

This is because, as stated above, SQL will assign a value to the variable once per post - meaning it won't do anything with the variable if the result contains no posts. So, the variable will still have the value it had before you ran the statement.

With the SET-SELECT statement the value will be null.

See also: SET versus SELECT when assigning variables?

How to Join to first row

@Quassnoi answer is good, in some cases (especially if the outer table is big), a more efficient query might be with using windowed functions, like this:

SELECT  Orders.OrderNumber, LineItems2.Quantity, LineItems2.Description
FROM    Orders
LEFT JOIN 
        (
        SELECT  LineItems.Quantity, LineItems.Description, OrderId, ROW_NUMBER()
                OVER (PARTITION BY OrderId ORDER BY (SELECT NULL)) AS RowNum
        FROM    LineItems

        ) LineItems2 ON LineItems2.OrderId = Orders.OrderID And RowNum = 1

Sometimes you just need to test which query gives better performance.

Check if String contains only letters

First import Pattern :

import java.util.regex.Pattern;

Then use this simple code:

String s = "smith23";
if (Pattern.matches("[a-zA-Z]+",s)) { 
  // Do something
  System.out.println("Yes, string contains letters only");
}else{
  System.out.println("Nope, Other characters detected");    
}

This will output:

Nope, Other characters detected

Prevent textbox autofill with previously entered values

Trying from the CodeBehind:

Textbox1.Attributes.Add("autocomplete", "off");

Delete all rows in a table based on another table

This will delete all rows in Table1 that match the criteria:

DELETE Table1 
FROM Table2 
WHERE Table1.JoinColumn = Table2.JoinColumn And Table1.SomeStuff = 'SomeStuff'

How to insert data into SQL Server

I think you lack to pass Connection object to your command object. and it is much better if you will use command and parameters for that.

using (SqlConnection connection = new SqlConnection("ConnectionStringHere"))
{
    using (SqlCommand command = new SqlCommand())
    {
        command.Connection = connection;            // <== lacking
        command.CommandType = CommandType.Text;
        command.CommandText = "INSERT into tbl_staff (staffName, userID, idDepartment) VALUES (@staffName, @userID, @idDepart)";
        command.Parameters.AddWithValue("@staffName", name);
        command.Parameters.AddWithValue("@userID", userId);
        command.Parameters.AddWithValue("@idDepart", idDepart);

        try
        {
            connection.Open();
            int recordsAffected = command.ExecuteNonQuery();
        }
        catch(SqlException)
        {
            // error here
        }
        finally
        {
            connection.Close();
        }
    }
}

reStructuredText tool support

Salvaging (and extending) the list from an old version of the Wikipedia page:

Documentation

Implementations

Although the reference implementation of reStructuredText is written in Python, there are reStructuredText parsers in other languages too.

Python - Docutils

The main distribution of reStructuredText is the Python Docutils package. It contains several conversion tools:

  • rst2html - from reStructuredText to HTML
  • rst2xml - from reStructuredText to XML
  • rst2latex - from reStructuredText to LaTeX
  • rst2odt - from reStructuredText to ODF Text (word processor) document.
  • rst2s5 - from reStructuredText to S5, a Simple Standards-based Slide Show System
  • rst2man - from reStructuredText to Man page

Haskell - Pandoc

Pandoc is a Haskell library for converting from one markup format to another, and a command-line tool that uses this library. It can read Markdown and (subsets of) reStructuredText, HTML, and LaTeX, and it can write Markdown, reStructuredText, HTML, LaTeX, ConTeXt, PDF, RTF, DocBook XML, OpenDocument XML, ODT, GNU Texinfo, MediaWiki markup, groff man pages, and S5 HTML slide shows.

There is an Pandoc online tool (POT) to try this library. Unfortunately, compared to the reStructuredText online renderer (ROR),

  • POT truncates input rather more shortly. The POT user must render input in chunks that could be rendered whole by the ROR.
  • POT output lacks the helpful error messages displayed by the ROR (and generated by docutils)

Java - JRst

JRst is a Java reStructuredText parser. It can currently output HTML, XHTML, DocBook xdoc and PDF, BUT seems to have serious problems: neither PDF or (X)HTML generation works using the current full download, result pages in (X)HTML are empty and PDF generation fails on IO problems with XSL files (not bundled??). Note that the original JRst has been removed from the website; a fork is found on GitHub.

Scala - Laika

Laika is a new library for transforming markup languages to other output formats. Currently it supports input from Markdown and reStructuredText and produce HTML output. The library is written in Scala but should be also usable from Java.

Perl

PHP

C#/.NET

Nim/C

The Nim compiler features the commands rst2htmland rst2tex which transform reStructuredText files to HTML and TeX files. The standard library provides the following modules (used by the compiler) to handle reStructuredText files programmatically:

  • rst - implements a reStructuredText parser
  • rstast - implements an AST for the reStructuredText parser
  • rstgen - implements a generator of HTML/Latex from reStructuredText

Other 3rd party converters

Most (but not all) of these tools are based on Docutils (see above) and provide conversion to or from formats that might not be supported by the main distribution.

From reStructuredText

  • restview - This pip-installable python package requires docutils, which does the actual rendering. restview's major ease-of-use feature is that, when you save changes to your document(s), it automagically re-renders and re-displays them. restview
    1. starts a small web server
    2. calls docutils to render your document(s) to HTML
    3. calls your device's browser to display the output HTML.
  • rst2pdf - from reStructuredText to PDF
  • rst2odp - from reStructuredText to ODF Presentation
  • rst2beamer - from reStructuredText to LaTeX beamer Presentation class
  • Wikir - from reStructuredText to a Google (and possibly other) Wiki formats
  • rst2qhc - Convert a collection of reStructuredText files into a Qt (toolkit) Help file and (optional) a Qt Help Project file

To reStructuredText

  • xml2rst is an XSLT script to convert Docutils internal XML representation (back) to reStructuredText
  • Pandoc (see above) can also convert from Markdown, HTML and LaTeX to reStructuredText
  • db2rst is a simple and limited DocBook to reStructuredText translator
  • pod2rst - convert .pod files to reStructuredText files

Extensions

Some projects use reStructuredText as a baseline to build on, or provide extra functionality extending the utility of the reStructuredText tools.

Sphinx

The Sphinx documentation generator translates a set of reStructuredText source files into various output formats, automatically producing cross-references, indices etc.

rest2web

rest2web is a simple tool that lets you build your website from a single template (or as many as you want), and keep the contents in reStructuredText.

Pygments

Pygments is a generic syntax highlighter for general use in all kinds of software such as forum systems, Wikis or other applications that need to prettify source code. See Using Pygments in reStructuredText documents.

Free Editors

While any plain text editor is suitable to write reStructuredText documents, some editors have better support than others.

Emacs

The Emacs support via rst-mode comes as part of the Docutils package under /docutils/tools/editors/emacs/rst.el

Vim

The vim-common package for that comes with most GNU/Linux distributions has reStructuredText syntax highlight and indentation support of reStructuredText out of the box:

Jed

There is a rst mode for the Jed programmers editor.

gedit

gedit, the official text editor of the GNOME desktop environment. There is a gedit reStructuredText plugin.

Geany

Geany, a small and lightweight Integrated Development Environment include support for reStructuredText from version 0.12 (October 10, 2007).

Leo

Leo, an outlining editor for programmers, supports reStructuredText via rst-plugin or via "@auto-rst" nodes (it's not well-documented, but @auto-rst nodes allow editing rst files directly, parsing the structure into the Leo outline).

It also provides a way to preview the resulting HTML, in a "viewrendered" pane.

FTE

The FTE Folding Text Editor - a free (licensed under the GNU GPL) text editor for developers. FTE has a mode for reStructuredText support. It provides color highlighting of basic RSTX elements and special menu that provide easy way to insert most popular RSTX elements to a document.

PyK

PyK is a successor of PyEdit and reStInPeace, written in Python with the help of the Qt4 toolkit.

Eclipse

The Eclipse IDE with the ReST Editor plug-in provides support for editing reStructuredText files.

NoTex

NoTex is a browser based (general purpose) text editor, with integrated project management and syntax highlighting. Plus it enables to write books, reports, articles etc. using rST and convert them to LaTex, PDF or HTML. The PDF files are of high publication quality and are produced via Sphinx with the Texlive LaTex suite.

Notepad++

Notepad++ is a general purpose text editor for Windows. It has syntax highlighting for many languages built-in and support for reStructuredText via a user defined language for reStructuredText.

Visual Studio Code

Visual Studio Code is a general purpose text editor for Windows/macOS/Linux. It has syntax highlighting for many languages built-in and supports reStructuredText via an extension from LeXtudio.

Dedicated reStructuredText Editors

Proprietary editors

Sublime Text

Sublime Text is a completely customizable and extensible source code editor available for Windows, OS X, and Linux. Registration is required for long-term use, but all functions are available in the unregistered version, with occasional reminders to purchase a license. Versions 2 and 3 (currently in beta) support reStructuredText syntax highlighting by default, and several plugins are available through the package manager Package Control to provide snippets and code completion, additional syntax highlighting, conversion to/from RST and other formats, and HTML preview in the browser.

BBEdit / TextWrangler

BBEdit (and its free variant TextWrangler) for Mac can syntax-highlight reStructuredText using this codeless language module.

TextMate

TextMate, a proprietary general-purpose GUI text editor for Mac OS X, has a bundle for reStructuredText.

Intype

Intype is a proprietary text editor for Windows, that support reStructuredText out of the box.

E Text Editor

E is a proprietary Text Editor licensed under the "Open Company License". It supports TextMate's bundles, so it should support reStructuredText the same way TextMate does.

PyCharm

PyCharm (and other IntelliJ platform IDEs?) has ReST/Sphinx support (syntax highlighting, autocomplete and preview).instant preview)

Wiki

here are some Wiki programs that support the reStructuredText markup as the native markup syntax, or as an add-on:

MediaWiki

MediaWiki reStructuredText extension allows for reStructuredText markup in MediaWiki surrounded by <rst> and </rst>.

MoinMoin

MoinMoin is an advanced, easy to use and extensible WikiEngine with a large community of users. Said in a few words, it is about collaboration on easily editable web pages.

There is a reStructuredText Parser for MoinMoin.

Trac

Trac is an enhanced wiki and issue tracking system for software development projects. There is a reStructuredText Support in Trac.

This Wiki

This Wiki is a Webware for Python Wiki written by Ian Bicking. This wiki uses ReStructuredText for its markup.

rstiki

rstiki is a minimalist single-file personal wiki using reStructuredText syntax (via docutils) inspired by pwyky. It does not support authorship indication, versioning, hierarchy, chrome/framing/templating or styling. It leverages docutils/reStructuredText as the wiki syntax. As such, it's under 200 lines of code, and in a single file. You put it in a directory and it runs.

ikiwiki

Ikiwiki is a wiki compiler. It converts wiki pages into HTML pages suitable for publishing on a website. Ikiwiki stores pages and history in a revision control system such as Subversion or Git. There are many other features, including support for blogging, as well as a large array of plugins. It's reStructuredText plugin, however is somewhat limited and is not recommended as its' main markup language at this time.

Web Services

Sandbox

An Online reStructuredText editor can be used to play with the markup and see the results immediately.

Blogging frameworks

WordPress

WordPreSt reStructuredText plugin for WordPress. (PHP)

Zine

reStructuredText parser plugin for Zine (will become obsolete in version 0.2 when Zine is scheduled to get a native reStructuredText support). Zine is discontinued. (Python)

pelican

Pelican is a static blog generator that supports writing articles in ReST. (Python)

hyde

Hyde is a static website generator that supports ReST. (Python)

Acrylamid

Acrylamid is a static blog generator that supports writing articles in ReST. (Python)

Nikola

Nikola is a Static Site and Blog Generator that supports ReST. (Python)

ipsum genera

Ipsum genera is a static blog generator written in Nim.

Yozuch

Yozuch is a static blog generator written in Python.

More

Android fastboot waiting for devices

In my case (on windows 10), it would connect fine to adb and I could type any adb commands. But as soon as it got to the bootloader using adb reboot bootloader I wasn't able to perform any fastboot commands.

What I did notice that in the device manager that it refreshed when I connected to device. Next thing to do was to check what changed when connecting. Apparently the fastboot device was inside the Kedacom USB Device. Not really sure what that was, but I updated the device to use a different driver, in my case the Fastboot interface (Google USB ID), and that fixed my waiting for device issue

jQuery each loop in table row

Use immediate children selector >:

$('#tblOne > tbody  > tr')

Description: Selects all direct child elements specified by "child" of elements specified by "parent".

Detect Scroll Up & Scroll down in ListView

To also detect scrolling with larger elements, I prefere an onTouch Listener:

listview.setOnTouchListener(new View.OnTouchListener() {

        int scrollEventListSize = 5; 
        float lastY;
        // Used to correct for occasions when user scrolls down(/up) but the onTouchListener detects it incorrectly. We will store detected up-/down-scrolls with -1/1 in this list and evaluate later which occured more often
        List<Integer> downScrolledEventsHappened;

        @Override
        public boolean onTouch(View v, MotionEvent event) {

            float diff = 0;
            if(event.getAction() == event.ACTION_DOWN){
                lastY = event.getY();
                downScrolledEventsHappened = new LinkedList<Integer>();
            }
            else if(event.getAction() == event.ACTION_MOVE){
                diff = event.getY() - lastY;
                lastY = event.getY();

                if(diff>0)
                    downScrolledEventsHappened.add(1);
                else 
                    downScrolledEventsHappened.add(-1);

               //List needs to be filled with some events, will happen very quickly
                if(downScrolledEventsHappened.size() == scrollEventListSize+1){
                    downScrolledEventsHappened.remove(0);
                    int res=0;
                    for(int i=0; i<downScrolledEventsHappened.size(); i++){
                        res+=downScrolledEventsHappened.get(i);
                    }

                    if (res > 0) 
                        Log.i("INFO", "Scrolled up");
                    else 
                        Log.i("INFO", "Scrolled down");
                }
            }
            return false; // don't interrupt the event-chain
        }
    });

if statement in ng-click

Write as

<input type="submit" ng-click="profileForm.$valid==true?updateMyProfile():''" name="submit" value="Save" class="submit" id="submit">

How to make promises work in IE11

You could try using a Polyfill. The following Polyfill was published in 2019 and did the trick for me. It assigns the Promise function to the window object.

used like: window.Promise https://www.npmjs.com/package/promise-polyfill

If you want more information on Polyfills check out the following MDN web doc https://developer.mozilla.org/en-US/docs/Glossary/Polyfill

Checking letter case (Upper/Lower) within a string in Java

package passwordValidator;

import java.util.Scanner;

public class Main {
    /**
     * @author felipe mello.
     */

    private static Scanner scanner = new Scanner(System.in);

     /*
     * Create a password validator(from an input string) via TDD
     * The validator should return true if
     *  The Password is at least 8 characters long
     *  The Password contains uppercase Letters(atLeastOne)
     *  The Password contains digits(at least one)
     *  The Password contains symbols(at least one)
     */


    public static void main(String[] args) {
        System.out.println("Please enter a password");
        String password = scanner.nextLine();   

        checkPassword(password);
    }
    /**
     * 
     * @param checkPassword the method check password is validating the input from the the user and check if it matches the password requirements
     * @return
     */
    public static boolean checkPassword(String password){
        boolean upperCase = !password.equals(password.toLowerCase()); //check if the input has a lower case letter
        boolean lowerCase = !password.equals(password.toUpperCase()); //check if the input has a CAPITAL case letter
        boolean isAtLeast8 = password.length()>=8;                    //check if the input is greater than 8 characters
        boolean hasSpecial = !password.matches("[A-Za-z0-9]*");       // check if the input has a special characters
        boolean hasNumber = !password.matches(".*\\d+.*");            //check if the input contains a digit
        if(!isAtLeast8){
            System.out.println("Your Password is not big enough\n please enter a password with minimun of 8 characters");
            return true;
        }else if(!upperCase){
            System.out.println("Password must contain at least one UPPERCASE letter");
            return true;
        }else if(!lowerCase){
            System.out.println("Password must contain at least one lower case letter");
            return true;
        }else if(!hasSpecial){
            System.out.println("Password must contain a special character");
            return true;
        }else if(hasNumber){
            System.out.println("Password must contain at least one number");
            return true;
        }else{
            System.out.println("Your password: "+password+", sucessfully match the requirements");
            return true;
        }

    }
}

explicit casting from super class to subclass

By using a cast you're essentially telling the compiler "trust me. I'm a professional, I know what I'm doing and I know that although you can't guarantee it, I'm telling you that this animal variable is definitely going to be a dog."

Since the animal isn't actually a dog (it's an animal, you could do Animal animal = new Dog(); and it'd be a dog) the VM throws an exception at runtime because you've violated that trust (you told the compiler everything would be ok and it's not!)

The compiler is a bit smarter than just blindly accepting everything, if you try and cast objects in different inheritence hierarchies (cast a Dog to a String for example) then the compiler will throw it back at you because it knows that could never possibly work.

Because you're essentially just stopping the compiler from complaining, every time you cast it's important to check that you won't cause a ClassCastException by using instanceof in an if statement (or something to that effect.)

How to check if a variable is empty in python?

Just use not:

if not your_variable:
    print("your_variable is empty")

and for your 0 as string use:

if your_variable == "0":
    print("your_variable is 0 (string)")

combine them:

if not your_variable or your_variable == "0":
    print("your_variable is empty")

Python is about simplicity, so is this answer :)

How can I get a collection of keys in a JavaScript dictionary?

Use Object.keys() or shim it in older browsers...

const keys = Object.keys(driversCounter);

If you wanted values, there is Object.values() and if you want key and value, you can use Object.entries(), often paired with Array.prototype.forEach() like this...

Object.entries(driversCounter).forEach(([key, value]) => {
   console.log(key, value);
});

Alternatively, considering your use case, maybe this will do it...

var selectBox, option, prop;

selectBox = document.getElementById("drivers");

for (prop in driversCounter) {
   option = document.createElement("option");
   option.textContent = prop;
   option.value = driversCounter[prop];
   selectBox.add(option);
}

Python "string_escape" vs "unicode_escape"

According to my interpretation of the implementation of unicode-escape and the unicode repr in the CPython 2.6.5 source, yes; the only difference between repr(unicode_string) and unicode_string.encode('unicode-escape') is the inclusion of wrapping quotes and escaping whichever quote was used.

They are both driven by the same function, unicodeescape_string. This function takes a parameter whose sole function is to toggle the addition of the wrapping quotes and escaping of that quote.

Select objects based on value of variable in object using jq

I had a similar related question: What if you wanted the original object format back (with key names, e.g. FOO, BAR)?

Jq provides to_entries and from_entries to convert between objects and key-value pair arrays. That along with map around the select

These functions convert between an object and an array of key-value pairs. If to_entries is passed an object, then for each k: v entry in the input, the output array includes {"key": k, "value": v}.

from_entries does the opposite conversion, and with_entries(foo) is a shorthand for to_entries | map(foo) | from_entries, useful for doing some operation to all keys and values of an object. from_entries accepts key, Key, name, Name, value and Value as keys.

jq15 < json 'to_entries | map(select(.value.location=="Stockholm")) | from_entries'

{
  "FOO": {
    "name": "Donald",
    "location": "Stockholm"
  },
  "BAR": {
    "name": "Walt",
    "location": "Stockholm"
  }
}

Using the with_entries shorthand, this becomes:

jq15 < json 'with_entries(select(.value.location=="Stockholm"))'
{
  "FOO": {
    "name": "Donald",
    "location": "Stockholm"
  },
  "BAR": {
    "name": "Walt",
    "location": "Stockholm"
  }
}

Java abstract interface

An abstract Interface is not as redundant as everyone seems to be saying, in theory at least.

An Interface can be extended, just as a Class can. If you design an Interface hierarchy for your application you may well have a 'Base' Interface, you extend other Interfaces from but do not want as an Object in itself.

Example:

public abstract interface MyBaseInterface {
    public String getName();
}

public interface MyBoat extends MyBaseInterface {
    public String getMastSize();
}

public interface MyDog extends MyBaseInterface {
    public long tinsOfFoodPerDay();
}

You do not want a Class to implement the MyBaseInterface, only the other two, MMyDog and MyBoat, but both interfaces share the MyBaseInterface interface, so have a 'name' property.

I know its kinda academic, but I thought some might find it interesting. :-)

It is really just a 'marker' in this case, to signal to implementors of the interface it wasn't designed to be implemented on its own. I should point out a compiler (At least the sun/ora 1.6 I tried it with) compiles a class that implements an abstract interface.

Could not load dynamic library 'cudart64_101.dll' on tensorflow CPU-only installation

I installed cudatoolkit 11 and copy dll C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v11.1\bin to C:\Windows\System32. It fixed for PyCharm but not for Anaconda jupyter:

[name: "/device:CPU:0" device_type: "CPU" memory_limit: 268435456 locality { } incarnation: 6812190123916921346 , name: "/device:GPU:0" device_type: "GPU" memory_limit: 13429637120 locality { bus_id: 1
links { } } incarnation: 18025633343883307728 physical_device_desc: "device: 0, name: Quadro P5000, pci bus id: 0000:02:00.0, compute capability: 6.1" ]

How to use a FolderBrowserDialog from a WPF application

OK, figured it out now - thanks to Jobi whose answer was close, but not quite.

From a WPF application, here's my code that works:

First a helper class:

private class OldWindow : System.Windows.Forms.IWin32Window
{    
    IntPtr _handle;    
    public OldWindow(IntPtr handle)
    {
        _handle = handle;
    }   

    #region IWin32Window Members    
    IntPtr System.Windows.Forms.IWin32Window.Handle
    {
        get { return _handle; }
    }    
    #endregion
}

Then, to use this:

    System.Windows.Forms.FolderBrowserDialog dlg = new FolderBrowserDialog();
    HwndSource source = PresentationSource.FromVisual(this) as HwndSource;
    System.Windows.Forms.IWin32Window win = new OldWindow(source.Handle);
    System.Windows.Forms.DialogResult result = dlg.ShowDialog(win);

I'm sure I can wrap this up better, but basically it works. Yay! :-)

Fixed position but relative to container

My project is .NET ASP Core 2 MVC Angular 4 template with Bootstrap 4. Adding "sticky-top" into main app component html (i.e. app.component.html) on the first row worked, as follows:

_x000D_
_x000D_
<div class='row sticky-top'>_x000D_
    <div class='col-sm-12'>_x000D_
        <nav-menu-top></nav-menu-top>_x000D_
    </div>_x000D_
</div>_x000D_
<div class="row">_x000D_
    <div class='col-sm-3'>_x000D_
        <nav-menu></nav-menu>_x000D_
    </div>_x000D_
    <div class='col-sm-9 body-content'>_x000D_
        <router-outlet></router-outlet>_x000D_
    </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Is that the convention or did I oversimplify this?

Multiple conditions in an IF statement in Excel VBA

In VBA we can not use if jj = 5 or 6 then we must use if jj = 5 or jj = 6 then

maybe this:

If inputWks.Range("d9") > 0 And (inputWks.Range("d11") = "Restricted_Expenditure" Or inputWks.Range("d11") = "Unrestricted_Expenditure") Then

How to generate List<String> from SQL query?

Where the data returned is a string; you could cast to a different data type:

(from DataRow row in dataTable.Rows select row["columnName"].ToString()).ToList();

How to sum the values of one column of a dataframe in spark/scala

You must first import the functions:

import org.apache.spark.sql.functions._

Then you can use them like this:

val df = CSV.load(args(0))
val sumSteps =  df.agg(sum("steps")).first.get(0)

You can also cast the result if needed:

val sumSteps: Long = df.agg(sum("steps").cast("long")).first.getLong(0)

Edit:

For multiple columns (e.g. "col1", "col2", ...), you could get all aggregations at once:

val sums = df.agg(sum("col1").as("sum_col1"), sum("col2").as("sum_col2"), ...).first

Edit2:

For dynamically applying the aggregations, the following options are available:

  • Applying to all numeric columns at once:
df.groupBy().sum()
  • Applying to a list of numeric column names:
val columnNames = List("col1", "col2")
df.groupBy().sum(columnNames: _*)
  • Applying to a list of numeric column names with aliases and/or casts:
val cols = List("col1", "col2")
val sums = cols.map(colName => sum(colName).cast("double").as("sum_" + colName))
df.groupBy().agg(sums.head, sums.tail:_*).show()

Best way to import Observable from rxjs

One thing I've learnt the hard way is being consistent

Watch out for mixing:

 import { BehaviorSubject } from "rxjs";

with

 import { BehaviorSubject } from "rxjs/BehaviorSubject";

This will probably work just fine UNTIL you try to pass the object to another class (where you did it the other way) and then this can fail

 (myBehaviorSubject instanceof Observable)

It fails because the prototype chain will be different and it will be false.

I can't pretend to understand exactly what is happening but sometimes I run into this and need to change to the longer format.

SVG rounded corner

Just to simplify implementing answer of @hmak.me, here's a commented piece of React code to generate rounded rectangles.

const Rect = ({width, height, round, strokeWidth}) => {
    // overhang over given width and height that we get due to stroke width
    const s = strokeWidth / 2;

    // how many pixels do we need to cut from vertical and horizontal parts
    // due to rounded corners and stroke width
    const over = 2 * round + strokeWidth;

    // lengths of straight lines
    const w = width - over;
    const h = height - over;

    // beware that extra spaces will not be minified
    // they are added for clarity
    const d = `
        M${round + s},${s}
        h${w}
        a${round},${round} 0 0 1 ${round},${round}
        v${h}
        a${round},${round} 0 0 1 -${round},${round}
        h-${w}
        a${round},${round} 0 0 1 -${round},-${round}
        v-${h}
        a${round},${round} 0 0 1 ${round},-${round}
        z
    `;
    return (
        <svg width={width} height={height}>
            <path d={d} fill="none" stroke="black" strokeWidth={strokeWidth} />
        </svg>
    );
};

ReactDOM.render(
    <Rect width={64} height={32} strokeWidth={2} round={4} />,
    document.querySelector('#app'),
);

Jsfiddle link.

Accessing Object Memory Address

With ctypes, you can achieve the same thing with

>>> import ctypes
>>> a = (1,2,3)
>>> ctypes.addressof(a)
3077760748L

Documentation:

addressof(C instance) -> integer
Return the address of the C instance internal buffer

Note that in CPython, currently id(a) == ctypes.addressof(a), but ctypes.addressof should return the real address for each Python implementation, if

  • ctypes is supported
  • memory pointers are a valid notion.

Edit: added information about interpreter-independence of ctypes

python pandas dataframe columns convert to dict key and value

You can also do this if you want to play around with pandas. However, I like punchagan's way.

# replicating your dataframe
lake = pd.DataFrame({'co tp': ['DE Lake', 'Forest', 'FR Lake', 'Forest'], 
                 'area': [10, 20, 30, 40], 
                 'count': [7, 5, 2, 3]})
lake.set_index('co tp', inplace=True)

# to get key value using pandas
area_dict = lake.set_index('area').T.to_dict('records')[0]
print(area_dict)

output: {10: 7, 20: 5, 30: 2, 40: 3}

Creating an instance of class

  1. Allocates some dynamic memory from the free store, and creates an object in that memory using its default constructor. You never delete it, so the memory is leaked.
  2. Does exactly the same as 1; in the case of user-defined types, the parentheses are optional.
  3. Allocates some automatic memory, and creates an object in that memory using its default constructor. The memory is released automatically when the object goes out of scope.
  4. Similar to 3. Notionally, the named object foo4 is initialised by default-constructing, copying and destroying a temporary object; usually, this is elided giving the same result as 3.
  5. Allocates a dynamic object, then initialises a second by copying the first. Both objects are leaked; and there's no way to delete the first since you don't keep a pointer to it.
  6. Does exactly the same as 5.
  7. Does not compile. Foo foo5 is a declaration, not an expression; function (and constructor) arguments must be expressions.
  8. Creates a temporary object, and initialises a dynamic object by copying it. Only the dynamic object is leaked; the temporary is destroyed automatically at the end of the full expression. Note that you can create the temporary with just Foo() rather than the equivalent Foo::Foo() (or indeed Foo::Foo::Foo::Foo::Foo())

When do I use each?

  1. Don't, unless you like unnecessary decorations on your code.
  2. When you want to create an object that outlives the current scope. Remember to delete it when you've finished with it, and learn how to use smart pointers to control the lifetime more conveniently.
  3. When you want an object that only exists in the current scope.
  4. Don't, unless you think 3 looks boring and what to add some unnecessary decoration.
  5. Don't, because it leaks memory with no chance of recovery.
  6. Don't, because it leaks memory with no chance of recovery.
  7. Don't, because it won't compile
  8. When you want to create a dynamic Bar from a temporary Foo.

Passing an array of data as an input parameter to an Oracle procedure

If the types of the parameters are all the same (varchar2 for example), you can have a package like this which will do the following:

CREATE OR REPLACE PACKAGE testuser.test_pkg IS

   TYPE assoc_array_varchar2_t IS TABLE OF VARCHAR2(4000) INDEX BY BINARY_INTEGER;

   PROCEDURE your_proc(p_parm IN assoc_array_varchar2_t);

END test_pkg;

CREATE OR REPLACE PACKAGE BODY testuser.test_pkg IS

   PROCEDURE your_proc(p_parm IN assoc_array_varchar2_t) AS
   BEGIN
      FOR i IN p_parm.first .. p_parm.last
      LOOP
         dbms_output.put_line(p_parm(i));
      END LOOP;

   END;

END test_pkg;

Then, to call it you'd need to set up the array and pass it:

DECLARE
  l_array testuser.test_pkg.assoc_array_varchar2_t;
BEGIN
  l_array(0) := 'hello';
  l_array(1) := 'there';  

  testuser.test_pkg.your_proc(l_array);
END;
/

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

You can try this code

Dictionary<string,string> AllFields = new Dictionary<string,string>();  
string value = (AllFields.TryGetValue(key, out index) ? AllFields[key] : null);

If the key is not present, it simply returns a null value.

React onClick and preventDefault() link refresh/redirect?

I didn't find any of the mentioned options to be correct or work for me when I came to this page. They did give me ideas to test things out and I found that this worked for me.

dontGoToLink(e) {
  e.preventDefault();
 }

render() {
  return (<a href="test.com" onClick={this.dontGoToLink} />});
}

How to change the font and font size of an HTML input tag?

in your css :

 #txtComputer {
      font-size: 24px;
 }

You can style an input entirely (background, color, etc.) and even use the hover event.

What is an .inc and why use it?

It's just a way for the developer to be able to easily identify files which are meant to be used as includes. It's a popular convention. It does not have any special meaning to PHP, and won't change the behaviour of PHP or the script itself.

Save plot to image file instead of displaying it using Matplotlib

You can do it like this:

def plotAFig():
  plt.figure()
  plt.plot(x,y,'b-')
  plt.savefig("figurename.png")
  plt.close()

VBScript How can I Format Date?

This snippet also solve this question with datePart function. I've also used the right() trick to perform a rpad(x,2,"0").

option explicit

Wscript.Echo "Today is " & myDate(now)

' date formatted as your request
Function myDate(dt)
    dim d,m,y, sep
    sep = "-"
    ' right(..) here works as rpad(x,2,"0")
    d = right("0" & datePart("d",dt),2)
    m = right("0" & datePart("m",dt),2)
    y = datePart("yyyy",dt)
    myDate= m & sep & d & sep & y
End Function

Calculate AUC in R?

Calculating AUC with Metrics package is very easy and straightforward:

library(Metrics)

actual <- c(0, 0, 1, 1)
predicted <- c(.1, .3, .3, .9)

auc(actual, predicted)

0.875

The localhost page isn’t working localhost is currently unable to handle this request. HTTP ERROR 500

Such kind of error normally happens when you try using functions like php_info() wrongly.

<?php 
     php_info(); // 500 error
     phpinfo(); // Works correctly
?>

A close look at your code will be better.

Error message "Linter pylint is not installed"

I would like to add my trials and my solution following rob3c's answer.

PS: My solution only concerns Windows users.

The problem:

I tried the following settings without success:

// settings.json
"python.linting.pylintPath": ${workspaceFolder}\\_tools\\python3\\Scripts\\pylint

and

"python.linting.pylintPath": ${workspaceFolder}\\_tools\\python3\\Scripts\\pylint.exe

I always had the following error message:

Linter 'pylint' is not installed. Please install it or select another linter".
Error: spawn c:\WS\myproject\_tools\python3\Scripts\pylint ENOENT

Even with a pylint file in my folder:

dir c:\WS\myproject\_tools\python3\Scripts\
...
05.07.2017  09:34 AM                52 pylint    # ! no pylint.exe !
...

As my toolchain is based on MSYS, the Pylint installed is without pylint.exe.

The content of _tools\python3\Scripts\pylint file:

#!python
from pylint import run_pylint
run_pylint()

The solution

My workaround was to create a batch file .vscode\pylint.bat with the following contents:

%PYTHON3_EXE% _prefix\python3\Scripts\pylint %*

(%PYTHON3_EXE% is an environment variable to the Python 3 interpreter C:\Python34\python.exe)

And to configure .vscode\settings.json as follows:

// settings.json
"python.linting.pylintPath": "${workspaceFolder}\\.vscode\\pylint.bat",

Result

Log from OUTPUT --> Python:

##########Linting Output - pylint##########

c:\WS\myproject> C:\Python34\python.exe _tools\python3\Scripts\pylint
--rcfile c:\WS\framework\pylintrc
--msg-template='{line},{column},{category},{msg_id}:{msg}'
--reports=n
--output-format=text
c:\WS\myproject\myScriptToLint.py
Using config file c:\WS\myproject\pylintrc

------------------------------------

Your code has been rated at 10.00/10

? Visual Studio Code uses the Pylint version from my toolchain!

Can a relative sitemap url be used in a robots.txt?

Google crawlers are not smart enough, they can't crawl relative URLs, that's why it's always recommended to use absolute URL's for better crawlability and indexability.

Therefore, you can not use this variation

> sitemap: /sitemap.xml

Recommended syntax is

Sitemap: https://www.yourdomain.com/sitemap.xml

Note:

  • Don't forgot to capitalise the first letter in "sitemap"
  • Don't forgot to put space after "Sitemap:"

Move SQL data from one table to another

Try this

INSERT INTO TABLE2 (Cols...) SELECT Cols... FROM TABLE1 WHERE Criteria

Then

DELETE FROM TABLE1 WHERE Criteria

How to check if a process is in hang state (Linux)

Unfortunately there is no hung state for a process. Now hung can be deadlock. This is block state. The threads in the process are blocked. The other things could be live lock where the process is running but doing the same thing again and again. This process is in running state. So as you can see there is no definite hung state. As suggested you can use the top command to see if the process is using 100% CPU or lot of memory.

What is the Auto-Alignment Shortcut Key in Eclipse?

Auto-alignment? Lawful good?

If you mean formatting, then Ctrl+Shift+F.

Node.js - SyntaxError: Unexpected token import

I'm shocked esm hasn't been mentioned. This small, but mighty package allows you to use either import or require.

Install esm in your project

$ npm install --save esm

Update your Node Start Script to use esm

node -r esm app.js

esm just works. I wasted a TON of time with .mjs and --experimental-modules only to find out a .mjs file cannot import a file that uses require or module.exports. This was a huge problem, whereas esm allows you to mix and match and it just figures it out... esm just works.

How to format time since xxx e.g. “4 minutes ago” similar to Stack Exchange sites

Simple and readable version:

const NOW = new Date()
const times = [["second", 1], ["minute", 60], ["hour", 3600], ["day", 86400], ["week", 604800], ["month", 2592000], ["year", 31536000]]

function timeAgo(date) {
    var diff = Math.round((NOW - date) / 1000)
    for (var t = 0; t < times.length; t++) {
        if (diff < times[t][1]) {
            if (t == 0) {
                return "Just now"
            } else {
                diff = Math.round(diff / times[t - 1][1])
                return diff + " " + times[t - 1][0] + (diff == 1?" ago":"s ago")
            }
        }
    }
}

Filtering Pandas Dataframe using OR statement

From the docs:

Another common operation is the use of boolean vectors to filter the data. The operators are: | for or, & for and, and ~ for not. These must be grouped by using parentheses.

http://pandas.pydata.org/pandas-docs/version/0.15.2/indexing.html#boolean-indexing

Try:

alldata_balance = alldata[(alldata[IBRD] !=0) | (alldata[IMF] !=0)]

Find the files existing in one directory but not in the other

This should do the job:

diff -rq dir1 dir2

Options explained (via diff(1) man page):

  • -r - Recursively compare any subdirectories found.
  • -q - Output only whether files differ.

The project type is not supported by this installation

If you are using VS 2010 and it is a ASP.NET project make sure you have the Visual Developer installed from the VS 2010 CD. This is not the free one, but part of what is required to work on ASP.NET projects in Visual Studio.

Migration: Cannot add foreign key constraint

Be aware: when Laravel sets up a table using

$table->increments('id');

which is standard in most migrations, this will set up an unsigned integer field. Therefore when making a foreign reference from another table to this field, ensure that in the referencing table, you set the field to UnsignedInteger and not (what I'd assumed to be an) UnsignedBigInteger field.

For example: in the migration file 2018_12_12_123456_create_users_table.php:

Schema::create('users', function (Blueprint $table){
    $table->increments('id');
    $table->string('name');
    $table->timestamps();

Then in the migration file 2018_12_12_18000000_create_permissions_table.php, which sets up the foreign reference back to users:

Schema::create('permissions', function (Blueprint $table){
    $table->increments('id');
    $table->UnsignedInteger('user_id'); // UnsignedInteger = "increments" in users table
    $table->boolean('admin');
    $table->boolean('enabled');
    $table->timestamps();

    // set up relationship
    $table->foreign('user_id')->reference('id')->on('users')->onDelete('cascade');
}

What's the difference between Invoke() and BeginInvoke()

Just to give a short, working example to see an effect of their difference

new Thread(foo).Start();

private void foo()
{
  this.Dispatcher.BeginInvoke(DispatcherPriority.Normal,
    (ThreadStart)delegate()
    {
        myTextBox.Text = "bing";
        Thread.Sleep(TimeSpan.FromSeconds(3));
    });
  MessageBox.Show("done");
}

If use BeginInvoke, MessageBox pops simultaneous to the text update. If use Invoke, MessageBox pops after the 3 second sleep. Hence, showing the effect of an asynchronous (BeginInvoke) and a synchronous (Invoke) call.

Woocommerce get products

Do not use WP_Query() or get_posts(). From the WooCommerce doc:

wc_get_products and WC_Product_Query provide a standard way of retrieving products that is safe to use and will not break due to database changes in future WooCommerce versions. Building custom WP_Queries or database queries is likely to break your code in future versions of WooCommerce as data moves towards custom tables for better performance.

You can retrieve the products you want like this:

$args = array(
    'category' => array( 'hoodies' ),
    'orderby'  => 'name',
);
$products = wc_get_products( $args );

WooCommerce documentation

Note: the category argument takes an array of slugs, not IDs.

Two decimal places using printf( )

Use: "%.2f" or variations on that.

See the POSIX spec for an authoritative specification of the printf() format strings. Note that it separates POSIX extras from the core C99 specification. There are some C++ sites which show up in a Google search, but some at least have a dubious reputation, judging from comments seen elsewhere on SO.

Since you're coding in C++, you should probably be avoiding printf() and its relatives.

java.net.BindException: Address already in use: JVM_Bind <null>:80

I do a goofy mistake and It take me 2 hour to solve It.I mentioned it here for other persons may be help them.The mistake was I enable ssl connector and changed both https and http ports to same number .

Execute PHP script in cron job

Automated Tasks: Cron

Cron is a time-based scheduling service in Linux / Unix-like computer operating systems. Cron job are used to schedule commands to be executed periodically. You can setup commands or scripts, which will repeatedly run at a set time. Cron is one of the most useful tool in Linux or UNIX like operating systems. The cron service (daemon) runs in the background and constantly checks the /etc/crontab file, /etc/cron./* directories. It also checks the /var/spool/cron/ directory.

Configuring Cron Tasks

In the following example, the crontab command shown below will activate the cron tasks automatically every ten minutes:

*/10 * * * * /usr/bin/php /opt/test.php

In the above sample, the */10 * * * * represents when the task should happen. The first figure represents minutes – in this case, on every "ten" minute. The other figures represent, respectively, hour, day, month and day of the week.

* is a wildcard, meaning "every time".

Start with finding out your PHP binary by typing in command line:

whereis php

The output should be something like:

php: /usr/bin/php /etc/php.ini /etc/php.d /usr/lib64/php /usr/include/php /usr/share/php /usr/share/man/man1/php.1.gz

Specify correctly the full path in your command.

Type the following command to enter cronjob:

crontab -e

To see what you got in crontab.

EDIT 1:

To exit from vim editor without saving just click:

Shift+:

And then type q!

Angular 2: How to call a function after get a response from subscribe http.post

get_categories(number){
 return this.http.post( url, body, {headers: headers, withCredentials:true})
      .map(t=>  {
          this.total = t.json();
          return total;
      }).share();
  );     
}

then

this.get_category(1).subscribe(t=> {
      this.callfunc();
});

How to convert from []byte to int in Go Programming

(reposting this answer)

You can use encoding/binary's ByteOrder to do this for 16, 32, 64 bit types

Play

package main

import "fmt"
import "encoding/binary"

func main() {
    var mySlice = []byte{244, 244, 244, 244, 244, 244, 244, 244}
    data := binary.BigEndian.Uint64(mySlice)
    fmt.Println(data)
}

What is the runtime performance cost of a Docker container?

Here's some more benchmarks for Docker based memcached server versus host native memcached server using Twemperf benchmark tool https://github.com/twitter/twemperf with 5000 connections and 20k connection rate

Connect time overhead for docker based memcached seems to agree with above whitepaper at roughly twice native speed.

Twemperf Docker Memcached

Connection rate: 9817.9 conn/s
Connection time [ms]: avg 341.1 min 73.7 max 396.2 stddev 52.11
Connect time [ms]: avg 55.0 min 1.1 max 103.1 stddev 28.14
Request rate: 83942.7 req/s (0.0 ms/req)
Request size [B]: avg 129.0 min 129.0 max 129.0 stddev 0.00
Response rate: 83942.7 rsp/s (0.0 ms/rsp)
Response size [B]: avg 8.0 min 8.0 max 8.0 stddev 0.00
Response time [ms]: avg 28.6 min 1.2 max 65.0 stddev 0.01
Response time [ms]: p25 24.0 p50 27.0 p75 29.0
Response time [ms]: p95 58.0 p99 62.0 p999 65.0

Twemperf Centmin Mod Memcached

Connection rate: 11419.3 conn/s
Connection time [ms]: avg 200.5 min 0.6 max 263.2 stddev 73.85
Connect time [ms]: avg 26.2 min 0.0 max 53.5 stddev 14.59
Request rate: 114192.6 req/s (0.0 ms/req)
Request size [B]: avg 129.0 min 129.0 max 129.0 stddev 0.00
Response rate: 114192.6 rsp/s (0.0 ms/rsp)
Response size [B]: avg 8.0 min 8.0 max 8.0 stddev 0.00
Response time [ms]: avg 17.4 min 0.0 max 28.8 stddev 0.01
Response time [ms]: p25 12.0 p50 20.0 p75 23.0
Response time [ms]: p95 28.0 p99 28.0 p999 29.0

Here's bencmarks using memtier benchmark tool

memtier_benchmark docker Memcached

4         Threads
50        Connections per thread
10000     Requests per thread
Type        Ops/sec     Hits/sec   Misses/sec      Latency       KB/sec
------------------------------------------------------------------------
Sets       16821.99          ---          ---      1.12600      2271.79
Gets      168035.07    159636.00      8399.07      1.12000     23884.00
Totals    184857.06    159636.00      8399.07      1.12100     26155.79

memtier_benchmark Centmin Mod Memcached

4         Threads
50        Connections per thread
10000     Requests per thread
Type        Ops/sec     Hits/sec   Misses/sec      Latency       KB/sec
------------------------------------------------------------------------
Sets       28468.13          ---          ---      0.62300      3844.59
Gets      284368.51    266547.14     17821.36      0.62200     39964.31
Totals    312836.64    266547.14     17821.36      0.62200     43808.90

How do I check to see if a value is an integer in MySQL?

I'll assume you want to check a string value. One nice way is the REGEXP operator, matching the string to a regular expression. Simply do

select field from table where field REGEXP '^-?[0-9]+$';

this is reasonably fast. If your field is numeric, just test for

ceil(field) = field

instead.

Regex Until But Not Including

The explicit way of saying "search until X but not including X" is:

(?:(?!X).)*

where X can be any regular expression.

In your case, though, this might be overkill - here the easiest way would be

[^z]*

This will match anything except z and therefore stop right before the next z.

So .*?quick[^z]* will match The quick fox jumps over the la.

However, as soon as you have more than one simple letter to look out for, (?:(?!X).)* comes into play, for example

(?:(?!lazy).)* - match anything until the start of the word lazy.

This is using a lookahead assertion, more specifically a negative lookahead.

.*?quick(?:(?!lazy).)* will match The quick fox jumps over the.

Explanation:

(?:        # Match the following but do not capture it:
 (?!lazy)  # (first assert that it's not possible to match "lazy" here
 .         # then match any character
)*         # end of group, zero or more repetitions.

Furthermore, when searching for keywords, you might want to surround them with word boundary anchors: \bfox\b will only match the complete word fox but not the fox in foxy.

Note

If the text to be matched can also include linebreaks, you will need to set the "dot matches all" option of your regex engine. Usually, you can achieve that by prepending (?s) to the regex, but that doesn't work in all regex engines (notably JavaScript).

Alternative solution:

In many cases, you can also use a simpler, more readable solution that uses a lazy quantifier. By adding a ? to the * quantifier, it will try to match as few characters as possible from the current position:

.*?(?=(?:X)|$)

will match any number of characters, stopping right before X (which can be any regex) or the end of the string (if X doesn't match). You may also need to set the "dot matches all" option for this to work. (Note: I added a non-capturing group around X in order to reliably isolate it from the alternation)

What's the best practice for primary keys in tables?

GUIDs can be used as a primary key, but you need to create the right type of GUID so that it performs well.

You need to generate COMB GUIDs. A good article about it and performance statistics is The Cost of GUIDs as Primary Keys.

Also some code on building COMB GUIDs in SQL is in Uniqueidentifier vs identity(archive).

XSL if: test with multiple test conditions

Just for completeness and those unaware XSL 1 has choose for multiple conditions.

<xsl:choose>
 <xsl:when test="expression">
  ... some output ...
 </xsl:when>
 <xsl:when test="another-expression">
  ... some output ...
 </xsl:when>
 <xsl:otherwise>
   ... some output ....
 </xsl:otherwise>
</xsl:choose>

Spring Boot application in eclipse, the Tomcat connector configured to listen on port XXXX failed to start

  1. Find the process ID (PID) for the port (e.g.: 8080)

    On Windows:

    netstat -ao | find "8080"
    

    Other Platforms other than windows :

    lsof -i:8080
    
  2. Kill the process ID you found (e.g.: 20712)

    On Windows:

    Taskkill /PID  20712 /F
    

    Other Platforms other than windows :

    kill -9 20712   or kill 20712
    

sql query distinct with Row_Number

Try this

SELECT distinct id
FROM  (SELECT id, ROW_NUMBER() OVER (ORDER BY  id) AS RowNum
      FROM table
      WHERE fid = 64) t

Or use RANK() instead of row number and select records DISTINCT rank

SELECT id
FROM  (SELECT id, ROW_NUMBER() OVER (PARTITION BY  id ORDER BY  id) AS RowNum
      FROM table
      WHERE fid = 64) t
WHERE t.RowNum=1

This also returns the distinct ids

use current date as default value for a column

You can use:

Insert into Event(Description,Date) values('teste', GETDATE());

Also, you can change your table so that 'Date' has a default, "GETDATE()"

How to find/identify large commits in git history?

If you only want to have a list of large files, then I'd like to provide you with the following one-liner:

join -o "1.1 1.2 2.3" <(git rev-list --objects --all | sort) <(git verify-pack -v objects/pack/*.idx | sort -k3 -n | tail -5 | sort) | sort -k3 -n

Whose output will be:

commit       file name                                  size in bytes

72e1e6d20... db/players.sql 818314
ea20b964a... app/assets/images/background_final2.png 6739212
f8344b9b5... data_test/pg_xlog/000000010000000000000001 1625545
1ecc2395c... data_development/pg_xlog/000000010000000000000001 16777216
bc83d216d... app/assets/images/background_1forfinal.psd 95533848

The last entry in the list points to the largest file in your git history.

You can use this output to assure that you're not deleting stuff with BFG you would have needed in your history.

Be aware, that you need to clone your repository with --mirror for this to work.

get the selected index value of <select> tag in php

As you said..

$Gender  = isset($_POST["gender"]); ' it returns a empty string 

because, you haven't mention method type either use POST or GET, by default it will use GET method. On the other side, you are trying to retrieve your value by using POST method, but in the form you haven't mentioned POST method. Which means miss-match method will result for empty.

Try this code..

<form name="signup_form"  action="./signup.php" onsubmit="return validateForm()"   method="post">
<table> 
  <tr> <td> First Name    </td><td> <input type="text" name="fname" size=10/></td></tr>
  <tr> <td> Last Name     </td><td> <input type="text" name="lname" size=10/></td></tr>
  <tr> <td> Your Email    </td><td> <input type="text" name="email" size=10/></td></tr>
  <tr> <td> Re-type Email </td><td> <input type="text" name="remail"size=10/></td></tr>
  <tr> <td> Password      </td><td> <input type="password" name="paswod" size=10/> </td></tr>
  <tr> <td> Gender        </td><td> <select name="gender">
  <option value="select">                Select </option>    
  <option value="male">   Male   </option>
  <option value="female"> Female </option></select></td></tr> 
  <tr> <td> <input type="submit" value="Sign up" id="signup"/> </td> </tr>
 </table>
 </form>

and on signup page

$Gender  = $_POST["gender"];

i'm sure.. now, you will get the value..

How to Split Image Into Multiple Pieces in Python

As an alternative to other solutions, we will construct the tiles by generating a grid of coordinates using itertools.product. We will ignore partial tiles on the edges, only iterating through the Cartesian product between the two intervals, i.e. range(0, h-h%d, d) X range(0, w-w%d, d).

Given fp: the file name to the image, d: the tile size, opt.path: the path to the directory containing the images, and opt.out: is the directory where tiles will be outputted:

def tile(filename, dir_in, dir_out, d):
    name, ext = os.path.splitext(filename)
    img = Image.open(os.path.join(dir_in, fp))
    w, h = img.size
    
    grid = list(product(range(0, h-h%d, d), range(0, w-w%d, d)))
    for i, j in grid:
        box = (j, i, j+d, i+d)
        out = os.path.join(dir_out, f'{name}_{i}_{j}{ext}')
        img.crop(box).save(out)

enter image description here

How to make HTML code inactive with comments

To comment block with nested comments: substitute inner (block) comments from "--" to "++"

<!-- *********************************************************************
     * IMPORTANT: To uncomment section
     *            sub inner comments "++" -> "--" & remove this comment
     *********************************************************************
<head>
   <title>My document's title</title> <++! My document's title ++>
   <link rel=stylesheet href="mydoc.css" type="text/css">
</head>

<body>
<++! My document's important HTML stuff ++>
...
...
...
</body>

*********************************************************************
* IMPORTANT: To uncomment section
*            sub inner comments "++" -> "--" & remove this comment
*********************************************************************
-->

Thus, the outer most comment ignores all "invalid" inner (block) comments.

Accessing localhost (xampp) from another computer over LAN network - how to?

Thanks for a detailed explanation.

Just to Elaborate, in Windows, Go to Control Panel -> Firewall, in exceptions "add http and port 80". Then in Services check mark "http (web server port 80)" and "https (web server port 443)" ONLY if you need https to work also. Ok, OK, Close

Then go to any computer on network and type http://computer-name (where you change the firewall and has the xampp running on it) in your web browser and happy days :)

Android center view in FrameLayout doesn't work

To center a view in Framelayout, there are some available tricks. The simplest one I used for my Webview and Progressbar(very similar to your two object layout), I just added android:layout_gravity="center"

Here is complete XML in case if someone else needs the same thing to do

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".WebviewPDFActivity"
    android:layout_gravity="center"
    >
    <WebView
        android:id="@+id/webView1"
        android:layout_width="match_parent"
        android:layout_height="match_parent"

        />
    <ProgressBar
        android:id="@+id/progress_circular"
        android:layout_width="250dp"
        android:layout_height="250dp"
        android:visibility="visible"
        android:layout_gravity="center"
        />


</FrameLayout>

Here is my output

screenshot

How to install JDBC driver in Eclipse web project without facing java.lang.ClassNotFoundexception

Put mysql-connector-java-5.1.38-bin.jar to the C:\Program Files\Apache Software Foundation\Tomcat 7.0\lib folder.by doing this program with execute

Parsing XML in Python using ElementTree example

So I have ElementTree 1.2.6 on my box now, and ran the following code against the XML chunk you posted:

import elementtree.ElementTree as ET

tree = ET.parse("test.xml")
doc = tree.getroot()
thingy = doc.find('timeSeries')

print thingy.attrib

and got the following back:

{'name': 'NWIS Time Series Instantaneous Values'}

It appears to have found the timeSeries element without needing to use numerical indices.

What would be useful now is knowing what you mean when you say "it doesn't work." Since it works for me given the same input, it is unlikely that ElementTree is broken in some obvious way. Update your question with any error messages, backtraces, or anything you can provide to help us help you.

SSL: CERTIFICATE_VERIFY_FAILED with Python3

I had this problem in MacOS, and I solved it by linking the brew installed python 3 version, with

brew link python3

After that, it worked without a problem.

jQuery Multiple ID selectors

If you give each of these instances a class you can use

$('.yourClass').upload()

Streaming via RTSP or RTP in HTML5

Technically 'Yes'

(but not really...)

HTML 5's <video> tag is protocol agnostic—it does not care. You place the protocol in the src attribute as part of the URL. E.g.:

<video src="rtp://myserver.com/path/to/stream">
    Your browser does not support the VIDEO tag and/or RTP streams.
</video>

or maybe

<video src="http://myserver.com:1935/path/to/stream/myPlaylist.m3u8">
    Your browser does not support the VIDEO tag and/or RTP streams.
</video>

That said, the implementation of the <video> tag is browser specific. Since it is early days for HTML 5, I expect frequently changing support (or lack of support).

From the W3C's HTML5 spec (The video element):

User agents may support any video and audio codecs and container formats

SQL Server Restore Error - Access is Denied

Recently I faced this issue with SQL 2008 R2 and the below solution worked for me:

1) Create a new database with the same name as the one you are trying to restore 2) While restoring, use the same name you used above and in the options, click the overwrite option

You might give the above a shot if the other solutions don't work.

checking if a number is divisible by 6 PHP

Use the Mod % (modulus) operator

if ($x % 6 == 0) return 1;


function nearest_multiple_of_6($x) {
    if ($x % 6 == 0) return $x;    

    return (($x / 6) + 1) * 6;
}

No server in Eclipse; trying to install Tomcat

I ended up installing a new copy of Eclipse - JAVA EE, and it all works now.

What is the best way to test for an empty string with jquery-out-of-the-box?

Try executing this in your browser console or in a node.js repl.

var string = ' ';
string ? true : false;
//-> true

string = '';
string ? true : false;
//-> false

Therefore, a simple branching construct will suffice for the test.

if(string) {
    // string is not empty
}

Does Ruby have a string.startswith("abc") built in method?

It's called String#start_with?, not String#startswith: In Ruby, the names of boolean-ish methods end with ? and the words in method names are separated with an _. Not sure where the s went, personally, I'd prefer String#starts_with? over the actual String#start_with?

How can I split a delimited string into an array in PHP?

explode has some very big problems in real life usage:

count(explode(',', null)); // 1 !! 
explode(',', null); // [""] not an empty array, but an array with one empty string!
explode(',', ""); // [""]
explode(',', "1,"); // ["1",""] ending commas are also unsupported, kinda like IE8

this is why i prefer preg_split

preg_split('@,@', $string, NULL, PREG_SPLIT_NO_EMPTY)

the entire boilerplate:

/** @brief wrapper for explode
 * @param string|int|array $val string will explode. '' return []. int return string in array (1 returns ['1']). array return itself. for other types - see $as_is
 * @param bool $as_is false (default): bool/null return []. true: bool/null return itself.
 * @param string $delimiter default ','
 * @return array|mixed
 */
public static function explode($val, $as_is = false, $delimiter = ',')
{
    // using preg_split (instead of explode) because it is the best way to handle ending comma and avoid empty string converted to ['']
    return (is_string($val) || is_int($val)) ?
        preg_split('@' . preg_quote($delimiter, '@') . '@', $val, NULL, PREG_SPLIT_NO_EMPTY)
        :
        ($as_is ? $val : (is_array($val) ? $val : []));
}

Difference between setTimeout with and without quotes and parentheses

Totally agree with Joseph.

Here is a fiddle to test this: http://jsfiddle.net/nicocube/63s2s/

In the context of the fiddle, the string argument do not work, in my opinion because the function is not defined in the global scope.

Apache: Restrict access to specific source IP inside virtual host

If you are using apache 2.2 inside your virtual host you should add following directive (mod_authz_host):

Order deny,allow
Deny from all
Allow from 10.0.0.1

You can even specify a subnet

Allow from 10.0.0

Apache 2.4 looks like a little different as configuration. Maybe better you specify which version of apache are you using.

Slicing of a NumPy 2d array, or how do I extract an mxm submatrix from an nxn array (n>m)?

If you want to skip every other row and every other column, then you can do it with basic slicing:

In [49]: x=np.arange(16).reshape((4,4))
In [50]: x[1:4:2,1:4:2]
Out[50]: 
array([[ 5,  7],
       [13, 15]])

This returns a view, not a copy of your array.

In [51]: y=x[1:4:2,1:4:2]

In [52]: y[0,0]=100

In [53]: x   # <---- Notice x[1,1] has changed
Out[53]: 
array([[  0,   1,   2,   3],
       [  4, 100,   6,   7],
       [  8,   9,  10,  11],
       [ 12,  13,  14,  15]])

while z=x[(1,3),:][:,(1,3)] uses advanced indexing and thus returns a copy:

In [58]: x=np.arange(16).reshape((4,4))
In [59]: z=x[(1,3),:][:,(1,3)]

In [60]: z
Out[60]: 
array([[ 5,  7],
       [13, 15]])

In [61]: z[0,0]=0

Note that x is unchanged:

In [62]: x
Out[62]: 
array([[ 0,  1,  2,  3],
       [ 4,  5,  6,  7],
       [ 8,  9, 10, 11],
       [12, 13, 14, 15]])

If you wish to select arbitrary rows and columns, then you can't use basic slicing. You'll have to use advanced indexing, using something like x[rows,:][:,columns], where rows and columns are sequences. This of course is going to give you a copy, not a view, of your original array. This is as one should expect, since a numpy array uses contiguous memory (with constant strides), and there would be no way to generate a view with arbitrary rows and columns (since that would require non-constant strides).

Executing multi-line statements in the one-line command-line?

single/double quotes and backslash everywhere:

$ python -c 'exec("import sys\nfor i in range(10): print \"bob\"")'

Much better:

$ python -c '
> import sys
> for i in range(10):
>   print "bob"
> '

undefined reference to WinMain@16 (codeblocks)

I was interested in setting up graphics for Code Blocks when I ran into a this error: (took me 2 hrs to solve it)

I guess you need to have a bit of luck with this. In my case i just changed the order of contents in Settings menu->Compiler and Debugger->Global compiler settings->Linker settings->Other Linker Options: The working sequence is: -lmingw32 -lSDL -lSDLmain

HTML Display Current date

var currentDate  = new Date(),
    currentDay   = currentDate.getDate() < 10 
                 ? '0' + currentDate.getDate() 
                 : currentDate.getDate(),
    currentMonth = currentDate.getMonth() < 9 
                 ? '0' + (currentDate.getMonth() + 1) 
                 : (currentDate.getMonth() + 1);

document.getElementById("date").innerHTML = currentDay + '/' + currentMonth + '/' +  currentDate.getFullYear();

You can read more about Date object

UnsupportedClassVersionError unsupported major.minor version 51.0 unable to load class

Well presumably it's not using the same version of Java when running it externally. Look through the startup scripts carefully to find where it picks up the version of Java to run. You should also check the startup logs to see whether they indicate which version is running.

Alternatively, unless you need the Java 7 features, you could always change your compiler preferences in Eclipse to target 1.6 instead.

How to check Spark Version

According to the Cloudera documentation - What's New in CDH 5.7.0 it includes Spark 1.6.0.

How to find index of list item in Swift?

You can also use the functional library Dollar to do an indexOf on an array as such http://www.dollarswift.org/#indexof-indexof

$.indexOf([1, 2, 3, 1, 2, 3], value: 2) 
=> 1

This version of Android Studio cannot open this project, please retry with Android Studio 3.4 or newer

I encountered with this error and just decrease gradle version and android plugin version to 5.1.1 and 3.4.2.

Linux cmd to search for a class file among jars irrespective of jar path

Linux, Walkthrough to find a class file among many jars.

Go to the directory that contains the jars underneath.

eric@dev /home/el/kafka_2.10-0.8.1.1/libs $ ls
blah.txt                             metrics-core-2.2.0.jar
jopt-simple-3.2.jar                  scala-library-2.10.1.jar
kafka_2.10-0.8.1.1-sources.jar       zkclient-0.3.jar
kafka_2.10-0.8.1.1-sources.jar.asc   zookeeper-3.3.4.jar
log4j-1.2.15.jar

I'm looking for which jar provides for the Producer class.

Understand how the for loop works:

eric@dev /home/el/kafka_2.10-0.8.1.1/libs $ for i in `seq 1 3`; do
> echo $i
> done
1
2
3

Understand why find this works:

eric@dev /home/el/kafka_2.10-0.8.1.1/libs $ find . -name "*.jar"
./slf4j-api-1.7.2.jar
./zookeeper-3.3.4.jar
./kafka_2.10-0.8.1.1-javadoc.jar
./slf4j-1.7.7/osgi-over-slf4j-1.7.7-sources.jar

You can pump all the jars underneath into the for loop:

eric@dev /home/el/kafka_2.10-0.8.1.1/libs $ for i in `find . -name "*.jar"`; do
> echo $i
> done

./slf4j-api-1.7.2.jar
./zookeeper-3.3.4.jar
./kafka_2.10-0.8.1.1-javadoc.jar
./kafka_2.10-0.8.1.1-sources.jar

Now we can operate on each one:

Do a jar tf on every jar and cram it into blah.txt:

for i in `find . -name "*.jar"`; do echo $i; jar tf $i; done > blah.txt

Inspect blah.txt, it's a list of all the classes in all the jars. You can search that file for the class you want, then look for the jar that came before it, that's the one you want.

How to count the number of true elements in a NumPy bool array

In terms of comparing two numpy arrays and counting the number of matches (e.g. correct class prediction in machine learning), I found the below example for two dimensions useful:

import numpy as np
result = np.random.randint(3,size=(5,2)) # 5x2 random integer array
target = np.random.randint(3,size=(5,2)) # 5x2 random integer array

res = np.equal(result,target)
print result
print target
print np.sum(res[:,0])
print np.sum(res[:,1])

which can be extended to D dimensions.

The results are:

Prediction:

[[1 2]
 [2 0]
 [2 0]
 [1 2]
 [1 2]]

Target:

[[0 1]
 [1 0]
 [2 0]
 [0 0]
 [2 1]]

Count of correct prediction for D=1: 1

Count of correct prediction for D=2: 2

How to replace item in array?

var index = items.indexOf(3452);

if (index !== -1) {
    items[index] = 1010;
}

Also it is recommend you not use the constructor method to initialize your arrays. Instead, use the literal syntax:

var items = [523, 3452, 334, 31, 5346];

You can also use the ~ operator if you are into terse JavaScript and want to shorten the -1 comparison:

var index = items.indexOf(3452);

if (~index) {
    items[index] = 1010;
}

Sometimes I even like to write a contains function to abstract this check and make it easier to understand what's going on. What's awesome is this works on arrays and strings both:

var contains = function (haystack, needle) {
    return !!~haystack.indexOf(needle);
};

// can be used like so now:
if (contains(items, 3452)) {
    // do something else...
}

Starting with ES6/ES2015 for strings, and proposed for ES2016 for arrays, you can more easily determine if a source contains another value:

if (haystack.includes(needle)) {
    // do your thing
}

How to format a java.sql Timestamp for displaying?

For this particular question, the standard suggestion of java.text.SimpleDateFormat works, but has the unfortunate side effect that SimpleDateFormat is not thread-safe and can be the source of particularly nasty problems since it'll corrupt your output in multi-threaded scenarios, and you won't get any exceptions!

I would strongly recommend looking at Joda for anything like this. Why ? It's a much richer and more intuitive time/date library for Java than the current library (and the basis of the up-and-coming new standard Java date/time library, so you'll be learning a soon-to-be-standard API).

Convert JSONArray to String Array

public static String[] getStringArray(JSONArray jsonArray) {
    String[] stringArray = null;
    if (jsonArray != null) {
        int length = jsonArray.length();
        stringArray = new String[length];
        for (int i = 0; i < length; i++) {
            stringArray[i] = jsonArray.optString(i);
        }
    }
    return stringArray;
}

whitespaces in the path of windows filepath

There is no problem with whitespaces in the path since you're not using the "shell" to open the file. Here is a session from the windows console to prove the point. You're doing something else wrong

Python 2.7.2 (default, Jun 12 2011, 14:24:46) [MSC v.1500 64 bit (AMD64)] on wi
32
Type "help", "copyright", "credits" or "license" for more information.
>>> import os
>>>
>>> os.makedirs("C:/ABC/SEM 2/testfiles")
>>> open("C:/ABC/SEM 2/testfiles/all.txt","w")
<open file 'C:/ABC/SEM 2/testfiles/all.txt', mode 'w' at 0x0000000001D95420>
>>> exit()

C:\Users\Gnibbler>dir "C:\ABC\SEM 2\testfiles"
 Volume in drive C has no label.
 Volume Serial Number is 46A0-BB64

 Directory of c:\ABC\SEM 2\testfiles

13/02/2013  10:20 PM    <DIR>          .
13/02/2013  10:20 PM    <DIR>          ..
13/02/2013  10:20 PM                 0 all.txt
               1 File(s)              0 bytes
               2 Dir(s)  78,929,309,696 bytes free

C:\Users\Gnibbler>

pypi UserWarning: Unknown distribution option: 'install_requires'

This is a warning from distutils, and is a sign that you do not have setuptools installed. Installing it from http://pypi.python.org/pypi/setuptools will remove the warning.

Can I apply multiple background colors with CSS3?

In this LIVE DEMO i've achieved this by using the :before css selector which seems to work quite nicely.

_x000D_
_x000D_
.myDiv  {_x000D_
position: relative; /*Parent MUST be relative*/_x000D_
z-index: 9;_x000D_
background: green;_x000D_
    _x000D_
/*Set width/height of the div in 'parent'*/    _x000D_
width:100px;_x000D_
height:100px;_x000D_
}_x000D_
_x000D_
_x000D_
.myDiv:before {_x000D_
content: "";_x000D_
position: absolute;/*set 'child' to be absolute*/_x000D_
z-index: -1; /*Make this lower so text appears in front*/_x000D_
   _x000D_
    _x000D_
/*You can choose to align it left, right, top or bottom here*/_x000D_
top: 0; _x000D_
right:0;_x000D_
bottom: 60%;_x000D_
left: 0;_x000D_
    _x000D_
    _x000D_
background: red;_x000D_
}
_x000D_
<div class="myDiv">this is my div with multiple colours. It work's with text too!</div>
_x000D_
_x000D_
_x000D_

I thought i would add this as I feel it could work quite well for a percentage bar/visual level of something.

It also means you're not creating multiple divs if you don't have to, and keeps this page up-to-date

Best way to check if a URL is valid

You can use this function, but its will return false if website offline.

  function isValidUrl($url) {
    $url = parse_url($url);
    if (!isset($url["host"])) return false;
    return !(gethostbyname($url["host"]) == $url["host"]);
}

How can I create a carriage return in my C# string

<br /> works for me

So...

String body = String.Format(@"New user: 
 <br /> Name: {0}
 <br /> Email: {1}
 <br /> Phone: {2}", Name, Email, Phone);

Produces...

New user:
Name: Name
Email: Email
Phone: Phone

Using jQuery To Get Size of Viewport

To get size of viewport on load and on resize (based on SimaWB response):

function getViewport() {
    var viewportWidth = $(window).width();
    var viewportHeight = $(window).height();
    $('#viewport').html('Viewport: '+viewportWidth+' x '+viewportHeight+' px');
}

getViewport();

$(window).resize(function() {
    getViewport()
});

Center the content inside a column in Bootstrap 4

Add class text-center to your column:

<div class="col text-center">
I am centered
</div>

List of swagger UI alternatives

Yes, there are a few of them.

Hosted solutions that support swagger:

Check the following articles for more details:

inline conditionals in angular.js

For checking a variable content and have a default text, you can use:

<span>{{myVar || 'Text'}}</span>

Google Play Services Missing in Emulator (Android 4.4.2)

google play service is just a library to create application but in order to use application that use google play service library , you need to install google play in your emulator.and for that it need the unique device id. and device id is only on the real device not have on emulator. so for testing it , you need real android device.

How to clear Flutter's Build cache?

If in android studio Tools->Flutter->Clean

enter image description here

How to list all the files in android phone by using adb shell?

This command will show also if the file is hidden adb shell ls -laR | grep filename

In-place type conversion of a NumPy array

You can change the array type without converting like this:

a.dtype = numpy.float32

but first you have to change all the integers to something that will be interpreted as the corresponding float. A very slow way to do this would be to use python's struct module like this:

def toi(i):
    return struct.unpack('i',struct.pack('f',float(i)))[0]

...applied to each member of your array.

But perhaps a faster way would be to utilize numpy's ctypeslib tools (which I am unfamiliar with)

- edit -

Since ctypeslib doesnt seem to work, then I would proceed with the conversion with the typical numpy.astype method, but proceed in block sizes that are within your memory limits:

a[0:10000] = a[0:10000].astype('float32').view('int32')

...then change the dtype when done.

Here is a function that accomplishes the task for any compatible dtypes (only works for dtypes with same-sized items) and handles arbitrarily-shaped arrays with user-control over block size:

import numpy

def astype_inplace(a, dtype, blocksize=10000):
    oldtype = a.dtype
    newtype = numpy.dtype(dtype)
    assert oldtype.itemsize is newtype.itemsize
    for idx in xrange(0, a.size, blocksize):
        a.flat[idx:idx + blocksize] = \
            a.flat[idx:idx + blocksize].astype(newtype).view(oldtype)
    a.dtype = newtype

a = numpy.random.randint(100,size=100).reshape((10,10))
print a
astype_inplace(a, 'float32')
print a

Visual Studio Code cannot detect installed git

open

C:\Users\nassim\AppData\Roaming\Code\User\settings.json

comment any git line there

// ...
// "git-graph.integratedTerminalShell": "E:\\Apps\\Git\\bin\\bash.exe",
// "git.path": ""
//...

and add git.exe to the OS path

Note for me fixing this git error also fixed the npm error too , since they are both defined in the path, if one fail , the remaining will fail as well

Removing padding gutter from grid columns in Bootstrap 4

You can use this css code to get gutterless grid in bootstrap.

.no-gutter.row,
.no-gutter.container,
.no-gutter.container-fluid{
  margin-left: 0;
  margin-right: 0;
}

.no-gutter>[class^="col-"]{
  padding-left: 0;
  padding-right: 0;
}

Java Returning method which returns arraylist?

You need to instantiate the class it is contained within, or make the method static.

So if it is contained within class Foo:

Foo x = new Foo();
List<Integer> stuff = x.myNumbers();

or alternatively shorthand:

List<Integer> stuff = new Foo().myNumbers();

or if you make it static like so:

public static List<Integer> myNumbers()    {
    List<Integer> numbers = new ArrayList<Integer>();
    numbers.add(5);
    numbers.add(11);
    numbers.add(3);
    return(numbers);
}

you can call it like so:

List<Integer> stuff = Foo.myNumbers();