Programs & Examples On #Indy 9

Indy 9 is a reference to a specific version of Indy.

How to prevent browser to invoke basic auth popup and handle 401 error using Jquery?

You can suppress basic auth popup with request url looking like this:

https://username:[email protected]/admin/...

If you get 401 error (wrong username or password) it will be correctly handled with jquery error callback. It can cause some security issues (in case of http protocol instead of https), but it's works.

UPD: This solution support will be removed in Chrome 59

Most efficient way to map function over numpy array

I've tested all suggested methods plus np.array(map(f, x)) with perfplot (a small project of mine).

Message #1: If you can use numpy's native functions, do that.

If the function you're trying to vectorize already is vectorized (like the x**2 example in the original post), using that is much faster than anything else (note the log scale):

enter image description here

If you actually need vectorization, it doesn't really matter much which variant you use.

enter image description here


Code to reproduce the plots:

import numpy as np
import perfplot
import math


def f(x):
    # return math.sqrt(x)
    return np.sqrt(x)


vf = np.vectorize(f)


def array_for(x):
    return np.array([f(xi) for xi in x])


def array_map(x):
    return np.array(list(map(f, x)))


def fromiter(x):
    return np.fromiter((f(xi) for xi in x), x.dtype)


def vectorize(x):
    return np.vectorize(f)(x)


def vectorize_without_init(x):
    return vf(x)


perfplot.show(
    setup=np.random.rand,
    n_range=[2 ** k for k in range(20)],
    kernels=[f, array_for, array_map, fromiter, vectorize, vectorize_without_init],
    xlabel="len(x)",
)

Deserialize json object into dynamic object using Json.net

Yes it is possible. I have been doing that all the while.

dynamic Obj = JsonConvert.DeserializeObject(<your json string>);

It is a bit trickier for non native type. Suppose inside your Obj, there is a ClassA, and ClassB objects. They are all converted to JObject. What you need to do is:

ClassA ObjA = Obj.ObjA.ToObject<ClassA>();
ClassB ObjB = Obj.ObjB.ToObject<ClassB>();

How to extract filename.tar.gz file

Check to make sure that the file is complete. This error message can occur if you only partially downloaded a file or if it has major issues. Check the MD5sum.

How do I analyze a program's core dump file with GDB when it has command-line parameters?

A slightly different approach will allow you to skip GDB entirely. If all you want is a backtrace, the Linux-specific utility 'catchsegv' will catch SIGSEGV and display a backtrace.

Duplicate and rename Xcode project & associated folders

For anybody else having issues with storyboard crashes after copying your project, head over to Main.storyboard under Identity Inspector.

Next, check that your current module is the correct renamed module and not the old one.

Eclipse No tests found using JUnit 5 caused by NoClassDefFoundError for LauncherFactory

I got the same problem after creating a new TestCase: Eclipse -> New -> JUnit Test Case. It creates a class without access level modifier. I could solve the problem by just putting a public before the class keyword.

What is the difference between ( for... in ) and ( for... of ) statements?

There are some already defined data types which allows us to iterate over them easily e.g Array, Map, String Objects

Normal for in iterates over the iterator and in response provides us with the keys that are in the order of insertion as shown in below example.

  const numbers = [1,2,3,4,5];
   for(let number in number) {
     console.log(number);
   }

   // result: 0, 1, 2, 3, 4

Now if we try same with for of, then in response it provides us with the values not the keys. e.g

  const numbers = [1,2,3,4,5];
   for(let numbers of numbers) {
    console.log(number);
  }

  // result: 1, 2, 3, 4, 5

So looking at both of the iterators we can easily differentiate the difference between both of them.

Note:- For of only works with the Symbol.iterator

So if we try to iterate over normal object, then it will give us an error e.g-

const Room = {
   area: 1000,
   height: 7,
   floor: 2
 }

for(let prop in Room) {
 console.log(prop);
 } 

// Result area, height, floor

for(let prop of Room) {
  console.log(prop);
 } 

Room is not iterable

Now for iterating over we need to define an ES6 Symbol.iterator e.g

  const Room= {
    area: 1000, height: 7, floor: 2,
   [Symbol.iterator]: function* (){
    yield this.area;
    yield this.height;
    yield this.floors;
  }
}


for(let prop of Room) {
  console.log(prop);
 } 

//Result 1000, 7, 2

This is the difference between For in and For of. Hope that it might clear the difference.

How do you turn a Mongoose document into a plain object?

Mongoose Models inherit from Documents, which have a toObject() method. I believe what you're looking for should be the result of doc.toObject().

http://mongoosejs.com/docs/api.html#document_Document-toObject

How do I remove diacritics (accents) from a string in .NET?

you can use string extension from MMLib.Extensions nuget package:

using MMLib.RapidPrototyping.Generators;
public void ExtensionsExample()
{
  string target = "aácceéií";
  Assert.AreEqual("aacceeii", target.RemoveDiacritics());
} 

Nuget page: https://www.nuget.org/packages/MMLib.Extensions/ Codeplex project site https://mmlib.codeplex.com/

Login failed for user 'NT AUTHORITY\NETWORK SERVICE'

The SQL Server login required is DOMAIN\machinename$. This is the how the calling NT AUTHORITY\NETWORK SERVICE appears to SQL Server (and file servers etc)

In SQL,

CREATE LOGIN [XYZ\Gandalf$] FROM WINDOWS

How to read a HttpOnly cookie using JavaScript

The whole point of HttpOnly cookies is that they can't be accessed by JavaScript.

The only way (except for exploiting browser bugs) for your script to read them is to have a cooperating script on the server that will read the cookie value and echo it back as part of the response content. But if you can and would do that, why use HttpOnly cookies in the first place?

jQuery UI Accordion Expand/Collapse All

Yes, it is possible. Put all div in separate accordion class as follows:

<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript" src="jquery-ui.js"></script>

<script type="text/javascript">

        $(function () {
            $("input[type=submit], button")
        .button()
        .click(function (event) {
            event.preventDefault();
        });
            $("#tabs").tabs();
            $(".accordion").accordion({
                heightStyle: "content",

                collapsible: true,
                active: 0



            });
        });

function expandAll()
{
  $(".accordion").accordion({
                heightStyle: "content",

                collapsible: true,
                active: 0

            });

            return false;   
}

function collapseAll()
{
  $(".accordion").accordion({
                heightStyle: "content",

                collapsible: true,
                active: false



            });
            return false;
}
</script>



<div class="accordion">
  <h3>Toggle 1</h3>
  <div >
    <p>text1.</p>
  </div>
</div>
<div class="accordion">
  <h3>Toggle 2</h3>
  <div >
    <p>text2.</p>
  </div>
</div>
<div class="accordion">
  <h3>Toggle 3</h3>
  <div >
    <p>text3.</p>
  </div>
</div>

What's the difference between a null pointer and a void pointer?

A Null pointer has the value 0. void pointer is a generic pointer introduced by ANSI. Generic pointer can hold the address of any data type.

How to get the current user in ASP.NET MVC

IPrincipal currentUser = HttpContext.Current.User;
bool writeEnable = currentUser.IsInRole("Administrator") ||
        ...
                   currentUser.IsInRole("Operator");

Change User Agent in UIWebView

Modern Swift

Here's a suggestion for Swift 3+ projects from StackOverflow users PassKit and Kheldar:

UserDefaults.standard.register(defaults: ["UserAgent" : "Custom Agent"])

Source: https://stackoverflow.com/a/27330998/128579

Earlier Objective-C Answer

With iOS 5 changes, I recommend the following approach, originally from this StackOverflow question: UIWebView iOS5 changing user-agent as pointed out in an answer below. In comments on that page, it appears to work in 4.3 and earlier also.

Change the "UserAgent" default value by running this code once when your app starts:

NSDictionary *dictionary = @{@"UserAgent": @"Your user agent"};
[[NSUserDefaults standardUserDefaults] registerDefaults:dictionary];
[[NSUserDefaults standardUserDefaults] synchronize];

See previous edits on this post if you need methods that work in versions of iOS before 4.3/5.0. Note that because of the extensive edits, the following comments / other answers on this page may not make sense. This is a four year old question, after all. ;-)

When is a timestamp (auto) updated?

An auto-updated column is automatically updated to the current timestamp when the value of any other column in the row is changed from its current value. An auto-updated column remains unchanged if all other columns are set to their current values.

To explain it let's imagine you have only one row:

-------------------------------
| price | updated_at          |
-------------------------------
|  2    | 2018-02-26 16:16:17 |
-------------------------------

Now, if you run the following update column:

 update my_table
 set price = 2

it will not change the value of updated_at, since price value wasn't actually changed (it was already 2).

But if you have another row with price value other than 2, then the updated_at value of that row (with price <> 3) will be updated to CURRENT_TIMESTAMP.

Notepad++ Multi editing

Yes: simply press and hold the Alt key, click and drag to select the lines whose columns you wish to edit, and begin typing.

You can also go to Settings > Preferences..., and in the Editing tab, turn on multi-editing, to enable selection of multiple separate regions or columns of text to edit at once.

It's much more intuitive, as you can see your edits live as you type.

Common HTTPclient and proxy

Starting from Apache HTTPComponents 4.3.x HttpClientBuilder class sets the proxy defaults from System properties http.proxyHost and http.proxyPort or else you can override them using setProxy method.

When running UPDATE ... datetime = NOW(); will all rows updated have the same date/time?

The sqlite answer is

update TABLE set mydatetime = datetime('now');

in case someone else was looking for it.

Clone() vs Copy constructor- which is recommended in java

Keep in mind that the copy constructor limits the class type to that of the copy constructor. Consider the example:

// Need to clone person, which is type Person
Person clone = new Person(person);

This doesn't work if person could be a subclass of Person (or if Person is an interface). This is the whole point of clone, is that it can can clone the proper type dynamically at runtime (assuming clone is properly implemented).

Person clone = (Person)person.clone();

or

Person clone = (Person)SomeCloneUtil.clone(person); // See Bozho's answer

Now person can be any type of Person assuming that clone is properly implemented.

Angular 2 Unit Tests: Cannot find name 'describe'

In my case, I was getting this error when I serve the app, not when testing. I didn't realise I had a different configuration setting in my tsconfig.app.json file.

I previously had this:

{
  ...
  "include": [
    "src/**/*.ts"
  ]
}

It was including all my .spec.ts files when serving the app. I changed the include property toexclude` and added a regex to exclude all test files like this:

{
  ...
  "exclude": [
    "**/*.spec.ts",
    "**/__mocks__"
  ]
}

Now it works as expected.

Set NOW() as Default Value for datetime datatype?

As of MySQL 5.6.5, you can use the DATETIME type with a dynamic default value:

CREATE TABLE foo (
    creation_time      DATETIME DEFAULT   CURRENT_TIMESTAMP,
    modification_time  DATETIME ON UPDATE CURRENT_TIMESTAMP
)

Or even combine both rules:

modification_time DATETIME DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP

Reference:
http://dev.mysql.com/doc/refman/5.7/en/timestamp-initialization.html
http://optimize-this.blogspot.com/2012/04/datetime-default-now-finally-available.html

Prior to 5.6.5, you need to use the TIMESTAMP data type, which automatically updates whenever the record is modified. Unfortunately, however, only one auto-updated TIMESTAMP field can exist per table.

CREATE TABLE mytable (
  mydate TIMESTAMP
)

See: http://dev.mysql.com/doc/refman/5.1/en/create-table.html

If you want to prevent MySQL from updating the timestamp value on UPDATE (so that it only triggers on INSERT) you can change the definition to:

CREATE TABLE mytable (
  mydate TIMESTAMP DEFAULT CURRENT_TIMESTAMP
)

Javascript | Set all values of an array

Actually, you can use this perfect approach:

let arr = Array.apply(null, Array(5)).map(() => 0);
// [0, 0, 0, 0, 0]

This code will create array and fill it with zeroes. Or just:

let arr = new Array(5).fill(0)

SQL: Return "true" if list of records exists?

Assuming you're using SQL Server, the boolean type doesn't exist, but the bit type does, which can hold only 0 or 1 where 0 represents False, and 1 represents True.

I would go this way:

select 1
    from Products
    where ProductId IN (1, 10, 100)

Here, a null or no row will be returned (if no row exists).

Or even:

select case when EXISTS (
    select 1
        from Products
        where ProductId IN (1, 10, 100)
    ) then 1 else 0 end as [ProductExists]

Here, either of the scalar values 1 or 0 will always be returned (if no row exists).

Run parallel multiple commands at once in the same terminal

This bash script is for N parallel threads. Each argument is a command.

trap will kill all subprocesses when SIGINT is catched.
wait $PID_LIST is waiting each process to complete. When all processes have completed, the program exits.

#!/bin/bash

for cmd in "$@"; do {
  echo "Process \"$cmd\" started";
  $cmd & pid=$!
  PID_LIST+=" $pid";
} done

trap "kill $PID_LIST" SIGINT

echo "Parallel processes have started";

wait $PID_LIST

echo
echo "All processes have completed";

Save this script as parallel_commands and make it executable.
This is how to use this script:

parallel_commands "cmd arg0 arg1 arg2" "other_cmd arg0 arg2 arg3"

Example:

parallel_commands "sleep 1" "sleep 2" "sleep 3" "sleep 4"

Start 4 parallel sleep and waits until "sleep 4" finishes.

Python not working in command prompt?

Just a few comments:

  1. Don't set PYTHONPATH if all you want is to get Python on the PATH. The PYTHONPATH environment variable tells Python where to look for modules to import. Setting it to C:\Python27\ will not accomplish anything useful, although it's probably harmless.

  2. Modifying environment variables (including PATH) from the "Edit System Variables" has no effect on already running processes. This means you have to re-launch cmd.exe for the changes to work. A reboot, however, is not required.

  3. When modifying the PATH, also add the Scripts subdirectory. Or, to put it in other words (and using the previous example): add ;C:\Python27;C:\Python27\Scripts. This will allow you to run scripts like easy_install, pip, virtualenv or sphinx from the command line - once you install those, that is. This is about as UNIX-y as it gets for Windows. (N.B. The Scripts subdirectory is not present after a clean install of Python, but will be created when needed.)

  4. Don't put any additional Lib or DLL directory on the PATH. There's no need, and it might do harm.

  5. If you have installed multiple versions of Python (which isn't all that uncommon) you might be better off not putting any of them on the PATH but instead create different shortcuts to cmd.exe for the different versions which set the PATH for each version. You might also be interested in PEP-397.

How can I stream webcam video with C#?

You could just use VideoLAN. VideoLAN will work as a server (or you can wrap your own C# application around it for more control). There are also .NET wrappers for the viewer that you can use and thus embed in your C# client.

java, get set methods

your panel class don't have a constructor that accepts a string

try change

RLS_strid_panel p = new RLS_strid_panel(namn1);

to

RLS_strid_panel p = new RLS_strid_panel();
p.setName1(name1);

How to send push notification to web browser?

May I redefine you question as below

Can we have our own back-end to send push notification to Chrome, Firefox, Opera & Safari?

Yes. By today (2017/05), you can use same client and server side implementation to handle Chrome, Firefox and Opera (no Safari). Because they have implemented web push notifications in a same way. That is Push API protocol by W3C. But Safari have their own old architecture. So we have to maintain Safari separately.

Refer browser-push repo for guide lines to implement web push notification for your web-app with your own back-end. It explains with examples how you can add web push notification support for your web application without any third party services.

How to detect iPhone 5 (widescreen devices)?

Relying in the size is wrong in so many levels. How about we ask to the system?

- (NSString *) getDeviceModel
{
    struct utsname systemInfo;
    uname(&systemInfo);
    return [NSString stringWithCString:systemInfo.machine encoding:NSUTF8StringEncoding];
}

Taken from Best way to detect hardware type, iPhone4 or iPhone5?, edzio27 answer.

Listing files in a specific "folder" of a AWS S3 bucket

If your goal is only to take the files and not the folder, the approach I made was to use the file size as a filter. This property is the current size of the file hosted by AWS. All the folders return 0 in that property. The following is a C# code using linq but it shouldn't be hard to translate to Java.

var amazonClient = new AmazonS3Client(key, secretKey, region);
var listObjectsRequest= new ListObjectsRequest
            {
                BucketName = 'someBucketName',
                Delimiter = 'someDelimiter',
                Prefix = 'somePrefix'
            };
var objects = amazonClient.ListObjects(listObjectsRequest);
var objectsInFolder = objects.S3Objects.Where(file => file.Size > 0).ToList();

Alternate output format for psql

I just needed to spend more time staring at the documentation. This command:

\x on

will do exactly what I wanted. Here is some sample output:

select * from dda where u_id=24 and dda_is_deleted='f';
-[ RECORD 1 ]------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
dda_id             | 1121
u_id               | 24
ab_id              | 10304
dda_type           | CHECKING
dda_status         | PENDING_VERIFICATION
dda_is_deleted     | f
dda_verify_op_id   | 44938
version            | 2
created            | 2012-03-06 21:37:50.585845
modified           | 2012-03-06 21:37:50.593425
c_id               | 
dda_nickname       | 
dda_account_name   | 
cu_id              | 1
abd_id             | 

What is the difference between "JPG" / "JPEG" / "PNG" / "BMP" / "GIF" / "TIFF" Image?

These names refers to different ways to encode pixel image data (JPG and JPEG are the same thing, and TIFF may just enclose a jpeg with some additional metadata).

These image formats may use different compression algorithms, different color representations, different capability in carrying additional data other than the image itself, and so on.

For web applications, I'd say jpeg or gif is good enough. Jpeg is used more often due to its higher compression ratio, and gif is typically used for light weight animation where a flash (or something similar) is an over kill, or places where transparent background is desired. PNG can be used too, but I don't have much experience with that. BMP and TIFF probably are not good candidates for web applications.

How can I display a modal dialog in Redux that performs asynchronous actions?

The approach I suggest is a bit verbose but I found it to scale pretty well into complex apps. When you want to show a modal, fire an action describing which modal you'd like to see:

Dispatching an Action to Show the Modal

this.props.dispatch({
  type: 'SHOW_MODAL',
  modalType: 'DELETE_POST',
  modalProps: {
    postId: 42
  }
})

(Strings can be constants of course; I’m using inline strings for simplicity.)

Writing a Reducer to Manage Modal State

Then make sure you have a reducer that just accepts these values:

const initialState = {
  modalType: null,
  modalProps: {}
}

function modal(state = initialState, action) {
  switch (action.type) {
    case 'SHOW_MODAL':
      return {
        modalType: action.modalType,
        modalProps: action.modalProps
      }
    case 'HIDE_MODAL':
      return initialState
    default:
      return state
  }
}

/* .... */

const rootReducer = combineReducers({
  modal,
  /* other reducers */
})

Great! Now, when you dispatch an action, state.modal will update to include the information about the currently visible modal window.

Writing the Root Modal Component

At the root of your component hierarchy, add a <ModalRoot> component that is connected to the Redux store. It will listen to state.modal and display an appropriate modal component, forwarding the props from the state.modal.modalProps.

// These are regular React components we will write soon
import DeletePostModal from './DeletePostModal'
import ConfirmLogoutModal from './ConfirmLogoutModal'

const MODAL_COMPONENTS = {
  'DELETE_POST': DeletePostModal,
  'CONFIRM_LOGOUT': ConfirmLogoutModal,
  /* other modals */
}

const ModalRoot = ({ modalType, modalProps }) => {
  if (!modalType) {
    return <span /> // after React v15 you can return null here
  }

  const SpecificModal = MODAL_COMPONENTS[modalType]
  return <SpecificModal {...modalProps} />
}

export default connect(
  state => state.modal
)(ModalRoot)

What have we done here? ModalRoot reads the current modalType and modalProps from state.modal to which it is connected, and renders a corresponding component such as DeletePostModal or ConfirmLogoutModal. Every modal is a component!

Writing Specific Modal Components

There are no general rules here. They are just React components that can dispatch actions, read something from the store state, and just happen to be modals.

For example, DeletePostModal might look like:

import { deletePost, hideModal } from '../actions'

const DeletePostModal = ({ post, dispatch }) => (
  <div>
    <p>Delete post {post.name}?</p>
    <button onClick={() => {
      dispatch(deletePost(post.id)).then(() => {
        dispatch(hideModal())
      })
    }}>
      Yes
    </button>
    <button onClick={() => dispatch(hideModal())}>
      Nope
    </button>
  </div>
)

export default connect(
  (state, ownProps) => ({
    post: state.postsById[ownProps.postId]
  })
)(DeletePostModal)

The DeletePostModal is connected to the store so it can display the post title and works like any connected component: it can dispatch actions, including hideModal when it is necessary to hide itself.

Extracting a Presentational Component

It would be awkward to copy-paste the same layout logic for every “specific” modal. But you have components, right? So you can extract a presentational <Modal> component that doesn’t know what particular modals do, but handles how they look.

Then, specific modals such as DeletePostModal can use it for rendering:

import { deletePost, hideModal } from '../actions'
import Modal from './Modal'

const DeletePostModal = ({ post, dispatch }) => (
  <Modal
    dangerText={`Delete post ${post.name}?`}
    onDangerClick={() =>
      dispatch(deletePost(post.id)).then(() => {
        dispatch(hideModal())
      })
    })
  />
)

export default connect(
  (state, ownProps) => ({
    post: state.postsById[ownProps.postId]
  })
)(DeletePostModal)

It is up to you to come up with a set of props that <Modal> can accept in your application but I would imagine that you might have several kinds of modals (e.g. info modal, confirmation modal, etc), and several styles for them.

Accessibility and Hiding on Click Outside or Escape Key

The last important part about modals is that generally we want to hide them when the user clicks outside or presses Escape.

Instead of giving you advice on implementing this, I suggest that you just don’t implement it yourself. It is hard to get right considering accessibility.

Instead, I would suggest you to use an accessible off-the-shelf modal component such as react-modal. It is completely customizable, you can put anything you want inside of it, but it handles accessibility correctly so that blind people can still use your modal.

You can even wrap react-modal in your own <Modal> that accepts props specific to your applications and generates child buttons or other content. It’s all just components!

Other Approaches

There is more than one way to do it.

Some people don’t like the verbosity of this approach and prefer to have a <Modal> component that they can render right inside their components with a technique called “portals”. Portals let you render a component inside yours while actually it will render at a predetermined place in the DOM, which is very convenient for modals.

In fact react-modal I linked to earlier already does that internally so technically you don’t even need to render it from the top. I still find it nice to decouple the modal I want to show from the component showing it, but you can also use react-modal directly from your components, and skip most of what I wrote above.

I encourage you to consider both approaches, experiment with them, and pick what you find works best for your app and for your team.

socket.error: [Errno 10013] An attempt was made to access a socket in a way forbidden by its access permissions

For me it was complaining like that on Windows 7 x64 when I had another process already listening on that same port.

It is possible to see currently occupied (bound) ports by running

netstat -ban

How to change default text color using custom theme?

You can't use @android:style/TextAppearance as the parent for the whole app's theme; that's why koopaking3's solution seems quite broken.

To change default text colour everywhere in your app using a custom theme, try something like this. Works at least on Android 4.0+ (API level 14+).

res/values/themes.xml:

<resources>    
    <style name="MyAppTheme" parent="android:Theme.Holo.Light">
        <!-- Change default text colour from dark grey to black -->
        <item name="android:textColor">@android:color/black</item>
    </style>
</resources>

Manifest:

<application
    ...
    android:theme="@style/MyAppTheme">

Update

A shortcoming with the above is that also disabled Action Bar overflow menu items use the default colour, instead of being greyed out. (Of course, if you don't use disabled menu items anywhere in your app, this may not matter.)

As I learned by asking this question, a better way is to define the colour using a drawable:

<item name="android:textColor">@drawable/default_text_color</item>

...with res/drawable/default_text_color.xml specifying separate state_enabled="false" colour:

<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_enabled="false" android:color="@android:color/darker_gray"/>
    <item android:color="@android:color/black"/>
</selector>

How to open Atom editor from command line in OS X?

Open the application by name:

open -a 'Atom' FILENAME

How to remove specific elements in a numpy array

Use numpy.delete() - returns a new array with sub-arrays along an axis deleted

numpy.delete(a, index)

For your specific question:

import numpy as np

a = np.array([1, 2, 3, 4, 5, 6, 7, 8, 9])
index = [2, 3, 6]

new_a = np.delete(a, index)

print(new_a) #Prints `[1, 2, 5, 6, 8, 9]`

Note that numpy.delete() returns a new array since array scalars are immutable, similar to strings in Python, so each time a change is made to it, a new object is created. I.e., to quote the delete() docs:

"A copy of arr with the elements specified by obj removed. Note that delete does not occur in-place..."

If the code I post has output, it is the result of running the code.

How do I syntax check a Bash script without running it?

I also enable the 'u' option on every bash script I write in order to do some extra checking:

set -u 

This will report the usage of uninitialized variables, like in the following script 'check_init.sh'

#!/bin/sh
set -u
message=hello
echo $mesage

Running the script :

$ check_init.sh

Will report the following :

./check_init.sh[4]: mesage: Parameter not set.

Very useful to catch typos

Detect if checkbox is checked or unchecked in Angular.js ng-change event

The state of the checkbox will be reflected on whatever model you have it bound to, in this case, $scope.answers[item.questID]

How to increase the clickable area of a <a> tag button?

the simple way I found out: add a "li" tag on the right side of an "a" tag List item

<li></span><a><span id="expand1"></span></a></li>

On CSS file create this below:

#expand1 {
 padding-left: 40px;
}

Inner join vs Where

It is true that, functionally, both queries should be processed the same way. However, experience has shown that if you are selecting from views that use the new join syntax, it is important to structure your queries using it as well. Oracle's optimizer can get confused if a view uses a "join" statement, but a query accessing the view uses the traditional method of joining in the "where" clause.

New self vs. new static

In addition to others' answers :

static:: will be computed using runtime information.

That means you can't use static:: in a class property because properties values :

Must be able to be evaluated at compile time and must not depend on run-time information.

class Foo {
    public $name = static::class;

}

$Foo = new Foo;
echo $Foo->name; // Fatal error

Using self::

class Foo {
    public $name = self::class;

}
$Foo = new Foo;
echo $Foo->name; // Foo

Please note that the Fatal error comment in the code i made doesn't indicate where the error happened, the error happened earlier before the object was instantiated as @Grapestain mentioned in the comments

IndexError: too many indices for array

The message that you are getting is not for the default Exception of Python:

For a fresh python list, IndexError is thrown only on index not being in range (even docs say so).

>>> l = []
>>> l[1]
IndexError: list index out of range

If we try passing multiple items to list, or some other value, we get the TypeError:

>>> l[1, 2]
TypeError: list indices must be integers, not tuple

>>> l[float('NaN')]
TypeError: list indices must be integers, not float

However, here, you seem to be using matplotlib that internally uses numpy for handling arrays. On digging deeper through the codebase for numpy, we see:

static NPY_INLINE npy_intp
unpack_tuple(PyTupleObject *index, PyObject **result, npy_intp result_n)
{
    npy_intp n, i;
    n = PyTuple_GET_SIZE(index);
    if (n > result_n) {
        PyErr_SetString(PyExc_IndexError,
                        "too many indices for array");
        return -1;
    }
    for (i = 0; i < n; i++) {
        result[i] = PyTuple_GET_ITEM(index, i);
        Py_INCREF(result[i]);
    }
    return n;
}

where, the unpack method will throw an error if it the size of the index is greater than that of the results.

So, Unlike Python which raises a TypeError on incorrect Indexes, Numpy raises the IndexError because it supports multidimensional arrays.

How do I install and use curl on Windows?

I was looking for the download process of Curl and every where they said copy curl.exe file in System32 but they haven't provided the direct link. so here it is enjoy, find curl.exe easily in bin folder just

unzip it and then go to bin folder there you get exe file

link to download curl generic

How to change text and background color?

You can also use PDCurses library. (http://pdcurses.sourceforge.net/)

Convert dictionary to list collection in C#

If you want to pass the Dictionary keys collection into one method argument.

List<string> lstKeys = Dict.Keys;
Methodname(lstKeys);
-------------------
void MethodName(List<String> lstkeys)
{
    `enter code here`
    //Do ur task
}

How to remove item from list in C#?

There is another approach. It uses List.FindIndex and List.RemoveAt.

While I would probably use the solution presented by KeithS (just the simple Where/ToList) this approach differs in that it mutates the original list object. This can be a good (or a bad) "feature" depending upon expectations.

In any case, the FindIndex (coupled with a guard) ensures the RemoveAt will be correct if there are gaps in the IDs or the ordering is wrong, etc, and using RemoveAt (vs Remove) avoids a second O(n) search through the list.

Here is a LINQPad snippet:

var list = new List<int> { 1, 3, 2 };
var index = list.FindIndex(i => i == 2); // like Where/Single
if (index >= 0) {   // ensure item found
    list.RemoveAt(index);
}
list.Dump();        // results -> 1, 3

Happy coding.

How to kill all processes matching a name?

From man 1 pkill

-f     The pattern is normally only matched against the process name.
       When -f is set, the full command line is used.

Which means, for example, if we see these lines in ps aux:

apache   24268  0.0  2.6 388152 27116 ?        S    Jun13   0:10 /usr/sbin/httpd
apache   24272  0.0  2.6 387944 27104 ?        S    Jun13   0:09 /usr/sbin/httpd
apache   24319  0.0  2.6 387884 27316 ?        S    Jun15   0:04 /usr/sbin/httpd

We can kill them all using the pkill -f option:

pkill -f httpd

Visual Studio Code - Convert spaces to tabs

{
  "editor.insertSpaces": true
}

True works for me.

CSS3 Box Shadow on Top, Left, and Right Only

It's better if you just cover the bottom part with another div and you will get consistent drop shadow across the board.

#servicesContainer {
  /*your css*/
  position: relative;
}

and it's fixed! like magic!

Regex Match all characters between two strings

For example

(?<=This is)(.*)(?=sentence)

Regexr

I used lookbehind (?<=) and look ahead (?=) so that "This is" and "sentence" is not included in the match, but this is up to your use case, you can also simply write This is(.*)sentence.

The important thing here is that you activate the "dotall" mode of your regex engine, so that the . is matching the newline. But how you do this depends on your regex engine.

The next thing is if you use .* or .*?. The first one is greedy and will match till the last "sentence" in your string, the second one is lazy and will match till the next "sentence" in your string.

Update

Regexr

This is(?s)(.*)sentence

Where the (?s) turns on the dotall modifier, making the . matching the newline characters.

Update 2:

(?<=is \()(.*?)(?=\s*\))

is matching your example "This is (a simple) sentence". See here on Regexr

What is "string[] args" in Main class for?

It's an array of the parameters/arguments (hence args) that you send to the program. For example ping 172.16.0.1 -t -4

These arguments are passed to the program as an array of strings.

string[] args // Array of Strings containing arguments.

CSS: How to position two elements on top of each other, without specifying a height?

I had to set

Container_height = Element1_height = Element2_height

.Container {
    position: relative;
}

.ElementOne, .Container ,.ElementTwo{
    width: 283px;
    height: 71px;
}

.ElementOne {
    position:absolute;
}

.ElementTwo{
    position:absolute;
}

Use can use z-index to set which one to be on top.

How can I replace newline or \r\n with <br/>?

I think str_replace(array("\\r\\n", "\\r", "\\n"), " ", $string); will work.

Android notification is not showing

Notifications may not be shown if you show the notifications rapidly one after the other or cancel an existing one, then right away show it again (e.g. to trigger a heads-up-notification to notify the user about a change in an ongoing notification). In these cases the system may decide to just block the notification when it feels they might become too overwhelming/spammy for the user.

Please note, that at least on stock Android (tested with 10) from the outside this behavior looks a bit random: it just sometimes happens and sometimes it doesn't. My guess is, there is a very short time threshold during which you are not allowed to send too many notifications. Calling NotificationManager.cancel() and then NotificationManager.notify() might then sometimes cause this behavior.

If you have the option, when updating a notification don't cancel it before, but just call NotificationManager.notify() with the updated notification. This doesn't seem to trigger the aforementioned blocking by the system.

JSON Parse File Path

Loading local JSON file

Use something like this

$.getJSON("../../data/file.json", function(json) {
    console.log(json); // this will show the info in firebug console 
    alert(json);
});

Showing which files have changed between two revisions

For people who are looking for a GUI solution, Git Cola has a very nice "Branch Diff Viewer (Diff -> Branches..).

Count textarea characters

This code gets the maximum value from the maxlength attribute of the textarea and decreases the value as the user types.

<DEMO>

_x000D_
_x000D_
var el_t = document.getElementById('textarea');_x000D_
var length = el_t.getAttribute("maxlength");_x000D_
var el_c = document.getElementById('count');_x000D_
el_c.innerHTML = length;_x000D_
el_t.onkeyup = function () {_x000D_
  document.getElementById('count').innerHTML = (length - this.value.length);_x000D_
};
_x000D_
<textarea id="textarea" name="text"_x000D_
 maxlength="500"></textarea>_x000D_
<span id="count"></span>
_x000D_
_x000D_
_x000D_

How to get every first element in 2 dimensional list

You can get the index [0] from each element in a list comprehension

>>> [i[0] for i in a]
[4.0, 3.0, 3.5]

Also just to be pedantic, you don't have a list of list, you have a tuple of tuple.

Where are my postgres *.conf files?

30-07-2019

In Windows 10 pro:

C:\Program Files\PostgreSQL\11\data

PHP isset() with multiple parameters

You just need:

if (!empty($_POST['search_term']) && !empty($_POST['postcode']))

isset && !empty is redundant.

Making an asynchronous task in Flask

Threading is another possible solution. Although the Celery based solution is better for applications at scale, if you are not expecting too much traffic on the endpoint in question, threading is a viable alternative.

This solution is based on Miguel Grinberg's PyCon 2016 Flask at Scale presentation, specifically slide 41 in his slide deck. His code is also available on github for those interested in the original source.

From a user perspective the code works as follows:

  1. You make a call to the endpoint that performs the long running task.
  2. This endpoint returns 202 Accepted with a link to check on the task status.
  3. Calls to the status link returns 202 while the taks is still running, and returns 200 (and the result) when the task is complete.

To convert an api call to a background task, simply add the @async_api decorator.

Here is a fully contained example:

from flask import Flask, g, abort, current_app, request, url_for
from werkzeug.exceptions import HTTPException, InternalServerError
from flask_restful import Resource, Api
from datetime import datetime
from functools import wraps
import threading
import time
import uuid

tasks = {}

app = Flask(__name__)
api = Api(app)


@app.before_first_request
def before_first_request():
    """Start a background thread that cleans up old tasks."""
    def clean_old_tasks():
        """
        This function cleans up old tasks from our in-memory data structure.
        """
        global tasks
        while True:
            # Only keep tasks that are running or that finished less than 5
            # minutes ago.
            five_min_ago = datetime.timestamp(datetime.utcnow()) - 5 * 60
            tasks = {task_id: task for task_id, task in tasks.items()
                     if 'completion_timestamp' not in task or task['completion_timestamp'] > five_min_ago}
            time.sleep(60)

    if not current_app.config['TESTING']:
        thread = threading.Thread(target=clean_old_tasks)
        thread.start()


def async_api(wrapped_function):
    @wraps(wrapped_function)
    def new_function(*args, **kwargs):
        def task_call(flask_app, environ):
            # Create a request context similar to that of the original request
            # so that the task can have access to flask.g, flask.request, etc.
            with flask_app.request_context(environ):
                try:
                    tasks[task_id]['return_value'] = wrapped_function(*args, **kwargs)
                except HTTPException as e:
                    tasks[task_id]['return_value'] = current_app.handle_http_exception(e)
                except Exception as e:
                    # The function raised an exception, so we set a 500 error
                    tasks[task_id]['return_value'] = InternalServerError()
                    if current_app.debug:
                        # We want to find out if something happened so reraise
                        raise
                finally:
                    # We record the time of the response, to help in garbage
                    # collecting old tasks
                    tasks[task_id]['completion_timestamp'] = datetime.timestamp(datetime.utcnow())

                    # close the database session (if any)

        # Assign an id to the asynchronous task
        task_id = uuid.uuid4().hex

        # Record the task, and then launch it
        tasks[task_id] = {'task_thread': threading.Thread(
            target=task_call, args=(current_app._get_current_object(),
                               request.environ))}
        tasks[task_id]['task_thread'].start()

        # Return a 202 response, with a link that the client can use to
        # obtain task status
        print(url_for('gettaskstatus', task_id=task_id))
        return 'accepted', 202, {'Location': url_for('gettaskstatus', task_id=task_id)}
    return new_function


class GetTaskStatus(Resource):
    def get(self, task_id):
        """
        Return status about an asynchronous task. If this request returns a 202
        status code, it means that task hasn't finished yet. Else, the response
        from the task is returned.
        """
        task = tasks.get(task_id)
        if task is None:
            abort(404)
        if 'return_value' not in task:
            return '', 202, {'Location': url_for('gettaskstatus', task_id=task_id)}
        return task['return_value']


class CatchAll(Resource):
    @async_api
    def get(self, path=''):
        # perform some intensive processing
        print("starting processing task, path: '%s'" % path)
        time.sleep(10)
        print("completed processing task, path: '%s'" % path)
        return f'The answer is: {path}'


api.add_resource(CatchAll, '/<path:path>', '/')
api.add_resource(GetTaskStatus, '/status/<task_id>')


if __name__ == '__main__':
    app.run(debug=True)

How to convert int to date in SQL Server 2008

Reading through this helps solve a similar problem. The data is in decimal datatype - [DOB] [decimal](8, 0) NOT NULL - eg - 19700109. I want to get at the month. The solution is to combine SUBSTRING with CONVERT to VARCHAR.

    SELECT [NUM]
       ,SUBSTRING(CONVERT(VARCHAR, DOB),5,2) AS mob
    FROM [Dbname].[dbo].[Tablename] 

Is it possible to have a HTML SELECT/OPTION value as NULL using PHP?

In php 7 you can do:

$_POST['value'] ?? null;

If value is equal to '' as said in other answers it will also send you null.

how to wait for first command to finish?

Shell scripts, no matter how they are executed, execute one command after the other. So your code will execute results.sh after the last command of st_new.sh has finished.

Now there is a special command which messes this up: &

cmd &

means: "Start a new background process and execute cmd in it. After starting the background process, immediately continue with the next command in the script."

That means & doesn't wait for cmd to do it's work. My guess is that st_new.sh contains such a command. If that is the case, then you need to modify the script:

cmd &
BACK_PID=$!

This puts the process ID (PID) of the new background process in the variable BACK_PID. You can then wait for it to end:

while kill -0 $BACK_PID ; do
    echo "Process is still active..."
    sleep 1
    # You can add a timeout here if you want
done

or, if you don't want any special handling/output simply

wait $BACK_PID

Note that some programs automatically start a background process when you run them, even if you omit the &. Check the documentation, they often have an option to write their PID to a file or you can run them in the foreground with an option and then use the shell's & command instead to get the PID.

Finding out current index in EACH loop (Ruby)

x.each_with_index { |v, i| puts "current index...#{i}" }

LabelEncoder: TypeError: '>' not supported between instances of 'float' and 'str'

This is due to the series df[cat] containing elements that have varying data types e.g.(strings and/or floats). This could be due to the way the data is read, i.e. numbers are read as float and text as strings or the datatype was float and changed after the fillna operation.

In other words

pandas data type 'Object' indicates mixed types rather than str type

so using the following line:

df[cat] = le.fit_transform(df[cat].astype(str))


should help

What causes an HTTP 405 "invalid method (HTTP verb)" error when POSTing a form to PHP on IIS?

I had this issue with a facebook application that I was developing for a fan page tab. If anyone faces this issue with a facebook application then

1-goto https://developers.facebook.com

2-select the application that you are developing

3-make sure that all the link to your application has tailing slash /

my issue was in the https://developers.facebook.com->Apps->MYAPPNAME->settings->Page Tab->Secure Page Tab URL, Page Tab Edit URL, Page Tab URL hope this will help

Open a webpage in the default browser

Dim URL As String 
Dim browser As String = TextBox1.Text
URL = TextBox1.Text
Try
    If Not (browser = TextBox1.Text) Then
        Try
            Process.Start(browser, URL)
        Catch ex As Exception
            Process.Start(URL)
        End Try
    Else
        Process.Start(URL)
    End If

Catch ex As Exception
    MsgBox("There's something wrong!")
End Try

Style input element to fill remaining width of its container

I suggest using Flexbox:

Be sure to add the proper vendor prefixes though!

_x000D_
_x000D_
form {_x000D_
  width: 400px;_x000D_
  border: 1px solid black;_x000D_
  display: flex;_x000D_
}_x000D_
_x000D_
input {_x000D_
  flex: 2;_x000D_
}_x000D_
_x000D_
input, label {_x000D_
  margin: 5px;_x000D_
}
_x000D_
<form method="post">_x000D_
  <label for="myInput">Sample label</label>_x000D_
  <input type="text" id="myInput" placeholder="Sample Input"/>_x000D_
</form>
_x000D_
_x000D_
_x000D_

Sort JavaScript object by key

Pure JavaScript answer to sort an Object. This is the only answer that I know of that will handle negative numbers. This function is for sorting numerical Objects.

Input obj = {1000: {}, -1200: {}, 10000: {}, 200: {}};

function osort(obj) {
var keys = Object.keys(obj);
var len = keys.length;
var rObj = [];
var rK = [];
var t = Object.keys(obj).length;
while(t > rK.length) {
    var l = null;
    for(var x in keys) {
        if(l && parseInt(keys[x]) < parseInt(l)) {
            l = keys[x];
            k = x;
        }
        if(!l) { // Find Lowest
            var l = keys[x];
            var k = x;
        }
    }
    delete keys[k];
    rK.push(l);
}

for (var i = 0; i < len; i++) {

    k = rK[i];
    rObj.push(obj[k]);
}
return rObj;
}

The output will be an object sorted by those numbers with new keys starting at 0.

Can't bind to 'ngModel' since it isn't a known property of 'input'

ngModel is coming from FormsModule. There are some cases when you can receive this kind of error:

  1. You didn't import the FormsModule into the import array of modules where your component is declared - the component in which the ngModel is used.
  2. You have import the FormsModule into one module which is inherited of another module. In this case you have two options:
  • let the FormsModule be imported into the import array from both modules:module1 and module2. As the rule: Importing a module does not provide access to its imported modules. (Imports are not inherited)

    Enter image description here

  • declare the FormsModule into the import and export arrays in module1 to be able to see it in model2 also

    Enter image description here

  1. (In some version I faced this problem) You have imported the FormsModule correctly, but the problem is on the input HTML tag. You must add the name tag attribute for the input, and the object bound name in [(ngModel)] must be the same as the name into the name attribute

    Enter image description here

Calling a function of a module by using its name (a string)

none of what was suggested helped me. I did discover this though.

<object>.__getattribute__(<string name>)(<params>)

I am using python 2.66

Hope this helps

CS1617: Invalid option ‘6’ for /langversion; must be ISO-1, ISO-2, 3, 4, 5 or Default

The easiest solution for me was upgrading the .Net Compilers via Package Manager

Install-Package Microsoft.Net.Compilers

and then changing the Web.Config lines to this

<system.codedom>
 <compilers>
  <compiler language="c#;cs;csharp" extension=".cs" type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.CSharpCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" warningLevel="4" compilerOptions="/langversion:6 /nowarn:1659;1699;1701" />
  <compiler language="vb;vbs;visualbasic;vbscript" extension=".vb" type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.VBCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" warningLevel="4" compilerOptions="/langversion:14 /nowarn:41008 /define:_MYTYPE=\&quot;Web\&quot; /optionInfer+" />
 </compilers>
</system.codedom>

Use Excel VBA to click on a button in Internet Explorer, when the button has no "name" associated

CSS selector:

Use a CSS selector of img[src='images/toolbar/b_edit.gif']

This says select element(s) with img tag with attribute src having value of 'images/toolbar/b_edit.gif'


CSS query:

CSS query


VBA:

You can apply the selector with the .querySelector method of document.

IE.document.querySelector("img[src='images/toolbar/b_edit.gif']").Click

How to set the max size of upload file

Also in Spring boot 1.4, you can add following lines to your application.properties to set the file size limit:

spring.http.multipart.max-file-size=128KB
spring.http.multipart.max-request-size=128KB

for spring boot 2.x and above its

spring.servlet.multipart.max-file-size=10MB
spring.servlet.multipart.max-request-size=10MB

Worked for me. Source: https://spring.io/guides/gs/uploading-files/

UPDATE:

Somebody asked the differences between the two properties.

Below are the formal definitions:

MaxFileSize: The maximum size allowed for uploaded files, in bytes. If the size of any uploaded file is greater than this size, the web container will throw an exception (IllegalStateException). The default size is unlimited.

MaxRequestSize: The maximum size allowed for a multipart/form-data request, in bytes. The web container will throw an exception if the overall size of all uploaded files exceeds this threshold. The default size is unlimited.

To explain each:

MaxFileSize: The limit for a single file to upload. This is applied for the single file limit only.

MaxRequestSize: The limit for the total size of all files in a single upload request. This checks the total limit. Let's say you have two files a.txt and b.txt for a single upload request. a.txt is 5kb and b.txt is 7kb so the MaxRequestSize should be above 12kb.

C# Generics and Type Checking

And, because C# has evolved, you can (now) use pattern matching.

private static string BuildClause<T>(IList<T> clause)
{
    if (clause.Count > 0)
    {
        switch (clause[0])
        {
            case int x: // do something with x, which is an int here...
            case decimal x: // do something with x, which is a decimal here...
            case string x: // do something with x, which is a string here...
            ...
            default: throw new ApplicationException("Invalid type");
        }
    }
}

And again with switch expressions in C# 8.0, the syntax gets even more succinct.

private static string BuildClause<T>(IList<T> clause)
{
    if (clause.Count > 0)
    {
        return clause[0] switch
        {
            int x => "some string related to this int",
            decimal x => "some string related to this decimal",
            string x => x,
            ...,
            _ => throw new ApplicationException("Invalid type")
        }
    }
}

T-SQL string replace in Update

The syntax for REPLACE:

REPLACE (string_expression,string_pattern,string_replacement)

So that the SQL you need should be:

UPDATE [DataTable] SET [ColumnValue] = REPLACE([ColumnValue], 'domain2', 'domain1')

Regular expression for validating names and surnames?

I sympathize with the need to constrain input in this situation, but I don't believe it is possible - Unicode is vast, expanding, and so is the subset used in names throughout the world.

Unlike email, there's no universally agreed-upon standard for the names people may use, or even which representations they may register as official with their respective governments. I suspect that any regex will eventually fail to pass a name considered valid by someone, somewhere in the world.

Of course, you do need to sanitize or escape input, to avoid the Little Bobby Tables problem. And there may be other constraints on which input you allow as well, such as the underlying systems used to store, render or manipulate names. As such, I recommend that you determine first the restrictions necessitated by the system your validation belongs to, and create a validation expression based on those alone. This may still cause inconvenience in some scenarios, but they should be rare.

What is a good regular expression to match a URL?

(https?:\/\/(?:www\.|(?!www))[a-zA-Z0-9][a-zA-Z0-9-]+[a-zA-Z0-9]\.[^\s]{2,}|www\.[a-zA-Z0-9][a-zA-Z0-9-]+[a-zA-Z0-9]\.[^\s]{2,}|https?:\/\/(?:www\.|(?!www))[a-zA-Z0-9]+\.[^\s]{2,}|www\.[a-zA-Z0-9]+\.[^\s]{2,})

Will match the following cases

  • http://www.foufos.gr
  • https://www.foufos.gr
  • http://foufos.gr
  • http://www.foufos.gr/kino
  • http://werer.gr
  • www.foufos.gr
  • www.mp3.com
  • www.t.co
  • http://t.co
  • http://www.t.co
  • https://www.t.co
  • www.aa.com
  • http://aa.com
  • http://www.aa.com
  • https://www.aa.com

Will NOT match the following

  • www.foufos
  • www.foufos-.gr
  • www.-foufos.gr
  • foufos.gr
  • http://www.foufos
  • http://foufos
  • www.mp3#.com

_x000D_
_x000D_
var expression = /(https?:\/\/(?:www\.|(?!www))[a-zA-Z0-9][a-zA-Z0-9-]+[a-zA-Z0-9]\.[^\s]{2,}|www\.[a-zA-Z0-9][a-zA-Z0-9-]+[a-zA-Z0-9]\.[^\s]{2,}|https?:\/\/(?:www\.|(?!www))[a-zA-Z0-9]+\.[^\s]{2,}|www\.[a-zA-Z0-9]+\.[^\s]{2,})/gi;_x000D_
var regex = new RegExp(expression);_x000D_
_x000D_
var check = [_x000D_
  'http://www.foufos.gr',_x000D_
  'https://www.foufos.gr',_x000D_
  'http://foufos.gr',_x000D_
  'http://www.foufos.gr/kino',_x000D_
  'http://werer.gr',_x000D_
  'www.foufos.gr',_x000D_
  'www.mp3.com',_x000D_
  'www.t.co',_x000D_
  'http://t.co',_x000D_
  'http://www.t.co',_x000D_
  'https://www.t.co',_x000D_
  'www.aa.com',_x000D_
  'http://aa.com',_x000D_
  'http://www.aa.com',_x000D_
  'https://www.aa.com',_x000D_
  'www.foufos',_x000D_
  'www.foufos-.gr',_x000D_
  'www.-foufos.gr',_x000D_
  'foufos.gr',_x000D_
  'http://www.foufos',_x000D_
  'http://foufos',_x000D_
  'www.mp3#.com'_x000D_
];_x000D_
_x000D_
check.forEach(function(entry) {_x000D_
  if (entry.match(regex)) {_x000D_
    $("#output").append( "<div >Success: " + entry + "</div>" );_x000D_
  } else {_x000D_
    $("#output").append( "<div>Fail: " + entry + "</div>" );_x000D_
  }_x000D_
});
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>_x000D_
<div id="output"></div>
_x000D_
_x000D_
_x000D_

Check it in rubular - NEW version

Check it in rubular - old version

Test if characters are in a string

Just in case you would also like check if a string (or a set of strings) contain(s) multiple sub-strings, you can also use the '|' between two substrings.

>substring="as|at"
>string_vector=c("ass","ear","eye","heat") 
>grepl(substring,string_vector)

You will get

[1]  TRUE FALSE FALSE  TRUE

since the 1st word has substring "as", and the last word contains substring "at"

Difference between Visibility.Collapsed and Visibility.Hidden

The difference is that Visibility.Hidden hides the control, but reserves the space it occupies in the layout. So it renders whitespace instead of the control. Visibilty.Collapsed does not render the control and does not reserve the whitespace. The space the control would take is 'collapsed', hence the name.

The exact text from the MSDN:

Collapsed: Do not display the element, and do not reserve space for it in layout.

Hidden: Do not display the element, but reserve space for the element in layout.

Visible: Display the element.

See: http://msdn.microsoft.com/en-us/library/system.windows.visibility.aspx

Postgresql Windows, is there a default password?

Try this:

Open PgAdmin -> Files -> Open pgpass.conf

You would get the path of pgpass.conf at the bottom of the window. Go to that location and open this file, you can find your password there.

Reference

If the above does not work, you may consider trying this:

 1. edit pg_hba.conf to allow trust authorization temporarily
 2. Reload the config file (pg_ctl reload)
 3. Connect and issue ALTER ROLE / PASSWORD to set the new password
 4. edit pg_hba.conf again and restore the previous settings
 5. Reload the config file again

How to enable MySQL Query Log?

for mysql>=5.5 only for slow queries (1 second and more) my.cfg

[mysqld]
slow-query-log = 1
slow-query-log-file = /var/log/mysql/mysql-slow.log
long_query_time = 1
log-queries-not-using-indexes

How to fetch data from local JSON file on react native?

Since React Native 0.4.3 you can read your local JSON file like this:

const customData = require('./customData.json');

and then access customData like a normal JS object.

Git - remote: Repository not found

If you are using Git Desktop application than you should try to push and pull form git desktop app instead of terminal. It will help you.

Programmatically add custom event in the iPhone Calendar

You can add the event using the Event API like Tristan outlined and you can also add a Google Calendar event which shows up in the iOS calendar.

using Google's API Objective-C Client

  - (void)addAnEvent {
  // Make a new event, and show it to the user to edit
  GTLCalendarEvent *newEvent = [GTLCalendarEvent object];
  newEvent.summary = @"Sample Added Event";
  newEvent.descriptionProperty = @"Description of sample added event";

  // We'll set the start time to now, and the end time to an hour from now,
  // with a reminder 10 minutes before
  NSDate *anHourFromNow = [NSDate dateWithTimeIntervalSinceNow:60*60];
  GTLDateTime *startDateTime = [GTLDateTime dateTimeWithDate:[NSDate date]
                                                    timeZone:[NSTimeZone systemTimeZone]];
  GTLDateTime *endDateTime = [GTLDateTime dateTimeWithDate:anHourFromNow
                                                  timeZone:[NSTimeZone systemTimeZone]];

  newEvent.start = [GTLCalendarEventDateTime object];
  newEvent.start.dateTime = startDateTime;

  newEvent.end = [GTLCalendarEventDateTime object];
  newEvent.end.dateTime = endDateTime;

  GTLCalendarEventReminder *reminder = [GTLCalendarEventReminder object];
  reminder.minutes = [NSNumber numberWithInteger:10];
  reminder.method = @"email";

  newEvent.reminders = [GTLCalendarEventReminders object];
  newEvent.reminders.overrides = [NSArray arrayWithObject:reminder];
  newEvent.reminders.useDefault = [NSNumber numberWithBool:NO];

  // Display the event edit dialog
  EditEventWindowController *controller = [[[EditEventWindowController alloc] init] autorelease];
  [controller runModalForWindow:[self window]
                          event:newEvent
              completionHandler:^(NSInteger returnCode, GTLCalendarEvent *event) {
                // Callback
                if (returnCode == NSOKButton) {
                  [self addEvent:event];
                }
              }];
}

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

Here is the very nice link which explains the storage of signed and unsigned INT in C -

http://answers.yahoo.com/question/index?qid=20090516032239AAzcX1O

Taken from this above article -

"process called two's complement is used to transform positive numbers into negative numbers. The side effect of this is that the most significant bit is used to tell the computer if the number is positive or negative. If the most significant bit is a 1, then the number is negative. If it's 0, the number is positive."

How to visualize an XML schema?

The open source command line java application xsdvi creates an interactive diagram in SVG format from an XML Schema Definition. The generated SVG file can be displayed by a modern web browser where the user can expand and collapse the tree by mouse clicking.

Here is an example of a generated diagram

http://xsdvi.sourceforge.net/ipo.svg

The software can be downloaded from

http://sourceforge.net/projects/xsdvi/

It can be run as follows (assuming Java is installed and java.exe is in the path):-

  1. Go to the dist/lib folder.
  2. Run the following command java -jar xsdvi.jar <input1.xsd> [<input2.xsd> [<input3.xsd> ...]] [style]

Trim whitespace from a String

#include <vector>
#include <numeric>
#include <sstream>
#include <iterator>

void Trim(std::string& inputString)
{
    std::istringstream stringStream(inputString);
    std::vector<std::string> tokens((std::istream_iterator<std::string>(stringStream)), std::istream_iterator<std::string>());

    inputString = std::accumulate(std::next(tokens.begin()), tokens.end(),
                                 tokens[0], // start with first element
                                 [](std::string a, std::string b) { return a + " " + b; });
}

Remove characters from C# string

Less specific to your question, it is possible to remove ALL punctuation from a string (except space) by white listing the acceptable characters in a regular expression:

string dirty = "My name @is ,Wan.;'; Wan";

// only space, capital A-Z, lowercase a-z, and digits 0-9 are allowed in the string
string clean = Regex.Replace(dirty, "[^A-Za-z0-9 ]", "");

Note there is a space after that 9 so as not to remove spaces from your sentence. The third argument is an empty string which serves to replace any substring that does not belong in the regular expression.

Get Bitmap attached to ImageView

Write below code

ImageView yourImageView = (ImageView) findViewById(R.id.yourImageView);
Bitmap bitmap = ((BitmapDrawable)yourImageView.getDrawable()).getBitmap();

append to url and refresh page

If you are developing for a modern browser, Instead of parsing the url parameters yourself- you can use the built in URL functions to do it for you like this:

const parser = new URL(url || window.location);
parser.searchParams.set(key, value);
window.location = parser.href;

How to force a hover state with jQuery?

You will have to use a class, but don't worry, it's pretty simple. First we'll assign your :hover rules to not only apply to physically-hovered links, but also to links that have the classname hovered.

a:hover, a.hovered { color: #ccff00; }

Next, when you click #btn, we'll toggle the .hovered class on the #link.

$("#btn").click(function() {
   $("#link").toggleClass("hovered");
});

If the link has the class already, it will be removed. If it doesn't have the class, it will be added.

Convert number to varchar in SQL with formatting

declare @t  tinyint
set @t =3
select right(replicate('0', 2) + cast(@t as varchar),2)

Ditto: on the cripping effect for numbers > 99

If you want to cater for 1-255 then you could use

select right(replicate('0', 2) + cast(@t as varchar),3)

But this would give you 001, 010, 100 etc

Simple insecure two-way data "obfuscation"?

A variant of Marks (excellent) answer

  • Add "using"s
  • Make the class IDisposable
  • Remove the URL encoding code to make the example simpler.
  • Add a simple test fixture to demonstrate usage

Hope this helps

[TestFixture]
public class RijndaelHelperTests
{
    [Test]
    public void UseCase()
    {
        //These two values should not be hard coded in your code.
        byte[] key = {251, 9, 67, 117, 237, 158, 138, 150, 255, 97, 103, 128, 183, 65, 76, 161, 7, 79, 244, 225, 146, 180, 51, 123, 118, 167, 45, 10, 184, 181, 202, 190};
        byte[] vector = {214, 11, 221, 108, 210, 71, 14, 15, 151, 57, 241, 174, 177, 142, 115, 137};

        using (var rijndaelHelper = new RijndaelHelper(key, vector))
        {
            var encrypt = rijndaelHelper.Encrypt("StringToEncrypt");
            var decrypt = rijndaelHelper.Decrypt(encrypt);
            Assert.AreEqual("StringToEncrypt", decrypt);
        }
    }
}

public class RijndaelHelper : IDisposable
{
    Rijndael rijndael;
    UTF8Encoding encoding;

    public RijndaelHelper(byte[] key, byte[] vector)
    {
        encoding = new UTF8Encoding();
        rijndael = Rijndael.Create();
        rijndael.Key = key;
        rijndael.IV = vector;
    }

    public byte[] Encrypt(string valueToEncrypt)
    {
        var bytes = encoding.GetBytes(valueToEncrypt);
        using (var encryptor = rijndael.CreateEncryptor())
        using (var stream = new MemoryStream())
        using (var crypto = new CryptoStream(stream, encryptor, CryptoStreamMode.Write))
        {
            crypto.Write(bytes, 0, bytes.Length);
            crypto.FlushFinalBlock();
            stream.Position = 0;
            var encrypted = new byte[stream.Length];
            stream.Read(encrypted, 0, encrypted.Length);
            return encrypted;
        }
    }

    public string Decrypt(byte[] encryptedValue)
    {
        using (var decryptor = rijndael.CreateDecryptor())
        using (var stream = new MemoryStream())
        using (var crypto = new CryptoStream(stream, decryptor, CryptoStreamMode.Write))
        {
            crypto.Write(encryptedValue, 0, encryptedValue.Length);
            crypto.FlushFinalBlock();
            stream.Position = 0;
            var decryptedBytes = new Byte[stream.Length];
            stream.Read(decryptedBytes, 0, decryptedBytes.Length);
            return encoding.GetString(decryptedBytes);
        }
    }

    public void Dispose()
    {
        if (rijndael != null)
        {
            rijndael.Dispose();
        }
    }
}

Printing all properties in a Javascript Object

What about this:

var txt="";
var nyc = {
    fullName: "New York City",
    mayor: "Michael Bloomberg",
    population: 8000000,
    boroughs: 5
};

for (var x in nyc){
    txt += nyc[x];
}

How to use boost bind with a member function

Use the following instead:

boost::function<void (int)> f2( boost::bind( &myclass::fun2, this, _1 ) );

This forwards the first parameter passed to the function object to the function using place-holders - you have to tell Boost.Bind how to handle the parameters. With your expression it would try to interpret it as a member function taking no arguments.
See e.g. here or here for common usage patterns.

Note that VC8s cl.exe regularly crashes on Boost.Bind misuses - if in doubt use a test-case with gcc and you will probably get good hints like the template parameters Bind-internals were instantiated with if you read through the output.

Convert byte[] to char[]

You must know the source encoding.

string someText = "The quick brown fox jumps over the lazy dog.";
byte[] bytes = Encoding.Unicode.GetBytes(someText);
char[] chars = Encoding.Unicode.GetChars(bytes);

Using %f with strftime() in Python to get microseconds

You can use datetime's strftime function to get this. The problem is that time's strftime accepts a timetuple that does not carry microsecond information.

from datetime import datetime
datetime.now().strftime("%H:%M:%S.%f")

Should do the trick!

How do I execute a bash script in Terminal?

Yet another way to execute it (this time without setting execute permissions):

bash /path/to/scriptname

How do I declare an array of undefined or no initial size?

malloc() (and its friends free() and realloc()) is the way to do this in C.

How do I detect what .NET Framework versions and service packs are installed?

I wanted to detect for the presence of .NET version 4.5.2 installed on my system, and I found no better solution than ASoft .NET Version Detector.

Snapshot of this tool showing different .NET versions:

Snapshot of this tool showing different .NET versions

Protect .NET code from reverse engineering?

Well, you cannot FULLY protect your product from being cracked, but you can maximize/enhance the security levels and make it a little bit too difficult to be cracked by newbies and intermediate crackers.

But bear in mind nothing is uncrackable, only the software on server side is well protected and cannot be cracked. Anyway, to enhance the security levels in your application, you can do some simple steps to prevent some crackers "not all" from cracking your applications. These steps will make these crackers go nuts and maybe desperate:

  • Obfuscate your source code, obviously this will make your source code look like a mess and unreadable.
  • Trigger several random checking routines inside your application like every two hours, 24 hours, one day, week, etc. or maybe after every action the user take.
  • Save your released application's MD5 checksum on your server and implement a routine that can check the current file MD5 checksum with the real one on you server side and make it randomly triggered. If the MD5 checksum has been changed that means this copy has been pirated. Now you can just block it or release an update to block it, etc.
  • Try to make a routine that can check if some of your codes (functions, classes, or specific routines) are actually have been modified or altered or even removed. I call it (code integrity check).
  • Use free unknown packers to pack your application. Or, if you have the money, go for commercial solutions such as Thamida or .NET Reactor. Those applications get updated regularly and once a cracker unpack your application, you can just get a new update from those companies and once you get the new update, you just pack your program and release a new update.
  • Release updates regularly and force your customer to download the latest update.
  • Finally make your application very cheap. Don't make it too expensive. Believe me, you will get more happy customers and crackers will just leave your application, because it isn't worth their time to crack a very cheap application.

Those are just simple methods to prevent newbies and intermediate crackers from cracking your application. If you have more ideas to protect your application just don't be shy to implement them. It will just make crackers lives hard, and they will get frustrated, and eventually they will leave your application, because it's just doesn't worth their time.

Lastly, you also need to consider spending your time on coding a good and quality applications. Don't waste your time on coding complicated security layers. If a good cracker wants to crack your application he/she will do no matter what you do...

Now go and implement some toys for the crackers...

Python concatenate text files

This should do it

For large files:

filenames = ['file1.txt', 'file2.txt', ...]
with open('path/to/output/file', 'w') as outfile:
    for fname in filenames:
        with open(fname) as infile:
            for line in infile:
                outfile.write(line)

For small files:

filenames = ['file1.txt', 'file2.txt', ...]
with open('path/to/output/file', 'w') as outfile:
    for fname in filenames:
        with open(fname) as infile:
            outfile.write(infile.read())

… and another interesting one that I thought of:

filenames = ['file1.txt', 'file2.txt', ...]
with open('path/to/output/file', 'w') as outfile:
    for line in itertools.chain.from_iterable(itertools.imap(open, filnames)):
        outfile.write(line)

Sadly, this last method leaves a few open file descriptors, which the GC should take care of anyway. I just thought it was interesting

What is the most efficient way to concatenate N arrays?

Use Array.prototype.concat.apply to handle multiple arrays' concatenation:

var resultArray = Array.prototype.concat.apply([], arrayOfArraysToConcat);

Example:

var a1 = [1, 2, 3],
    a2 = [4, 5],
    a3 = [6, 7, 8, 9];
Array.prototype.concat.apply([], [a1, a2, a3]); // [1, 2, 3, 4, 5, 6, 7, 8, 9]

How to programmatically close a JFrame

If you really do not want your application to terminate when a JFrame is closed then,

use : setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);

instead of : setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

Here's a synopsis of what the solution looks like,

 myFrame.dispatchEvent(new WindowEvent(myFrame, WindowEvent.WINDOW_CLOSING));

Discard all and get clean copy of latest revision?

hg up -C

This will remove all the changes and update to the latest head in the current branch.

And you can turn on purge extension to be able to remove all unversioned files too.

What is the '.well' equivalent class in Bootstrap 4

This worked best for me:

<div class="card bg-light p-3">
 <p class="mb-0">Some text here</p>
</div>

How to get the Parent's parent directory in Powershell?

You can use

(get-item $scriptPath).Directoryname

to get the string path or if you want the Directory type use:

(get-item $scriptPath).Directory

How to read barcodes with the camera on Android?

Here is sample code using camera api

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.util.SparseArray;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import java.io.IOException;
import com.google.android.gms.vision.CameraSource;
import com.google.android.gms.vision.Detector;
import com.google.android.gms.vision.Frame;
import com.google.android.gms.vision.barcode.Barcode;
import com.google.android.gms.vision.barcode.BarcodeDetector;

public class MainActivity extends AppCompatActivity {

TextView barcodeInfo;
SurfaceView cameraView;
CameraSource cameraSource;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    cameraView = (SurfaceView) findViewById(R.id.camera_view);
      barcodeInfo = (TextView) findViewById(R.id.txtContent);


    BarcodeDetector barcodeDetector =
            new BarcodeDetector.Builder(this)
                    .setBarcodeFormats(Barcode.CODE_128)//QR_CODE)
                    .build();

    cameraSource = new CameraSource
            .Builder(this, barcodeDetector)
            .setRequestedPreviewSize(640, 480)
            .build();

    cameraView.getHolder().addCallback(new SurfaceHolder.Callback() {
        @Override
        public void surfaceCreated(SurfaceHolder holder) {

            try {
                cameraSource.start(cameraView.getHolder());
            } catch (IOException ie) {
                Log.e("CAMERA SOURCE", ie.getMessage());
            }
        }

        @Override
        public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
        }

        @Override
        public void surfaceDestroyed(SurfaceHolder holder) {
            cameraSource.stop();
        }
    });


    barcodeDetector.setProcessor(new Detector.Processor<Barcode>() {
        @Override
        public void release() {
        }

        @Override
        public void receiveDetections(Detector.Detections<Barcode> detections) {

            final SparseArray<Barcode> barcodes = detections.getDetectedItems();

            if (barcodes.size() != 0) {
                barcodeInfo.post(new Runnable() {    // Use the post method of the TextView
                    public void run() {
                        barcodeInfo.setText(    // Update the TextView
                                barcodes.valueAt(0).displayValue
                        );
                    }
                });
            }
        }
    });
}
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.gateway.cameraapibarcode.MainActivity">

<LinearLayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="vertical">

    <SurfaceView
        android:layout_width="640px"
        android:layout_height="480px"
        android:layout_centerVertical="true"
        android:layout_alignParentLeft="true"
        android:id="@+id/camera_view"/>

    <TextView
        android:text=" code reader"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/txtContent"/>
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Process"
        android:id="@+id/button"
        android:layout_alignParentTop="true"
        android:layout_alignParentStart="true" />
    <ImageView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/imgview"/>
</LinearLayout>
</RelativeLayout>

build.gradle(Module:app)

add compile 'com.google.android.gms:play-services:7.8.+' in dependencies

Test method is inconclusive: Test wasn't run. Error?

I'm was having the same problem to run any test using NUnit framework. "Inconclusive: Test not run" Visual Studio 2017 15.5.6

ReSharper Ultimate 2017.3.3 Build 111.0.20180302.65130

SOLVED Adding project dependency to Microsoft.NET.Test.Sdk

How to split a string to 2 strings in C

char *line = strdup("user name"); // don't do char *line = "user name"; see Note

char *first_part = strtok(line, " "); //first_part points to "user"
char *sec_part = strtok(NULL, " ");   //sec_part points to "name"

Note: strtok modifies the string, so don't hand it a pointer to string literal.

Gradle version 2.2 is required. Current version is 2.10

Use ./gradlew instead of gradle to resolve this issue.

How to display full (non-truncated) dataframe information in html when converting from pandas dataframe to html?

pd.set_option('display.max_columns', None)  

id (second argument) can fully show the columns.

SELECT CASE WHEN THEN (SELECT)

For a start the first select has 6 columns and the second has 4 columns. Perhaps make both have the same number of columns (adding nulls?).

Displaying a message in iOS which has the same functionality as Toast in Android

For the ones that using Xamarin.IOS you can do like this:

new UIAlertView(null, message, null, "OK", null).Show();

using UIKit; is required.

concat yesterdays date with a specific time

where date_dt = to_date(to_char(sysdate-1, 'YYYY-MM-DD') || ' 19:16:08', 'YYYY-MM-DD HH24:MI:SS') 

should work.

How to use android emulator for testing bluetooth application?

Download Androidx86 from this This is an iso file, so you'd
need something like VMWare or VirtualBox to run it When creating the virtual machine, you need to set the type of guest OS as Linux instead of Other.

After creating the virtual machine set the network adapter to 'Bridged'. · Start the VM and select 'Live CD VESA' at boot.

Now you need to find out the IP of this VM. Go to terminal in VM (use Alt+F1 & Alt+F7 to toggle) and use the netcfg command to find this.

Now you need open a command prompt and go to your android install folder (on host). This is usually C:\Program Files\Android\android-sdk\platform-tools>.

Type adb connect IP_ADDRESS. There done! Now you need to add Bluetooth. Plug in your USB Bluetooth dongle/Bluetooth device.

In VirtualBox screen, go to Devices>USB devices. Select your dongle.

Done! now your Android VM has Bluetooth. Try powering on Bluetooth and discovering/paring with other devices.

Now all that remains is to go to Eclipse and run your program. The Android AVD manager should show the VM as a device on the list.

Alternatively, Under settings of the virtual machine, Goto serialports -> Port 1 check Enable serial port select a port number then select port mode as disconnected click ok. now, start virtual machine. Under Devices -> USB Devices -> you can find your laptop bluetooth listed. You can simply check the option and start testing the android bluetooth application .

Source

Calling a class method raises a TypeError in Python

You never created an instance.

You've defined average as an instance method, thus, in order to use average you need to create an instance first.

How to disable GCC warnings for a few lines of code

For those who found this page looking for a way to do this in IAR, try this:

#pragma diag_suppress=Pe177
void foo1( void )
{
   /* The following line of code would normally provoke diagnostic 
      message #177-D: variable "x" was declared but never referenced.
      Instead, we have suppressed this warning throughout the entire 
      scope of foo1(). 
   */
   int x;
}
#pragma diag_default=Pe177

See http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0472m/chr1359124244797.html for reference.

SQL: Select columns with NULL values only

I would also recommend to search for fields which all have the same value, not just NULL.

That is, for each column in each table do the query:

SELECT COUNT(DISTINCT field) FROM tableName

and concentrate on those which return 1 as a result.

How to get the title of HTML page with JavaScript?

Can use getElementsByTagName

var x = document.getElementsByTagName("title")[0];

alert(x.innerHTML)

// or

alert(x.textContent)

// or

document.querySelector('title')

Edits as suggested by Paul

How to program a fractal?

Here's a simple and easy to understand code in Java for mandelbrot and other fractal examples

http://code.google.com/p/gaima/wiki/VLFImages

Just download the BuildFractal.jar to test it in Java and run with command:

java -Xmx1500M -jar BuildFractal.jar 1000 1000 default MANDELBROT

The source code is also free to download/explore/edit/expand.

Check if String contains only letters

What do you want? Speed or simplicity? For speed, go for a loop based approach. For simplicity, go for a one liner RegEx based approach.

Speed

public boolean isAlpha(String name) {
    char[] chars = name.toCharArray();

    for (char c : chars) {
        if(!Character.isLetter(c)) {
            return false;
        }
    }

    return true;
}

Simplicity

public boolean isAlpha(String name) {
    return name.matches("[a-zA-Z]+");
}

How can I check if a Perl module is installed on my system from the command line?

What you're doing there is not recursing into directories. It is only listing the modules in the root directory of the @INC directory.

The module XML::Simple will live in one of the @INC paths under XML/Simple.pm.

What he said above to find specific modules.

CPAN explains how to find all modules here, see How to find installed modules.

How to use an environment variable inside a quoted string in Bash

If unsure, you might use the 'cols' request on the terminal, and forget COLUMNS:

COLS=$(tput cols)

Windows 7 - 'make' is not recognized as an internal or external command, operable program or batch file

This is an old question, but none of the answers here provide enough context for a beginner to choose which one to pick.

What is make?

make is a traditional Unix utility which reads a Makefile to decide what programs to run to reach a particular goal. Typically, that goal is to build a single piece of software; but make is general enough to be used for various other tasks, too, like assembling a PDF from a collection of TeX source files, or retrieving the newest versions of each of a set of web pages.

Besides encapsulating the steps to reach an individual target, make reduces processing time by avoiding to re-execute steps which are already complete. It does this by comparing time stamps between dependencies; if A depends on B but A is newer than B, there is no need to make A. Of course, in order for this to work properly, the Makefile needs to document all such dependencies.

A: B
    commands to produce A from B

Notice that the indentation needs to consist of a literal tab character. This is a common beginner mistake.

Common Versions of make

The original make was rather pedestrian. Its lineage continues to this day into BSD make, from which nmake is derived. Roughly speaking, this version provides the make functionality defined by POSIX, with a few minor enhancements and variations.

GNU make, by contrast, significantly extends the formalism, to the point where a GNU Makefile is unlikely to work with other versions (or occasionally even older versions of GNU make). There is a convention to call such files GNUmakefile instead of Makefile, but this convention is widely ignored, especially on platforms like Linux where GNU make is the de facto standard make.

Telltale signs that a Makefile uses GNU make conventions are the use of := instead of = for variable assignments (though this is not exclusively a GNU feature) and a plethora of functions like $(shell ...), $(foreach ...), $(patsubst ...) etc.

So Which Do I Need?

Well, it really depends on what you are hoping to accomplish.

If the software you are hoping to build has a vcproj file or similar, you probably want to use that instead, and not try to use make at all.

In the general case, MinGW make is a Windows port of GNU make for Windows, It should generally cope with any Makefile you throw at it.

If you know the software was written to use nmake and you already have it installed, or it is easy for you to obtain, maybe go with that.

You should understand that if the software was not written for, or explicitly ported to, Windows, it is unlikely to compile without significant modifications. In this scenario, getting make to run is the least of your problems, and you will need a good understanding of the differences between the original platform and Windows to have a chance of pulling it off yourself.

In some more detail, if the Makefile contains Unix commands like grep or curl or yacc then your system needs to have those commands installed, too. But quite apart from that, C or C++ (or more generally, source code in any language) which was written for a different platform might simply not work - at all, or as expected (which is often worse) - on Windows.

Find the last element of an array while using a foreach loop in PHP

I kinda like the following as I feel it is fairly neat. Let's assume we're creating a string with separators between all the elements: e.g. a,b,c

$first = true;
foreach ( $items as $item ) {
    $str = ($first)?$first=false:", ".$item;
}

This declaration has no storage class or type specifier in C++

You can declare an object of a class in another Class,that's possible but you cant initialize that object. For that you need to do something like this :--> (inside main)

Orderbook o1;
o1.m.check(side)

but that would be unnecessary. Keeping things short :-

You can't call functions inside a Class

How do I properly set the Datetimeindex for a Pandas datetime object in a dataframe?

To simplify Kirubaharan's answer a bit:

df['Datetime'] = pd.to_datetime(df['date'] + ' ' + df['time'])
df = df.set_index('Datetime')

And to get rid of unwanted columns (as OP did but did not specify per se in the question):

df = df.drop(['date','time'], axis=1)

How to iterate over array of objects in Handlebars?

Handlebars can use an array as the context. You can use . as the root of the data. So you can loop through your array data with {{#each .}}.

_x000D_
_x000D_
var data = [_x000D_
  {_x000D_
    Category: "General",_x000D_
    DocumentList: [_x000D_
      {_x000D_
        DocumentName: "Document Name 1 - General",_x000D_
        DocumentLocation: "Document Location 1 - General"_x000D_
      },_x000D_
      {_x000D_
        DocumentName: "Document Name 2 - General",_x000D_
        DocumentLocation: "Document Location 2 - General"_x000D_
      }_x000D_
    ]_x000D_
  },_x000D_
  {_x000D_
    Category: "Unit Documents",_x000D_
    DocumentList: [_x000D_
      {_x000D_
        DocumentName: "Document Name 1 - Unit Documents",_x000D_
        DocumentList: "Document Location 1 - Unit Documents"_x000D_
      }_x000D_
    ]_x000D_
  },_x000D_
  {_x000D_
    Category: "Minutes"_x000D_
  }_x000D_
];_x000D_
_x000D_
$(function() {_x000D_
  var source = $("#document-template").html();_x000D_
  var template = Handlebars.compile(source);_x000D_
  var html = template(data);_x000D_
  $('#DocumentResults').html(html);_x000D_
});
_x000D_
.row {_x000D_
  border: 1px solid red;_x000D_
}
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/handlebars.js/1.0.0/handlebars.js"></script>_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.0.2/jquery.min.js"></script>_x000D_
<div id="DocumentResults">pos</div>_x000D_
<script id="document-template" type="text/x-handlebars-template">_x000D_
  <div>_x000D_
  {{#each .}}_x000D_
    <div class="row">_x000D_
      <div class="col-md-12">_x000D_
        <h2>{{Category}}</h2>_x000D_
        {{#DocumentList}}_x000D_
        <p>{{DocumentName}} at {{DocumentLocation}}</p>_x000D_
        {{/DocumentList}}_x000D_
      </div>_x000D_
    </div>_x000D_
  {{/each}}_x000D_
  </div>_x000D_
</script>
_x000D_
_x000D_
_x000D_

Rails: select unique values from a column

This works too.

Model.pluck("DISTINCT rating")

jQuery Datepicker with text input that doesn't allow user input

Instead of using textbox you can use button also. Works best for me, where I don't want users to write date manually.

enter image description here

React Error: Target Container is not a DOM Element

webpack solution

If you got this error while working in React with webpack and HMR.

You need to create template index.html and save it in src folder:

<html>
    <body>
       <div id="root"></root>
    </body>
</html>

Now when we have template with id="root" we need to tell webpack to generate index.html which will mirror our index.html file.

To do that:

plugins: [
    new HtmlWebpackPlugin({
        title: "Application name",
        template: './src/index.html'
    })
],

template property will tell webpack how to build index.html file.

How do I paste multi-line bash codes into terminal and run it all at once?

In addition to backslash, if a line ends with | or && or ||, it will be continued on the next line.

Does the join order matter in SQL?

for regular Joins, it doesn't. TableA join TableB will produce the same execution plan as TableB join TableA (so your C and D examples would be the same)

for left and right joins it does. TableA left Join TableB is different than TableB left Join TableA, BUT its the same than TableB right Join TableA

How to sum up an array of integers in C#

An alternative also it to use the Aggregate() extension method.

var sum = arr.Aggregate((temp, x) => temp+x);

'this' is undefined in JavaScript class methods

I just wanted to point out that sometimes this error happens because a function has been used as a high order function (passed as an argument) and then the scope of this got lost. In such cases, I would recommend passing such function bound to this. E.g.

this.myFunction.bind(this);

Status bar and navigation bar appear over my view's bounds in iOS 7

In your apps plist file add a row, call it "View controller-based status bar appearance" and set it to NO.

MySQL command line client for Windows

When you go to the MySQL download page, choose the platform "Microsoft Windows". Then download the "Windows (x86, xx-bit), ZIP Archive" (be sure to select the one with size over 140M.

The binaries will be in the "bin" folder.

I understand that this is not just the client binaries, but at least you don't have to install and setup the entire server.

Git's famous "ERROR: Permission to .git denied to user"

If problem is coming on windows then remove the Credentials from the Windows history.

  • Go to Credential Manager
  • Go to Windows Credentials
  • Delete the entries under Generic Credentials
  • Try connecting again.This time , it should prompt you for the correct username and password.

enter image description here enter image description here

remove credentials from git

Saving utf-8 texts with json.dumps as UTF8, not as \u escape sequence

Using ensure_ascii=False in json.dumps is the right direction to solve this problem, as pointed out by Martijn. However, this may raise an exception:

UnicodeDecodeError: 'ascii' codec can't decode byte 0xe7 in position 1: ordinal not in range(128)

You need extra settings in either site.py or sitecustomize.py to set your sys.getdefaultencoding() correct. site.py is under lib/python2.7/ and sitecustomize.py is under lib/python2.7/site-packages.

If you want to use site.py, under def setencoding(): change the first if 0: to if 1: so that python will use your operation system's locale.

If you prefer to use sitecustomize.py, which may not exist if you haven't created it. simply put these lines:

import sys
reload(sys)
sys.setdefaultencoding('utf-8')

Then you can do some Chinese json output in utf-8 format, such as:

name = {"last_name": u"?"}
json.dumps(name, ensure_ascii=False)

You will get an utf-8 encoded string, rather than \u escaped json string.

To verify your default encoding:

print sys.getdefaultencoding()

You should get "utf-8" or "UTF-8" to verify your site.py or sitecustomize.py settings.

Please note that you could not do sys.setdefaultencoding("utf-8") at interactive python console.

Easy way to make a confirmation dialog in Angular?

You could use sweetalert: https://sweetalert.js.org/guides/

npm install sweetalert --save

Then, simply import it into your application:

import swal from 'sweetalert';

If you pass two arguments, the first one will be the modal's title, and the second one its text.

swal("Here's the title!", "...and here's the text!");

Send HTTP GET request with header

You do it exactly as you showed with this line:

get.setHeader("Content-Type", "application/x-zip");

So your header is fine and the problem is some other input to the web service. You'll want to debug that on the server side.

Print string to text file

If you are using numpy, printing a single (or multiply) strings to a file can be done with just one line:

numpy.savetxt('Output.txt', ["Purchase Amount: %s" % TotalAmount], fmt='%s')

Selecting only first-level elements in jquery

$("ul > li a")

But you would need to set a class on the root ul if you specifically want to target the outermost ul:

<ul class="rootlist">
...

Then it's:

$("ul.rootlist > li a")....

Another way of making sure you only have the root li elements:

$("ul > li a").not("ul li ul a")

It looks kludgy, but it should do the trick

Must JDBC Resultsets and Statements be closed separately although the Connection is closed afterwards?

As far as I remember, in the current JDBC, Resultsets and statements implement the AutoCloseable interface. That means they are closed automatically upon being destroyed or going out of scope.

Checking if date is weekend PHP

Another way is to use the DateTime class, this way you can also specify the timezone. Note: PHP 5.3 or higher.

// For the current date
function isTodayWeekend() {
    $currentDate = new DateTime("now", new DateTimeZone("Europe/Amsterdam"));
    return $currentDate->format('N') >= 6;
}

If you need to be able to check a certain date string, you can use DateTime::createFromFormat

function isWeekend($date) {
    $inputDate = DateTime::createFromFormat("d-m-Y", $date, new DateTimeZone("Europe/Amsterdam"));
    return $inputDate->format('N') >= 6;
}

The beauty of this way is that you can specify the timezone without changing the timezone globally in PHP, which might cause side-effects in other scripts (for ex. Wordpress).

installing urllib in Python3.6

The corrected code is

import urllib.request
fhand = urllib.request.urlopen('http://data.pr4e.org/romeo.txt')
counts = dict()
for line in fhand: 
    words = line.decode().split() 
for word in words: 
    counts[word] = counts.get(word, 0) + 1 
print(counts) 

running the code above produces

{'Who': 1, 'is': 1, 'already': 1, 'sick': 1, 'and': 1, 'pale': 1, 'with': 1, 'grief': 1}

Facebook login message: "URL Blocked: This redirect failed because the redirect URI is not whitelisted in the app’s Client OAuth Settings."

In my case, I was integrating Facebook login within a Rails app tutorial. I had added http://localhost:3000/adsf to my Valid OAuth Redirect URIs, but the Rails app would open the url as http://0.0.0.0:3000 and would therefore try to redirect to http://0.0.0.0:3000/asdf. After adding http://0.0.0.0:3000/asdf to the Valid OAuth Redirect URIs, or navigating to http://localhost:3000/asdf, it worked as expected.

Finding all possible permutations of a given string in python

You can get all N! permutations without much code

def permutations(string, step = 0):

    # if we've gotten to the end, print the permutation
    if step == len(string):
        print "".join(string)

    # everything to the right of step has not been swapped yet
    for i in range(step, len(string)):

        # copy the string (store as array)
        string_copy = [character for character in string]

        # swap the current index with the step
        string_copy[step], string_copy[i] = string_copy[i], string_copy[step]

        # recurse on the portion of the string that has not been swapped yet (now it's index will begin with step + 1)
        permutations(string_copy, step + 1)

Python argparse command line flags without arguments

Adding a quick snippet to have it ready to execute:

Source: myparser.py

import argparse
parser = argparse.ArgumentParser(description="Flip a switch by setting a flag")
parser.add_argument('-w', action='store_true')

args = parser.parse_args()
print args.w

Usage:

python myparser.py -w
>> True

How do I print colored output to the terminal in Python?

Compared to the methods listed here, I prefer the method that comes with the system. Here, I provide a better method without third-party libraries.

class colors: # You may need to change color settings
    RED = '\033[31m'
    ENDC = '\033[m'
    GREEN = '\033[32m'
    YELLOW = '\033[33m'
    BLUE = '\033[34m'

print(colors.RED + "something you want to print in red color" + colors.ENDC)
print(colors.GREEN + "something you want to print in green color" + colors.ENDC)
print("something you want to print in system default color")

More color code , ref to : Printing Colored Text in Python

Enjoy yourself!

How do you determine the size of a file in C?

Don't use int. Files over 2 gigabytes in size are common as dirt these days

Don't use unsigned int. Files over 4 gigabytes in size are common as some slightly-less-common dirt

IIRC the standard library defines off_t as an unsigned 64 bit integer, which is what everyone should be using. We can redefine that to be 128 bits in a few years when we start having 16 exabyte files hanging around.

If you're on windows, you should use GetFileSizeEx - it actually uses a signed 64 bit integer, so they'll start hitting problems with 8 exabyte files. Foolish Microsoft! :-)

How to determine the content size of a UIWebView?

Xcode8 swift3.1:

  1. Set webView height to 0 first.
  2. In webViewDidFinishLoad Delegate:

let height = webView.scrollView.contentSize.height

Without step1, if webview.height > actual contentHeight, step 2 will return webview.height but not contentsize.height.

How could I put a border on my grid control in WPF?

This is my solution, wish useful for you:

public class Sheet : Grid
{
    public static readonly DependencyProperty BorderBrushProperty = DependencyProperty.Register(nameof(BorderBrush), typeof(Brush), typeof(Sheet), new FrameworkPropertyMetadata(Brushes.Transparent, FrameworkPropertyMetadataOptions.AffectsMeasure | FrameworkPropertyMetadataOptions.AffectsRender, OnBorderBrushChanged));

    public static readonly DependencyProperty BorderThicknessProperty = DependencyProperty.Register(nameof(BorderThickness), typeof(double), typeof(Sheet), new FrameworkPropertyMetadata(1D, FrameworkPropertyMetadataOptions.AffectsMeasure | FrameworkPropertyMetadataOptions.AffectsRender, OnBorderThicknessChanged, CoerceBorderThickness));
    public static readonly DependencyProperty CellSpacingProperty = DependencyProperty.Register(nameof(CellSpacing), typeof(double), typeof(Sheet), new FrameworkPropertyMetadata(0D, FrameworkPropertyMetadataOptions.AffectsMeasure | FrameworkPropertyMetadataOptions.AffectsRender, OnCellSpacingChanged, CoerceCellSpacing));

    public Brush BorderBrush
    {
        get => this.GetValue(BorderBrushProperty) as Brush;
        set => this.SetValue(BorderBrushProperty, value);
    }

    public double BorderThickness
    {
        get => (double)this.GetValue(BorderThicknessProperty);
        set => this.SetValue(BorderThicknessProperty, value);
    }

    public double CellSpacing
    {
        get => (double)this.GetValue(CellSpacingProperty);
        set => this.SetValue(CellSpacingProperty, value);
    }

    protected override Size ArrangeOverride(Size arrangeSize)
    {
        Size size = base.ArrangeOverride(arrangeSize);
        double border = this.BorderThickness;
        double doubleBorder = border * 2D;
        double spacing = this.CellSpacing;
        double halfSpacing = spacing * 0.5D;
        if (border > 0D || spacing > 0D)
        {
            foreach (UIElement child in this.InternalChildren)
            {
                this.GetChildBounds(child, out double left, out double top, out double width, out double height);

                left += halfSpacing + border;
                top += halfSpacing + border;
                height -= spacing + doubleBorder;
                width -= spacing + doubleBorder;

                if (width < 0D)
                {
                    width = 0D;
                }

                if (height < 0D)
                {
                    height = 0D;
                }

                left -= left % 0.5D;
                top -= top % 0.5D;
                width -= width % 0.5D;
                height -= height % 0.5D;

                child.Arrange(new Rect(left, top, width, height));
            }

            if (border > 0D && this.BorderBrush != null)
            {
                this.InvalidateVisual();
            }
        }

        return size;
    }
    
    protected override void OnRender(DrawingContext dc)
    {
        base.OnRender(dc);

        if (this.BorderThickness > 0D && this.BorderBrush != null)
        {
            if (this.CellSpacing == 0D)
            {
                this.DrawCollapsedBorder(dc);
            }
            else
            {
                this.DrawSeperatedBorder(dc);
            }
        }
    }

    private void DrawSeperatedBorder(DrawingContext dc)
    {
        double spacing = this.CellSpacing;
        double halfSpacing = spacing * 0.5D;


        #region draw border
        Pen pen = new Pen(this.BorderBrush, this.BorderThickness);
        UIElementCollection children = this.InternalChildren;
        foreach (UIElement child in children)
        {
            this.GetChildBounds(child, out double left, out double top, out double width, out double height);
            left += halfSpacing;
            top += halfSpacing;
            width -= spacing;
            height -= spacing;

            dc.DrawRectangle(null, pen, new Rect(left, top, width, height));
        }
        #endregion
    }

    private void DrawCollapsedBorder(DrawingContext dc)
    {
        RowDefinitionCollection rows = this.RowDefinitions;
        ColumnDefinitionCollection columns = this.ColumnDefinitions;
        int rowCount = rows.Count;
        int columnCount = columns.Count;
        const byte BORDER_LEFT = 0x08;
        const byte BORDER_TOP = 0x04;
        const byte BORDER_RIGHT = 0x02;
        const byte BORDER_BOTTOM = 0x01;
        byte[,] borderState = new byte[rowCount, columnCount];
        int column = columnCount - 1;
        int columnSpan;
        int row = rowCount - 1;
        int rowSpan;
        #region generate main border data
        for (int i = 0; i < rowCount; i++)
        {
            borderState[i, 0] = BORDER_LEFT;
            borderState[i, column] = BORDER_RIGHT;
        }

        for (int i = 0; i < columnCount; i++)
        {
            borderState[0, i] |= BORDER_TOP;
            borderState[row, i] |= BORDER_BOTTOM;
        }
        #endregion

        #region generate child border data
        UIElementCollection children = this.InternalChildren;
        foreach (UIElement child in children)
        {
            this.GetChildLayout(child, out row, out rowSpan, out column, out columnSpan);
            for (int i = 0; i < rowSpan; i++)
            {
                borderState[row + i, column] |= BORDER_LEFT;
                borderState[row + i, column + columnSpan - 1] |= BORDER_RIGHT;
            }
            for (int i = 0; i < columnSpan; i++)
            {
                borderState[row, column + i] |= BORDER_TOP;
                borderState[row + rowSpan - 1, column + i] |= BORDER_BOTTOM;
            }
        }
        #endregion

        #region draw border
        Pen pen = new Pen(this.BorderBrush, this.BorderThickness);
        double left;
        double top;
        double width, height;


        for (int r = 0; r < rowCount; r++)
        {
            RowDefinition v = rows[r];
            top = v.Offset;
            height = v.ActualHeight;
            for (int c = 0; c < columnCount; c++)
            {
                byte state = borderState[r, c];

                ColumnDefinition h = columns[c];
                left = h.Offset;
                width = h.ActualWidth;
                if ((state & BORDER_LEFT) == BORDER_LEFT)
                {
                    dc.DrawLine(pen, new Point(left, top), new Point(left, top + height));
                }
                if ((state & BORDER_TOP) == BORDER_TOP)
                {
                    dc.DrawLine(pen, new Point(left, top), new Point(left + width, top));
                }
                if ((state & BORDER_RIGHT) == BORDER_RIGHT && (c + 1 >= columnCount || (borderState[r, c + 1] & BORDER_LEFT) == 0))
                {
                    dc.DrawLine(pen, new Point(left + width, top), new Point(left + width, top + height));
                }
                if ((state & BORDER_BOTTOM) == BORDER_BOTTOM && (r + 1 >= rowCount || (borderState[r + 1, c] & BORDER_TOP) == 0))
                {
                    dc.DrawLine(pen, new Point(left, top + height), new Point(left + width, top + height));
                }
            }

        }
        #endregion
    }

    private void GetChildBounds(UIElement child, out double left, out double top, out double width, out double height)
    {
        ColumnDefinitionCollection columns = this.ColumnDefinitions;
        RowDefinitionCollection rows = this.RowDefinitions;
        int rowCount = rows.Count;

        int row = (int)child.GetValue(Grid.RowProperty);
        if (row >= rowCount)
        {
            row = rowCount - 1;
        }

        int rowSpan = (int)child.GetValue(Grid.RowSpanProperty);
        if (row + rowSpan > rowCount)
        {
            rowSpan = rowCount - row;
        }
        int columnCount = columns.Count;

        int column = (int)child.GetValue(Grid.ColumnProperty);
        if (column >= columnCount)
        {
            column = columnCount - 1;
        }

        int columnSpan = (int)child.GetValue(Grid.ColumnSpanProperty);
        if (column + columnSpan > columnCount)
        {
            columnSpan = columnCount - column;
        }

        left = columns[column].Offset;
        top = rows[row].Offset;
        ColumnDefinition right = columns[column + columnSpan - 1];
        width = right.Offset + right.ActualWidth - left;
        RowDefinition bottom = rows[row + rowSpan - 1];
        height = bottom.Offset + bottom.ActualHeight - top;
        if (width < 0D)
        {
            width = 0D;
        }

        if (height < 0D)
        {
            height = 0D;
        }

    }
    private void GetChildLayout(UIElement child, out int row, out int rowSpan, out int column, out int columnSpan)
    {
        int rowCount = this.RowDefinitions.Count;

        row = (int)child.GetValue(Grid.RowProperty);
        if (row >= rowCount)
        {
            row = rowCount - 1;
        }

        rowSpan = (int)child.GetValue(Grid.RowSpanProperty);
        if (row + rowSpan > rowCount)
        {
            rowSpan = rowCount - row;
        }
        int columnCount = this.ColumnDefinitions.Count;

        column = (int)child.GetValue(Grid.ColumnProperty);
        if (column >= columnCount)
        {
            column = columnCount - 1;
        }

        columnSpan = (int)child.GetValue(Grid.ColumnSpanProperty);
        if (column + columnSpan > columnCount)
        {
            columnSpan = columnCount - column;
        }
    }

    private static void OnBorderBrushChanged(DependencyObject d, DependencyPropertyChangedEventArgs args)
    {
        if (d is UIElement element)
        {
            element.InvalidateVisual();
        }
    }

    private static void OnBorderThicknessChanged(DependencyObject d, DependencyPropertyChangedEventArgs args)
    {
        if (d is UIElement element)
        {
            element.InvalidateArrange();
        }
    }

    private static void OnCellSpacingChanged(DependencyObject d, DependencyPropertyChangedEventArgs args)
    {
        if (d is UIElement element)
        {
            element.InvalidateArrange();
        }
    }

    private static object CoerceBorderThickness(DependencyObject d, object baseValue)
    {
        if (baseValue is double value)
        {
            return value < 0D || double.IsNaN(value) || double.IsInfinity(value) ? 0D : value;
        }

        return 0D;
    }
    private static object CoerceCellSpacing(DependencyObject d, object baseValue)
    {
        if (baseValue is double value)
        {
            return value < 0D || double.IsNaN(value) || double.IsInfinity(value) ? 0D : value;
        }

        return 0D;
    }
}

a demo: demo of a table with collapsed border

Getting a list of all subdirectories in the current directory

use a filter function os.path.isdir over os.listdir() something like this filter(os.path.isdir,[os.path.join(os.path.abspath('PATH'),p) for p in os.listdir('PATH/')])

Difference between FetchType LAZY and EAGER in Java Persistence API?

The Lazy Fetch type is by default selected by Hibernate unless you explicitly mark Eager Fetch type. To be more accurate and concise, difference can be stated as below.

FetchType.LAZY = This does not load the relationships unless you invoke it via the getter method.

FetchType.EAGER = This loads all the relationships.

Pros and Cons of these two fetch types.

Lazy initialization improves performance by avoiding unnecessary computation and reduce memory requirements.

Eager initialization takes more memory consumption and processing speed is slow.

Having said that, depends on the situation either one of these initialization can be used.

How to do logging in React Native?

enter image description hereUse react native debugger for logging and redux store https://github.com/jhen0409/react-native-debugg

Just download it and run as software then enable Debug mode from the simulator.

It supports other debugging feature just like element in chrome developer tools, which helps to see the styling provided to any component.

Last complete support for redux dev tools

How to compare 2 dataTables

You would need to loop through the rows of each table, and then through each column within that loop to compare individual values.

There's a code sample here: http://canlu.blogspot.com/2009/05/how-to-compare-two-datatables-in-adonet.html

Android Studio don't generate R.java for my import project

Goto File -> Settings -> Compiler now check use external build

then rebuild project

How to change maven java home

I have two Java versions on my Ubuntu server 14.04: java 1.7 and java 1.8.

I have a project that I need to build using java 1.8.

If I check my Java version using java -version

I get

java version "1.8.0_144"

But when I did mvn -version I get:

Java version: 1.7.0_79, vendor: Oracle Corporation

To set the mvn version to java8

I do this:

export JAVA_HOME=/usr/lib/jvm/java-8-oracle/jre/

Then when I do mvn -version I get:

Java version: 1.8.0_144, vendor: Oracle Corporation

How to open a specific port such as 9090 in Google Compute Engine

Creating firewall rules

Please review the firewall rule components [1] if you are unfamiliar with firewall rules in GCP. Firewall rules are defined at the network level, and only apply to the network where they are created; however, the name you choose for each of them must be unique to the project.

For Cloud Console:

  1. Go to the Firewall rules page in the Google Cloud Platform Console.
  2. Click Create firewall rule.
  3. Enter a Name for the firewall rule. This name must be unique for the project.
  4. Specify the Network where the firewall rule will be implemented.
  5. Specify the Priority of the rule. The lower the number, the higher the priority.
  6. For the Direction of traffic, choose ingress or egress.
  7. For the Action on match, choose allow or deny.
  8. Specify the Targets of the rule.

    • If you want the rule to apply to all instances in the network, choose All instances in the network.
    • If you want the rule to apply to select instances by network (target) tags, choose Specified target tags, then type the tags to which the rule should apply into the Target tags field.
    • If you want the rule to apply to select instances by associated service account, choose Specified service account, indicate whether the service account is in the current project or another one under Service account scope, and choose or type the service account name in the Target service account field.
  9. For an ingress rule, specify the Source filter:

    • Choose IP ranges and type the CIDR blocks into the Source IP ranges field to define the source for incoming traffic by IP address ranges. Use 0.0.0.0/0 for a source from any network.
    • Choose Subnets then mark the ones you need from the Subnets pop-up button to define the source for incoming traffic by subnet name.
    • To limit source by network tag, choose Source tags, then type the network tags in to the Source tags field. For the limit on the number of source tags, see VPC Quotas and Limits. Filtering by source tag is only available if the target is not specified by service account. For more information, see filtering by service account vs.network tag.
    • To limit source by service account, choose Service account, indicate whether the service account is in the current project or another one under Service account scope, and choose or type the service account name in the Source service account field. Filtering by source service account is only available if the target is not specified by network tag. For more information, see filtering by service account vs. network tag.
    • Specify a Second source filter if desired. Secondary source filters cannot use the same filter criteria as the primary one.
  10. For an egress rule, specify the Destination filter:

    • Choose IP ranges and type the CIDR blocks into the Destination IP ranges field to define the destination for outgoing traffic by IP address ranges. Use 0.0.0.0/0 to mean everywhere.
    • Choose Subnets then mark the ones you need from the Subnets pop-up button to define the destination for outgoing traffic by subnet name.
  11. Define the Protocols and ports to which the rule will apply:

    • Select Allow all or Deny all, depending on the action, to have the rule apply to all protocols and ports.

    • Define specific protocols and ports:

      • Select tcp to include the TCP protocol and ports. Enter all or a comma delimited list of ports, such as 20-22, 80, 8080.
      • Select udp to include the UDP protocol and ports. Enter all or a comma delimited list of ports, such as 67-69, 123.
      • Select Other protocols to include protocols such as icmp or sctp.
  12. (Optional) You can create the firewall rule but not enforce it by setting its enforcement state to disabled. Click Disable rule, then select Disabled.

  13. (Optional) You can enable firewall rules logging:

    • Click Logs > On.
    • Click Turn on.
  14. Click Create.

Link: [1] https://cloud.google.com/vpc/docs/firewalls#firewall_rule_components

How to get an Android WakeLock to work?

sample code snippet from android developers site

public class MainActivity extends Activity {
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
  }

Best Practices for Background Jobs

Develop Android app using C#

Having used Mono, I would NOT recommend it. The Mono runtime is bundled with your app, so your apk ends up being bloated at more than 6MB. A better programming solution for C# would be dot42. Both Mono and dot42 are licensed products.

Personally, I would recommend using Java with the IntelliJ IDEA dev environment. I say this for 3 reasons:

  1. There is so much Java code out there for Android already; do yourself a favour and don't re-invent the wheel.
  2. IDEA is similar enough to Visual Studio as to be a cinch to learn; it is made by JetBrains and the intelli-sense is better than VS.
  3. IDEA is free.

I have been a C# programmer for 12 years and started developing for Android with C# but ended up jumping ship and going the Java route. The languages are so similar you really won't notice much of a learning curve.

P.S. If you want to use LINQ, serialization and other handy features that are native to C# then you just need to look for the equivalent java library.

Angular2, what is the correct way to disable an anchor element?

My answer might be late for this post. It can be achieved through inline css within anchor tag only.

<a [routerLink]="['/user']" [style.pointer-events]="isDisabled ?'none':'auto'">click-label</a>

Considering isDisabled is a property in component which can be true or false.

Plunker for it: https://embed.plnkr.co/TOh8LM/

Set style for TextView programmatically

I do not believe you can set the style programatically. To get around this you can create a template layout xml file with the style assigned, for example in res/layout create tvtemplate.xml as with the following content:

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="This is a template"
        style="@style/my_style" />

then inflate this to instantiate your new TextView:

TextView myText = (TextView)getLayoutInflater().inflate(R.layout.tvtemplate, null);

Hope this helps.

What is a good alternative to using an image map generator?

I have found Adobe Dreamweaver to be quite good at that. However, it's not free.

Call ASP.NET function from JavaScript?

Well, if you don't want to do it using Ajax or any other way and just want a normal ASP.NET postback to happen, here is how you do it (without using any other libraries):

It is a little tricky though... :)

i. In your code file (assuming you are using C# and .NET 2.0 or later) add the following Interface to your Page class to make it look like

public partial class Default : System.Web.UI.Page, IPostBackEventHandler{}

ii. This should add (using Tab-Tab) this function to your code file:

public void RaisePostBackEvent(string eventArgument) { }

iii. In your onclick event in JavaScript, write the following code:

var pageId = '<%=  Page.ClientID %>';
__doPostBack(pageId, argumentString);

This will call the 'RaisePostBackEvent' method in your code file with the 'eventArgument' as the 'argumentString' you passed from the JavaScript. Now, you can call any other event you like.

P.S: That is 'underscore-underscore-doPostBack' ... And, there should be no space in that sequence... Somehow the WMD does not allow me to write to underscores followed by a character!

Jackson how to transform JsonNode to ArrayNode without casting?

I would assume at the end of the day you want to consume the data in the ArrayNode by iterating it. For that:

Iterator<JsonNode> iterator = datasets.withArray("datasets").elements();
while (iterator.hasNext()) 
        System.out.print(iterator.next().toString() + " "); 

or if you're into streams and lambda functions:

import com.google.common.collect.Streams;
Streams.stream(datasets.withArray("datasets").elements())
    .forEach( item -> System.out.print(item.toString()) )

How to run an .ipynb Jupyter Notebook from terminal?

You can also use the boar package to run your notebook within a python code.

from boar.running import run_notebook

outputs = run_notebook("nb.ipynb")

If you update your notebook, you won't have to convert it again to a python file.


More information at:

https://github.com/alexandreCameron/boar/blob/master/USAGE.md

java.lang.NullPointerException: Attempt to invoke virtual method on a null object reference

Your app is crashing at:

welcomePlayer.setText("Welcome Back, " + String.valueOf(mPlayer.getName(this)) + " !");

because mPlayer=null.

You forgot to initialize Player mPlayer in your PlayGame Activity.

mPlayer = new Player(context,"");

random number generator between 0 - 1000 in c#

Use this:

static int RandomNumber(int min, int max)
{
    Random random = new Random(); return random.Next(min, max);

}

This is example for you to modify and use in your application.

Get week day name from a given month, day and year individually in SQL Server

select to_char(sysdate,'DAY') from dual; It's work try it

SQL Server equivalent of MySQL's NOW()?

getdate() or getutcdate().

AngularJS toggle class using ng-class

autoscroll will be defined and modified in the controller:

<span ng-class= "autoscroll?'class_if_true':'class_if_false'"></span>

Add multiple classes based on condition by:

<span ng-class= "autoscroll?'first second third':'classes_if_false'"></span>

How to use KeyListener

In addition to using KeyListener (as shown by others' answers), sometimes you have to ensure that the JComponent you are using is Focusable. This can be set by adding this to your component(if you are subclassing):

@Override
public void setFocusable(boolean b) {
    super.setFocusable(b);
}

And by adding this to your constructor:

setFocusable(true);

Or, if you are calling the function from a parent class/container:

JComponent childComponent = new JComponent();
childComponent.setFocusable(true);

And then doing all the KeyListener stuff mentioned by others.

How to access the value of a promise?

Maybe this small Typescript code example will help.

private getAccount(id: Id) : Account {
    let account = Account.empty();
    this.repository.get(id)
        .then(res => account = res)
        .catch(e => Notices.results(e));
    return account;
}

Here the repository.get(id) returns a Promise<Account>. I assign it to the variable account within the then statement.

Can git undo a checkout of unstaged files

I believe if a file is modified but not yet added (staged), it is purely "private".
Meaning it cannot be restored by GIT if overwritten with the index or the HEAD version (unless you have a copy of your current work somewhere).

A "private" content is one only visible in your current directory, but not registered in any way in Git.

Note: As explained in other answers, you can recover your changes if you use an IDE (with local history) or have an open editor (ctrl+Z).

List of Java class file format major version numbers?

These come from the class version. If you try to load something compiled for java 6 in a java 5 runtime you'll get the error, incompatible class version, got 50, expected 49. Or something like that.

See here in byte offset 7 for more info.

Additional info can also be found here.

Regular Expression: Allow letters, numbers, and spaces (with at least one letter or number)

for me @"^[\w ]+$" is working, allow number, alphabet and space, but need to type at least one letter or number.

SQL Server 2012 column identity increment jumping from 6 to 1000+ on 7th entry

This is all perfectly normal. Microsoft added sequences in SQL Server 2012, finally, i might add and changed the way identity keys are generated. Have a look here for some explanation.

If you want to have the old behaviour, you can:

  1. use trace flag 272 - this will cause a log record to be generated for each generated identity value. The performance of identity generation may be impacted by turning on this trace flag.
  2. use a sequence generator with the NO CACHE setting (http://msdn.microsoft.com/en-us/library/ff878091.aspx)

TypeScript, Looping through a dictionary

How about this?

for (let [key, value] of Object.entries(obj)) {
    ...
}

Find mouse position relative to element

Here is what I got.

    $(".some-class").click(function(e) {

    var posx = 0;
    var posy = 0;

    posx = e.pageX;
    posy = e.pageY;

    alert(posx);
    alert(posy);
});

Getting a 'source: not found' error when using source in a bash script

In Ubuntu if you execute the script with sh scriptname.sh you get this problem.

Try executing the script with ./scriptname.sh instead.

How to query a MS-Access Table from MS-Excel (2010) using VBA

The Provider piece must be Provider=Microsoft.ACE.OLEDB.12.0 if your target database is ACCDB format. Provider=Microsoft.Jet.OLEDB.4.0 only works for the older MDB format.

You shouldn't even need Access installed if you're running 32 bit Windows. Jet 4 is included as part of the operating system. If you're using 64 bit Windows, Jet 4 is not included, but you still wouldn't need Access itself installed. You can install the Microsoft Access Database Engine 2010 Redistributable. Make sure to download the matching version (AccessDatabaseEngine.exe for 32 bit Windows, or AccessDatabaseEngine_x64.exe for 64 bit).

You can avoid the issue about which ADO version reference by using late binding, which doesn't require any reference.

Dim conn As Object
Set conn = CreateObject("ADODB.Connection")

Then assign your ConnectionString property to the conn object. Here is a quick example which runs from a code module in Excel 2003 and displays a message box with the row count for MyTable. It uses late binding for the ADO connection and recordset objects, so doesn't require setting a reference.

Public Sub foo()
    Dim cn As Object
    Dim rs As Object
    Dim strSql As String
    Dim strConnection As String
    Set cn = CreateObject("ADODB.Connection")
    strConnection = "Provider=Microsoft.Jet.OLEDB.4.0;" & _
        "Data Source=C:\Access\webforums\whiteboard2003.mdb"
    strSql = "SELECT Count(*) FROM MyTable;"
    cn.Open strConnection
    Set rs = cn.Execute(strSql)
    MsgBox rs.fields(0) & " rows in MyTable"
    rs.Close
    Set rs = Nothing
    cn.Close
    Set cn = Nothing
End Sub

If this answer doesn't resolve the problem, edit your question to show us the full connection string you're trying to use and the exact error message you get in response for that connection string.

jQuery window scroll event does not fire up

The solution is:

 $('body').scroll(function(e){
    console.log(e);
});

CORS with POSTMAN

CORS (Cross-Origin Resource Sharing) and SOP (Same-Origin Policy) are server-side configurations that clients decide to enforce or not.

Related to clients

  • Most Browsers do enforce it to prevent issues related to CSRF attack.
  • Most Development tools don't care about it.

How to stash my previous commit?

It's works for me;

  1. Checkout on commit that is a origin of current branch.
  2. Create new branch from this commit.
  3. Checkout to new branch.
  4. Merge branch with code for stash in new branch.
  5. Make soft reset in new branch.
  6. Stash your target code.
  7. Remove new branch.

I recommend use something like a SourceTree for this.

Android Studio marks R in red with error message "cannot resolve symbol R", but build succeeds

When creating a project from a sample,while not importing the existing project is good (prevents clashes with gradle, .idea, .iml, build, jars and apks, i.e. all unnecessary build-generated files), after creating a new project, copying and pasting all relevant resources, I'd recommend :

checking packages and imports from packages within the project {AndroidManifest declaration and all imports in java classes}, all resources (drawable, mip-map, layouts and menus & your build.gradle (a sample of build.gradle to use with the latest sdk can be provided on request)) to see if they are there & if declared strings and ids actually exist and have been used, after which your only error should be the question asked:

Bulid->Clean Project

Tools->Android->Sync Project with Gradle Files

File->Invalidate Caches and Restart

In worst cases restarting your machine helps.

The above should work. Feel free to ask questions if necessary, i.e. post comments.

Make Axios send cookies in its requests automatically

You are getting the two thinks mixed.

You have "react-cookie" and "axios"

react-cookie => is for handling the cookie on the client side

axios => is for sending ajax requests to the server

With that info, if you want the cookies from the client side to be communicated in the backend side as well, you will need to connect them together.

Note from "react-cookie" Readme:

Isomorphic cookies!

To be able to access user cookies while doing server-rendering, you can use plugToRequest or setRawCookie.

link to readme

If this is what you need, great.

If not, please comment so I could elaborate more.