Programs & Examples On #Backbone.js

Backbone.js is a JavaScript framework with a RESTful JSON interface and is based on the model–view–presenter (MVP) application design paradigm

How to convert 1 to true or 0 to false upon model fetch

Here's another option that's longer but may be more readable:

Boolean(Number("0")); // false
Boolean(Number("1")); // true

Origin http://localhost is not allowed by Access-Control-Allow-Origin

I fixed this (for development) with a simple nginx proxy...

# /etc/nginx/sites-enabled/default
server {
  listen 80;
  root /path/to/Development/dir;
  index index.html;

  # from your example
  location /search {
    proxy_pass http://api.master18.tiket.com;
  }
}

JavaScript console.log causes error: "Synchronous XMLHttpRequest on the main thread is deprecated..."

The warning message MAY BE due to an XMLHttpRequest request within the main thread with the async flag set to false.

https://xhr.spec.whatwg.org/#synchronous-flag:

Synchronous XMLHttpRequest outside of workers is in the process of being removed from the web platform as it has detrimental effects to the end user's experience. (This is a long process that takes many years.) Developers must not pass false for the async argument when the JavaScript global environment is a document environment. User agents are strongly encouraged to warn about such usage in developer tools and may experiment with throwing an InvalidAccessError exception when it occurs.

The future direction is to only allow XMLHttpRequests in worker threads. The message is intended to be a warning to that effect.

Explanation of <script type = "text/template"> ... </script>

It's legit and very handy!

Try this:

<script id="hello" type="text/template">
  Hello world
</script>
<script>
  alert($('#hello').html());
</script>

Several Javascript templating libraries use this technique. Handlebars.js is a good example.

"Uncaught TypeError: undefined is not a function" - Beginner Backbone.js Application

[Joke mode on]

You can fix this by adding this:

https://github.com/donavon/undefined-is-a-function

import { undefined } from 'undefined-is-a-function';
// Fixed! undefined is now a function.

[joke mode off]

Uncaught SyntaxError: Failed to execute 'querySelector' on 'Document'

Although this is valid in HTML, you can't use an ID starting with an integer in CSS selectors.

As pointed out, you can use getElementById instead, but you can also still achieve the same with a querySelector:

document.querySelector("[id='22']")

Destroy or remove a view in Backbone.js

I know I am late to the party, but hopefully this will be useful for someone else. If you are using backbone v0.9.9+, you could use, listenTo and stopListening

initialize: function () {
    this.listenTo(this.model, 'change', this.render);
    this.listenTo(this.model, 'destroy', this.remove);
}

stopListening is called automatically by remove. You can read more here and here

What is the purpose of backbone.js?

A web application involving lot of user interaction with many AJAX requests, which needs to be changed from time to time, and which runs in real time (such as Facebook or StackOverflow) ought to use an MVC framework such as Backbone.js. It's the best way to build good code.

If the application is only small though, then Backbone.js is overkill, especially for first time users.

Backbone gives you client side MVC, and all the advantages implied by this.

Backbone.js fetch with parameters

changing:

collection.fetch({ data: { page: 1} });

to:

collection.fetch({ data: $.param({ page: 1}) });

So with out over doing it, this is called with your {data: {page:1}} object as options

Backbone.sync = function(method, model, options) {
    var type = methodMap[method];

    // Default JSON-request options.
    var params = _.extend({
      type:         type,
      dataType:     'json',
      processData:  false
    }, options);

    // Ensure that we have a URL.
    if (!params.url) {
      params.url = getUrl(model) || urlError();
    }

    // Ensure that we have the appropriate request data.
    if (!params.data && model && (method == 'create' || method == 'update')) {
      params.contentType = 'application/json';
      params.data = JSON.stringify(model.toJSON());
    }

    // For older servers, emulate JSON by encoding the request into an HTML-form.
    if (Backbone.emulateJSON) {
      params.contentType = 'application/x-www-form-urlencoded';
      params.processData = true;
      params.data        = params.data ? {model : params.data} : {};
    }

    // For older servers, emulate HTTP by mimicking the HTTP method with `_method`
    // And an `X-HTTP-Method-Override` header.
    if (Backbone.emulateHTTP) {
      if (type === 'PUT' || type === 'DELETE') {
        if (Backbone.emulateJSON) params.data._method = type;
        params.type = 'POST';
        params.beforeSend = function(xhr) {
          xhr.setRequestHeader('X-HTTP-Method-Override', type);
        };
      }
    }

    // Make the request.
    return $.ajax(params);
};

So it sends the 'data' to jQuery.ajax which will do its best to append whatever params.data is to the URL.

Angular.js vs Knockout.js vs Backbone.js

It depends on the nature of your application. And, since you did not describe it in great detail, it is an impossible question to answer. I find Backbone to be the easiest, but I work in Angular all day. Performance is more up to the coder than the framework, in my opinion.

Are you doing heavy DOM manipulation? I would use jQuery and Backbone.

Very data driven app? Angular with its nice data binding.

Game programming? None - direct to canvas; maybe a game engine.

Error: getaddrinfo ENOTFOUND in nodejs for get call

Struggling for hours, couldn't afford for more.

The solution that worked for me in less than 3 minutes was:

npm install axios

Code ended up even shorter:

const url = `${this.env.someMicroservice.address}/v1/my-end-point`;

const { data } = await axios.get<MyInterface[]>(url, {
  auth: {
    username: this.env.auth.user,
    password: this.env.auth.pass
  }
});

return data;

What is two way binding?

Two-way binding means that any data-related changes affecting the model are immediately propagated to the matching view(s), and that any changes made in the view(s) (say, by the user) are immediately reflected in the underlying model. When app data changes, so does the UI, and conversely.

This is a very solid concept to build a web application on top of, because it makes the "Model" abstraction a safe, atomic data source to use everywhere within the application. Say, if a model, bound to a view, changes, then its matching piece of UI (the view) will reflect that, no matter what. And the matching piece of UI (the view) can safely be used as a mean of collecting user inputs/data, so as to maintain the application data up-to-date.

A good two-way binding implementation should obviously make this connection between a model and some view(s) as simple as possible, from a developper point of view.

It is then quite untrue to say that Backbone does not support two-way binding: while not a core feature of the framework, it can be performed quite simply using Backbone's Events though. It costs a few explicit lines of code for the simple cases; and can become quite hazardous for more complex bindings. Here is a simple case (untested code, written on the fly just for the sake of illustration):

Model = Backbone.Model.extend
  defaults:
    data: ''

View = Backbone.View.extend
  template: _.template("Edit the data: <input type='text' value='<%= data %>' />")

  events:
    # Listen for user inputs, and edit the model.
    'change input': @setData

  initialize: (options) ->
    # Listen for model's edition, and trigger UI update
    @listenTo @model, 'change:data', @render

  render: ->
    @$el.html @template(@model.attributes)
    @

  setData: (e) =>
    e.preventDefault()
    @model.set 'data', $(e.currentTarget).value()

model: new Model()
view = new View {el: $('.someEl'), model: model}

This is a pretty typical pattern in a raw Backbone application. As one can see, it requires a decent amount of (pretty standard) code.

AngularJS and some other alternatives (Ember, Knockout…) provide two-way binding as a first-citizen feature. They abstract many edge-cases under some DSL, and do their best at integrating two-way binding within their ecosystem. Our example would look something like this with AngularJS (untested code, see above):

<div ng-app="app" ng-controller="MainCtrl">
  Edit the data:
  <input name="mymodel.data" ng-model="mymodel.data">
</div>
angular.module('app', [])
  .controller 'MainCtrl', ($scope) ->
    $scope.mymodel = {data: ''}

Rather short!

But, be aware that some fully-fledged two-way binding extensions do exist for Backbone as well (in raw, subjective order of decreasing complexity): Epoxy, Stickit, ModelBinder

One cool thing with Epoxy, for instance, is that it allows you to declare your bindings (model attributes <-> view's DOM element) either within the template (DOM), or within the view implementation (JavaScript). Some people strongly dislike adding "directives" to the DOM/template (such as the ng-* attributes required by AngularJS, or the data-bind attributes of Ember).

Taking Epoxy as an example, one can rework the raw Backbone application into something like this (…):

Model = Backbone.Model.extend
  defaults:
    data: ''

View = Backbone.Epoxy.View.extend
  template: _.template("Edit the data: <input type='text' />")
  # or, using the inline form: <input type='text' data-bind='value:data' />

  bindings:
    'input': 'value:data'

  render: ->
    @$el.html @template(@model.attributes)
    @

model: new Model()
view = new View {el: $('.someEl'), model: model}

All in all, pretty much all "mainstream" JS frameworks support two-way binding. Some of them, such as Backbone, do require some extra work to make it work smoothly, but those are the same which do not enforce a specific way to do it, to begin with. So it is really about your state of mind.

Also, you may be interested in Flux, a different architecture for web applications promoting one-way binding through a circular pattern. It is based on the concept of fast, holistic re-rendering of UI components upon any data change to ensure cohesiveness and make it easier to reason about the code/dataflow. In the same trend, you might want to check the concept of MVI (Model-View-Intent), for instance Cycle.

Lodash .clone and .cloneDeep behaviors

Thanks to Gruff Bunny and Louis' comments, I found the source of the issue.

As I use Backbone.js too, I loaded a special build of Lodash compatible with Backbone and Underscore that disables some features. In this example:

var clone = _.clone(data, true);

data[1].values.d = 'x';

I just replaced the Underscore build with the Normal build in my Backbone application and the application is still working. So I can now use the Lodash .clone with the expected behaviour.

Edit 2018: the Underscore build doesn't seem to exist anymore. If you are reading this in 2018, you could be interested by this documentation (Backbone and Lodash).

What does `void 0` mean?

void is a reserved JavaScript keyword. It evaluates the expression and always returns undefined.

How to use if statements in underscore.js templates?

Here is a simple if/else check in underscore.js, if you need to include a null check.

<div class="editor-label">
    <label>First Name : </label>
</div>
<div class="editor-field">
    <% if(FirstName == null) { %>
        <input type="text" id="txtFirstName" value="" />
    <% } else { %>
        <input type="text" id="txtFirstName" value="<%=FirstName%>" />
    <% } %>
</div>

npm install error from the terminal

I came across this, and my issue was using an older version of node (3.X), when a newer version was required.

The error message actually suggested this as well:

...
Make sure you have the latest version of node.js and npm installed
...

So the solution may be as simple as upgrading node/npm. You can easily do this using nvm, the "Node Version Manager"

After you've installed nvm, you can install and use the latest version of node by simply running this command:

nvm install node

For example:

$ nvm install node                                                             
Downloading https://nodejs.org/dist/v8.2.1/node-v8.2.1-darwin-x64.tar.xz...
######################################################################## 100.0%
Now using node v8.2.1 (npm v5.3.0)

$ node --version                                                               
v8.2.1

Bootstrap - Uncaught TypeError: Cannot read property 'fn' of undefined

solve this issue for angular

"styles": [
              "src/styles.css",
              "node_modules/bootstrap/dist/css/bootstrap.min.css"
            ],
            "scripts": [
              "node_modules/jquery/dist/jquery.min.js",
              "node_modules/bootstrap/dist/js/bootstrap.min.js"
            ]

Serialize form data to JSON

Well, here's a handy plugin for it: https://github.com/macek/jquery-serialize-object

The issue for it is:

Moving ahead, on top of core serialization, .serializeObject will support correct serializaton for boolean and number values, resulting valid types for both cases.

Look forward to these in >= 2.1.0

How to get week number in Python?

For the integer value of the instantaneous week of the year try:

import datetime
datetime.datetime.utcnow().isocalendar()[1]

No Exception while type casting with a null in java

This is very handy when using a method that would otherwise be ambiguous. For example: JDialog has constructors with the following signatures:

JDialog(Frame, String, boolean, GraphicsConfiguration)
JDialog(Dialog, String, boolean, GraphicsConfiguration)

I need to use this constructor, because I want to set the GraphicsConfiguration, but I have no parent for this dialog, so the first argument should be null. Using

JDialog(null, String, boolean, Graphicsconfiguration) 

is ambiguous, so in this case I can narrow the call by casting null to one of the supported types:

JDialog((Frame) null, String, boolean, GraphicsConfiguration)

Multiline TextBox multiple newline

I had the same problem. If I add one Environment.Newline I get one new line in the textbox. But if I add two Environment.Newline I get one new line. In my web app I use a whitespace modul that removes all unnecessary white spaces. If i disable this module I get two new lines in my textbox. Hope that helps.

Add two textbox values and display the sum in a third textbox automatically

Try this: Open given fiddle in CHROME

function sum() {
      var txtFirstNumberValue = document.getElementById('txt1').value;
      var txtSecondNumberValue = document.getElementById('txt2').value;
      var result = parseInt(txtFirstNumberValue) + parseInt(txtSecondNumberValue);
      if (!isNaN(result)) {
         document.getElementById('txt3').value = result;
      }
}

HTML

<input type="text" id="txt1"  onkeyup="sum();" />
<input type="text" id="txt2"  onkeyup="sum();" />
<input type="text" id="txt3" />

DEMO HERE

ThreadStart with parameters

Thread thread = new Thread(Work);
thread.Start(Parameter);

private void Work(object param)
{
    string Parameter = (string)param;
}

The parameter type must be an object.

EDIT:

While this answer isn't incorrect I do recommend against this approach. Using a lambda expression is much easier to read and doesn't require type casting. See here: https://stackoverflow.com/a/1195915/52551

MYSQL: How to copy an entire row from one table to another in mysql with the second table having one extra column?

INSERT INTO dues_storage
SELECT field1, field2, ..., fieldN, CURRENT_DATE()
FROM dues
WHERE id = 5;

Check if a row exists, otherwise insert

I assume a single row for each flight? If so:

IF EXISTS (SELECT * FROM Bookings WHERE FLightID = @Id)
BEGIN
    --UPDATE HERE
END
ELSE
BEGIN
   -- INSERT HERE
END

I assume what I said, as your way of doing things can overbook a flight, as it will insert a new row when there are 10 tickets max and you are booking 20.

Android button background color

In order to keep the style, use:

int color = Color.parseColor("#99cc00");
button.getBackground().mutate().setColorFilter(new PorterDuffColorFilter(color, PorterDuff.Mode.SRC));

How do I show a message in the foreach loop?

You are looking to see if a single value is in an array. Use in_array.

However note that case is important, as are any leading or trailing spaces. Use var_dump to find out the length of the strings too, and see if they fit.

set option "selected" attribute from dynamic created option

Make option defaultSelected

HTMLOptionElement.defaultSelected = true;     // JS
$('selector').prop({defaultSelected: true});  // jQuery  

HTMLOptionElement MDN

If the SELECT element is already added to the document (statically or dynamically), to set an option to Attribute-selected and to make it survive a HTMLFormElement.reset() - defaultSelected is used:

_x000D_
_x000D_
const EL_country = document.querySelector('#country');_x000D_
EL_country.value = 'ID';   // Set SELECT value to 'ID' ("Indonesia")_x000D_
EL_country.options[EL_country.selectedIndex].defaultSelected = true; // Add Attribute selected to Option Element_x000D_
_x000D_
document.forms[0].reset(); // "Indonesia" is still selected
_x000D_
<form>_x000D_
  <select name="country" id="country">_x000D_
    <option value="AF">Afghanistan</option>_x000D_
    <option value="AL">Albania</option>_x000D_
    <option value="HR">Croatia</option>_x000D_
    <option value="ID">Indonesia</option>_x000D_
    <option value="ZW">Zimbabwe</option>_x000D_
  </select>_x000D_
</form>
_x000D_
_x000D_
_x000D_

The above will also work if you build the options dynamically, and than (only afterwards) you want to set one option to be defaultSelected.

_x000D_
_x000D_
const countries = {_x000D_
  AF: 'Afghanistan',_x000D_
  AL: 'Albania',_x000D_
  HR: 'Croatia',_x000D_
  ID: 'Indonesia',_x000D_
  ZW: 'Zimbabwe',_x000D_
};_x000D_
_x000D_
const EL_country = document.querySelector('#country');_x000D_
_x000D_
// (Bad example. Ideally use .createDocumentFragment() and .appendChild() methods)_x000D_
EL_country.innerHTML = Object.keys(countries).reduce((str, key) => str += `<option value="${key}">${countries[key]}</option>`, ''); _x000D_
_x000D_
EL_country.value = 'ID';_x000D_
EL_country.options[EL_country.selectedIndex].defaultSelected = true;_x000D_
_x000D_
document.forms[0].reset(); // "Indonesia" is still selected
_x000D_
<form>_x000D_
  <select name="country" id="country"></select>_x000D_
</form>
_x000D_
_x000D_
_x000D_

Option gets Attribute selected by using defaultSelected

Make option defaultSelected while dynamically creating options

To make an option selected while populating the SELECT Element, use the Option() constructor MDN

var optionElementReference = new Option(text, value, defaultSelected, selected);

_x000D_
_x000D_
const countries = {_x000D_
  AF: 'Afghanistan',_x000D_
  AL: 'Albania',_x000D_
  HR: 'Croatia',_x000D_
  ID: 'Indonesia',     // <<< make this one defaultSelected_x000D_
  ZW: 'Zimbabwe',_x000D_
};_x000D_
_x000D_
const EL_country = document.querySelector('#country');_x000D_
const DF_options = document.createDocumentFragment();_x000D_
_x000D_
Object.keys(countries).forEach(key => {_x000D_
  const isIndonesia = key === 'ID';  // Boolean_x000D_
  DF_options.appendChild(new Option(countries[key], key, isIndonesia, isIndonesia))_x000D_
});_x000D_
_x000D_
EL_country.appendChild(DF_options);_x000D_
_x000D_
document.forms[0].reset(); // "Indonesia" is still selected
_x000D_
<form>_x000D_
  <select name="country" id="country"></select>_x000D_
</form>
_x000D_
_x000D_
_x000D_

In the demo above Document.createDocumentFragment is used to prevent rendering elements inside the DOM in a loop. Instead, the fragment (containing all the Options) is appended to the Select only once.


SELECT.value vs. OPTION.setAttribute vs. OPTION.selected vs. OPTION.defaultSelected

Although some (older) browsers interpret the OPTION's selected attribute as a "string" state, the WHATWG HTML Specifications html.spec.whatwg.org state that it should represent a Boolean selectedness

The selectedness of an option element is a boolean state, initially false. Except where otherwise specified, when the element is created, its selectedness must be set to true if the element has a selected attribute.
html.spec.whatwg.org - Option selectedness

one can correctly deduce that just the name selected in <option value="foo" selected> is enough to set a truthy state.


Comparison test of the different methods

_x000D_
_x000D_
const EL_select = document.querySelector('#country');_x000D_
const TPL_options = `_x000D_
  <option value="AF">Afghanistan</option>_x000D_
  <option value="AL">Albania</option>_x000D_
  <option value="HR">Croatia</option>_x000D_
  <option value="ID">Indonesia</option>_x000D_
  <option value="ZW">Zimbabwe</option>_x000D_
`;_x000D_
_x000D_
// https://developer.mozilla.org/en-US/docs/Web/API/MutationObserver/MutationObserver_x000D_
const mutationCB = (mutationsList, observer) => {_x000D_
  mutationsList.forEach(mu => {_x000D_
    const EL = mu.target;_x000D_
    if (mu.type === 'attributes') {_x000D_
      return console.log(`* Attribute ${mu.attributeName} Mutation. ${EL.value}(${EL.text})`);_x000D_
    }_x000D_
  });_x000D_
};_x000D_
_x000D_
// (PREPARE SOME TEST FUNCTIONS)_x000D_
_x000D_
const testOptionsSelectedByProperty = () => {_x000D_
  const test = 'OPTION with Property selected:';_x000D_
  try {_x000D_
    const EL = [...EL_select.options].find(opt => opt.selected);_x000D_
    console.log(`${test} ${EL.value}(${EL.text}) PropSelectedValue: ${EL.selected}`);_x000D_
  } catch (e) {_x000D_
    console.log(`${test} NOT FOUND!`);_x000D_
  }_x000D_
} _x000D_
_x000D_
const testOptionsSelectedByAttribute = () => {_x000D_
  const test = 'OPTION with Attribute selected:'_x000D_
  try {_x000D_
    const EL = [...EL_select.options].find(opt => opt.hasAttribute('selected'));_x000D_
    console.log(`${test} ${EL.value}(${EL.text}) AttrSelectedValue: ${EL.getAttribute('selected')}`);_x000D_
  } catch (e) {_x000D_
    console.log(`${test} NOT FOUND!`);_x000D_
  }_x000D_
} _x000D_
_x000D_
const testSelect = () => {_x000D_
  console.log(`SELECT value:${EL_select.value} selectedIndex:${EL_select.selectedIndex}`);_x000D_
}_x000D_
_x000D_
const formReset = () => {_x000D_
  EL_select.value = '';_x000D_
  EL_select.innerHTML = TPL_options;_x000D_
  // Attach MutationObserver to every Option to track if Attribute will change_x000D_
  [...EL_select.options].forEach(EL_option => {_x000D_
    const observer = new MutationObserver(mutationCB);_x000D_
    observer.observe(EL_option, {attributes: true});_x000D_
  });_x000D_
}_x000D_
_x000D_
// -----------_x000D_
// LET'S TEST! _x000D_
_x000D_
console.log('\n1. Set SELECT value');_x000D_
formReset();_x000D_
EL_select.value = 'AL'; // Constatation: MutationObserver did NOT triggered!!!!_x000D_
testOptionsSelectedByProperty();_x000D_
testOptionsSelectedByAttribute();_x000D_
testSelect();_x000D_
_x000D_
console.log('\n2. Set HTMLElement.setAttribute()');_x000D_
formReset();_x000D_
EL_select.options[2].setAttribute('selected', true); // MutationObserver triggers_x000D_
testOptionsSelectedByProperty();_x000D_
testOptionsSelectedByAttribute();_x000D_
testSelect();_x000D_
_x000D_
console.log('\n3. Set HTMLOptionElement.defaultSelected');_x000D_
formReset();_x000D_
EL_select.options[3].defaultSelected = true; // MutationObserver triggers_x000D_
testOptionsSelectedByProperty();_x000D_
testOptionsSelectedByAttribute();_x000D_
testSelect();_x000D_
_x000D_
console.log('\n4. Set SELECT value and HTMLOptionElement.defaultSelected');_x000D_
formReset();_x000D_
EL_select.value = 'ZW'_x000D_
EL_select.options[EL_select.selectedIndex].defaultSelected = true; // MutationObserver triggers_x000D_
testOptionsSelectedByProperty();_x000D_
testOptionsSelectedByAttribute();_x000D_
testSelect();_x000D_
_x000D_
/* END */_x000D_
console.log('\n*. Getting MutationObservers out from call-stack...');
_x000D_
<form>_x000D_
  <select name="country" id="country"></select>_x000D_
</form>
_x000D_
_x000D_
_x000D_

Although the test 2. using .setAttribute() seems at first the best solution since both the Element Property and Attribute are unison, it can lead to confusion, specially because .setAttribute expects two parameters:

EL_select.options[1].setAttribute('selected', false);
// <option value="AL" selected="false"> // But still selected!

will actually make the option selected

Should one use .removeAttribute() or perhaps .setAttribute('selected', ???) to another value? Or should one read the state by using .getAttribute('selected') or by using .hasAttribute('selected')?

Instead test 3. (and 4.) using defaultSelected gives the expected results:

  • Attribute selected as a named Selectedness state.
  • Property selected on the Element Object, with a Boolean value.

Check if number is prime number

/***
 * Check a number is prime or not
 * @param n the number
 * @return {@code true} if {@code n} is prime
 */
public static boolean isPrime(int n) {
    if (n == 2) {
        return true;
    }
    if (n < 2 || n % 2 == 0) {
        return false;
    }
    for (int i = 3; i <= Math.sqrt(n); i += 2) {
        if (n % i == 0) {
            return false;
        }
    }
    return true;
}

Convert floating point number to a certain precision, and then copy to string

The str function has a bug. Please try the following. You will see '0,196553' but the right output is '0,196554'. Because the str function's default value is ROUND_HALF_UP.

>>> value=0.196553500000 
>>> str("%f" % value).replace(".", ",")

JSON for List of int

JSON is perfectly capable of expressing lists of integers, and the JSON you have posted is valid. You can simply separate the integers by commas:

{
    "Id": "610",
    "Name": "15",
    "Description": "1.99",
    "ItemModList": [42, 47, 139]
}

tsc throws `TS2307: Cannot find module` for a local file

In my case ,

   //app.UseWebpackDevMiddleware(new WebpackDevMiddlewareOptions
            //{
            //    HotModuleReplacement = true
            //});

i commented it in startup.cs

SQL Server datetime LIKE select?

Unfortunately, It is not possible to compare datetime towards varchar using 'LIKE' But the desired output is possible in another way.

    select * from record where datediff(dd,[record].[register_date],'2009-10-10')=0

A default document is not configured for the requested URL, and directory browsing is not enabled on the server

I know its too late to post answer, but i found completely differently scenario. I tried all possible solution given above but that not works for me. I found very silly mistake / ignorance in my case I checked IIS manager window carefully and found asp.net section was missing there. I have made Turn Windows features on for ASP.net, below is the steps

  1. Open Control Panel
  2. Programs\Turn Windows Features on or off Internet
  3. Information Services World Wide Web Services Application development
  4. Check for - >Features ASP.Net

I have closed IIS manager window and reopened it, now ASP.NET section is visible. enter image description here just browse hosted website and it's up on browser.

OpenCV - Saving images to a particular folder of choice

You can use this simple code in loop by incrementing count

cv2.imwrite("C:\Sharat\Python\Images\frame%d.jpg" % count, image)

images will be saved in the folder by name line frame0.jpg, frame1.jpg frame2.jpg etc..

preg_match in JavaScript?

var thisRegex = new RegExp('\[(\d+)\]\[(\d+)\]');

if(!thisRegex.test(text)){
    alert('fail');
}

I found test to act more preg_match as it provides a Boolean return. However you do have to declare a RegExp var.

TIP: RegExp adds it's own / at the start and finish, so don't pass them.

Generate pdf from HTML in div using Javascript

To capture div as PDF you can use https://grabz.it solution. It's got a JavaScript API which is easy and flexible and will allow you to capture the contents of a single HTML element such as a div or a span

In order to implement it you will need to first get an app key and secret and download the (free) SDK.

And now an example.

Let's say you have the HTML:

<div id="features">
    <h4>Acme Camera</h4>
    <label>Price</label>$399<br />
    <label>Rating</label>4.5 out of 5
</div>
<p>Cras ut velit sed purus porttitor aliquam. Nulla tristique magna ac libero tempor, ac vestibulum felisvulput ate. Nam ut velit eget
risus porttitor tristique at ac diam. Sed nisi risus, rutrum a metus suscipit, euismod tristique nulla. Etiam venenatis rutrum risus at
blandit. In hac habitasse platea dictumst. Suspendisse potenti. Phasellus eget vehicula felis.</p>

To capture what is under the features id you will need to:

//add the sdk
<script type="text/javascript" src="grabzit.min.js"></script>
<script type="text/javascript">
//login with your key and secret. 
GrabzIt("KEY", "SECRET").ConvertURL("http://www.example.com/my-page.html",
{"target": "#features", "format": "pdf"}).Create();
</script>

Please note the target: #feature. #feature is you CSS selector, like in the previous example. Now, when the page is loaded an image screenshot will now be created in the same location as the script tag, which will contain all of the contents of the features div and nothing else.

The are other configuration and customization you can do to the div-screenshot mechanism, please check them out here

How to sign in kubernetes dashboard?

The skip login has been disabled by default due to security issues. https://github.com/kubernetes/dashboard/issues/2672

in your dashboard yaml add this arg

- --enable-skip-login

to get it back

How can I reverse a NSArray in Objective-C?

Some benchmarks

1. reverseObjectEnumerator allObjects

This is the fastest method:

NSArray *anArray = @[@"aa", @"ab", @"ac", @"ad", @"ae", @"af", @"ag",
        @"ah", @"ai", @"aj", @"ak", @"al", @"am", @"an", @"ao", @"ap", @"aq", @"ar", @"as", @"at",
        @"au", @"av", @"aw", @"ax", @"ay", @"az", @"ba", @"bb", @"bc", @"bd", @"bf", @"bg", @"bh",
        @"bi", @"bj", @"bk", @"bl", @"bm", @"bn", @"bo", @"bp", @"bq", @"br", @"bs", @"bt", @"bu",
        @"bv", @"bw", @"bx", @"by", @"bz", @"ca", @"cb", @"cc", @"cd", @"ce", @"cf", @"cg", @"ch",
        @"ci", @"cj", @"ck", @"cl", @"cm", @"cn", @"co", @"cp", @"cq", @"cr", @"cs", @"ct", @"cu",
        @"cv", @"cw", @"cx", @"cy", @"cz"];

NSDate *methodStart = [NSDate date];

NSArray *reversed = [[anArray reverseObjectEnumerator] allObjects];

NSDate *methodFinish = [NSDate date];
NSTimeInterval executionTime = [methodFinish timeIntervalSinceDate:methodStart];
NSLog(@"executionTime = %f", executionTime);

Result: executionTime = 0.000026

2. Iterating over an reverseObjectEnumerator

This is between 1.5x and 2.5x slower:

NSDate *methodStart = [NSDate date];
NSMutableArray *array = [NSMutableArray arrayWithCapacity:[anArray count]];
NSEnumerator *enumerator = [anArray reverseObjectEnumerator];
for (id element in enumerator) {
    [array addObject:element];
}
NSDate *methodFinish = [NSDate date];
NSTimeInterval executionTime = [methodFinish timeIntervalSinceDate:methodStart];
NSLog(@"executionTime = %f", executionTime);

Result: executionTime = 0.000071

3. sortedArrayUsingComparator

This is between 30x and 40x slower (no surprises here):

NSDate *methodStart = [NSDate date];
NSArray *reversed = [anArray sortedArrayUsingComparator: ^(id obj1, id obj2) {
    return [anArray indexOfObject:obj1] < [anArray indexOfObject:obj2] ? NSOrderedDescending : NSOrderedAscending;
}];

NSDate *methodFinish = [NSDate date];
NSTimeInterval executionTime = [methodFinish timeIntervalSinceDate:methodStart];
NSLog(@"executionTime = %f", executionTime);

Result: executionTime = 0.001100

So [[anArray reverseObjectEnumerator] allObjects] is the clear winner when it comes to speed and ease.

How to test that no exception is thrown?

You can expect that exception is not thrown by creating a rule.

@Rule
public ExpectedException expectedException = ExpectedException.none();

How does numpy.newaxis work and when to use it?

What is np.newaxis?

The np.newaxis is just an alias for the Python constant None, which means that wherever you use np.newaxis you could also use None:

>>> np.newaxis is None
True

It's just more descriptive if you read code that uses np.newaxis instead of None.

How to use np.newaxis?

The np.newaxis is generally used with slicing. It indicates that you want to add an additional dimension to the array. The position of the np.newaxis represents where I want to add dimensions.

>>> import numpy as np
>>> a = np.arange(10)
>>> a
array([0, 1, 2, 3, 4, 5, 6, 7, 8, 9])
>>> a.shape
(10,)

In the first example I use all elements from the first dimension and add a second dimension:

>>> a[:, np.newaxis]
array([[0],
       [1],
       [2],
       [3],
       [4],
       [5],
       [6],
       [7],
       [8],
       [9]])
>>> a[:, np.newaxis].shape
(10, 1)

The second example adds a dimension as first dimension and then uses all elements from the first dimension of the original array as elements in the second dimension of the result array:

>>> a[np.newaxis, :]  # The output has 2 [] pairs!
array([[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]])
>>> a[np.newaxis, :].shape
(1, 10)

Similarly you can use multiple np.newaxis to add multiple dimensions:

>>> a[np.newaxis, :, np.newaxis]  # note the 3 [] pairs in the output
array([[[0],
        [1],
        [2],
        [3],
        [4],
        [5],
        [6],
        [7],
        [8],
        [9]]])
>>> a[np.newaxis, :, np.newaxis].shape
(1, 10, 1)

Are there alternatives to np.newaxis?

There is another very similar functionality in NumPy: np.expand_dims, which can also be used to insert one dimension:

>>> np.expand_dims(a, 1)  # like a[:, np.newaxis]
>>> np.expand_dims(a, 0)  # like a[np.newaxis, :]

But given that it just inserts 1s in the shape you could also reshape the array to add these dimensions:

>>> a.reshape(a.shape + (1,))  # like a[:, np.newaxis]
>>> a.reshape((1,) + a.shape)  # like a[np.newaxis, :]

Most of the times np.newaxis is the easiest way to add dimensions, but it's good to know the alternatives.

When to use np.newaxis?

In several contexts is adding dimensions useful:

  • If the data should have a specified number of dimensions. For example if you want to use matplotlib.pyplot.imshow to display a 1D array.

  • If you want NumPy to broadcast arrays. By adding a dimension you could for example get the difference between all elements of one array: a - a[:, np.newaxis]. This works because NumPy operations broadcast starting with the last dimension 1.

  • To add a necessary dimension so that NumPy can broadcast arrays. This works because each length-1 dimension is simply broadcast to the length of the corresponding1 dimension of the other array.


1 If you want to read more about the broadcasting rules the NumPy documentation on that subject is very good. It also includes an example with np.newaxis:

>>> a = np.array([0.0, 10.0, 20.0, 30.0])
>>> b = np.array([1.0, 2.0, 3.0])
>>> a[:, np.newaxis] + b
array([[  1.,   2.,   3.],
       [ 11.,  12.,  13.],
       [ 21.,  22.,  23.],
       [ 31.,  32.,  33.]])

phpmailer - The following SMTP Error: Data not accepted

For AWS users who work with Amazon SES in conjunction with PHPMailer, this error also appears when your "from" mail sender isn't a verified sender.

To add a verified sender:

  1. Log in to your Amazon AWS console: https://console.aws.amazon.com

  2. Select "Amazon SES" from your list of available AWS applications

  3. Select, under "Verified Senders", the "Email Addresses" --> "Verify a new email address"

  4. Navigate to that new sender's email, click the confirmation e-mail's link.

And you're all set.

How to get SQL from Hibernate Criteria API (*not* for logging)

For anyone wishing to do this in a single line (e.g in the Display/Immediate window, a watch expression or similar in a debug session), the following will do so and "pretty print" the SQL:

new org.hibernate.jdbc.util.BasicFormatterImpl().format((new org.hibernate.loader.criteria.CriteriaJoinWalker((org.hibernate.persister.entity.OuterJoinLoadable)((org.hibernate.impl.CriteriaImpl)crit).getSession().getFactory().getEntityPersister(((org.hibernate.impl.CriteriaImpl)crit).getSession().getFactory().getImplementors(((org.hibernate.impl.CriteriaImpl)crit).getEntityOrClassName())[0]),new org.hibernate.loader.criteria.CriteriaQueryTranslator(((org.hibernate.impl.CriteriaImpl)crit).getSession().getFactory(),((org.hibernate.impl.CriteriaImpl)crit),((org.hibernate.impl.CriteriaImpl)crit).getEntityOrClassName(),org.hibernate.loader.criteria.CriteriaQueryTranslator.ROOT_SQL_ALIAS),((org.hibernate.impl.CriteriaImpl)crit).getSession().getFactory(),(org.hibernate.impl.CriteriaImpl)crit,((org.hibernate.impl.CriteriaImpl)crit).getEntityOrClassName(),((org.hibernate.impl.CriteriaImpl)crit).getSession().getEnabledFilters())).getSQLString());

...or here's an easier to read version:

new org.hibernate.jdbc.util.BasicFormatterImpl().format(
  (new org.hibernate.loader.criteria.CriteriaJoinWalker(
     (org.hibernate.persister.entity.OuterJoinLoadable)
      ((org.hibernate.impl.CriteriaImpl)crit).getSession().getFactory().getEntityPersister(
        ((org.hibernate.impl.CriteriaImpl)crit).getSession().getFactory().getImplementors(
          ((org.hibernate.impl.CriteriaImpl)crit).getEntityOrClassName())[0]),
     new org.hibernate.loader.criteria.CriteriaQueryTranslator(
          ((org.hibernate.impl.CriteriaImpl)crit).getSession().getFactory(),
          ((org.hibernate.impl.CriteriaImpl)crit),
          ((org.hibernate.impl.CriteriaImpl)crit).getEntityOrClassName(),
          org.hibernate.loader.criteria.CriteriaQueryTranslator.ROOT_SQL_ALIAS),
     ((org.hibernate.impl.CriteriaImpl)crit).getSession().getFactory(),
     (org.hibernate.impl.CriteriaImpl)crit,
     ((org.hibernate.impl.CriteriaImpl)crit).getEntityOrClassName(),
     ((org.hibernate.impl.CriteriaImpl)crit).getSession().getEnabledFilters()
   )
  ).getSQLString()
);

Notes:

  1. The answer is based on the solution posted by ramdane.i.
  2. It assumes the Criteria object is named crit. If named differently, do a search and replace.
  3. It assumes the Hibernate version is later than 3.3.2.GA but earlier than 4.0 in order to use BasicFormatterImpl to "pretty print" the HQL. If using a different version, see this answer for how to modify. Or perhaps just remove the pretty printing entirely as it's just a "nice to have".
  4. It's using getEnabledFilters rather than getLoadQueryInfluencers() for backwards compatibility since the latter was introduced in a later version of Hibernate (3.5???)
  5. It doesn't output the actual parameter values used if the query is parameterized.

AngularJS: Uncaught Error: [$injector:modulerr] Failed to instantiate module?

Try using No Wrap - In Head or No wrap - in body in your fiddle:

Working fiddle: http://jsfiddle.net/Q5hd6/

Explanation:

Angular begins compiling the DOM when the DOM is fully loaded. You register your code to run onLoad (onload option in fiddle) => it's too late to register your myApp module because angular begins compiling the DOM and angular sees that there is no module named myApp and throws an exception.

By using No Wrap - In Head, your code looks like this:

<head>

    <script type='text/javascript' src='//cdnjs.cloudflare.com/ajax/libs/angular.js/1.2.1/angular.js'></script>

    <script type='text/javascript'>
      //Your script.
    </script>

</head>

Your script has a chance to run before angular begins compiling the DOM and myApp module is already created when angular starts compiling the DOM.

How to generate random number in Bash?

Try this from your shell:

$ od -A n -t d -N 1 /dev/urandom

Here, -t d specifies that the output format should be signed decimal; -N 1 says to read one byte from /dev/urandom.

How can I concatenate two arrays in Java?

public String[] concat(String[]... arrays)
{
    int length = 0;
    for (String[] array : arrays) {
        length += array.length;
    }
    String[] result = new String[length];
    int destPos = 0;
    for (String[] array : arrays) {
        System.arraycopy(array, 0, result, destPos, array.length);
        destPos += array.length;
    }
    return result;
}

HTML5 tag for horizontal line break

You can make a div that has the same attributes as the <hr> tag. This way it is fully able to be customized. Here is some sample code:

The HTML:

<h3>This is a header.</h3>
<div class="customHr">.</div>

<p>Here is some sample paragraph text.<br>
This demonstrates what could go below a custom hr.</p>

The CSS:

.customHr {
    width: 95%
    font-size: 1px;
    color: rgba(0, 0, 0, 0);
    line-height: 1px;

    background-color: grey;
    margin-top: -6px;
    margin-bottom: 10px;
}

To see how the project turns out, here is a JSFiddle for the above code: http://jsfiddle.net/SplashHero/qmccsc06/1/

Set Locale programmatically

As no answer is complete for the current way to solve this problem, I try to give instructions for a complete solution. Please comment if something is missing or could be done better.

General information

First, there exist some libraries that want to solve the problem but they all seem outdated or are missing some features:

Further I think writing a library might not be a good/easy way to solve this problem because there is not very much to do, and what has to be done is rather changing existing code than using something completely decoupled. Therefore I composed the following instructions that should be complete.

My solution is mainly based on https://github.com/gunhansancar/ChangeLanguageExample (as already linked to by localhost). It is the best code I found to orientate at. Some remarks:

  • As necessary, it provides different implementations to change locale for Android N (and above) and below
  • It uses a method updateViews() in each Activity to manually update all strings after changing locale (using the usual getString(id)) which is not necessary in the approach shown below
  • It only supports languages and not complete locales (which also include region (country) and variant codes)

I changed it a bit, decoupling the part which persists the chosen locale (as one might want to do that separately, as suggested below).

Solution

The solution consists of the following two steps:

  • Permanently change the locale to be used by the app
  • Make the app use the custom locale set, without restarting

Step 1: Change the locale

Use the class LocaleHelper, based on gunhansancar's LocaleHelper:

  • Add a ListPreference in a PreferenceFragment with the available languages (has to be maintained when languages should be added later)
import android.annotation.TargetApi;
import android.content.Context;
import android.content.SharedPreferences;
import android.content.res.Configuration;
import android.content.res.Resources;
import android.os.Build;
import android.preference.PreferenceManager;

import java.util.Locale;

import mypackage.SettingsFragment;

/**
 * Manages setting of the app's locale.
 */
public class LocaleHelper {

    public static Context onAttach(Context context) {
        String locale = getPersistedLocale(context);
        return setLocale(context, locale);
    }

    public static String getPersistedLocale(Context context) {
        SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context);
        return preferences.getString(SettingsFragment.KEY_PREF_LANGUAGE, "");
    }

    /**
     * Set the app's locale to the one specified by the given String.
     *
     * @param context
     * @param localeSpec a locale specification as used for Android resources (NOTE: does not
     *                   support country and variant codes so far); the special string "system" sets
     *                   the locale to the locale specified in system settings
     * @return
     */
    public static Context setLocale(Context context, String localeSpec) {
        Locale locale;
        if (localeSpec.equals("system")) {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
                locale = Resources.getSystem().getConfiguration().getLocales().get(0);
            } else {
                //noinspection deprecation
                locale = Resources.getSystem().getConfiguration().locale;
            }
        } else {
            locale = new Locale(localeSpec);
        }
        Locale.setDefault(locale);
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
            return updateResources(context, locale);
        } else {
            return updateResourcesLegacy(context, locale);
        }
    }

    @TargetApi(Build.VERSION_CODES.N)
    private static Context updateResources(Context context, Locale locale) {
        Configuration configuration = context.getResources().getConfiguration();
        configuration.setLocale(locale);
        configuration.setLayoutDirection(locale);

        return context.createConfigurationContext(configuration);
    }

    @SuppressWarnings("deprecation")
    private static Context updateResourcesLegacy(Context context, Locale locale) {
        Resources resources = context.getResources();

        Configuration configuration = resources.getConfiguration();
        configuration.locale = locale;
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
            configuration.setLayoutDirection(locale);
        }

        resources.updateConfiguration(configuration, resources.getDisplayMetrics());

        return context;
    }
}

Create a SettingsFragment like the following:

import android.content.SharedPreferences;
import android.os.Bundle;
import android.preference.PreferenceFragment;
import android.preference.PreferenceManager;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import mypackage.LocaleHelper;
import mypackage.R;

/**
 * Fragment containing the app's main settings.
 */
public class SettingsFragment extends PreferenceFragment implements SharedPreferences.OnSharedPreferenceChangeListener {
    public static final String KEY_PREF_LANGUAGE = "pref_key_language";

    public SettingsFragment() {
        // Required empty public constructor
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        addPreferencesFromResource(R.xml.preferences);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_settings, container, false);
        return view;
    }

    @Override
    public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
        switch (key) {
            case KEY_PREF_LANGUAGE:
                LocaleHelper.setLocale(getContext(), PreferenceManager.getDefaultSharedPreferences(getContext()).getString(key, ""));
                getActivity().recreate(); // necessary here because this Activity is currently running and thus a recreate() in onResume() would be too late
                break;
        }
    }

    @Override
    public void onResume() {
        super.onResume();
        // documentation requires that a reference to the listener is kept as long as it may be called, which is the case as it can only be called from this Fragment
        getPreferenceScreen().getSharedPreferences().registerOnSharedPreferenceChangeListener(this);
    }

    @Override
    public void onPause() {
        super.onPause();
        getPreferenceScreen().getSharedPreferences().unregisterOnSharedPreferenceChangeListener(this);
    }
}

Create a resource locales.xml listing all locales with available translations in the following way (list of locale codes):

<!-- Lists available locales used for setting the locale manually.
     For now only language codes (locale codes without country and variant) are supported.
     Has to be in sync with "settings_language_values" in strings.xml (the entries must correspond).
  -->
<resources>
    <string name="system_locale" translatable="false">system</string>
    <string name="default_locale" translatable="false"></string>
    <string-array name="locales">
        <item>@string/system_locale</item> <!-- system setting -->
        <item>@string/default_locale</item> <!-- default locale -->
        <item>de</item>
    </string-array>
</resources>

In your PreferenceScreen you can use the following section to let the user select the available languages:

<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
    <PreferenceCategory
        android:title="@string/preferences_category_general">
        <ListPreference
            android:key="pref_key_language"
            android:title="@string/preferences_language"
            android:dialogTitle="@string/preferences_language"
            android:entries="@array/settings_language_values"
            android:entryValues="@array/locales"
            android:defaultValue="@string/system_locale"
            android:summary="%s">
        </ListPreference>
    </PreferenceCategory>
</PreferenceScreen>

which uses the following strings from strings.xml:

<string name="preferences_category_general">General</string>
<string name="preferences_language">Language</string>
<!-- NOTE: Has to correspond to array "locales" in locales.xml (elements in same orderwith) -->
<string-array name="settings_language_values">
    <item>Default (System setting)</item>
    <item>English</item>
    <item>German</item>
</string-array>

Step 2: Make the app use the custom locale

Now setup each Activity to use the custom locale set. The easiest way to accomplish this is to have a common base class for all activities with the following code (where the important code is in attachBaseContext(Context base) and onResume()):

import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;

import mypackage.LocaleHelper;
import mypackage.R;

/**
 * {@link AppCompatActivity} with main menu in the action bar. Automatically recreates
 * the activity when the locale has changed.
 */
public class MenuAppCompatActivity extends AppCompatActivity {
    private String initialLocale;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        initialLocale = LocaleHelper.getPersistedLocale(this);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.menu, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case R.id.menu_settings:
                Intent intent = new Intent(this, SettingsActivity.class);
                startActivity(intent);
                return true;
            default:
                return super.onOptionsItemSelected(item);
        }
    }

    @Override
    protected void attachBaseContext(Context base) {
        super.attachBaseContext(LocaleHelper.onAttach(base));
    }

    @Override
    protected void onResume() {
        super.onResume();
        if (initialLocale != null && !initialLocale.equals(LocaleHelper.getPersistedLocale(this))) {
            recreate();
        }
    }
}

What it does is

  • Override attachBaseContext(Context base) to use the locale previously persisted with LocaleHelper
  • Detect a change of the locale and recreate the Activity to update its strings

Notes on this solution

  • Recreating an Activity does not update the title of the ActionBar (as already observed here: https://github.com/gunhansancar/ChangeLanguageExample/issues/1).

    • This can be achieved by simply having a setTitle(R.string.mytitle) in the onCreate() method of each activity.
  • It lets the user chose the system default locale, as well as the default locale of the app (which can be named, in this case "English").

  • Only language codes, no region (country) and variant codes (like fr-rCA) are supported so far. To support full locale specifications, a parser similar to that in the Android-Languages library can be used (which supports region but no variant codes).

    • If someone finds or has written a good parser, add a comment so I can include it in the solution.

VBA: Counting rows in a table (list object)

You need to go one level deeper in what you are retrieving.

Dim tbl As ListObject
Set tbl = ActiveSheet.ListObjects("MyTable")
MsgBox tbl.Range.Rows.Count
MsgBox tbl.HeaderRowRange.Rows.Count
MsgBox tbl.DataBodyRange.Rows.Count
Set tbl = Nothing

More information at:

ListObject Interface
ListObject.Range Property
ListObject.DataBodyRange Property
ListObject.HeaderRowRange Property

How to bring back "Browser mode" in IE11?

[UPDATE]

The original question, and the answer below applied specifically to the IE11 preview releases.

The final release version of IE11 does in fact provide the ability to switch browser modes from the Emulation tab in the dev tools:

Screenshot showing browser mode selection in the emulation tab

Having said that, the advice I've given here (and elsewhere) to avoid using compatibility modes for testing is still valid: If you want to test your site for compatibility with older IE versions, you should always do your testing in a real copy of those IE version.

However, this does mean that the registry hack described in @EugeneXa's answer to bring back the old dev tools is no longer necessary, since the new dev tools do now have the feature he was missing.


[ORIGINAL ANSWER]

The IE devs have deliberately deprecated the ability to switch browser mode.

There are not many reasons why people would be switching modes in the dev tools, but one of the main reasons is because they want to test their site in old IE versions. Unfortunately, the various compatibility modes that IE supplies have never really been fully compatible with old versions of IE, and testing using compat mode is simply not a good enough substitute for testing in real copies of IE8, IE9, etc.

The IE devs have recognised this and are deliberately making it harder for devs to make this mistake.

The best practice is to use real copies of each IE version to test your site instead.

The various compatiblity modes are still available inside IE11, but can only be accessed if a site explicitly states that it wants to run in compat mode. You would do this by including an X-UA-Compatible header on your page.

And the Document Mode drop-box is still available, but will only ever offer the options of "Edge" (that is, the best mode available to the current IE version, so IE11 mode in IE11) or the mode that the page is running in.

So if you go to a page that is loaded in compat mode, you will have the option to switch between the specific compat mode that the page was loaded in or IE11 "Edge" mode.

And if you go to a page that loads in IE11 mode, then you will only be offered the 'edge' mode and nothing else.

This means that it does still allow you to test how a compat mode page reacts to being updated to work in Edge mode, which is about the only really legitimate use-case for the document mode drop-box anyway.

The IE11 Document Mode drop box has an i icon next to it which takes you to the modern.ie website. The point of this is to encourage you to download the VMs that MS are supplying for us to test our sites using real copies of each version of IE. This will give you a much more accurate testing experience, and is strongly enouraged as a much better practice than testing by switching the mode in dev tools.

Hope that explains things a bit for you.

How to differ sessions in browser-tabs?

I'll be honest here. . .everything above may or may not be true, but it all seems WAY too complicated, or doesn't address knowing what tab is being used server side.

Sometimes we need to apply Occam's razor.

Here's the Occam's approach: (no, I'm not Occam, he died in 1347)

1) assign a browser unique id to your page on load. . . if and only if the window doesn't have an id yet (so use a prefix and a detection)

2) on every page you have (use a global file or something) simply put code in place to detect the focus event and/or mouseover event. (I'll use jquery for this part, for ease of code writing)

3) in your focus (and/or mouseover) function, set a cookie with the window.name in it

4) read that cookie value from your server side when you need to read/write tab specific data.

Client side:

//Events 
$(window).ready(function() {generateWindowID()});
$(window).focus(function() {setAppId()});
$(window).mouseover(function() {setAppId()});


function generateWindowID()
{
    //first see if the name is already set, if not, set it.
    if (se_appframe().name.indexOf("SEAppId") == -1){
            "window.name = 'SEAppId' + (new Date()).getTime()
    }
    setAppId()
}

function setAppId()
{
    //generate the cookie
    strCookie = 'seAppId=' + se_appframe().name + ';';
    strCookie += ' path=/';

    if (window.location.protocol.toLowerCase() == 'https:'){
        strCookie += ' secure;';
    }

    document.cookie = strCookie;
}

server side (C# - for example purposes)

//variable name 
string varname = "";
HttpCookie aCookie = Request.Cookies["seAppId"];
if(aCookie != null) {
     varname  = Request.Cookies["seAppId"].Value + "_";
}
varname += "_mySessionVariable";

//write session data 
Session[varname] = "ABC123";

//readsession data 
String myVariable = Session[varname];

Done.

Right query to get the current number of connections in a PostgreSQL DB

From looking at the source code, it seems like the pg_stat_database query gives you the number of connections to the current database for all users. On the other hand, the pg_stat_activity query gives the number of connections to the current database for the querying user only.

How to update Xcode from command line

xCode version 11.2.1 is necessary for building app in iPad 13.2.3, When I directly try to upgrade from xcode 11.1 to 11.2.1 through App Store it get struck, So after some research , I found a solution to upgrade by removing the existing xcode from the system

So here I am adding the steps to upgrade after uninstalling existing xcode.

  1. Go to Applications and identify Xcode and drag it to trash.
  2. Empty trash to permenently delete Xcode.
  3. Now go to ~/Library/Developer/ folder and remove the contents completely Use sudo rm -rf ~/Library/Developer/ to avoid any permission issue while deleting
  4. Lastly remove any cache directory associated with xcode in the path ~/Library/Caches/com.apple.dt.Xcode sudo rm -rf ~/Library/Caches/com.apple.dt.Xcode/*
  5. After completing the above steps you can easly install xcode from App Store, which will install the current latest version of xcode

Note: Please take a backup of your existing projects before making the above changes

Disabling Chrome Autofill

You have to add this attribute :

autocomplete="new-password"

Source Link : Full Article

How does one check if a table exists in an Android SQLite database?

Try this one:

public boolean isTableExists(String tableName, boolean openDb) {
    if(openDb) {
        if(mDatabase == null || !mDatabase.isOpen()) {
            mDatabase = getReadableDatabase();
        }

        if(!mDatabase.isReadOnly()) {
            mDatabase.close();
            mDatabase = getReadableDatabase();
        }
    }

    String query = "select DISTINCT tbl_name from sqlite_master where tbl_name = '"+tableName+"'";
    try (Cursor cursor = mDatabase.rawQuery(query, null)) {
        if(cursor!=null) {
            if(cursor.getCount()>0) {
                return true;
            }
        }
        return false;
    }
}

How do I create a new Git branch from an old commit?

git checkout -b NEW_BRANCH_NAME COMMIT_ID

This will create a new branch called 'NEW_BRANCH_NAME' and check it out.

("check out" means "to switch to the branch")

git branch NEW_BRANCH_NAME COMMIT_ID

This just creates the new branch without checking it out.


in the comments many people seem to prefer doing this in two steps. here's how to do so in two steps:

git checkout COMMIT_ID
# you are now in the "detached head" state
git checkout -b NEW_BRANCH_NAME

Upload files with HTTPWebrequest (multipart/form-data)

This method work for upload multiple image simultaneously

        var flagResult = new viewModel();
        string boundary = "---------------------------" + DateTime.Now.Ticks.ToString("x");
        byte[] boundarybytes = System.Text.Encoding.ASCII.GetBytes("\r\n--" + boundary + "\r\n");

        HttpWebRequest wr = (HttpWebRequest)WebRequest.Create(url);
        wr.ContentType = "multipart/form-data; boundary=" + boundary;
        wr.Method = method;
        wr.KeepAlive = true;
        wr.Credentials = System.Net.CredentialCache.DefaultCredentials;

        Stream rs = wr.GetRequestStream();


        string path = @filePath;
        System.IO.DirectoryInfo folderInfo = new DirectoryInfo(path);

        foreach (FileInfo file in folderInfo.GetFiles())
        {
            rs.Write(boundarybytes, 0, boundarybytes.Length);
            string headerTemplate = "Content-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"\r\nContent-Type: {2}\r\n\r\n";
            string header = string.Format(headerTemplate, paramName, file, contentType);
            byte[] headerbytes = System.Text.Encoding.UTF8.GetBytes(header);
            rs.Write(headerbytes, 0, headerbytes.Length);

            FileStream fileStream = new FileStream(file.FullName, FileMode.Open, FileAccess.Read);
            byte[] buffer = new byte[4096];
            int bytesRead = 0;
            while ((bytesRead = fileStream.Read(buffer, 0, buffer.Length)) != 0)
            {
                rs.Write(buffer, 0, bytesRead);
            }
            fileStream.Close();
        }

        byte[] trailer = System.Text.Encoding.ASCII.GetBytes("\r\n--" + boundary + "--\r\n");
        rs.Write(trailer, 0, trailer.Length);
        rs.Close();

        WebResponse wresp = null;
        try
        {
            wresp = wr.GetResponse();
            Stream stream2 = wresp.GetResponseStream();
            StreamReader reader2 = new StreamReader(stream2);
            var result = reader2.ReadToEnd();
            var cList = JsonConvert.DeserializeObject<HttpViewModel>(result);
            if (cList.message=="images uploaded!")
            {
                flagResult.success = true;
            }

        }
        catch (Exception ex)
        {
            //log.Error("Error uploading file", ex);
            if (wresp != null)
            {
                wresp.Close();
                wresp = null;
            }
        }
        finally
        {
            wr = null;
        }
        return flagResult;
    }

How to get a web page's source code from Java

I am sure that you have found a solution somewhere over the past 2 years but the following is a solution that works for your requested site

package javasandbox;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

/**
*
* @author Ryan.Oglesby
*/
public class JavaSandbox {

private static String sURL;

/**
 * @param args the command line arguments
 */
public static void main(String[] args) throws MalformedURLException, IOException {
    sURL = "http://www.cumhuriyet.com.tr/?hn=298710";
    System.out.println(sURL);
    URL url = new URL(sURL);
    HttpURLConnection httpCon = (HttpURLConnection) url.openConnection();
    //set http request headers
            httpCon.addRequestProperty("Host", "www.cumhuriyet.com.tr");
            httpCon.addRequestProperty("Connection", "keep-alive");
            httpCon.addRequestProperty("Cache-Control", "max-age=0");
            httpCon.addRequestProperty("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8");
            httpCon.addRequestProperty("User-Agent", "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/30.0.1599.101 Safari/537.36");
            httpCon.addRequestProperty("Accept-Encoding", "gzip,deflate,sdch");
            httpCon.addRequestProperty("Accept-Language", "en-US,en;q=0.8");
            //httpCon.addRequestProperty("Cookie", "JSESSIONID=EC0F373FCC023CD3B8B9C1E2E2F7606C; lang=tr; __utma=169322547.1217782332.1386173665.1386173665.1386173665.1; __utmb=169322547.1.10.1386173665; __utmc=169322547; __utmz=169322547.1386173665.1.1.utmcsr=stackoverflow.com|utmccn=(referral)|utmcmd=referral|utmcct=/questions/8616781/how-to-get-a-web-pages-source-code-from-java; __gads=ID=3ab4e50d8713e391:T=1386173664:S=ALNI_Mb8N_wW0xS_wRa68vhR0gTRl8MwFA; scrElm=body");
            HttpURLConnection.setFollowRedirects(false);
            httpCon.setInstanceFollowRedirects(false);
            httpCon.setDoOutput(true);
            httpCon.setUseCaches(true);

            httpCon.setRequestMethod("GET");

            BufferedReader in = new BufferedReader(new InputStreamReader(httpCon.getInputStream(), "UTF-8"));
            String inputLine;
            StringBuilder a = new StringBuilder();
            while ((inputLine = in.readLine()) != null)
                a.append(inputLine);
            in.close();

            System.out.println(a.toString());

            httpCon.disconnect();
}
}

Removing page title and date when printing web page (with CSS?)

Try this;

@media print{ @page { margin-top: 30px; margin-bottom: 30px;}}

Spring MVC Missing URI template variable

This error may happen when mapping variables you defined in REST definition do not match with @PathVariable names.

Example: Suppose you defined in the REST definition

@GetMapping(value = "/{appId}", produces = "application/json", consumes = "application/json")

Then during the definition of the function, it should be

public ResponseEntity<List> getData(@PathVariable String appId)

This error may occur when you use any other variable other than defined in the REST controller definition with @PathVariable. Like, the below code will raise the error as ID is different than appId variable name:

public ResponseEntity<List> getData(@PathVariable String ID)

git diff file against its last change

One of the ways to use git diff is:

git diff <commit> <path>

And a common way to refer one commit of the last commit is as a relative path to the actual HEAD. You can reference previous commits as HEAD^ (in your example this will be 123abc) or HEAD^^ (456def in your example), etc ...

So the answer to your question is:

git diff HEAD^^ myfile

Bootstrap 3 with remote Modal

I did this:

$('#myModal').on 'shown.bs.modal', (e) ->  
  $(e.target).find('.modal-body').load('http://yourserver.com/content')

Node.js - SyntaxError: Unexpected token import

I've been trying to get this working. Here's what works:

  1. Use a recent node version. I'm using v14.15.5. Verify your version by running: node --version
  2. Name the files so that they all end with .mjs rather than .js

Example:

mod.mjs

export const STR = 'Hello World'

test.mjs

import {STR} from './mod.mjs'
console.log(STR)

Run: node test.mjs

You should see "Hello World".

how to set background image in submit button?

.button {
    border: none;
    background: url('/forms/up.png') no-repeat top left;
    padding: 2px 8px;
}

Twitter Bootstrap date picker

Some people posted the link to this bootstrap-datepicker.js implementation. I used that one in the following way, it works with Bootstrap 3.

This is the markup I used:

<div class="input-group date col-md-3" data-date-format="dd-mm-yyyy" data-date="01-01-2014">                        
    <input id="txtHomeLoanStartDate" class="form-control" type="text" readonly="" value="01-01-2014" size="14" />
    <span class="input-group-addon add-on">
        <span class="glyphicon glyphicon-calendar"</span>
    </span>
</div>

This is the javascript:

$('.date').datepicker();

I also included the javascript file downloaded from the link above, along with it's css file, and of course, you should remove any bootstrap grid classes like the col-md-3 to suit your needs.

Verify ImageMagick installation

In Bash you can check if Imagick is an installed module:

$ php -m | grep imagick

If the response is blank it is not installed.

How do you read a file into a list in Python?

To summarize a bit from what people have been saying:

f=open('data.txt', 'w') # will make a new file or erase a file of that name if it is present
f=open('data.txt', 'r') # will open a file as read-only
f=open('data.txt', 'a') # will open a file for appending (appended data goes to the end of the file)

If you wish have something in place similar to a try/catch

with open('data.txt') as f:
    for line in f:
        print line

I think @movieyoda code is probably what you should use however

Hide html horizontal but not vertical scrollbar

Disable horizontal scrollbar completely by adding this code.

body{
  overflow-x: hidden;
  overflow-y: scroll;
}

Convert Uri to String and String to Uri

I am not sure if you got this resolved. To follow up on "CommonsWare's" comment.

That is not a valid string representation of a Uri. A Uri has a scheme, and "/external/images/media/470939" does not have a scheme.

Change

Uri uri=Uri.parse("/external/images/media/470939");

to

Uri uri=Uri.parse("content://external/images/media/470939");

in my case

Uri uri = Uri.parse("content://media/external/images/media/6562");

DLL Load Library - Error Code 126

Windows dll error 126 can have many root causes. The most useful methods I have found to debug this are:

  1. Use dependency walker to look for any obvious problems (which you have already done)
  2. Use the sysinternals utility Process Monitor http://technet.microsoft.com/en-us/sysinternals/bb896645 from Microsoft to trace all file access while your dll is trying to load. With this utility, you will see everything that that dll is trying to pull in and usually the problem can be determined from there.

How do I connect to this localhost from another computer on the same network?

For testing on both laptops on the same wireless and across the internet you could use a service like http://localhost.run/ or https://ngrok.com/

How to instantiate a javascript class in another js file?

Possible Suggestions to make it work:

Some modifications (U forgot to include a semicolon in the statement this.getName=function(){...} it should be this.getName=function(){...};)

function Customer(){
this.name="Jhon";
this.getName=function(){
return this.name;
};
}

(This might be one of the problem.)

and

Make sure U Link the JS files in the correct order

<script src="file1.js" type="text/javascript"></script>
<script src="file2.js" type="text/javascript"></script>

How can I get the active screen dimensions?

You can use this to get desktop workspace bounds of the primary screen:

System.Windows.SystemParameters.WorkArea

This is also useful for getting just the size of the primary screen:

System.Windows.SystemParameters.PrimaryScreenWidth System.Windows.SystemParameters.PrimaryScreenHeight

Why are there two ways to unstage a file in Git?

1.

D:\code\gt2>git status
# On branch master
#
# Initial commit
#
# Changes to be committed:
#   (use "git rm --cached <file>..." to unstage)
#
#       new file:   a

(use "git rm --cached ..." to unstage)

  • git is a system of pointers

  • you do not have a commit yet to change your pointer to

  • the only way to 'take files out of the bucket being pointed to' is to remove files you told git to watch for changes

2.

D:\code\gt2>git commit -m a
[master (root-commit) c271e05] a
0 files changed, 0 insertions(+), 0 deletions(-) create mode 100644 a

git commit -m a

  • you commited, 'saved'

3.

D:\code\gt2>git status
# On branch master
# Changes to be committed:
#   (use "git reset HEAD <file>..." to unstage)
#
#       new file:   b
#

(use "git reset HEAD ..." to unstage)

  • you made a commit in your code at this time
  • now you can reset your pointer to your commit 'revert back to last save'

collapse cell in jupyter notebook

There's also an improved version of Pan Yan suggestion. It adds the button that shows code cells back:

%%html
<style id=hide>div.input{display:none;}</style>
<button type="button" 
onclick="var myStyle = document.getElementById('hide').sheet;myStyle.insertRule('div.input{display:inherit !important;}', 0);">
Show inputs</button>

Or python:

# Run me to hide code cells

from IPython.core.display import display, HTML
display(HTML(r"""<style id=hide>div.input{display:none;}</style><button type="button"onclick="var myStyle = document.getElementById('hide').sheet;myStyle.insertRule('div.input{display:inherit !important;}', 0);">Show inputs</button>"""))

In MySQL, can I copy one row to insert into the same table?

This can be achieved with some creativity:

SET @sql = CONCAT('INSERT INTO <table> SELECT null, 
    ', (SELECT GROUP_CONCAT(COLUMN_NAME) 
    FROM information_schema.columns 
    WHERE table_schema = '<database>' 
    AND table_name = '<table>' 
    AND column_name NOT IN ('id')), ' 
from <table> WHERE id = <id>');  

PREPARE stmt1 FROM @sql;
EXECUTE stmt1;

This will result in the new row getting an auto incremented id instead of the id from the selected row.

What does "&" at the end of a linux command mean?

In addition, you can use the "&" sign to run many processes through one (1) ssh connections in order to to keep minimum number of terminals. For example, I have one process that listens for messages in order to extract files, the second process listens for messages in order to upload files: Using the "&" I can run both services in one terminal, through single ssh connection to my server.


*****I just realized that these processes running through the "&" will also "stay alive" after ssh session is closed! pretty neat and useful if your connection to the server is interrupted**

Equivalent of Oracle's RowID in SQL Server

I took this example from MS SQL example and you can see the @ID can be interchanged with integer or varchar or whatever. This was the same solution I was looking for, so I am sharing it. Enjoy!!

-- UPDATE statement with CTE references that are correctly matched.
DECLARE @x TABLE (ID int, Stad int, Value int, ison bit);
INSERT @x VALUES (1, 0, 10, 0), (2, 1, 20, 0), (6, 0, 40, 0), (4, 1, 50, 0), (5, 3, 60, 0), (9, 6, 20, 0), (7, 5, 10, 0), (8, 8, 220, 0);
DECLARE @Error int;
DECLARE @id int;

WITH cte AS (SELECT top 1 * FROM @x WHERE Stad=6)
UPDATE x -- cte is referenced by the alias.
SET ison=1, @id=x.ID
FROM cte AS x

SELECT *, @id as 'random' from @x
GO

Convert form data to JavaScript object with jQuery

Here's a non-jQuery way:

    var getFormData = function(form) {
        //Ignore the submit button
        var elements = Array.prototype.filter.call(form.elements, function(element) {
            var type = element.getAttribute('type');
            return !type || type.toLowerCase() !== 'submit';
        });

You can use it like this:

function() {

    var getFormData = function(form) {
        //Ignore the submit button
        var elements = Array.prototype.filter.call(form.elements, function(element) {
            var type = element.getAttribute('type');
            return !type || type.toLowerCase() !== 'submit';
        });

        //Make an object out of the form data: {name: value}
        var data = elements.reduce(function(data, element) {
            data[element.name] = element.value;
            return data;
        }, {});

        return data;
    };

    var post = function(action, data, callback) {
        var request = new XMLHttpRequest();
        request.onload = callback;
        request.open('post', action);
        request.setRequestHeader("Content-Type", "application/json;charset=UTF-8");
        request.send(JSON.stringify(data), true);
        request.send();
    };

    var submit = function(e) {
        e.preventDefault();
        var form = e.target;
        var action = form.action;
        var data = getFormData(form);
        //change the third argument in order to do something
        //more intersting with the response than just print it
        post(action, data, console.log.bind(console));
    }

    //change formName below
    document.formName.onsubmit = submit;

})();

How can I apply styles to multiple classes at once?

Don’t Repeat Your CSS

 a.abc, a.xyz{
    margin-left:20px;
 }

OR

 a{
    margin-left:20px;
 }

How do I check if a directory exists? "is_dir", "file_exists" or both?

I think realpath() may be the best way to validate if a path exist http://www.php.net/realpath

Here is an example function:

<?php
/**
 * Checks if a folder exist and return canonicalized absolute pathname (long version)
 * @param string $folder the path being checked.
 * @return mixed returns the canonicalized absolute pathname on success otherwise FALSE is returned
 */
function folder_exist($folder)
{
    // Get canonicalized absolute pathname
    $path = realpath($folder);

    // If it exist, check if it's a directory
    if($path !== false AND is_dir($path))
    {
        // Return canonicalized absolute pathname
        return $path;
    }

    // Path/folder does not exist
    return false;
}

Short version of the same function

<?php
/**
 * Checks if a folder exist and return canonicalized absolute pathname (sort version)
 * @param string $folder the path being checked.
 * @return mixed returns the canonicalized absolute pathname on success otherwise FALSE is returned
 */
function folder_exist($folder)
{
    // Get canonicalized absolute pathname
    $path = realpath($folder);

    // If it exist, check if it's a directory
    return ($path !== false AND is_dir($path)) ? $path : false;
}

Output examples

<?php
/** CASE 1 **/
$input = '/some/path/which/does/not/exist';
var_dump($input);               // string(31) "/some/path/which/does/not/exist"
$output = folder_exist($input);
var_dump($output);              // bool(false)

/** CASE 2 **/
$input = '/home';
var_dump($input);
$output = folder_exist($input);         // string(5) "/home"
var_dump($output);              // string(5) "/home"

/** CASE 3 **/
$input = '/home/..';
var_dump($input);               // string(8) "/home/.."
$output = folder_exist($input);
var_dump($output);              // string(1) "/"

Usage

<?php

$folder = '/foo/bar';

if(FALSE !== ($path = folder_exist($folder)))
{
    die('Folder ' . $path . ' already exist');
}

mkdir($folder);
// Continue do stuff

Python pandas insert list into a cell

df3.set_value(1, 'B', abc) works for any dataframe. Take care of the data type of column 'B'. Eg. a list can not be inserted into a float column, at that case df['B'] = df['B'].astype(object) can help.

How to implement onBackPressed() in Fragments?

onBackPressed() cause Fragment to be detach from Activity.

According to @Sterling Diaz answer I think he is right. BUT some situation will be wrong. (ex. Rotate Screen)

So, I think we could detect whether isRemoving() to achieve goals.

You can write it at onDetach() or onDestroyView(). It is work.

@Override
public void onDetach() {
    super.onDetach();
    if(isRemoving()){
        // onBackPressed()
    }
}

@Override
public void onDestroyView() {
    super.onDestroyView();
    if(isRemoving()){
        // onBackPressed()
    }
}

Flask-SQLalchemy update a row's information

This does not work if you modify a pickled attribute of the model. Pickled attributes should be replaced in order to trigger updates:

from flask import Flask
from flask.ext.sqlalchemy import SQLAlchemy
from pprint import pprint

app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqllite:////tmp/users.db'
db = SQLAlchemy(app)


class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(80), unique=True)
    data = db.Column(db.PickleType())

    def __init__(self, name, data):
        self.name = name
        self.data = data

    def __repr__(self):
        return '<User %r>' % self.username

db.create_all()

# Create a user.
bob = User('Bob', {})
db.session.add(bob)
db.session.commit()

# Retrieve the row by its name.
bob = User.query.filter_by(name='Bob').first()
pprint(bob.data)  # {}

# Modifying data is ignored.
bob.data['foo'] = 123
db.session.commit()
bob = User.query.filter_by(name='Bob').first()
pprint(bob.data)  # {}

# Replacing data is respected.
bob.data = {'bar': 321}
db.session.commit()
bob = User.query.filter_by(name='Bob').first()
pprint(bob.data)  # {'bar': 321}

# Modifying data is ignored.
bob.data['moo'] = 789
db.session.commit()
bob = User.query.filter_by(name='Bob').first()
pprint(bob.data)  # {'bar': 321}

How to change the icon of .bat file programmatically?

try with shortcutjs.bat to create a shortcut:

call shortcutjs.bat -linkfile mybat3.lnk -target "%cd%\Ascii2All.bat" -iconlocation "%SystemRoot%\System32\SHELL32.dll,77"

you can use the -iconlocation switch to point to a icon .

REST / SOAP endpoints for a WCF service

This post has already a very good answer by "Community wiki" and I also recommend to look at Rick Strahl's Web Blog, there are many good posts about WCF Rest like this.

I used both to get this kind of MyService-service... Then I can use the REST-interface from jQuery or SOAP from Java.

This is from my Web.Config:

<system.serviceModel>
 <services>
  <service name="MyService" behaviorConfiguration="MyServiceBehavior">
   <endpoint name="rest" address="" binding="webHttpBinding" contract="MyService" behaviorConfiguration="restBehavior"/>
   <endpoint name="mex" address="mex" binding="mexHttpBinding" contract="MyService"/>
   <endpoint name="soap" address="soap" binding="basicHttpBinding" contract="MyService"/>
  </service>
 </services>
 <behaviors>
  <serviceBehaviors>
   <behavior name="MyServiceBehavior">
    <serviceMetadata httpGetEnabled="true"/>
    <serviceDebug includeExceptionDetailInFaults="true" />
   </behavior>
  </serviceBehaviors>
  <endpointBehaviors>
   <behavior name="restBehavior">
    <webHttp/>
   </behavior>
  </endpointBehaviors>
 </behaviors>
</system.serviceModel>

And this is my service-class (.svc-codebehind, no interfaces required):

    /// <summary> MyService documentation here ;) </summary>
[ServiceContract(Name = "MyService", Namespace = "http://myservice/", SessionMode = SessionMode.NotAllowed)]
//[ServiceKnownType(typeof (IList<MyDataContractTypes>))]
[ServiceBehavior(Name = "MyService", Namespace = "http://myservice/")]
public class MyService
{
    [OperationContract(Name = "MyResource1")]
    [WebGet(ResponseFormat = WebMessageFormat.Xml, UriTemplate = "MyXmlResource/{key}")]
    public string MyResource1(string key)
    {
        return "Test: " + key;
    }

    [OperationContract(Name = "MyResource2")]
    [WebGet(ResponseFormat = WebMessageFormat.Json, UriTemplate = "MyJsonResource/{key}")]
    public string MyResource2(string key)
    {
        return "Test: " + key;
    }
}

Actually I use only Json or Xml but those both are here for a demo purpose. Those are GET-requests to get data. To insert data I would use method with attributes:

[OperationContract(Name = "MyResourceSave")]
[WebInvoke(Method = "POST", ResponseFormat = WebMessageFormat.Json, UriTemplate = "MyJsonResource")]
public string MyResourceSave(string thing){
    //...

What is the default stack size, can it grow, how does it work with garbage collection?

As you say, local variables and references are stored on the stack. When a method returns, the stack pointer is simply moved back to where it was before the method started, that is, all local data is "removed from the stack". Therefore, there is no garbage collection needed on the stack, that only happens in the heap.

To answer your specific questions:

  • See this question on how to increase the stack size.
  • You can limit the stack growth by:
    • grouping many local variables in an object: that object will be stored in the heap and only the reference is stored on the stack
    • limit the number of nested function calls (typically by not using recursion)
  • For windows, the default stack size is 320k for 32bit and 1024k for 64bit, see this link.

SQL Statement with multiple SETs and WHEREs

No, you would need to create a seperate query for each update.

stdlib and colored output in C

#include <stdio.h>

#define BLUE(string) "\x1b[34m" string "\x1b[0m"
#define RED(string) "\x1b[31m" string "\x1b[0m"

int main(void)
{
    printf("this is " RED("red") "!\n");

    // a somewhat more complex ...
    printf("this is " BLUE("%s") "!\n","blue");

    return 0;
}

reading Wikipedia:

  • \x1b[0m resets all attributes
  • \x1b[31m sets foreground color to red
  • \x1b[44m would set the background to blue.
  • both : \x1b[31;44m
  • both but inversed : \x1b[31;44;7m
  • remember to reset afterwards \x1b[0m ...

"An exception occurred while processing your request. Additionally, another exception occurred while executing the custom error page..."

I had this problem with only with redirectMode="ResponseRewrite" (redirectMode="ResponseRedirect" worked fine) and none of the above solutions helped my resolve the issue. However, once I changed the server's application pool's "Managed Pipeline Mode" from "Classic" to "Integrated" the custom error page appeared as expected.

How to change file encoding in NetBeans?

On project explorer, right click on the project, Properties -> General -> Encoding. This will allow you to choose the encoding per project.

retrieve links from web page using python and BeautifulSoup

Others have recommended BeautifulSoup, but it's much better to use lxml. Despite its name, it is also for parsing and scraping HTML. It's much, much faster than BeautifulSoup, and it even handles "broken" HTML better than BeautifulSoup (their claim to fame). It has a compatibility API for BeautifulSoup too if you don't want to learn the lxml API.

Ian Blicking agrees.

There's no reason to use BeautifulSoup anymore, unless you're on Google App Engine or something where anything not purely Python isn't allowed.

lxml.html also supports CSS3 selectors so this sort of thing is trivial.

An example with lxml and xpath would look like this:

import urllib
import lxml.html
connection = urllib.urlopen('http://www.nytimes.com')

dom =  lxml.html.fromstring(connection.read())

for link in dom.xpath('//a/@href'): # select the url in href for all a tags(links)
    print link

Understanding Bootstrap's clearfix class

.clearfix is defined in less/mixins.less. Right above its definition is a comment with a link to this article:

A new micro clearfix hack

The article explains how it all works.

UPDATE: Yes, link-only answers are bad. I knew this even at the time that I posted this answer, but I didn't feel like copying and pasting was OK due to copyright, plagiarism, and what have you. However, I now feel like it's OK since I have linked to the original article. I should also mention the author's name, though, for credit: Nicolas Gallagher. Here is the meat of the article (note that "Thierry’s method" is referring to Thierry Koblentz’s “clearfix reloaded”):

This “micro clearfix” generates pseudo-elements and sets their display to table. This creates an anonymous table-cell and a new block formatting context that means the :before pseudo-element prevents top-margin collapse. The :after pseudo-element is used to clear the floats. As a result, there is no need to hide any generated content and the total amount of code needed is reduced.

Including the :before selector is not necessary to clear the floats, but it prevents top-margins from collapsing in modern browsers. This has two benefits:

  • It ensures visual consistency with other float containment techniques that create a new block formatting context, e.g., overflow:hidden

  • It ensures visual consistency with IE 6/7 when zoom:1 is applied.

N.B.: There are circumstances in which IE 6/7 will not contain the bottom margins of floats within a new block formatting context. Further details can be found here: Better float containment in IE using CSS expressions.

The use of content:" " (note the space in the content string) avoids an Opera bug that creates space around clearfixed elements if the contenteditable attribute is also present somewhere in the HTML. Thanks to Sergio Cerrutti for spotting this fix. An alternative fix is to use font:0/0 a.

Legacy Firefox

Firefox < 3.5 will benefit from using Thierry’s method with the addition of visibility:hidden to hide the inserted character. This is because legacy versions of Firefox need content:"." to avoid extra space appearing between the body and its first child element, in certain circumstances (e.g., jsfiddle.net/necolas/K538S/.)

Alternative float-containment methods that create a new block formatting context, such as applying overflow:hidden or display:inline-block to the container element, will also avoid this behaviour in legacy versions of Firefox.

How do I get a HttpServletRequest in my spring beans?

If FlexContext is not available:

Solution 1: inside method (>= Spring 2.0 required)

HttpServletRequest request = 
        ((ServletRequestAttributes)RequestContextHolder.getRequestAttributes())
                .getRequest();

Solution 2: inside bean (supported by >= 2.5, Spring 3.0 for singelton beans required!)

@Autowired
private HttpServletRequest request;

How to join two sets in one line without using "|"

If you are fine with modifying the original set (which you may want to do in some cases), you can use set.update():

S.update(T)

The return value is None, but S will be updated to be the union of the original S and T.

How do you send a Firebase Notification to all devices via CURL?

One way to do that is to make all your users' devices subscribe to a topic. That way when you target a message to a specific topic, all devices will get it. I think this how the Notifications section in the Firebase console does it.

Javascript - Replace html using innerHTML

You should chain the replace() together instead of assigning the result and replacing again.

var strMessage1 = document.getElementById("element1") ;
strMessage1.innerHTML = strMessage1.innerHTML
                        .replace(/aaaaaa./g,'<a href=\"http://www.google.com/')
                        .replace(/.bbbbbb/g,'/world\">Helloworld</a>');

See DEMO.

AngularJS Folder Structure

enter image description here

Sort By Type

On the left we have the app organized by type. Not too bad for smaller apps, but even here you can start to see it gets more difficult to find what you are looking for. When I want to find a specific view and its controller, they are in different folders. It can be good to start here if you are not sure how else to organize the code as it is quite easy to shift to the technique on the right: structure by feature.

Sort By Feature (preferred)

On the right the project is organized by feature. All of the layout views and controllers go in the layout folder, the admin content goes in the admin folder, and the services that are used by all of the areas go in the services folder. The idea here is that when you are looking for the code that makes a feature work, it is located in one place. Services are a bit different as they “service” many features. I like this once my app starts to take shape as it becomes a lot easier to manage for me.

A well written blog post: http://www.johnpapa.net/angular-growth-structure/

Example App: https://github.com/angular-app/angular-app

Uninstall all installed gems, in OSX?

The only command helped me to cleanup all gems and ignores default gems, which can't be uninstalled

for x in `gem list --no-versions`; do gem uninstall $x -a -x -I; done

Compiling simple Hello World program on OS X via command line

Also, you can use an IDE like CLion (JetBrains) or a text editor like Atom, with the gpp-compiler plugin, works like a charm (F5 to compile & execute).

List files recursively in Linux CLI with path relative to the current directory

You could create a shell function, e.g. in your .zshrc or .bashrc:

filepath() {
    echo $PWD/$1
}

filepath2() {
    for i in $@; do
        echo $PWD/$i
    done
}

The first one would work on single files only, obviously.

Android EditText Max Length

I had the same problem.

Here is a workaround

android:inputType="textNoSuggestions|textVisiblePassword"
android:maxLength="6"

Thx to How can I turnoff suggestions in EditText?

Transpose a data frame

You can use the transpose function from the data.table library. Simple and fast solution that keeps numeric values as numeric.

library(data.table)

# get data
  data("mtcars")

# transpose
  t_mtcars <- transpose(mtcars)

# get row and colnames in order
  colnames(t_mtcars) <- rownames(mtcars)
  rownames(t_mtcars) <- colnames(mtcars)

What's the difference between REST & RESTful

"REST" is an architectural paradigm. "RESTful" describes using that paradigm.

Business logic in MVC

Q1:

Business logics can be considered in two categories:

  1. Domain logics like controls on an email address (uniqueness, constraints, etc.), obtaining the price of a product for invoice, or, calculating the shoppingCart's total price based of its product objects.

  2. More broad and complicated workflows which are called business processes, like controlling the registration process for the student (which usually includes several steps and needs different checks and has more complicated constraints).

The first category goes into model and the second one belongs to controller. This is because the cases in the second category are broad application logics and putting them in the model may mix the model's abstraction (for example, it is not clear if we need to put those decisions in one model class or another, since they are related to both!).

See this answer for a specific distinction between model and controller, this link for very exact definitions and also this link for a nice Android example.

The point is that the notes mentioned by "Mud" and "Frank" above both can be true as well as "Pete"'s (business logic can be put in model, or controller, according to the type of business logic).

Finally, note that MVC differs from context to context. For example, in Android applications, some alternative definitions are suggested that differs from web-based ones (see this post for example).


Q2:

Business logic is more general and (as "decyclone" mentioned above) we have the following relation between them:

business rules ? business logics

how to increase the limit for max.print in R

Use the options command, e.g. options(max.print=1000000).

See ?options:

 ‘max.print’: integer, defaulting to ‘99999’.  ‘print’ or ‘show’
      methods can make use of this option, to limit the amount of
      information that is printed, to something in the order of
      (and typically slightly less than) ‘max.print’ _entries_.

Add an object to a python list

Is your problem similar to this:

l = [[0]] * 4
l[0][0] += 1
print l # prints "[[1], [1], [1], [1]]"

If so, you simply need to copy the objects when you store them:

import copy
l = [copy.copy(x) for x in [[0]] * 4]
l[0][0] += 1
print l # prints "[[1], [0], [0], [0]]"

The objects in question should implement a __copy__ method to copy objects. See the documentation for copy. You may also be interested in copy.deepcopy, which is there as well.

EDIT: Here's the problem:

arrayList = []
for x in allValues:
    result = model(x)
    arrayList.append(wM) # appends the wM object to the list
    wM.reset()           # clears  the wM object

You need to append a copy:

import copy
arrayList = []
for x in allValues:
    result = model(x)
    arrayList.append(copy.copy(wM)) # appends a copy to the list
    wM.reset()                      # clears the wM object

But I'm still confused as to where wM is coming from. Won't you just be copying the same wM object over and over, except clearing it after the first time so all the rest will be empty? Or does model() modify the wM (which sounds like a terrible design flaw to me)? And why are you throwing away result?

How to check for null in Twig?

How to set default values in twig: http://twig.sensiolabs.org/doc/filters/default.html

{{ my_var | default("my_var doesn't exist") }}

Or if you don't want it to display when null:

{{ my_var | default("") }}

PNG transparency issue in IE8

please try below code.

 background: transparent\0/;
 filter: progid:DXImageTransform.Microsoft.gradient(startColorstr=#00FFFFFF,endColorstr=#00FFFFFF)progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled='true',sizingMethod='image',src='assets/img/bgSmall.png');   /* IE7 */      
-ms-filter: "progid:DXImageTransform.Microsoft.gradient(startColorstr=#00FFFFFF,endColorstr=#00FFFFFF)progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled='true',sizingMethod='image',src='assets/img/bgSmall.png')"; /* IE8 */   

Tkinter example code for multiple windows, why won't buttons load correctly?

What you could do is copy the code from tkinter.py into a file called mytkinter.py, then do this code:

import tkinter, mytkinter
root = tkinter.Tk()
window = mytkinter.Tk()
button = mytkinter.Button(window, text="Search", width = 7,
                               command=cmd)
button2 = tkinter.Button(root, text="Search", width = 7,
                               command=cmdtwo)

And you have two windows which don't collide!

How to get ER model of database from server with Workbench

  1. Go to "Database" Menu option
  2. Select the "Reverse Engineer" option.
  3. A wizard will be open and it will generate the ER Diagram for you.

how to check redis instance version?

$ redis-server --version

gives you the version.

How to directly execute SQL query in C#?

Something like this should suffice, to do what your batch file was doing (dumping the result set as semi-colon delimited text to the console):

// sqlcmd.exe
// -S .\PDATA_SQLEXPRESS
// -U sa
// -P 2BeChanged!
// -d PDATA_SQLEXPRESS
// -s ; -W -w 100
// -Q "SELECT tPatCulIntPatIDPk, tPatSFirstname, tPatSName, tPatDBirthday  FROM  [dbo].[TPatientRaw] WHERE tPatSName = '%name%' "

DataTable dt            = new DataTable() ;
int       rows_returned ;

const string credentials = @"Server=(localdb)\.\PDATA_SQLEXPRESS;Database=PDATA_SQLEXPRESS;User ID=sa;Password=2BeChanged!;" ;
const string sqlQuery = @"
  select tPatCulIntPatIDPk ,
         tPatSFirstname    ,
         tPatSName         ,
         tPatDBirthday
  from dbo.TPatientRaw
  where tPatSName = @patientSurname
  " ;

using ( SqlConnection connection = new SqlConnection(credentials) )
using ( SqlCommand    cmd        = connection.CreateCommand() )
using ( SqlDataAdapter sda       = new SqlDataAdapter( cmd ) )
{
  cmd.CommandText = sqlQuery ;
  cmd.CommandType = CommandType.Text ;
  connection.Open() ;
  rows_returned = sda.Fill(dt) ;
  connection.Close() ;
}

if ( dt.Rows.Count == 0 )
{
  // query returned no rows
}
else
{

  //write semicolon-delimited header
  string[] columnNames = dt.Columns
                           .Cast<DataColumn>()
                           .Select( c => c.ColumnName )
                           .ToArray()
                           ;
  string   header      = string.Join("," , columnNames) ;
  Console.WriteLine(header) ;

  // write each row
  foreach ( DataRow dr in dt.Rows )
  {

    // get each rows columns as a string (casting null into the nil (empty) string
    string[] values = new string[dt.Columns.Count];
    for ( int i = 0 ; i < dt.Columns.Count ; ++i )
    {
      values[i] = ((string) dr[i]) ?? "" ; // we'll treat nulls as the nil string for the nonce
    }

    // construct the string to be dumped, quoting each value and doubling any embedded quotes.
    string data = string.Join( ";" , values.Select( s => "\""+s.Replace("\"","\"\"")+"\"") ) ;
    Console.WriteLine(values);

  }

}

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

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

jquery $(window).width() and $(window).height() return different values when viewport has not been resized

I think what you're seeing is the hiding and showing of scrollbars. Here's a quick demo showing the width change.

As an aside: do you need to poll constantly? You might be able to optimize your code to run on the resize event, like this:

$(window).resize(function() {
  //update stuff
});

Is there a way to SELECT and UPDATE rows at the same time?

Many years later...

The accepted answer of using the OUTPUT clause is good. I had to dig up the actual syntax, so here it is:

DECLARE @UpdatedIDs table (ID int)
UPDATE 
    Table1 
SET 
    AlertDate = getutcdate() 
OUTPUT
    inserted.Id
INTO
    @UpdatedIDs
WHERE 
    AlertDate IS NULL;

ADDED SEP 14, 2015:

"Can I use a scalar variable instead of a table variable?" one may ask... Sorry, but no you can't. You'll have to SELECT @SomeID = ID from @UpdatedIDs if you need a single ID.

Python extract pattern matches

Here's a way to do it without using groups (Python 3.6 or above):

>>> re.search('2\d\d\d[01]\d[0-3]\d', 'report_20191207.xml')[0]
'20191207'

XCOPY switch to create specified directory if it doesn't exist?

I tried this on the command.it is working for me.

if "$(OutDir)"=="bin\Debug\"  goto Visual
:TFSBuild
goto exit
:Visual
xcopy /y "$(TargetPath)$(TargetName).dll" "$(ProjectDir)..\Demo"
xcopy /y "$(TargetDir)$(TargetName).pdb" "$(ProjectDir)..\Demo"
goto exit
:exit

How to escape double quotes in a title attribute

Perhaps you can use JavaScript to solve your cross-browser problem. It uses a different escape mechanism, one with which you're obviously already familiar:

(reference-to-the-tag).title = "Some \"text\"";

It doesn't strictly separate the functions of HTML, JavaScript, and CSS the way folks want you to nowadays, but whom do you need to make happy? Your users or techies you don't know?

How to send email from Terminal?

in the terminal on your mac os or linux os type this code

mail -s (subject) (receiversEmailAddress)  <<< "how are you?"

for an example try this

mail -s "hi" [email protected] <<< "how are you?"<br>

Where is the Global.asax.cs file?

That's because you created a Web Site instead of a Web Application. The cs/vb files can only be seen in a Web Application, but in a website you can't have a separate cs/vb file.

Edit: In the website you can add a cs file behavior like..

<%@ Application CodeFile="Global.asax.cs" Inherits="ApplicationName.MyApplication" Language="C#" %>

~/Global.asax.cs:

namespace ApplicationName
{
    public partial class MyApplication : System.Web.HttpApplication
    {
        protected void Application_Start()
        {
        }
    }
}

How to write UTF-8 in a CSV file

It's very simple for Python 3.x (docs).

import csv

with open('output_file_name', 'w', newline='', encoding='utf-8') as csv_file:
    writer = csv.writer(csv_file, delimiter=';')
    writer.writerow('my_utf8_string')

For Python 2.x, look here.

Converting time stamps in excel to dates

Use this simple formula. It works.

Suppose time stamp in A2:

=DATE(YEAR(A2),MONTH(A2),DAY(A2))

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

Like this:

The Controller

[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult MethodName(FormCollection formCollection)
{
     ...
     Code Block
     ...
}

The View:

@using(Html.BeginForm())
{
     @Html.AntiForgeryToken()
     <input name="..." type="text" />
     // rest
}

Why would one use nested classes in C++?

I don't use nested classes much, but I do use them now and then. Especially when I define some kind of data type, and I then want to define a STL functor designed for that data type.

For example, consider a generic Field class that has an ID number, a type code and a field name. If I want to search a vector of these Fields by either ID number or name, I might construct a functor to do so:

class Field
{
public:
  unsigned id_;
  string name_;
  unsigned type_;

  class match : public std::unary_function<bool, Field>
  {
  public:
    match(const string& name) : name_(name), has_name_(true) {};
    match(unsigned id) : id_(id), has_id_(true) {};
    bool operator()(const Field& rhs) const
    {
      bool ret = true;
      if( ret && has_id_ ) ret = id_ == rhs.id_;
      if( ret && has_name_ ) ret = name_ == rhs.name_;
      return ret;
    };
    private:
      unsigned id_;
      bool has_id_;
      string name_;
      bool has_name_;
  };
};

Then code that needs to search for these Fields can use the match scoped within the Field class itself:

vector<Field>::const_iterator it = find_if(fields.begin(), fields.end(), Field::match("FieldName"));

Android, Java: HTTP POST Request

You can reuse the implementation I added to ACRA: http://code.google.com/p/acra/source/browse/tags/REL-3_1_0/CrashReport/src/org/acra/HttpUtils.java?r=236

(See the doPost(Map, Url) method, working over http and https even with self signed certs)

Android ListView selected item stay highlighted

One way you can do this, is to Keep track of the current selected position in your activity:

@Override
    public void onItemClick(AdapterView<?> arg0, View arg1, int position,
            long arg3) {
        currentPosition = position
        lv_cli.notifyDataSetChanged();
    }

Now, be sure you assign an ID to the parent layout (linearLayout, boxLayout, relativeLayout, .. Whatever you prefer) of your list item.

Then in your ListView you can do something Like this:

layoutBackground = (LinearLayout) convertView.findViewById(R.id.layout_background);

if (YourActivity.this.currentPosition == position) {
    layoutBackground.setBackgroundColor(YourActivity.this.getResources().getColor(R.color.hilight_color));
} else{
    layoutBackground.setBackgroundResource(R.drawable.list_item_drawable);
}

Basically, you just set the hilight color to the layout as a background when it equals your current selected position. Notice how I set a drawable background resource when the item is not selected. This could be in your case different (since you posted no code). In my case, this drawable is a selector which makes sure the item is hi-lighted when pressed.

NOTE: This simple code doesn't use a view-holder, but I really recommend using one.

jQuery get the location of an element relative to window

TL;DR

headroom_by_jQuery = $('#id').offset().top - $(window).scrollTop();

headroom_by_DOM = $('#id')[0].getBoundingClientRect().top;   // if no iframe

.getBoundingClientRect() appears to be universal. .offset() and .scrollTop() have been supported since jQuery 1.2. Thanks @user372551 and @prograhammer. To use DOM in an iframe see @ImranAnsari's solution.

Multiple Image Upload PHP form with one input

PHP Code

<?php
error_reporting(0);
session_start();
include('config.php');
//define session id
$session_id='1'; 
define ("MAX_SIZE","9000"); 
function getExtension($str)
{
         $i = strrpos($str,".");
         if (!$i) { return ""; }
         $l = strlen($str) - $i;
         $ext = substr($str,$i+1,$l);
         return $ext;
}

//set the image extentions
$valid_formats = array("jpg", "png", "gif", "bmp","jpeg");
if(isset($_POST) and $_SERVER['REQUEST_METHOD'] == "POST") 
{

    $uploaddir = "uploads/"; //image upload directory
    foreach ($_FILES['photos']['name'] as $name => $value)
    {

        $filename = stripslashes($_FILES['photos']['name'][$name]);
        $size=filesize($_FILES['photos']['tmp_name'][$name]);
        //get the extension of the file in a lower case format
          $ext = getExtension($filename);
          $ext = strtolower($ext);

         if(in_array($ext,$valid_formats))
         {
           if ($size < (MAX_SIZE*1024))
           {
           $image_name=time().$filename;
           echo "<img src='".$uploaddir.$image_name."' class='imgList'>";
           $newname=$uploaddir.$image_name;

           if (move_uploaded_file($_FILES['photos']['tmp_name'][$name], $newname)) 
           {
           $time=time();
               //insert in database
           mysql_query("INSERT INTO user_uploads(image_name,user_id_fk,created) VALUES('$image_name','$session_id','$time')");
           }
           else
           {
            echo '<span class="imgList">You have exceeded the size limit! so moving unsuccessful! </span>';
            }

           }
           else
           {
            echo '<span class="imgList">You have exceeded the size limit!</span>';

           }

          }
          else
         { 
             echo '<span class="imgList">Unknown extension!</span>';

         }

     }
}

?>

Jquery Code

<script>
 $(document).ready(function() { 

            $('#photoimg').die('click').live('change', function()            { 

                $("#imageform").ajaxForm({target: '#preview', 
                     beforeSubmit:function(){ 

                    console.log('ttest');
                    $("#imageloadstatus").show();
                     $("#imageloadbutton").hide();
                     }, 
                    success:function(){ 
                    console.log('test');
                     $("#imageloadstatus").hide();
                     $("#imageloadbutton").show();
                    }, 
                    error:function(){ 
                    console.log('xtest');
                     $("#imageloadstatus").hide();
                    $("#imageloadbutton").show();
                    } }).submit();


            });
        }); 
</script>

PHP CURL & HTTPS

I was trying to use CURL to do some https API calls with php and ran into this problem. I noticed a recommendation on the php site which got me up and running: http://php.net/manual/en/function.curl-setopt.php#110457

Please everyone, stop setting CURLOPT_SSL_VERIFYPEER to false or 0. If your PHP installation doesn't have an up-to-date CA root certificate bundle, download the one at the curl website and save it on your server:

http://curl.haxx.se/docs/caextract.html

Then set a path to it in your php.ini file, e.g. on Windows:

curl.cainfo=c:\php\cacert.pem

Turning off CURLOPT_SSL_VERIFYPEER allows man in the middle (MITM) attacks, which you don't want!

How can I test an AngularJS service from the console?

First of all, a modified version of your service.

a )

var app = angular.module('app',[]);

app.factory('ExampleService',function(){
    return {
        f1 : function(world){
            return 'Hello' + world;
        }
    };
});

This returns an object, nothing to new here.

Now the way to get this from the console is

b )

var $inj = angular.injector(['app']);
var serv = $inj.get('ExampleService');
serv.f1("World");

c )

One of the things you were doing there earlier was to assume that the app.factory returns you the function itself or a new'ed version of it. Which is not the case. In order to get a constructor you would either have to do

app.factory('ExampleService',function(){
        return function(){
            this.f1 = function(world){
                return 'Hello' + world;
            }
        };
    });

This returns an ExampleService constructor which you will next have to do a 'new' on.

Or alternatively,

app.service('ExampleService',function(){
            this.f1 = function(world){
                return 'Hello' + world;
            };
    });

This returns new ExampleService() on injection.

Can I set state inside a useEffect hook

? 1. Can I set state inside a useEffect hook?

In principle, you can set state freely where you need it - including inside useEffect and even during rendering. Just make sure to avoid infinite loops by settting Hook deps properly and/or state conditionally.


? 2. Lets say I have some state that is dependent on some other state. Is it appropriate to create a hook that observes A and sets B inside the useEffect hook?

You just described the classic use case for useReducer:

useReducer is usually preferable to useState when you have complex state logic that involves multiple sub-values or when the next state depends on the previous one. (React docs)

When setting a state variable depends on the current value of another state variable, you might want to try replacing them both with useReducer. [...] When you find yourself writing setSomething(something => ...), it’s a good time to consider using a reducer instead. (Dan Abramov, Overreacted blog)

_x000D_
_x000D_
let MyComponent = () => {_x000D_
  let [state, dispatch] = useReducer(reducer, { a: 1, b: 2 });_x000D_
_x000D_
  useEffect(() => {_x000D_
    console.log("Some effect with B");_x000D_
  }, [state.b]);_x000D_
_x000D_
  return (_x000D_
    <div>_x000D_
      <p>A: {state.a}, B: {state.b}</p>_x000D_
      <button onClick={() => dispatch({ type: "SET_A", payload: 5 })}>_x000D_
        Set A to 5 and Check B_x000D_
      </button>_x000D_
      <button onClick={() => dispatch({ type: "INCREMENT_B" })}>_x000D_
        Increment B_x000D_
      </button>_x000D_
    </div>_x000D_
  );_x000D_
};_x000D_
_x000D_
// B depends on A. If B >= A, then reset B to 1._x000D_
function reducer(state, { type, payload }) {_x000D_
  const someCondition = state.b >= state.a;_x000D_
_x000D_
  if (type === "SET_A")_x000D_
    return someCondition ? { a: payload, b: 1 } : { ...state, a: payload };_x000D_
  else if (type === "INCREMENT_B") return { ...state, b: state.b + 1 };_x000D_
  return state;_x000D_
}_x000D_
_x000D_
ReactDOM.render(<MyComponent />, document.getElementById("root"));
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.13.0/umd/react.production.min.js" integrity="sha256-32Gmw5rBDXyMjg/73FgpukoTZdMrxuYW7tj8adbN8z4=" crossorigin="anonymous"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.13.0/umd/react-dom.production.min.js" integrity="sha256-bjQ42ac3EN0GqK40pC9gGi/YixvKyZ24qMP/9HiGW7w=" crossorigin="anonymous"></script>_x000D_
<div id="root"></div>_x000D_
<script>var { useReducer, useEffect } = React</script>
_x000D_
_x000D_
_x000D_


? 3. Will the effects cascade such that, when I click the button, the first effect will fire, causing b to change, causing the second effect to fire, before the next render?

useEffect always runs after the render is committed and DOM changes are applied. The first effect fires, changes b and causes a re-render. After this render has completed, second effect will run due to b changes.

_x000D_
_x000D_
let MyComponent = props => {_x000D_
  console.log("render");_x000D_
  let [a, setA] = useState(1);_x000D_
  let [b, setB] = useState(2);_x000D_
_x000D_
  let isFirstRender = useRef(true);_x000D_
_x000D_
  useEffect(() => {_x000D_
    console.log("useEffect a, value:", a);_x000D_
    if (isFirstRender.current) isFirstRender.current = false;_x000D_
    else setB(3);_x000D_
    return () => {_x000D_
      console.log("unmount useEffect a, value:", a);_x000D_
    };_x000D_
  }, [a]);_x000D_
  useEffect(() => {_x000D_
    console.log("useEffect b, value:", b);_x000D_
    return () => {_x000D_
      console.log("unmount useEffect b, value:", b);_x000D_
    };_x000D_
  }, [b]);_x000D_
_x000D_
  return (_x000D_
    <div>_x000D_
      <p>a: {a}, b: {b}</p>_x000D_
      <button_x000D_
        onClick={() => {_x000D_
          console.log("Clicked!");_x000D_
          setA(5);_x000D_
        }}_x000D_
      >_x000D_
        click me_x000D_
      </button>_x000D_
    </div>_x000D_
  );_x000D_
};_x000D_
_x000D_
ReactDOM.render(<MyComponent />, document.getElementById("root"));
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.13.0/umd/react.production.min.js" integrity="sha256-32Gmw5rBDXyMjg/73FgpukoTZdMrxuYW7tj8adbN8z4=" crossorigin="anonymous"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.13.0/umd/react-dom.production.min.js" integrity="sha256-bjQ42ac3EN0GqK40pC9gGi/YixvKyZ24qMP/9HiGW7w=" crossorigin="anonymous"></script>_x000D_
<div id="root"></div>_x000D_
<script>var { useReducer, useEffect, useState, useRef } = React</script>
_x000D_
_x000D_
_x000D_


? 4. Are there any performance downsides to structuring code like this?

Yes. By wrapping the state change of b in a separate useEffect for a, the browser has an additional layout/paint phase - these effects are potentially visible for the user. If there is no way you want give useReducer a try, you could change b state together with a directly:

_x000D_
_x000D_
let MyComponent = () => {_x000D_
  console.log("render");_x000D_
  let [a, setA] = useState(1);_x000D_
  let [b, setB] = useState(2);_x000D_
_x000D_
  useEffect(() => {_x000D_
    console.log("useEffect b, value:", b);_x000D_
    return () => {_x000D_
      console.log("unmount useEffect b, value:", b);_x000D_
    };_x000D_
  }, [b]);_x000D_
_x000D_
  const handleClick = () => {_x000D_
    console.log("Clicked!");_x000D_
    setA(5);_x000D_
    b >= 5 ? setB(1) : setB(b + 1);_x000D_
  };_x000D_
_x000D_
  return (_x000D_
    <div>_x000D_
      <p>_x000D_
        a: {a}, b: {b}_x000D_
      </p>_x000D_
      <button onClick={handleClick}>click me</button>_x000D_
    </div>_x000D_
  );_x000D_
};_x000D_
_x000D_
ReactDOM.render(<MyComponent />, document.getElementById("root"));
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.13.0/umd/react.production.min.js" integrity="sha256-32Gmw5rBDXyMjg/73FgpukoTZdMrxuYW7tj8adbN8z4=" crossorigin="anonymous"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.13.0/umd/react-dom.production.min.js" integrity="sha256-bjQ42ac3EN0GqK40pC9gGi/YixvKyZ24qMP/9HiGW7w=" crossorigin="anonymous"></script>_x000D_
<div id="root"></div>_x000D_
<script>var { useReducer, useEffect, useState, useRef } = React</script>
_x000D_
_x000D_
_x000D_

Why use prefixes on member variables in C++ classes

Lately I have been tending to prefer m_ prefix instead of having no prefix at all, the reasons isn't so much that its important to flag member variables, but that it avoids ambiguity, say you have code like:

void set_foo(int foo) { foo = foo; }

That of cause doesn't work, only one foo allowed. So your options are:

  • this->foo = foo;

    I don't like it, as it causes parameter shadowing, you no longer can use g++ -Wshadow warnings, its also longer to type then m_. You also still run into naming conflicts between variables and functions when you have a int foo; and a int foo();.

  • foo = foo_; or foo = arg_foo;

    Been using that for a while, but it makes the argument lists ugly, documentation shouldn't have do deal with name disambiguity in the implementation. Naming conflicts between variables and functions also exist here.

  • m_foo = foo;

    API Documentation stays clean, you don't get ambiguity between member functions and variables and its shorter to type then this->. Only disadvantage is that it makes POD structures ugly, but as POD structures don't suffer from the name ambiguity in the first place, one doesn't need to use it with them. Having a unique prefix also makes a few search&replace operations easier.

  • foo_ = foo;

    Most of the advantages of m_ apply, but I reject it for aesthetic reasons, a trailing or leading underscore just makes the variable look incomplete and unbalanced. m_ just looks better. Using m_ is also more extendable, as you can use g_ for globals and s_ for statics.

PS: The reason why you don't see m_ in Python or Ruby is because both languages enforce the their own prefix, Ruby uses @ for member variables and Python requires self..

Push JSON Objects to array in localStorage

var arr = [ 'a', 'b', 'c'];
arr.push('d'); // insert as last item

how to change namespace of entire project?

In asp.net is more to do, to get completely running under another namespace.

  • Copy your source folder and rename it to your new project name.
  • Open it and Replace all by Ctrl + H and be sure to include all Replace everything
  • Press F2 on your Projectname and rename it to your new project name
  • go to your project properties and adjust it, coz everything has gone and you need to make a new Debug Profile Profile to Create
  • All dependencies have now an exclamation mark - restart visual studio
  • Clean your solution and Run it and it should work :)

Java count occurrence of each item in an array

You could use a MultiSet from Google Collections/Guava or a Bag from Apache Commons.

If you have a collection instead of an array, you can use addAll() to add the entire contents to the above data structure, and then apply the count() method to each value. A SortedMultiSet or SortedBag would give you the items in a defined order.

Google Collections actually has very convenient ways of going from arrays to a SortedMultiset.

Why is System.Web.Mvc not listed in Add References?

You can also add this from the Nuget Package Manager Console, something like:

Install-Package Microsoft.AspNet.Mvc -Version 4.0.20710.0 -ProjectName XXXXX

Microsoft.AspNet.Mvc has dependencies on:

  • 'Microsoft.AspNet.WebPages (= 2.0.20710.0 && < 2.1)'
  • 'Microsoft.Web.Infrastructure (= 1.0.0.0)'
  • 'Microsoft.AspNet.Razor (= 2.0.20710.0 && < 2.1)'

...which seems like no biggie to me. In our case, this is a class library that exists solely to provide support for our Mvc apps. So, we figure it's a benign dependency at worst.

I definitely prefer this to pointing to an assembly on the file system or in the GAC, since updating the package in the future will likely be a lot less painful than experiences I've had with the GAC and file system assembly references in the past.

Extract only right most n letters from a string

Probably nicer to use an extension method:

public static class StringExtensions
{
    public static string Right(this string str, int length)
    {
        return str.Substring(str.Length - length, length);
    }
}

Usage

string myStr = "PER 343573";
string subStr = myStr.Right(6);

Rails: Missing host to link to! Please provide :host parameter or set default_url_options[:host]

Funny thing, that setting config.action_mailer.default_url_options does not help for me. Also, messing around with environment-independent settings in places I felt like it does not belong was not satisfying for me. Additionally, I wanted a solution that worked when generating urls in sidekiq/resque workers.

My approach so far, which goes into config/environments/{development, production}.rb:

MyApp::Application.configure do
    # Stuff omitted...

    config.action_mailer.default_url_options = {
      # Set things here as usual
    }
end

MyApp::Application.default_url_options = MyApp::Application.config.action_mailer.default_url_options

This works for me in rails >= 3.2.x.

get all the elements of a particular form

document.forms["form_name"].getElementsByTagName("input");

Change background color of R plot

Old question but I have a much better way of doing this. Rather than using rect() use polygon. This allows you to keep everything in plot without using points. Also you don't have to mess with par at all. If you want to keep things automated make the coordinates of polygon a function of your data.

plot.new()
polygon(c(-min(df[,1])^2,-min(df[,1])^2,max(df[,1])^2,max(df[,1])^2),c(-min(df[,2])^2,max(df[,2])^2,max(df[,2])^2,-min(df[,2])^2), col="grey")
par(new=T)
plot(df)

How can I get the count of milliseconds since midnight for the current?

You can use java.util.Calendar class to get time in milliseconds. Example:

Calendar cal = Calendar.getInstance();
int milliSec = cal.get(Calendar.MILLISECOND);
// print milliSec

java.util.Date date = cal.getTime();
System.out.println("Output: " +  new SimpleDateFormat("yyyy/MM/dd-HH:mm:ss:SSS").format(date));

jQuery AJAX file upload PHP

You need a script that runs on the server to move the file to the uploads directory. The jQuery ajax method (running in the browser) sends the form data to the server, then a script on the server handles the upload. Here's an example using PHP.

Your HTML is fine, but update your JS jQuery script to look like this:

$('#upload').on('click', function() {
    var file_data = $('#sortpicture').prop('files')[0];   
    var form_data = new FormData();                  
    form_data.append('file', file_data);
    alert(form_data);                             
    $.ajax({
        url: 'upload.php', // point to server-side PHP script 
        dataType: 'text',  // what to expect back from the PHP script, if anything
        cache: false,
        contentType: false,
        processData: false,
        data: form_data,                         
        type: 'post',
        success: function(php_script_response){
            alert(php_script_response); // display response from the PHP script, if any
        }
     });
});

And now for the server-side script, using PHP in this case.

upload.php: a PHP script that runs on the server and directs the file to the uploads directory:

<?php

    if ( 0 < $_FILES['file']['error'] ) {
        echo 'Error: ' . $_FILES['file']['error'] . '<br>';
    }
    else {
        move_uploaded_file($_FILES['file']['tmp_name'], 'uploads/' . $_FILES['file']['name']);
    }

?>

Also, a couple things about the destination directory:

  1. Make sure you have the correct server path, i.e., starting at the PHP script location what is the path to the uploads directory, and
  2. Make sure it's writeable.

And a little bit about the PHP function move_uploaded_file, used in the upload.php script:

move_uploaded_file(

    // this is where the file is temporarily stored on the server when uploaded
    // do not change this
    $_FILES['file']['tmp_name'],

    // this is where you want to put the file and what you want to name it
    // in this case we are putting in a directory called "uploads"
    // and giving it the original filename
    'uploads/' . $_FILES['file']['name']
);

$_FILES['file']['name'] is the name of the file as it is uploaded. You don't have to use that. You can give the file any name (server filesystem compatible) you want:

move_uploaded_file(
    $_FILES['file']['tmp_name'],
    'uploads/my_new_filename.whatever'
);

And finally, be aware of your PHP upload_max_filesize AND post_max_size configuration values, and be sure your test files do not exceed either. Here's some help how you check PHP configuration and how you set max filesize and post settings.

How to set connection timeout with OkHttp

As of OkHttp3 you can do this through the Builder like so

client = new OkHttpClient.Builder()
    .connectTimeout(10, TimeUnit.SECONDS)
    .writeTimeout(10, TimeUnit.SECONDS)
    .readTimeout(30, TimeUnit.SECONDS)
    .build();

You can also view the recipe here.

For older versions, you simply have to do this

OkHttpClient client = new OkHttpClient();
client.setConnectTimeout(15, TimeUnit.SECONDS); // connect timeout
client.setReadTimeout(15, TimeUnit.SECONDS);    // socket timeout

Request request = new Request.Builder().url(url).build();
Response response = client.newCall(request).execute();

Be aware that value set in setReadTimeout is the one used in setSoTimeout on the Socket internally in the OkHttp Connection class.

Not setting any timeout on the OkHttpClient is the equivalent of setting a value of 0 on setConnectTimeout or setReadTimeout and will result in no timeout at all. Description can be found here.

As mentioned by @marceloquinta in the comments setWriteTimeout can also be set.

As of version 2.5.0 read / write / connect timeout values are set to 10 seconds by default as mentioned by @ChristerNordvik. This can be seen here.

Javascript - sort array based on another array

_x000D_
_x000D_
function sortFunc(a, b) {
  var sortingArr = ["A", "B", "C"];
  return sortingArr.indexOf(a.type) - sortingArr.indexOf(b.type);
}

const itemsArray = [
  {
    type: "A",
  },
  {
    type: "C",
  },
  {
    type: "B",
  },
];
console.log(itemsArray);
itemsArray.sort(sortFunc);
console.log(itemsArray);
_x000D_
_x000D_
_x000D_

How to execute a query in ms-access in VBA code?

How about something like this...

Dim rs As RecordSet
Set rs = Currentdb.OpenRecordSet("SELECT PictureLocation, ID FROM MyAccessTable;")

Do While Not rs.EOF
   Debug.Print rs("PictureLocation") & " - " & rs("ID")
   rs.MoveNext
Loop

How to support placeholder attribute in IE8 and 9

the $.Browser.msie is not on the latest JQuery anymore... you have to use the $.support

like below:

 <script>

     (function ($) {
         $.support.placeholder = ('placeholder' in document.createElement('input'));
     })(jQuery);


     //fix for IE7 and IE8
     $(function () {
         if (!$.support.placeholder) {
             $("[placeholder]").focus(function () {
                 if ($(this).val() == $(this).attr("placeholder")) $(this).val("");
             }).blur(function () {
                 if ($(this).val() == "") $(this).val($(this).attr("placeholder"));
             }).blur();

             $("[placeholder]").parents("form").submit(function () {
                 $(this).find('[placeholder]').each(function() {
                     if ($(this).val() == $(this).attr("placeholder")) {
                         $(this).val("");
                     }
                 });
             });
         }
     });
 </script>

Enums in Javascript with ES6

Check how TypeScript does it. Basically they do the following:

const MAP = {};

MAP[MAP[1] = 'A'] = 1;
MAP[MAP[2] = 'B'] = 2;

MAP['A'] // 1
MAP[1] // A

Use symbols, freeze object, whatever you want.

POSTing JsonObject With HttpClient From Web API

Thank you pomber but for

var result = client.PostAsync(url, content).Result;

I used

var result = await client.PostAsync(url, content);

because Result makes app lock for high request

Android Studio build fails with "Task '' not found in root project 'MyProject'."

I got this problem because it could not find the Android SDK path. I was missing a local.properties file with it or an ANDROID_HOME environment variable with it.

Get only part of an Array in Java?

Yes, you can use Arrays.copyOfRange

It does about the same thing (note there is a copy : you don't change the initial array).

How to configure the web.config to allow requests of any length

It will also generate error when you pass large string in ajax call parameter.

so for that alway use type post in ajax will resolve your issue 100% and no need to set the length in web.config.

// var UserId= array of 1000 userids

$.ajax({ global: false, url: SitePath + "/User/getAussizzMembersData", "data": { UserIds: UserId}, "type": "POST", "dataType": "JSON" }}

A table name as a variable

You need to use the SQL Server dynamic SQL:

DECLARE @table     NVARCHAR(128),
        @sql       NVARCHAR(MAX);

SET @table = N'tableName';

SET @sql = N'SELECT * FROM ' + @table;

Use EXEC to execute any SQL:

EXEC (@sql)

Use EXEC sp_executesql to execute any SQL:

EXEC sp_executesql @sql;

Use EXECUTE sp_executesql to execute any SQL:

EXECUTE sp_executesql @sql

Pointer vs. Reference

A reference is an implicit pointer. Basically you can change the value the reference points to but you can't change the reference to point to something else. So my 2 cents is that if you only want to change the value of a parameter pass it as a reference but if you need to change the parameter to point to a different object pass it using a pointer.

input type="submit" Vs button tag are they interchangeable?

While the other answers are great and answer the question there is one thing to consider when using input type="submit" and button. With an input type="submit" you cannot use a CSS pseudo element on the input but you can for a button!

This is one reason to use a button element over an input when it comes to styling.

Good Free Alternative To MS Access

The issue is finding an alternative to MS Access that includes a visual, drag and drop development environment with a "reasonable" database where the whole kit and caboodle can be deployed free of charge.

My first suggestion would be to look at this very complete list of MS Access alternatives (many of which are free), followed by a gander at this list of open source database development tools on osalt.com.

My second suggestion would be to check out WaveMaker, which is sort of an open source PowerBuilder for the cloud (disclaimer: I work there so should not be considered to be an unbiased source of information ;-)

WaveMaker combines a drag and drop IDE with an open source Java back end. It is licensed under the Apache license and boasts a 15,000-strong developer community.

Promise Error: Objects are not valid as a React child

You can't do this: {this.state.arrayFromJson} As your error suggests what you are trying to do is not valid. You are trying to render the whole array as a React child. This is not valid. You should iterate through the array and render each element. I use .map to do that.

I am pasting a link from where you can learn how to render elements from an array with React.

http://jasonjl.me/blog/2015/04/18/rendering-list-of-elements-in-react-with-jsx/

Hope it helps!

How to center buttons in Twitter Bootstrap 3?

I had this problem. I used

<div class = "col-xs-8 text-center">

On my div containing a few h3 lines, a couple h4 lines and a Bootstrap button. Everything besides the button jumped to the center after I used text-center so I went into my CSS sheet overriding Bootstrap and gave the button a

margin: auto;

which seems to have solved the problem.

How to set image width to be 100% and height to be auto in react native?

You always have to set the width and height of an Image. It is not going to automatically size things for you. The React Native docs says so.

You should measure the total height of the ScrollView using onLayout and set the height of the Images based on it. If you use resizeMode of cover it will keep the aspect ratio of your Images but it will obviously crop them if it's bigger than the container.

"unexpected token import" in Nodejs5 and babel?

@jovi all you need to do is add .babelrc file like this:

{
  "plugins": [
    "transform-strict-mode",
    "transform-es2015-modules-commonjs",
    "transform-es2015-spread",
    "transform-es2015-destructuring",
    "transform-es2015-parameters"
  ]
}

and install these plugins as devdependences with npm.

then try babel-node ***.js again. hope this can help you.

Python DNS module import error

I solved this by uninstalling and then re-installing the dnspython module with PIP.

$ pip uninstall dnspython

After the long list of files within pycache, type y to continue with the uninstall. After complete type:

$ pip install dnspython

I then ran my script and the errors were resolved.

Understanding `scale` in R

log simply takes the logarithm (base e, by default) of each element of the vector.
scale, with default settings, will calculate the mean and standard deviation of the entire vector, then "scale" each element by those values by subtracting the mean and dividing by the sd. (If you use scale(x, scale=FALSE), it will only subtract the mean but not divide by the std deviation.)

Note that this will give you the same values

   set.seed(1)
   x <- runif(7)

   # Manually scaling
   (x - mean(x)) / sd(x)

   scale(x)

'Source code does not match the bytecode' when debugging on a device

I had the same issue and found a solution. If you have a line flagged in red, it will give you this error, but if you un-flag all of the lines it will work normally.

by flagged I mean when you click on the left side where the line numbers are and it highlights the line. If that is not clear here are pictures.
go from: flagged line to: not flagged line

How is the 'use strict' statement interpreted in Node.js?

"use strict";

Basically it enables the strict mode.

Strict Mode is a feature that allows you to place a program, or a function, in a "strict" operating context. In strict operating context, the method form binds this to the objects as before. The function form binds this to undefined, not the global set objects.

As per your comments you are telling some differences will be there. But it's your assumption. The Node.js code is nothing but your JavaScript code. All Node.js code are interpreted by the V8 JavaScript engine. The V8 JavaScript Engine is an open source JavaScript engine developed by Google for Chrome web browser.

So, there will be no major difference how "use strict"; is interpreted by the Chrome browser and Node.js.

Please read what is strict mode in JavaScript.

For more information:

  1. Strict mode
  2. ECMAScript 5 Strict mode support in browsers
  3. Strict mode is coming to town
  4. Compatibility table for strict mode
  5. Stack Overflow questions: what does 'use strict' do in JavaScript & what is the reasoning behind it


ECMAScript 6:

ECMAScript 6 Code & strict mode. Following is brief from the specification:

10.2.1 Strict Mode Code

An ECMAScript Script syntactic unit may be processed using either unrestricted or strict mode syntax and semantics. Code is interpreted as strict mode code in the following situations:

  • Global code is strict mode code if it begins with a Directive Prologue that contains a Use Strict Directive (see 14.1.1).
  • Module code is always strict mode code.
  • All parts of a ClassDeclaration or a ClassExpression are strict mode code.
  • Eval code is strict mode code if it begins with a Directive Prologue that contains a Use Strict Directive or if the call to eval is a direct eval (see 12.3.4.1) that is contained in strict mode code.
  • Function code is strict mode code if the associated FunctionDeclaration, FunctionExpression, GeneratorDeclaration, GeneratorExpression, MethodDefinition, or ArrowFunction is contained in strict mode code or if the code that produces the value of the function’s [[ECMAScriptCode]] internal slot begins with a Directive Prologue that contains a Use Strict Directive.
  • Function code that is supplied as the arguments to the built-in Function and Generator constructors is strict mode code if the last argument is a String that when processed is a FunctionBody that begins with a Directive Prologue that contains a Use Strict Directive.

Additionally if you are lost on what features are supported by your current version of Node.js, this node.green can help you (leverages from the same data as kangax).

What is an IndexOutOfRangeException / ArgumentOutOfRangeException and how do I fix it?

What Is It?

This exception means that you're trying to access a collection item by index, using an invalid index. An index is invalid when it's lower than the collection's lower bound or greater than or equal to the number of elements it contains.

When It Is Thrown

Given an array declared as:

byte[] array = new byte[4];

You can access this array from 0 to 3, values outside this range will cause IndexOutOfRangeException to be thrown. Remember this when you create and access an array.

Array Length
In C#, usually, arrays are 0-based. It means that first element has index 0 and last element has index Length - 1 (where Length is total number of items in the array) so this code doesn't work:

array[array.Length] = 0;

Moreover please note that if you have a multidimensional array then you can't use Array.Length for both dimension, you have to use Array.GetLength():

int[,] data = new int[10, 5];
for (int i=0; i < data.GetLength(0); ++i) {
    for (int j=0; j < data.GetLength(1); ++j) {
        data[i, j] = 1;
    }
}

Upper Bound Is Not Inclusive
In the following example we create a raw bidimensional array of Color. Each item represents a pixel, indices are from (0, 0) to (imageWidth - 1, imageHeight - 1).

Color[,] pixels = new Color[imageWidth, imageHeight];
for (int x = 0; x <= imageWidth; ++x) {
    for (int y = 0; y <= imageHeight; ++y) {
        pixels[x, y] = backgroundColor;
    }
}

This code will then fail because array is 0-based and last (bottom-right) pixel in the image is pixels[imageWidth - 1, imageHeight - 1]:

pixels[imageWidth, imageHeight] = Color.Black;

In another scenario you may get ArgumentOutOfRangeException for this code (for example if you're using GetPixel method on a Bitmap class).

Arrays Do Not Grow
An array is fast. Very fast in linear search compared to every other collection. It is because items are contiguous in memory so memory address can be calculated (and increment is just an addition). No need to follow a node list, simple math! You pay this with a limitation: they can't grow, if you need more elements you need to reallocate that array (this may take a relatively long time if old items must be copied to a new block). You resize them with Array.Resize<T>(), this example adds a new entry to an existing array:

Array.Resize(ref array, array.Length + 1);

Don't forget that valid indices are from 0 to Length - 1. If you simply try to assign an item at Length you'll get IndexOutOfRangeException (this behavior may confuse you if you think they may increase with a syntax similar to Insert method of other collections).

Special Arrays With Custom Lower Bound
First item in arrays has always index 0. This is not always true because you can create an array with a custom lower bound:

var array = Array.CreateInstance(typeof(byte), new int[] { 4 }, new int[] { 1 });

In that example, array indices are valid from 1 to 4. Of course, upper bound cannot be changed.

Wrong Arguments
If you access an array using unvalidated arguments (from user input or from function user) you may get this error:

private static string[] RomanNumbers =
    new string[] { "I", "II", "III", "IV", "V" };

public static string Romanize(int number)
{
    return RomanNumbers[number];
}

Unexpected Results
This exception may be thrown for another reason too: by convention, many search functions will return -1 (nullables has been introduced with .NET 2.0 and anyway it's also a well-known convention in use from many years) if they didn't find anything. Let's imagine you have an array of objects comparable with a string. You may think to write this code:

// Items comparable with a string
Console.WriteLine("First item equals to 'Debug' is '{0}'.",
    myArray[Array.IndexOf(myArray, "Debug")]);

// Arbitrary objects
Console.WriteLine("First item equals to 'Debug' is '{0}'.",
    myArray[Array.FindIndex(myArray, x => x.Type == "Debug")]);

This will fail if no items in myArray will satisfy search condition because Array.IndexOf() will return -1 and then array access will throw.

Next example is a naive example to calculate occurrences of a given set of numbers (knowing maximum number and returning an array where item at index 0 represents number 0, items at index 1 represents number 1 and so on):

static int[] CountOccurences(int maximum, IEnumerable<int> numbers) {
    int[] result = new int[maximum + 1]; // Includes 0

    foreach (int number in numbers)
        ++result[number];

    return result;
}

Of course, it's a pretty terrible implementation but what I want to show is that it'll fail for negative numbers and numbers above maximum.

How it applies to List<T>?

Same cases as array - range of valid indexes - 0 (List's indexes always start with 0) to list.Count - accessing elements outside of this range will cause the exception.

Note that List<T> throws ArgumentOutOfRangeException for the same cases where arrays use IndexOutOfRangeException.

Unlike arrays, List<T> starts empty - so trying to access items of just created list lead to this exception.

var list = new List<int>();

Common case is to populate list with indexing (similar to Dictionary<int, T>) will cause exception:

list[0] = 42; // exception
list.Add(42); // correct

IDataReader and Columns
Imagine you're trying to read data from a database with this code:

using (var connection = CreateConnection()) {
    using (var command = connection.CreateCommand()) {
        command.CommandText = "SELECT MyColumn1, MyColumn2 FROM MyTable";

        using (var reader = command.ExecuteReader()) {
            while (reader.Read()) {
                ProcessData(reader.GetString(2)); // Throws!
            }
        }
    }
}

GetString() will throw IndexOutOfRangeException because you're dataset has only two columns but you're trying to get a value from 3rd one (indices are always 0-based).

Please note that this behavior is shared with most IDataReader implementations (SqlDataReader, OleDbDataReader and so on).

You can get the same exception also if you use the IDataReader overload of the indexer operator that takes a column name and pass an invalid column name.
Suppose for example that you have retrieved a column named Column1 but then you try to retrieve the value of that field with

 var data = dr["Colum1"];  // Missing the n in Column1.

This happens because the indexer operator is implemented trying to retrieve the index of a Colum1 field that doesn't exist. The GetOrdinal method will throw this exception when its internal helper code returns a -1 as the index of "Colum1".

Others
There is another (documented) case when this exception is thrown: if, in DataView, data column name being supplied to the DataViewSort property is not valid.

How to Avoid

In this example, let me assume, for simplicity, that arrays are always monodimensional and 0-based. If you want to be strict (or you're developing a library), you may need to replace 0 with GetLowerBound(0) and .Length with GetUpperBound(0) (of course if you have parameters of type System.Array, it doesn't apply for T[]). Please note that in this case, upper bound is inclusive then this code:

for (int i=0; i < array.Length; ++i) { }

Should be rewritten like this:

for (int i=array.GetLowerBound(0); i <= array.GetUpperBound(0); ++i) { }

Please note that this is not allowed (it'll throw InvalidCastException), that's why if your parameters are T[] you're safe about custom lower bound arrays:

void foo<T>(T[] array) { }

void test() {
    // This will throw InvalidCastException, cannot convert Int32[] to Int32[*]
    foo((int)Array.CreateInstance(typeof(int), new int[] { 1 }, new int[] { 1 }));
}

Validate Parameters
If index comes from a parameter you should always validate them (throwing appropriate ArgumentException or ArgumentOutOfRangeException). In the next example, wrong parameters may cause IndexOutOfRangeException, users of this function may expect this because they're passing an array but it's not always so obvious. I'd suggest to always validate parameters for public functions:

static void SetRange<T>(T[] array, int from, int length, Func<i, T> function)
{
    if (from < 0 || from>= array.Length)
        throw new ArgumentOutOfRangeException("from");

    if (length < 0)
        throw new ArgumentOutOfRangeException("length");

    if (from + length > array.Length)
        throw new ArgumentException("...");

    for (int i=from; i < from + length; ++i)
        array[i] = function(i);
}

If function is private you may simply replace if logic with Debug.Assert():

Debug.Assert(from >= 0 && from < array.Length);

Check Object State
Array index may not come directly from a parameter. It may be part of object state. In general is always a good practice to validate object state (by itself and with function parameters, if needed). You can use Debug.Assert(), throw a proper exception (more descriptive about the problem) or handle that like in this example:

class Table {
    public int SelectedIndex { get; set; }
    public Row[] Rows { get; set; }

    public Row SelectedRow {
        get {
            if (Rows == null)
                throw new InvalidOperationException("...");

            // No or wrong selection, here we just return null for
            // this case (it may be the reason we use this property
            // instead of direct access)
            if (SelectedIndex < 0 || SelectedIndex >= Rows.Length)
                return null;

            return Rows[SelectedIndex];
        }
}

Validate Return Values
In one of previous examples we directly used Array.IndexOf() return value. If we know it may fail then it's better to handle that case:

int index = myArray[Array.IndexOf(myArray, "Debug");
if (index != -1) { } else { }

How to Debug

In my opinion, most of the questions, here on SO, about this error can be simply avoided. The time you spend to write a proper question (with a small working example and a small explanation) could easily much more than the time you'll need to debug your code. First of all, read this Eric Lippert's blog post about debugging of small programs, I won't repeat his words here but it's absolutely a must read.

You have source code, you have exception message with a stack trace. Go there, pick right line number and you'll see:

array[index] = newValue;

You found your error, check how index increases. Is it right? Check how array is allocated, is coherent with how index increases? Is it right according to your specifications? If you answer yes to all these questions, then you'll find good help here on StackOverflow but please first check for that by yourself. You'll save your own time!

A good start point is to always use assertions and to validate inputs. You may even want to use code contracts. When something went wrong and you can't figure out what happens with a quick look at your code then you have to resort to an old friend: debugger. Just run your application in debug inside Visual Studio (or your favorite IDE), you'll see exactly which line throws this exception, which array is involved and which index you're trying to use. Really, 99% of the times you'll solve it by yourself in a few minutes.

If this happens in production then you'd better to add assertions in incriminated code, probably we won't see in your code what you can't see by yourself (but you can always bet).

The VB.NET side of the story

Everything that we have said in the C# answer is valid for VB.NET with the obvious syntax differences but there is an important point to consider when you deal with VB.NET arrays.

In VB.NET, arrays are declared setting the maximum valid index value for the array. It is not the count of the elements that we want to store in the array.

' declares an array with space for 5 integer 
' 4 is the maximum valid index starting from 0 to 4
Dim myArray(4) as Integer

So this loop will fill the array with 5 integers without causing any IndexOutOfRangeException

For i As Integer = 0 To 4
    myArray(i) = i
Next

The VB.NET rule

This exception means that you're trying to access a collection item by index, using an invalid index. An index is invalid when it's lower than the collection's lower bound or greater than equal to the number of elements it contains. the maximum allowed index defined in the array declaration

Wget output document and headers to STDOUT

Try the following, no extra headers

wget -qO- www.google.com

Note the trailing -. This is part of the normal command argument for -O to cat out to a file, but since we don't use > to direct to a file, it goes out to the shell. You can use -qO- or -qO -.

Order discrete x scale by frequency/value

The best way for me was using vector with categories in order I need as limits parameter to scale_x_discrete. I think it is pretty simple and straightforward solution.

ggplot(mtcars, aes(factor(cyl))) + 
  geom_bar() + 
  scale_x_discrete(limits=c(8,4,6))

enter image description here

Could not find a base address that matches scheme https for the endpoint with binding WebHttpBinding. Registered base address schemes are [http]

In the endpoint tag you need to include the property address=""

<endpoint address="" binding="webHttpBinding" bindingConfiguration="SecureBasicRest" behaviorConfiguration="svcEndpoint" name="webHttp" contract="SvcContract.Authenticate" />

How to create Select List for Country and States/province in MVC

So many ways to do this... for #NetCore use Lib..

    using System;
    using System.Collections.Generic;
    using System.Linq; // only required when .AsEnumerable() is used
    using System.ComponentModel.DataAnnotations;
    using Microsoft.AspNetCore.Mvc.Rendering;

Model...

namespace MyProject.Models
{
  public class MyModel
  {
    [Required]
    [Display(Name = "State")]
    public string StatePick { get; set; }
    public string state { get; set; }
    [StringLength(35, ErrorMessage = "State cannot be longer than 35 characters.")]
    public SelectList StateList { get; set; }
  }
}

Controller...

namespace MyProject.Controllers
{
    /// <summary>
    /// create SelectListItem from strings
    /// </summary>
    /// <param name="isValue">defaultValue is SelectListItem.Value is true, SelectListItem.Text if false</param>
    /// <returns></returns>
    private SelectListItem newItem(string value, string text, string defaultValue = "", bool isValue = false)
    {
        SelectListItem ss = new SelectListItem();
        ss.Text = text;
        ss.Value = value;

        // select default by Value or Text
        if (isValue && ss.Value == defaultValue || !isValue && ss.Text == defaultValue)
        {
            ss.Selected = true;
        }

        return ss;
    }

    /// <summary>
    /// this pulls the state name from _context and sets it as the default for the selectList
    /// </summary>
    /// <param name="myState">sets default value for list of states</param>
    /// <returns></returns>
    private SelectList getStateList(string myState = "")
    {
        List<SelectListItem> states = new List<SelectListItem>();
        SelectListItem chosen = new SelectListItem();

        // set default selected state to OHIO
        string defaultValue = "OH";
        if (!string.IsNullOrEmpty(myState))
        {
            defaultValue = myState;
        }

        try
        {
            states.Add(newItem("AL", "Alabama", defaultValue, true));
            states.Add(newItem("AK", "Alaska", defaultValue, true));
            states.Add(newItem("AZ", "Arizona", defaultValue, true));
            states.Add(newItem("AR", "Arkansas", defaultValue, true));
            states.Add(newItem("CA", "California", defaultValue, true));
            states.Add(newItem("CO", "Colorado", defaultValue, true));
            states.Add(newItem("CT", "Connecticut", defaultValue, true));
            states.Add(newItem("DE", "Delaware", defaultValue, true));
            states.Add(newItem("DC", "District of Columbia", defaultValue, true));
            states.Add(newItem("FL", "Florida", defaultValue, true));
            states.Add(newItem("GA", "Georgia", defaultValue, true));
            states.Add(newItem("HI", "Hawaii", defaultValue, true));
            states.Add(newItem("ID", "Idaho", defaultValue, true));
            states.Add(newItem("IL", "Illinois", defaultValue, true));
            states.Add(newItem("IN", "Indiana", defaultValue, true));
            states.Add(newItem("IA", "Iowa", defaultValue, true));
            states.Add(newItem("KS", "Kansas", defaultValue, true));
            states.Add(newItem("KY", "Kentucky", defaultValue, true));
            states.Add(newItem("LA", "Louisiana", defaultValue, true));
            states.Add(newItem("ME", "Maine", defaultValue, true));
            states.Add(newItem("MD", "Maryland", defaultValue, true));
            states.Add(newItem("MA", "Massachusetts", defaultValue, true));
            states.Add(newItem("MI", "Michigan", defaultValue, true));
            states.Add(newItem("MN", "Minnesota", defaultValue, true));
            states.Add(newItem("MS", "Mississippi", defaultValue, true));
            states.Add(newItem("MO", "Missouri", defaultValue, true));
            states.Add(newItem("MT", "Montana", defaultValue, true));
            states.Add(newItem("NE", "Nebraska", defaultValue, true));
            states.Add(newItem("NV", "Nevada", defaultValue, true));
            states.Add(newItem("NH", "New Hampshire", defaultValue, true));
            states.Add(newItem("NJ", "New Jersey", defaultValue, true));
            states.Add(newItem("NM", "New Mexico", defaultValue, true));
            states.Add(newItem("NY", "New York", defaultValue, true));
            states.Add(newItem("NC", "North Carolina", defaultValue, true));
            states.Add(newItem("ND", "North Dakota", defaultValue, true));
            states.Add(newItem("OH", "Ohio", defaultValue, true));
            states.Add(newItem("OK", "Oklahoma", defaultValue, true));
            states.Add(newItem("OR", "Oregon", defaultValue, true));
            states.Add(newItem("PA", "Pennsylvania", defaultValue, true));
            states.Add(newItem("RI", "Rhode Island", defaultValue, true));
            states.Add(newItem("SC", "South Carolina", defaultValue, true));
            states.Add(newItem("SD", "South Dakota", defaultValue, true));
            states.Add(newItem("TN", "Tennessee", defaultValue, true));
            states.Add(newItem("TX", "Texas", defaultValue, true));
            states.Add(newItem("UT", "Utah", defaultValue, true));
            states.Add(newItem("VT", "Vermont", defaultValue, true));
            states.Add(newItem("VA", "Virginia", defaultValue, true));
            states.Add(newItem("WA", "Washington", defaultValue, true));
            states.Add(newItem("WV", "West Virginia", defaultValue, true));
            states.Add(newItem("WI", "Wisconsin", defaultValue, true));
            states.Add(newItem("WY", "Wyoming", defaultValue, true));

            foreach (SelectListItem state in states)
            {
                if (state.Selected)
                {
                    chosen = state;
                    break;
                }
            }
        }
        catch (Exception err)
        {
            string ss = "ERR!   " + err.Source + "   " + err.GetType().ToString() + "\r\n" + err.Message.Replace("\r\n", "   ");
            ss = this.sendError("Online getStateList Request", ss, _errPassword);
            // return error
        }

        // .AsEnumerable() is not required in the pass.. it is an extension of Linq
        SelectList myList = new SelectList(states.AsEnumerable(), "Value", "Text", chosen);

        object val = myList.SelectedValue;

        return myList;
    }

    public ActionResult pickState(MyModel pData)
    {
        if (pData.StateList == null)
        {
            if (String.IsNullOrEmpty(pData.StatePick)) // state abbrev, value collected onchange
            {
                pData.StateList = getStateList();
            }
            else
            {
                pData.StateList = getStateList(pData.StatePick);
            }

            // assign values to state list items
            try
            {
                SelectListItem si = (SelectListItem)pData.StateList.SelectedValue;
                pData.state = si.Value;
                pData.StatePick = si.Value;
            }
            catch { }
        } 
    return View(pData);
    }
}

pickState.cshtml...

@model MyProject.Models.MyModel

@{
ViewBag.Title = "United States of America";
Layout = "~/Views/Shared/_Layout.cshtml";
}
<h2>@ViewBag.Title - Where are you...</h2>

@using (Html.BeginForm()) {
@Html.AntiForgeryToken()
@Html.ValidationSummary(true)

<fieldset>

    <div class="editor-label">
        @Html.DisplayNameFor(model => model.state)
    </div>
    <div class="display-field">            
        @Html.DropDownListFor(m => m.StatePick, Model.StateList, new { OnChange = "state.value = this.value;" })
        @Html.EditorFor(model => model.state)
        @Html.ValidationMessageFor(model => model.StateList)
    </div>         
</fieldset>
}

<div>
@Html.ActionLink("Back to List", "Index")
</div>

How to make a .NET Windows Service start right after the installation?

You need to add a Custom Action to the end of the 'ExecuteImmediate' sequence in the MSI, using the component name of the EXE or a batch (sc start) as the source. I don't think this can be done with Visual Studio, you may have to use a real MSI authoring tool for that.

How to Multi-thread an Operation Within a Loop in Python

You can split the processing into a specified number of threads using an approach like this:

import threading                                                                

def process(items, start, end):                                                 
    for item in items[start:end]:                                               
        try:                                                                    
            api.my_operation(item)                                              
        except Exception:                                                       
            print('error with item')                                            


def split_processing(items, num_splits=4):                                      
    split_size = len(items) // num_splits                                       
    threads = []                                                                
    for i in range(num_splits):                                                 
        # determine the indices of the list this thread will handle             
        start = i * split_size                                                  
        # special case on the last chunk to account for uneven splits           
        end = None if i+1 == num_splits else (i+1) * split_size                 
        # create the thread                                                     
        threads.append(                                                         
            threading.Thread(target=process, args=(items, start, end)))         
        threads[-1].start() # start the thread we just created                  

    # wait for all threads to finish                                            
    for t in threads:                                                           
        t.join()                                                                



split_processing(items)

ReferenceError: Invalid left-hand side in assignment

Common reasons for the error:

  • use of assignment (=) instead of equality (==/===)
  • assigning to result of function foo() = 42 instead of passing arguments (foo(42))
  • simply missing member names (i.e. assuming some default selection) : getFoo() = 42 instead of getFoo().theAnswer = 42 or array indexing getArray() = 42 instead of getArray()[0]= 42

In this particular case you want to use == (or better === - What exactly is Type Coercion in Javascript?) to check for equality (like if(one === "rock" && two === "rock"), but it the actual reason you are getting the error is trickier.

The reason for the error is Operator precedence. In particular we are looking for && (precedence 6) and = (precedence 3).

Let's put braces in the expression according to priority - && is higher than = so it is executed first similar how one would do 3+4*5+6 as 3+(4*5)+6:

 if(one= ("rock" && two) = "rock"){...

Now we have expression similar to multiple assignments like a = b = 42 which due to right-to-left associativity executed as a = (b = 42). So adding more braces:

 if(one= (  ("rock" && two) = "rock" )  ){...

Finally we arrived to actual problem: ("rock" && two) can't be evaluated to l-value that can be assigned to (in this particular case it will be value of two as truthy).

Note that if you'd use braces to match perceived priority surrounding each "equality" with braces you get no errors. Obviously that also producing different result than you'd expect - changes value of both variables and than do && on two strings "rock" && "rock" resulting in "rock" (which in turn is truthy) all the time due to behavior of logial &&:

if((one = "rock") && (two = "rock"))
{
   // always executed, both one and two are set to "rock"
   ...
}

For even more details on the error and other cases when it can happen - see specification:

Assignment

LeftHandSideExpression = AssignmentExpression
...
Throw a SyntaxError exception if the following conditions are all true:
...
IsStrictReference(lref) is true

Left-Hand-Side Expressions

and The Reference Specification Type explaining IsStrictReference:

... function calls are permitted to return references. This possibility is admitted purely for the sake of host objects. No built-in ECMAScript function defined by this specification returns a reference and there is no provision for a user-defined function to return a reference...

How to check if variable is array?... or something array-like

Since PHP 7.1 there is a pseudo-type iterable for exactly this purpose. Type-hinting iterable accepts any array as well as any implementation of the Traversable interface. PHP 7.1 also introduced the function is_iterable(). For older versions, see other answers here for accomplishing the equivalent type enforcement without the newer built-in features.

Fair play: As BlackHole pointed out, this question appears to be a duplicate of Iterable objects and array type hinting? and his or her answer goes into further detail than mine.

Are there pointers in php?

PHP can use something like pointers:

$y=array(&$x);

Now $y acts like a pointer to $x and $y[0] dereferences a pointer.

The value array(&$x) is just a value, so it can be passed to functions, stored in other arrays, copied to other variables, etc. You can even create a pointer to this pointer variable. (Serializing it will break the pointer, however.)

Check if a string contains a substring in SQL Server 2005, using a stored procedure

CHARINDEX() searches for a substring within a larger string, and returns the position of the match, or 0 if no match is found

if CHARINDEX('ME',@mainString) > 0
begin
    --do something
end

Edit or from daniels answer, if you're wanting to find a word (and not subcomponents of words), your CHARINDEX call would look like:

CHARINDEX(' ME ',' ' + REPLACE(REPLACE(@mainString,',',' '),'.',' ') + ' ')

(Add more recursive REPLACE() calls for any other punctuation that may occur)

Heroku "psql: FATAL: remaining connection slots are reserved for non-replication superuser connections"

I actually tried to implement connection pooling on the django end using:

https://github.com/gmcguire/django-db-pool

but I still received this error, despite lowering the number of connections available to below the standard development DB quota of 20 open connections.

There is an article here about how to move your postgresql database to the free/cheap tier of Amazon RDS. This would allow you to set max_connections higher. This will also allow you to pool connections at the database level using PGBouncer.

https://www.lewagon.com/blog/how-to-migrate-heroku-postgres-database-to-amazon-rds

UPDATE:

Heroku responded to my open ticket and stated that my database was improperly load balanced in their network. They said that improvements to their system should prevent similar problems in the future. Nonetheless, support manually relocated my database and performance is noticeably improved.

Python: Pandas pd.read_excel giving ImportError: Install xlrd >= 0.9.0 for Excel support

I don't know if this will be helpful for someone, but I had the same problem. I wrote pip install xlrd in the anaconda prompt while in the specific environment and it said it was installed, but when I looked at the installed packages it wasn't there. What solved the problem was "moving" (I don't know the terminology for it) into the Scripts folder of the specific environment and do the pip install xlrd there. Hope this is useful for someone :D

C multi-line macro: do/while(0) vs scope block

Andrey Tarasevich provides the following explanation:

  1. On Google Groups
  2. On bytes.com

[Minor changes to formatting made. Parenthetical annotations added in square brackets []].

The whole idea of using 'do/while' version is to make a macro which will expand into a regular statement, not into a compound statement. This is done in order to make the use of function-style macros uniform with the use of ordinary functions in all contexts.

Consider the following code sketch:

if (<condition>)
  foo(a);
else
  bar(a);

where foo and bar are ordinary functions. Now imagine that you'd like to replace function foo with a macro of the above nature [named CALL_FUNCS]:

if (<condition>)
  CALL_FUNCS(a);
else
  bar(a);

Now, if your macro is defined in accordance with the second approach (just { and }) the code will no longer compile, because the 'true' branch of if is now represented by a compound statement. And when you put a ; after this compound statement, you finished the whole if statement, thus orphaning the else branch (hence the compilation error).

One way to correct this problem is to remember not to put ; after macro "invocations":

if (<condition>)
  CALL_FUNCS(a)
else
  bar(a);

This will compile and work as expected, but this is not uniform. The more elegant solution is to make sure that macro expand into a regular statement, not into a compound one. One way to achieve that is to define the macro as follows:

#define CALL_FUNCS(x) \
do { \
  func1(x); \
  func2(x); \
  func3(x); \
} while (0)

Now this code:

if (<condition>)
  CALL_FUNCS(a);
else
  bar(a);

will compile without any problems.

However, note the small but important difference between my definition of CALL_FUNCS and the first version in your message. I didn't put a ; after } while (0). Putting a ; at the end of that definition would immediately defeat the entire point of using 'do/while' and make that macro pretty much equivalent to the compound-statement version.

I don't know why the author of the code you quoted in your original message put this ; after while (0). In this form both variants are equivalent. The whole idea behind using 'do/while' version is not to include this final ; into the macro (for the reasons that I explained above).

String array initialization in Java

You can do the following during declaration:

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

And if you want to do this somewhere after declaration:

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

centos: Another MySQL daemon already running with the same unix socket

Just open a bug report with your OS vendor asking them to put the socket in /var/run so it automagically gets removed at reboot. It's a bug to keep this socket after an unclean reboot, /var/run is the spot for these kinds of files.

How can I sort an ArrayList of Strings in Java?

Take a look at the Collections.sort(List<T> list).

You can simply remove the first element, sort the list and then add it back again.

Bootstrap 3 Collapse show state with Chevron icon

If you are trying to use this with panels only (not accordeon), try this code:

<div class="panel panel-default">
    <div class="panel-heading">
        <h4 class="panel-title">
            <a class="collapse-toggle" data-toggle="collapse" href="#collapseExample" aria-expanded="false" aria-controls="collapseExample">Panel heading with title</a>
        </h4>
    </div>
    <div id="collapseExample" class="panel-collapse collapse in">
        <div class="panel-body">
            Panel content
        </div>
    </div>
</div>

Excel Define a range based on a cell value

Old post but this is exactly what I needed, simple question, how to change it to count column rather than Row. Thankyou in advance. Novice to Excel.

=SUM(A1:INDIRECT(CONCATENATE("A",C5)))

I.e My data is A1 B1 C1 D1 etc rather then A1 A2 A3 A4.

Reset Entity-Framework Migrations

Enable-Migrations -EnableAutomaticMigrations -Force

PHP Email sending BCC

You were setting BCC but then overwriting the variable with the FROM

$to = "[email protected]";
     $subject .= "".$emailSubject."";
 $headers .= "Bcc: ".$emailList."\r\n";
 $headers .= "From: [email protected]\r\n" .
     "X-Mailer: php";
     $headers .= "MIME-Version: 1.0\r\n";
     $headers .= "Content-Type: text/html; charset=ISO-8859-1\r\n";
 $message = '<html><body>';
 $message .= 'THE MESSAGE FROM THE FORM';

     if (mail($to, $subject, $message, $headers)) {
     $sent = "Your email was sent!";
     } else {
      $sent = ("Error sending email.");
     }

Formula px to dp, dp to px android

Here's a other way to do it using kotlin extensions:

val Int.dpToPx: Int
    get() = Math.round(this * Resources.getSystem().displayMetrics.density)

val Int.pxToDp: Int
    get() = Math.round(this / Resources.getSystem().displayMetrics.density)

and then it can be used like this from anywhere

12.dpToPx

244.pxToDp

How to format Joda-Time DateTime to only mm/dd/yyyy?

DateTime date = DateTime.now().withTimeAtStartOfDay();
date.toString("HH:mm:ss")

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

By using Chrome or Opera

without any plugins, without writing any single XPath syntax character

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

;)

Enter image description here

input[type='text'] CSS selector does not apply to default-type text inputs?

Because, it is not supposed to do that.

input[type=text] { } is an attribute selector, and will only select those element, with the matching attribute.

Windows batch script launch program and exit console

Try to start path\to\cygwin\bin\bash.exe

GetType used in PowerShell, difference between variables

Select-Object creates a new psobject and copies the properties you requested to it. You can verify this with GetType():

PS > $a.GetType().fullname
System.DayOfWeek

PS > $b.GetType().fullname
System.Management.Automation.PSCustomObject

How can I change the font size using seaborn FacetGrid?

You can scale up the fonts in your call to sns.set().

import numpy as np
import matplotlib.pyplot as plt
import seaborn as sns
x = np.random.normal(size=37)
y = np.random.lognormal(size=37)

# defaults
sns.set()
fig, ax = plt.subplots()
ax.plot(x, y, marker='s', linestyle='none', label='small')
ax.legend(loc='upper left', bbox_to_anchor=(0, 1.1))

enter image description here

sns.set(font_scale=5)  # crazy big
fig, ax = plt.subplots()
ax.plot(x, y, marker='s', linestyle='none', label='big')
ax.legend(loc='upper left', bbox_to_anchor=(0, 1.3))

enter image description here

How do I fix the indentation of selected lines in Visual Studio

To fix the indentation and formatting in all files of your solution:

  1. Install the Format All Files extension => close VS, execute the .vsix file and reopen VS;
  2. Menu Tools > Options... > Text Editor > All Languages > Tabs:
    1. Click on Smart (for resolving conflicts);
    2. Type the Tab Size and Indent Size you want (e.g. 2);
    3. Click on Insert Spaces if you want to replace tabs by spaces;
  3. In the Solution Explorer (Ctrl+Alt+L) right click in any file and choose from the menu Format All Files (near the bottom).

This will recursively open and save all files in your solution, setting the indentation you defined above.

You might want to check other programming languages tabs (Options...) for Code Style > Formatting as well.

transform object to array with lodash

There are quite a few ways to get the result you are after. Lets break them in categories:

ES6 Values only:

Main method for this is Object.values. But using Object.keys and Array.map you could as well get to the expected result:

Object.values(obj)
Object.keys(obj).map(k => obj[k])

_x000D_
_x000D_
var obj = {_x000D_
  A: {_x000D_
    name: "John"_x000D_
  },_x000D_
  B: {_x000D_
    name: "Ivan"_x000D_
  }_x000D_
}_x000D_
_x000D_
console.log('Object.values:', Object.values(obj))_x000D_
console.log('Object.keys:', Object.keys(obj).map(k => obj[k]))
_x000D_
_x000D_
_x000D_

ES6 Key & Value:

Using map and ES6 dynamic/computed properties and destructuring you can retain the key and return an object from the map.

Object.keys(obj).map(k => ({[k]: obj[k]}))
Object.entries(obj).map(([k,v]) => ({[k]:v}))

_x000D_
_x000D_
var obj = {_x000D_
  A: {_x000D_
    name: "John"_x000D_
  },_x000D_
  B: {_x000D_
    name: "Ivan"_x000D_
  }_x000D_
}_x000D_
_x000D_
console.log('Object.keys:', Object.keys(obj).map(k => ({_x000D_
  [k]: obj[k]_x000D_
})))_x000D_
console.log('Object.entries:', Object.entries(obj).map(([k, v]) => ({_x000D_
  [k]: v_x000D_
})))
_x000D_
_x000D_
_x000D_

Lodash Values only:

The method designed for this is _.values however there are "shortcuts" like _.map and the utility method _.toArray which would also return an array containing only the values from the object. You could also _.map though the _.keys and get the values from the object by using the obj[key] notation.

Note: _.map when passed an object would use its baseMap handler which is basically forEach on the object properties.

_.values(obj)
_.map(obj)
_.toArray(obj)
_.map(_.keys(obj), k => obj[k])

_x000D_
_x000D_
var obj = {_x000D_
  A: {_x000D_
    name: "John"_x000D_
  },_x000D_
  B: {_x000D_
    name: "Ivan"_x000D_
  }_x000D_
}_x000D_
_x000D_
console.log('values:', _.values(obj))_x000D_
console.log('map:', _.map(obj))_x000D_
console.log('toArray:', _.toArray(obj))_x000D_
console.log('keys:', _.map(_.keys(obj), k => obj[k]))
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.10/lodash.min.js"></script>
_x000D_
_x000D_
_x000D_

Lodash Key & Value:

// Outputs an array with [[KEY, VALUE]]
_.entries(obj)
_.toPairs(obj)

// Outputs array with objects containing the keys and values
_.map(_.entries(obj), ([k,v]) => ({[k]:v}))
_.map(_.keys(obj), k => ({[k]: obj[k]}))
_.transform(obj, (r,c,k) => r.push({[k]:c}), [])
_.reduce(obj, (r,c,k) => (r.push({[k]:c}), r), [])

_x000D_
_x000D_
var obj = {_x000D_
  A: {_x000D_
    name: "John"_x000D_
  },_x000D_
  B: {_x000D_
    name: "Ivan"_x000D_
  }_x000D_
}_x000D_
_x000D_
// Outputs an array with [KEY, VALUE]_x000D_
console.log('entries:', _.entries(obj))_x000D_
console.log('toPairs:', _.toPairs(obj))_x000D_
_x000D_
// Outputs array with objects containing the keys and values_x000D_
console.log('entries:', _.map(_.entries(obj), ([k, v]) => ({_x000D_
  [k]: v_x000D_
})))_x000D_
console.log('keys:', _.map(_.keys(obj), k => ({_x000D_
  [k]: obj[k]_x000D_
})))_x000D_
console.log('transform:', _.transform(obj, (r, c, k) => r.push({_x000D_
  [k]: c_x000D_
}), []))_x000D_
console.log('reduce:', _.reduce(obj, (r, c, k) => (r.push({_x000D_
  [k]: c_x000D_
}), r), []))
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.10/lodash.min.js"></script>
_x000D_
_x000D_
_x000D_

Note that in the above examples ES6 is used (arrow functions and dynamic properties). You can use lodash _.fromPairs and other methods to compose an object if ES6 is an issue.

ORA-00060: deadlock detected while waiting for resource

I ran into this issue as well. I don't know the technical details of what was actually happening. However, in my situation, the root cause was that there was cascading deletes setup in the Oracle database and my JPA/Hibernate code was also trying to do the cascading delete calls. So my advice is to make sure that you know exactly what is happening.

String length in bytes in JavaScript

Actually, I figured out what's wrong. For the code to work the page <head> should have this tag:

<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

Or, as suggested in comments, if server sends HTTP Content-Encoding header, it should work as well.

Then results from different browsers are consistent.

Here is an example:

<html>
<head>
  <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> 
  <title>mini string length test</title>
</head>
<body>

<script type="text/javascript">
document.write('<div style="font-size:100px">' 
    + (unescape(encodeURIComponent("???! Naïve?")).length) + '</div>'
  );
</script>
</body>
</html>

Note: I suspect that specifying any (accurate) encoding would fix the encoding problem. It is just a coincidence that I need UTF-8.

Properties order in Margin

Just because @MartinCapodici 's comment is awesome I write here as an answer to give visibility.

All clockwise:

  • WPF start West (left->top->right->bottom)
  • Netscape (ie CSS) start North (top->right->bottom->left)

How to deal with SQL column names that look like SQL keywords?

While you are doing it - alias it as something else (or better yet, use a view or an SP and deprecate the old direct access method).

SELECT [from] AS TransferFrom -- Or something else more suitable
FROM TableName

How to terminate a Python script

While you should generally prefer sys.exit because it is more "friendly" to other code, all it actually does is raise an exception.

If you are sure that you need to exit a process immediately, and you might be inside of some exception handler which would catch SystemExit, there is another function - os._exit - which terminates immediately at the C level and does not perform any of the normal tear-down of the interpreter; for example, hooks registered with the "atexit" module are not executed.

Rewrite all requests to index.php with nginx

Perfect solution I have tried it and succeed to get my index page when I have append this code in my site configuration file.

location / {
            try_files $uri $uri/ /index.php;
}

In configuration file itself explained that at "First attempt to serve request as file, then as directory, then fall back to index.html in my case it is index.php as I am providing page through php code.

Split text file into smaller multiple text file using command line

Syntax looks like:

$ split [OPTION] [INPUT [PREFIX]] 

where prefix is PREFIXaa, PREFIXab, ...

Just use proper one and youre done or just use mv for renameing. I think $ mv * *.txt should work but test it first on smaller scale.

:)

How/when to generate Gradle wrapper files?

Generating the Gradle Wrapper

Project build gradle

// Top-level build file where you can add configuration options common to all sub-projects/modules.

// Running 'gradle wrapper' will generate gradlew - Getting gradle wrapper working and using it will save you a lot of pain.
task wrapper(type: Wrapper) {
    gradleVersion = '2.2' 
}

// Look Google doesn't use Maven Central, they use jcenter now.
buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:1.0.1'

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        jcenter()
    }
}

Then at the command-line run

gradle wrapper

If you're missing gradle on your system install it or the above won't work. On a Mac it is best to install via Homebrew.

brew install gradle

After you have successfully run the wrapper task and generated gradlew, don't use your system gradle. It will save you a lot of headaches.

./gradlew assemble

What about the gradle plugin seen above?

com.android.tools.build:gradle:1.0.1

You should set the version to be the latest and you can check the tools page and edit the version accordingly.

See what Android Studio generates

The addition of gradle and the newest Android Studio have changed project layout dramatically. If you have an older project I highly recommend creating a clean one with the latest Android Studio and see what Google considers the standard project.

Android Studio has facilities for importing older projects which can also help.

How can I split a text file using PowerShell?

Here is my solution to split a file called patch6.txt (about 32,000 lines) into separate files of 1000 lines each. Its not quick, but it does the job.

$infile = "D:\Malcolm\Test\patch6.txt"
$path = "D:\Malcolm\Test\"
$lineCount = 1
$fileCount = 1

foreach ($computername in get-content $infile)
{
    write $computername | out-file -Append $path_$fileCount".txt"
    $lineCount++

    if ($lineCount -eq 1000)
    {
        $fileCount++
        $lineCount = 1
    }
}

Install sbt on ubuntu

It seems like you installed a zip version of sbt, which is fine. But I suggest you install the native debian package if you are on Ubuntu. That is how I managed to install it on my Ubuntu 12.04. Check it out here: http://www.scala-sbt.org/release/docs/Installing-sbt-on-Linux.html Or simply directly download it from here.

javax.websocket client simple example

Use this library org.java_websocket

First thing you should import that library in build.gradle

repositories {
 mavenCentral()
 }

then add the implementation in dependency{}

implementation "org.java-websocket:Java-WebSocket:1.3.0"

Then you can use this code

In your activity declare object for Websocketclient like

private WebSocketClient mWebSocketClient;

then add this method for callback

 private void ConnectToWebSocket() {
URI uri;
try {
    uri = new URI("ws://your web socket url");
} catch (URISyntaxException e) {
    e.printStackTrace();
    return;
}

mWebSocketClient = new WebSocketClient(uri) {
    @Override
    public void onOpen(ServerHandshake serverHandshake) {
        Log.i("Websocket", "Opened");
        mWebSocketClient.send("Hello from " + Build.MANUFACTURER + " " + Build.MODEL);
    }

    @Override
    public void onMessage(String s) {
        final String message = s;
        runOnUiThread(new Runnable() {
            @Override
            public void run() {
                TextView textView = (TextView)findViewById(R.id.edittext_chatbox);
                textView.setText(textView.getText() + "\n" + message);
            }
        });
    }

    @Override
    public void onClose(int i, String s, boolean b) {
        Log.i("Websocket", "Closed " + s);
    }

    @Override
    public void onError(Exception e) {
        Log.i("Websocket", "Error " + e.getMessage());
    }
};
mWebSocketClient.connect();

}

How to change the remote repository for a git submodule?

You should just be able to edit the .gitmodules file to update the URL and then run git submodule sync --recursive to reflect that change to the superproject and your working copy.

Then you need to go to the .git/modules/path_to_submodule dir and change its config file to update git path.

If repo history is different then you need to checkout new branch manually:

git submodule sync --recursive
cd <submodule_dir> 

git fetch
git checkout origin/master
git branch master -f
git checkout master

Convert a number range to another range, maintaining ratio

There is a condition, when all of the values that you are checking are the same, where @jerryjvl's code would return NaN.

if (OldMin != OldMax && NewMin != NewMax):
    return (((OldValue - OldMin) * (NewMax - NewMin)) / (OldMax - OldMin)) + NewMin
else:
    return (NewMax + NewMin) / 2

Visual Studio 2013 License Product Key

I solved this, without having to completely reinstall Visual Studio 2013.

For those who may come across this in the future, the following steps worked for me:

  1. Run the ISO (or vs_professional.exe).
  2. If you get the error below, you need to update the Windows Registry to trick the installer into thinking you still have the base version. If you don't get this error, skip to step 3 "The product version that you are trying to set up is earlier than the version already installed on this computer."

    • Click the link for 'examine the log file' and look near the bottom of the log, for this line: Detected related bundle ... operation: Downgrade

    • open regedit.exe and do an Edit > Find... for that GUID. In my case it was {6dff50d0-3bc3-4a92-b724-bf6d6a99de4f}. This was found in:

      HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall{6dff50d0-3bc3-4a92-b724-bf6d6a99de4f}

    • Edit the BundleVersion value and change it to a lower version. I changed mine from 12.0.21005.13 to 12.0.21000.13: BundleVersion for Visual Studio lower the version for BundleVersion

    • Exit the registry

  3. Run the ISO (or vs_professional.exe) again. If it has a repair button like the image below, you can skip to step 4.

    Visual Studio Repair button

    • Otherwise you have to let the installer fix the registry. I did this by "installing" at least one feature, even though I think I already had all features (they were not detected). This took about 20 minutes.
  4. Run the ISO (or vs_professional.exe) again. This time repair should be visible.

  5. Click Repair and let it update your installation and apply its embedded license key. This took about 20 minutes.


Now when you run Visual Studio 2013, it should indicate that a license key was applied, under Help > Register Product:

License: Product key applied

Hope this helps somebody in the future!

Reference blog 'story'

ReactNative: how to center text?

used

textalign:center

at the view

Aligning label and textbox on same line (left and right)

You should use CSS to align the textbox. The reason your code above does not work is because by default a div's width is the same as the container it's in, therefore in your example it is pushed below.

The following would work.

<td  colspan="2" class="cell">
                <asp:Label ID="Label6" runat="server" Text="Label"></asp:Label>        
                <asp:TextBox ID="TextBox3" runat="server" CssClass="righttextbox"></asp:TextBox>       
</td>

In your CSS file:

.cell
{
text-align:left;
}

.righttextbox
{
float:right;
}

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

In my opinion the bare minimum implementation has two requirements. A state that keeps track of whether the modal is open or not, and a portal to render the modal outside of the standard react tree.

The ModalContainer component below implements those requirements along with corresponding render functions for the modal and the trigger, which is responsible for executing the callback to open the modal.

import React from 'react';
import PropTypes from 'prop-types';
import Portal from 'react-portal';

class ModalContainer extends React.Component {
  state = {
    isOpen: false,
  };

  openModal = () => {
    this.setState(() => ({ isOpen: true }));
  }

  closeModal = () => {
    this.setState(() => ({ isOpen: false }));
  }

  renderModal() {
    return (
      this.props.renderModal({
        isOpen: this.state.isOpen,
        closeModal: this.closeModal,
      })
    );
  }

  renderTrigger() {
     return (
       this.props.renderTrigger({
         openModal: this.openModal
       })
     )
  }

  render() {
    return (
      <React.Fragment>
        <Portal>
          {this.renderModal()}
        </Portal>
        {this.renderTrigger()}
      </React.Fragment>
    );
  }
}

ModalContainer.propTypes = {
  renderModal: PropTypes.func.isRequired,
  renderTrigger: PropTypes.func.isRequired,
};

export default ModalContainer;

And here's a simple use case...

import React from 'react';
import Modal from 'react-modal';
import Fade from 'components/Animations/Fade';
import ModalContainer from 'components/ModalContainer';

const SimpleModal = ({ isOpen, closeModal }) => (
  <Fade visible={isOpen}> // example use case with animation components
    <Modal>
      <Button onClick={closeModal}>
        close modal
      </Button>
    </Modal>
  </Fade>
);

const SimpleModalButton = ({ openModal }) => (
  <button onClick={openModal}>
    open modal
  </button>
);

const SimpleButtonWithModal = () => (
   <ModalContainer
     renderModal={props => <SimpleModal {...props} />}
     renderTrigger={props => <SimpleModalButton {...props} />}
   />
);

export default SimpleButtonWithModal;

I use render functions, because I want to isolate state management and boilerplate logic from the implementation of the rendered modal and trigger component. This allows the rendered components to be whatever you want them to be. In your case, I suppose the modal component could be a connected component that receives a callback function that dispatches an asynchronous action.

If you need to send dynamic props to the modal component from the trigger component, which hopefully doesn't happen too often, I recommend wrapping the ModalContainer with a container component that manages the dynamic props in its own state and enhance the original render methods like so.

import React from 'react'
import partialRight from 'lodash/partialRight';
import ModalContainer from 'components/ModalContainer';

class ErrorModalContainer extends React.Component {
  state = { message: '' }

  onError = (message, callback) => {
    this.setState(
      () => ({ message }),
      () => callback && callback()
    );
  }

  renderModal = (props) => (
    this.props.renderModal({
       ...props,
       message: this.state.message,
    })
  )

  renderTrigger = (props) => (
    this.props.renderTrigger({
      openModal: partialRight(this.onError, props.openModal)
    })
  )

  render() {
    return (
      <ModalContainer
        renderModal={this.renderModal}
        renderTrigger={this.renderTrigger}
      />
    )
  }
}

ErrorModalContainer.propTypes = (
  ModalContainer.propTypes
);

export default ErrorModalContainer;

Why binary_crossentropy and categorical_crossentropy give different performances for the same problem?

You are passing a target array of shape (x-dim, y-dim) while using as loss categorical_crossentropy. categorical_crossentropy expects targets to be binary matrices (1s and 0s) of shape (samples, classes). If your targets are integer classes, you can convert them to the expected format via:

from keras.utils import to_categorical
y_binary = to_categorical(y_int)

Alternatively, you can use the loss function sparse_categorical_crossentropy instead, which does expect integer targets.

model.compile(loss='sparse_categorical_crossentropy', optimizer='adam', metrics=['accuracy'])

Can I escape html special chars in javascript?

If you already use modules in your app, you can use escape-html module.

import escapeHtml from 'escape-html';
const unsafeString = '<script>alert("XSS");</script>';
const safeString = escapeHtml(unsafeString);

Random number from a range in a Bash Script

You can do this

cat /dev/urandom|od -N2 -An -i|awk -v f=2000 -v r=65000 '{printf "%i\n", f + r * $1 / 65536}'

If you need more details see Shell Script Random Number Generator.