Tutorial by Examples: ces

The following code will attempt to execute loadFromHttp() up to 5 times (maxAttempts), with each attempt delayed by as many seconds. If maxAttempts is surpassed, the Observable gives up. // assume loadFromHttp() returns a Promise, which might fail. Rx.Observable.from(loadFromHttp()) ....

Executable C++ program code is usually produced by a compiler. A compiler is a program that translates code from a programming language into another form which is (more) directly executable for a computer. Using a compiler to translate code is called compilation. C++ inherits the form of its compi...

project('Mixed sources Project', 'vala') glib_dep = dependency('glib-2.0') gobject_dep = dependency('gobject-2.0') executable('foo', 'foo.vala', 'bar.c', dependencies: [glib_dep, gobject_dep]) In foo.vala: namespace Foo { public extern int bar (); public int main (string[] arg...

Access modifiers are used to control the access to an object or to a function/method. This is a main part of the concept of Abstraction. Different programming languages use different access modifiers. Here are some examples: Java Java has 4 access modifiers. private - These attributes can ...

The preprocessor is an important part of the compiler. It edits the source code, cutting some bits out, changing others, and adding other things. In source files, we can include preprocessor directives. These directives tells the preprocessor to perform specific actions. A directive starts with a ...

Individual pixel access in OpenCV Mat structure can be achieved in multiple ways. To understand how to access, it is better to learn the data types first. Basic Structures explains the basic datatypes. Shortly, CV_<bit-depth>{U|S|F}C(<number_of_channels>) is the basic structure of a typ...

This is the typical approach for novice developers building SQL action queries. They are vulnerable to the Bobby Tables type SQL Injection attacks. Dim strSQL As String strSQL = "INSERT INTO Employees chrFirstName, chrLastName, chrPhone " _ & "VALUES ('" & M...

A program can easily waste time by calling a processor-intensive function multiple times. For example, take a function which looks like this: it returns an integer if the input value can produce one, else None: def intensive_f(value): # int -> Optional[int] # complex, and time-consuming cod...

Here we can create UUID String with in one line. Represents UUID strings, which can be used to uniquely identify types, interfaces, and other items. Swift 3.0 print(UUID().uuidString) It is very useful for identify multiple devices with unique id.

As of Jekyll 3.2, you can use the filter where_exp to filter a collection by any of its properties. Say you have the following collection item in an "albums" collection: --- title: My Amazing Album --- ... You can combine the where_exp and first filters to grab just that one item: ...

Sometimes, you need to output to more than one index in ElasticSearch, or have a custom mapping you want to apply to new indices as they roll in. There are two ways to apply a custom mapping. One way, is to upload an ElasticSearch template. See the ElasticSearch documentation for that. The other ...

In Twig template, Request object is available at {{ app.request }} When you want display request method in Twig, try this: <p>Request method: {{ app.request.method }}</p> In PHP template <p>Request method: <?php echo $app->getRequest()->getMethod() ?></p>...

In order to expose Thymeleaf templates we need to define controllers. Example: @Controller @RequestMapping("/") public class MessageController { @Autowired private MessageRepository messageRepository; @GetMapping public ModelAndView index() { It...

First, install ipset if needed. Please refer to your distribution to know how to do it. As an example, here is the command for Debian-like distributions. $ apt-get update $ apt-get install ipset Then create a configuration file to define an ipset containing the IPs for which you want to open ac...

Work in progress

To get OAuth2 access token simply do curl https://login.salesforce.com/services/oauth2/token -d "grant_type=password" -d "client_id=myclientid" -d "client_secret=myclientsecret" -d "[email protected]" -d "password=mypassword123456" Y...

In mathematics, especially Set Theory, we have a collection of things which is called set and we name those things as elements. We show a set with its name like A, B, C, ... or explicitly with putting its member on brace notation: {a, b, c, d, e}. Suppose we have an arbitrary element x and a set Z, ...

In this example, User Table will have a column that references the Agency table. CREATE TABLE agencies ( -- first create the agency table id SERIAL PRIMARY KEY, name TEXT NOT NULL ) CREATE TABLE users ( id SERIAL PRIMARY KEY, agency_id NOT NULL INTEGER REFERENCES agencies(id) DEFERR...

Suppose we'd like to wrap the Google Maps JavaScript API google.maps: @JS('google.maps') library maps; import "package:js/js.dart"; @JS() class Map { external Map(Location location); external Location getLocation(); } We now have the Map Dart class which corresponds to t...

// gets the Class objects from the net.mminecraft.server package with the given name public Class<?> getNmsClass(String name) throws ClassNotFoundException { // explode the Server interface implementation's package name into its components String[] packageArray = Bukkit.getServer()....