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Grand Central Dispatch (GCD) In iOS, Apple provides two ways to do multitasking: The Grand Central Dispatch (GCD) and NSOperationQueue frameworks.We will discuss here about GCD. GCD is a lightweight way to represent units of work that are going to be executed concurrently You don’t schedule thes...

How to create charts with EPPlus

WCSessionDelegate works with watch OS2 + using WatchConnectivity. var watchSession : WCSession? func startWatchSession(){ if(WCSession.isSupported()){ watchSession = WCSession.default() watchSession!.delegate = self ...

How to import data from an existing Excel or CSV file.

At certain points, you will be evaluating a range of data and you will need to locate the duplicates in it. For bigger data sets, there are a number of approaches you can take that use either VBA code or conditional functions. This example uses a simple if-then condition within two nested for-next l...

Scala allows you to use dynamic invocation when calling methods or accessing fields on an object. Instead of having this built deep into the language, this is accomplished through rewriting rules similar to those of implicit conversions, enabled by the marker trait [scala.Dynamic][Dynamic scaladoc]....

Accessors and mutators allow you to format Eloquent attribute values when you retrieve or set them on model instances. For example, you may want to use the Laravel encrypter to encrypt a value while it is stored in the database, and then automatically decrypt the attribute when you access it on an E...

Continuation passing style is a form of control flow that involves passing to functions the rest of the computation as a "continuation" argument. The function in question later invokes that continuation to continue program execution. One way to think of a continuation is as a closure. The ...

This tutorial shows how to create a workspace. A workspace is a set of directories in which a related set of ROS code lives. One can have multiple ROS workspaces, but it is possible to work only in one at a time.

This tutorial shows how to create a package in ROS. Packages sit inside workspaces, in the src directory. Each package directory must have a CMakeLists.txt and a package.xml files.

This topic shows the uses of different CMake configurations like Debug or Release, in different environments.

Modern mobile devices include hardware for vibrations. The Vibration API offers Web apps the ability to access this hardware, if it exists, and does nothing if the device doesn't support it. let success = window.navigator.vibrate( pattern ); Support by browsers might be limited. Also su...

Often you need to execute commands under a different user or get root privileges. Those options allow you to become another user in the guest system. become: can be set to true or yes and triggers the user escalation settings. become_user: set to the desired user in the remote host. become_metho...

The Date Time Picker allows a user to choose both a date (month/date/year) as well as a time of day (hours/minutes/seconds). A user can then output the date format and return format based on [PHP date()][1] acceptable methods. This is helpful for querying custom post types like events, tour dates, o...

A DataFrame is an abstraction of data organized in rows and typed columns. It is similar to the data found in relational SQL-based databases. Although it has been transformed into just a type alias for Dataset[Row] in Spark 2.0, it is still widely used and useful for complex processing pipelines mak...

Batch and bash are quite different. Batch flags are indicated with a /, while bash flags use a -. Capitalization matters in bash, but (almost) not at all in batch. Batch variable names can contain spaces, bash variable names can not. Ultimately, both are ways of manipulating and interacting wit...

A materialized view is a view whose results are physically stored and must be periodically refreshed in order to remain current. They are therefore useful for storing the results of complex, long-running queries when realtime results are not required. Materialized views can be created in Oracle and...

Datatables 1.10.x is the latest release as of now. Though it is backwards compatible to the previous versions (1.9 etc.), it is highly advisable to use the latest version which directly returns a datatable api object. Another major change, that is the most visible, is the change from Hungarian Nota...