Tutorial by Examples: d

This is a tutorial to create a hello world example: Used for this example: Android Studio 2.3; To Start use Android Studio to create a new Project with an empty activity. Then we add some simple functionality to the App that we can test: We add a button which when clicks displays "Hello World...

Getting set up to use webdev takes some time, if you're doing anything more than tweaking a bit of text. Here are the initial setup steps: $ mkdir site $ cd site $ git clone [email protected]:dart-lang/site-webdev.git $ source ./scripts/env-set.sh $ ./scripts/install-dart-sdk.sh $ ./s...

This code will prompt you to create the directory with :w, or just do it with :w!: augroup vimrc-auto-mkdir autocmd! autocmd BufWritePre * call s:auto_mkdir(expand('<afile>:p:h'), v:cmdbang) function! s:auto_mkdir(dir, force) if !isdirectory(a:dir) \ && (a:f...

It is very common for C functions to accept pointers to other functions as arguments. Most popular example is setting an action to be executed when a button is clicked in some GUI toolkit library. It is possible to pass Haskell functions as C callbacks. To call this C function: void event_callback...

Yesod project can be created with stack new using following templates: yesod-minimal. Simplest Yesod scaffold possible. yesod-mongo. Uses MongoDB as DB engine. yesod-mysql. Uses MySQL as DB engine. yesod-postgres. Uses PostgreSQL as DB engine. yesod-postgres-fay. Uses PostgreSQL as DB engine....

In this example, we will try to find JavaScript data which containing backgroundColor:'#FFF'. Then, we will change value of backgroundColor '#FFF' ⇨ '#ddd'. This code uses getWholeData() and setWholeData() methods to manipulate JavaScript data. Alternatively, html() method can be used to get data of...

Run-time memory management with Rc can be very useful, but it can also be difficult to wrap one's head around, especially if your code is very complex and a single instance is referenced by tens or even hundreds of other types in many scopes. Writing a Drop trait that includes println!("Droppi...

Processing provides the method triangle in order to draw a triangle. The code below draws a nearly equilateral triangle of 25 pixels between each defining point. void setup() { size(500, 500); background(0); } void draw() { triangle(0, 0, 25, 0, 12, 12); } The signature of tria...

Android extensions also work with multiple Android Product Flavors. For example if we have flavors in build.gradle like so: android { productFlavors { paid { ... } free { ... } } } And for example, only the free flavor has ...

Given a ByteBuffer instance one can write primitive-type data to it using relative and absolute put. The striking difference is that putting data using the relative method keeps track of the index the data is inserted at for you, while the absolute method always requires giving an index to put the d...

Below is an Employer entity class which is mapped to the table employer. As you can see I used fetch = FetchType.LAZY instead of fetch = FetchType.EAGER. The reason I am using LAZY is because Employer may have a lot of properties later on and every time I may not need to know all the fields of an Em...

The interactive mode The most basic way to use R is the interactive mode. You type commands and immediately get the result from R. Using R as a calculator Start R by typing R at the command prompt of your operating system or by executing RGui on Windows. Below you can see a screenshot of an inter...

Each standard Oracle error is associated with an error number. Its important to anticipate what could go wrong in your code. Here for a connection to another database it can be: -28000 account is locked -28001 password expired -28002 grace period -1017 wrong user / password Here is a way to...

To illustrate this, here is a function that has 3 different "wrong" behaviors parameter is completely stupid: we use a user-defined expression parameter has a typo: we use Oracle standard NO_DATA_FOUND error another, but not handled case Feel free to adapt it to your standards: DE...

You can use the ng generate or ng g command to generate Angular building blocks (components, services, pipes, etc.). You can find all possible blueprints in the table below: ScaffoldUsageShortenedComponentng generate component component-nameng g c component-nameDirectiveng generate directive direc...

class MyToolbarControl { public: MyToolbarControl(HWND hWndToolbar, HWND hWndNotifyParent = nullptr) : _Handle(hWndToolbar) { if (hWndNotifyParent == nullptr) { hWndNotifyParent = GetAncestor(hWndToolbar, GA_ROOTOWNER); } SetWindowSubclass( ...

PyDotPlus is an improved version of the old pydot project that provides a Python Interface to Graphviz’s Dot language. Installation For the latest stable version: pip install pydotplus For the development version: pip install https://github.com/carlos-jenkins/pydotplus/archive/master.zip L...

Native string functions are mapped to single byte functions, they do not work well with Unicode. The extentions iconv and mbstring offer some support for Unicode, while the Intl-extention offers full support. Intl is a wrapper for the facto de standard ICU library, see http://site.icu-project.org fo...

AppDelegate contains your app’s startup code. It responds to key changes in the state of your app. Specifically, it responds to both temporary interruptions and to changes in the execution state of your app, such as when your app transitions from the foreground to the background. It responds to ...

Asks the delegate to open a resource specified by a URL, and provides a dictionary of launch options. Example of usage: func application(_ app: UIApplication, open url: URL, options: [UIApplicationOpenURLOptionsKey : Any] = [:]) -> Bool { return SomeManager.shared.handle( ...