Tutorial by Examples: r

eventReactives are similar to reactives, they are constructed as follows: eventReactive( event { code to run }) eventReactives are not dependent on all reactive expressions in their body ('code to run' in the snippet above). Instead, they are only dependent on the expressions specified in the ...

reactiveValues can be used to store objects, to which other expressions can take a dependency. In the example below, a reactiveValues object is initialized with value "No text has been submitted yet.". A separate observer is created to update the reactiveValues object whenever the submit ...

An observeEvent object can be used to trigger a piece of code when a certain event occurs. It is constructed as: observeEvent( event { code to run }) The observeEvent will only be dependent on the 'event' section in the small piece of code above. It will not be dependent on anything in the 'co...

Valgrind is GPLv2-licensed collection of dynamic analysis tools, which uses binary instrumentation (dynamic recompilation). Six tools are included to detect memory management (Memcheck) and threading errors (Helgrind and DRD), to generate call-graph and profile programs (with optional cache and bran...

One can use the command-line launching facility is when one wants to customize some aspects of the way MySQL Workbench operates. MySQL Workbench has the following common command line options: --admin instance - Launch MySQL Workbench and load the server instance specified. --query connection - ...

/app/i18n/<Vendor Namespace>/<language package directory>/composer.json { "name": "<vendor namespance>/<language package directory>", "description": "<language package description>", "version": "100....

An observe expression is triggered every time one of its inputs changes. The major difference with regards to a reactive expression is that it yields no output, and it should only be used for its side effects (such as modifying a reactiveValues object, or triggering a pop-up). Also, note that obser...

Here i will show you how to fetch All parent(configuarble products) A parent product and all of its children.

We will start by making a simple class that gets all our parent(Configurable products) <?php namespace Test\Test\Controller\Test; use Magento\Framework\App\Action\Context; class Products extends \Magento\Framework\App\Action\Action { public function __construct( \...

Here we first fetch our parent product and the we will get all children products that this parent have. <?php namespace Test\Test\Controller\Test; use Magento\Framework\App\Action\Context; class Products extends \Magento\Framework\App\Action\Action { public function __cons...

Arrays values should be accessed using a number specifying the location of the desired value in the array. This number is called Index. Indexes starts at 0 and finish at array length -1. To access a value, you have to do something like this: arrayName[index], replacing "index" by the num...

EPPlus also supports the ability to insert text in a cell using the Insert() method. For example: var file = new FileInfo(filePath); using (var p = new ExcelPackage(file)) { var wb = p.Workbook; var ws = wb.Worksheets.FirstOrDefault() ?? wb.Worksheets.Add("Sheet1"); var...

val re = """\((.*?)\)""".r val str = "(The)(example)(of)(repeating)(pattern)(in)(a)(single)(string)(I)(had)(some)(trouble)(with)(once)" re.findAllMatchIn(str).map(_.group(1)).toList res2: List[String] = List(The, example, of, repeating, pattern, in, a, ...

Using DOSKEY, we can create macros to simplify typing many commands in command prompt. Take a look at the following example. DOSKEY macro=echo Hello World Now if you type macro in the command prompt, it would return Hello World.

There are 3 usages of the $ character in a DOSKEY macro. Command separator $T is the equivalent of & in a batch script. One can join commands together like so. DOSKEY test=echo hello $T echo world Command-line arguments Like bash(not batch), we use $ to indicate command-line argument....

class AppDelegate: UIResponder, UIApplicationDelegate { var window: UIWindow? var firstTabNavigationController : UINavigationController! var secondTabNavigationControoller : UINavigationController! var thirdTabNavigationController : UINavigationController! var fourth...

For this, we will use the function aggregate, which can be used as follows: aggregate(formula,function,data) The following code shows various ways of using the aggregate function. CODE: df = data.frame(group=c("Group 1","Group 1","Group 2","Group 2",&quo...

Aggregating with dplyr is easy! You can use the group_by() and the summarize() functions for this. Some examples are given below. CODE: # Aggregating with dplyr library(dplyr) df = data.frame(group=c("Group 1","Group 1","Group 2","Group 2","Group 2&...

Sometimes the download takes longer than the cell is being displayed. In this case it can happen, that the downloaded image is shown in the wrong cell. To fix this we can not use the UIImageView Extension. We still will be using Alamofire however we will use the completion handler to display the im...

Use .outerHTML to get the HTML Here is a code sample to get the entire HTML of the website private async void GetHTMLAsync() { var siteHtML = await webView.InvokeScriptAsync("eval", new string[] { "document.documentElement.outerHTML;" }); }