Tutorial by Examples: r

If you want to use a podfile in more than one target, you can do like this. You can choose the download address when you pod this lib. def testpods pod 'YSDPush', :git => 'https://github.com/youshaoduo/YSDPush.git' end target 'One' do testpods end target 'Two' do testpods ...

Calendar : Key : Privacy - Calendars Usage Description Value : $(PRODUCT_NAME) calendar events Reminder : Key : Privacy - Reminders Usage Description Value : $(PRODUCT_NAME) reminder use Contact : Key : Privacy - Contacts Usage Description Value : $(PRODUCT_...

When compared to a other database types, a measurement in Influx can be considered, on a very high level, as being similar to a table in relational databases or a collection in document databases. List all measurements for the currently active database: $ show measurements Lists all measurement...

In DRF, serializer validation is run in a specific, undocumented order Field deserialization called (serializer.to_internal_value and field.run_validators) serializer.validate_[field] is called for each field. Serializer-level validators are called (serializer.run_validation followed by seriali...

Detailed instructions on getting kdb set up or installed.

It is possible to DELETE data from a table if it matches (or mismatches) certain data in other tables. Let's assume we want to DELETEdata from Source once its loaded into Target. DELETE FROM Source WHERE EXISTS ( SELECT 1 -- specific value in SELECT doesn't matter FROM Target ...

6 class Item { constructor(text, type) { this.text = text; this.emphasis = false; this.type = type; } toHtml() { return `<${this.type}>${this.emphasis ? '<em>' : ''}${this.text}${this.emphasis ? '</em>' : ''}</${this.type}...

In this example we will extract all the web links from a website. I am using http://stackoverflow.com/ for illustration. Here recursion is used, where each obtained link's page is parsed for presence of an anchor tag and that link is again submitted to the same function. The condition if(add &&...

This example shows how to create a pyramid using borders and 2D transformation methods skewY() and rotate() on pseudo elements. HTML: <div class="pyramid"></div> CSS: .pyramid { width: 100px; height: 200px; position: relative; margin: 50px; } .pyramid::b...

The NSInteger is just a typedef for either an int or a long depending on the architecture. The same goes for a NSUInteger which is a typedef for the unsigned variants. If you check the NSInteger you will see the following: #if __LP64__ || (TARGET_OS_EMBEDDED && !TARGET_OS_IPHONE) || TARGET_...

SCSS syntax resembles more like a CSS syntax but SASS syntax is little bit different from SCSS but both produces exactly the same CSS code. In SASS we are not ending the style properties with semicolon(;) but in SCSS we are ending the style properties with (;). In SCSS we used paranthesis {} to ...

Option Explicit Sub CheckWorksheetsDiagram() Debug.Print Worksheets(1).Name Debug.Print Charts(1).Name Debug.Print Sheets(1).Name End Sub The result: Sheet1 Chart1 Chart1

By default the state of a promise is pending when it is created. The state of a promise is changed when the deferred object which created the promise either resolves/rejects it. var deferred = new $.Deferred(); var d1= deferred.promise({ prop: "value" }); var d2= $("div"...

public class Foobar { public static void main(String[] args) { // example: Boolean ignore = null; if (ignore == false) { System.out.println("Do not ignore!"); } } } The pitfall here is that null is compared to false. Since w...

Here is an example of custom UITextField that takes only numerical text and discards all other. NOTE: For iPhone it is easy to do this using Number type keyboard, but for iPad there is no keyboard with Numbers only class NumberTextField: UITextField { required init(coder aDecoder: NSCoder) ...

Function xyz returns two values a and b: def xyz(): return a, b Code calling xyz stores result into one variable assuming xyz returns only one value: t = xyz() Value of t is actually a tuple (a, b) so any action on t assuming it is not a tuple may fail deep in the code with a an unexpecte...

%TYPE: Used to declare a field with the same type as that of a specified table's column. DECLARE vEmployeeName Employee.Name%TYPE; BEGIN SELECT Name INTO vEmployeeName FROM Employee WHERE RowNum = 1; DBMS_OUTPUT.PUT_LINE(vEmp...

In this example we are going to create a view. A view is mostly used as a simple way of fetching data from multiple tables. Example 1: View with a select on one table. CREATE OR REPLACE VIEW LessonView AS SELECT L.* FROM Lesson L; Example 2: View with a select o...

Below we are going to create a table with 3 columns. The column Id must be filled is, so we define it NOT NULL. On the column Contract we also add a check so that the only value allowed is 'Y' or 'N'. If an insert in done and this column is not specified during the insert then default a 'N' is i...

iOS apps needs to be written in a way to provide security to data which is being transported over network. SSL is the common way to do it. Whenever app tries to call web services to pull or push data to servers, it should use SSL over HTTP, i.e. HTTPS. To do this, app must call https://server.com...