Tutorial by Examples: g

Swift Playgrounds app is a great way to get started coding Swift on the go. To use it: 1- Download Swift Playgrounds for iPad from App Store. 2- Open the app. 3- In the My Playgrounds tab, tap + on the top left corner and then select Blank template. 4- Enter your code. 5- Tap Run My Code to r...

Django's signals are restricted to precise class signatures upon registration, and thus subclassed models are not immediately registered onto the same signal. Take this model and signal for example class Event(models.Model): user = models.ForeignKey(User) class StatusChange(Event): ...

Creating a Scala function that receives an python RDD is easy. What you need to build is a function that get a JavaRDD[Any] import org.apache.spark.api.java.JavaRDD def doSomethingByPythonRDD(rdd :JavaRDD[Any]) = { //do something rdd.map { x => ??? } }

Sometimes, the straight forward loop cannot be entirely contained within the loop body. This is because, the loop needs to be primed by some statements B. Then, the iteration begins with some statements A, which are then followed by B again before looping. do_B(); while (condition) { do_A(); ...

Using many ECHO commands to create a batch file: ( echo echo hi, this is the date today echo date /T echo echo created on %DATE% echo pause >nul )>hi.bat The command interpreter treats the whole section in parenthesis as a single command, then saves all the output to hi.bat. ...

There are two ways to define models in sequelize; with sequelize.define(...), or sequelize.import(...). Both functions return a sequelize model object. 1. sequelize.define(modelName, attributes, [options]) This is the way to go if you'd like to define all your models in one file, or if you want to...

One of the major use case when a developer needs to take mutability into account is when passing arguments to a function. This is very important, because this will determine the ability for the function to modify objects that doesn't belong to its scope, or in other words if the function has side ef...

There are four ways to work with JavaScript plugins, Ember add-on Import JavaScript plugins globally Consume named AMD plugins Via ember-browserify

First, complete the installation and setup to connect your app to Firebase. Then from anywhere in your class, you can write: // Write a message to the database FirebaseDatabase database = FirebaseDatabase.getInstance(); DatabaseReference myRef = database.getReference("message"); myRe...

Gradle (All Versions) This method works for all versions of gradle Add the buildscript code at the beginning of your build.gradle file. buildscript { repositories { maven { url "https://plugins.gradle.org/m2/" } } dependencies { classpath "org.example...

Gradle (All Versions) When adding multiple third party plugins you do not need to separate them into different instances of the buildscript(All) or plugin(2.1+) code, new plug ins can be added alongside pre-existing plugins. buildscript { repositories { maven { url "https://plu...

When using d3.request() or one of the convenience constructors (d3.json, d3.csv, d3.tsv, d3.html and d3.xml) there are many sources for error. There may be problems with the issued request or its response due to network errors, or the parsing might fail if the content is not well-formed. Within the...

Like page caching, action caching caches the whole page. The difference is that the request hits the Rails stack so before filters are run before the cache is served. It's extracted from Rails to actionpack-action_caching gem. A common example is caching of an action that requires authentication: ...

Sample Data: CREATE TABLE table_name ( id, list ) AS SELECT 1, 'a,b,c,d' FROM DUAL UNION ALL -- Multiple items in the list SELECT 2, 'e' FROM DUAL UNION ALL -- Single item in the list SELECT 3, NULL FROM DUAL UNION ALL -- NULL list SELECT 4, 'f,,g' FROM DUAL; -- NULL item...

In config.ini: [DEFAULT] debug = True name = Test password = password [FILES] path = /path/to/file In Python: from ConfigParser import ConfigParser config = ConfigParser() #Load configuration file config.read("config.ini") # Access the key "debug" in "DEF...

Decryption Code public static string Decrypt(string cipherText) { if (cipherText == null) return null; byte[] cipherBytes = Convert.FromBase64String(cipherText); using (Aes encryptor = Aes.Create()) { Rfc2898DeriveBytes pdb = ...

We can use command uname with various options to get complete details of running kernel. uname -a Linux df1-ws-5084 4.4.0-64-generic #85-Ubuntu SMP Mon Feb 20 11:50:30 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux As per man page here few more options Usage: uname [OPTION]... Print certain system inf...

If you want to replace parts of your website, ajax is an easy way to do it. The website.html where you want to replace the content based on the selected value: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml" xmlns:th="http://www.thymeleaf.org"> ...

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>...

While designing a form, you might like to group a few input fields into a group to help organise the form layout. This can be done by using the tag . Here is an example for using it. For each fieldset, you can set a legend for the set using the tag LEGEND TEXT Example <form> <fieldset...