Tutorial by Examples: l

A custom control does not have to limit itself to trivial things like primitives; it can edit more interesting things. Here we present two types of custom controls, one for editing persons and one for editing addresses. The address control is used to edit the person's address. An example of usage wo...

Passing a context with a timeout (or with a cancel function) to a long running function can be used to cancel that functions work: ctx, _ := context.WithTimeout(context.Background(), 200*time.Millisecond) for { select { case <-ctx.Done(): return ctx.Err() default: ...

The components in angularJS can be visualised as a custom directive (< html > this in an HTML directive, and something like this will be a custom directive < ANYTHING >). A component contains a view and a controller. Controller contains the business logic which is binded with an view , w...

There are four principle ways to declare a variable in JavaScript: using the var, let or const keywords, or without a keyword at all ("bare" declaration). The method used determines the resulting scope of the variable, or reassignability in the case of const. The var keyword creates a f...

String literal types allow you to specify the exact value a string can have. let myFavoritePet: "dog"; myFavoritePet = "dog"; Any other string will give a error. // Error: Type '"rock"' is not assignable to type '"dog"'. // myFavoritePet = "rock&qu...

3.0 let someString = " Swift Language \n" let trimmedString = someString.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceAndNewlineCharacterSet()) // "Swift Language" Method stringByTrimmingCharactersInSet returns a new string made by removing from both ends of t...

In addition to functional constructs such as Try, Option and Either for error handling, Scala also supports a syntax similar to Java's, using a try-catch clause (with a potential finally block as well). The catch clause is a pattern match: try { // ... might throw exception } catch { case i...

A method can be converted to a closure using the & operator. def add(def a, def b) { a + b } Closure addClosure = this.&add assert this.add(4, 5) == addClosure(4, 5)

Add a keystore using: keytool -genkey -v -keystore example.keystore -alias example -keyalg RSA -keysize 2048 -validity 10000 Note: This should be at root of project. Though not a hard requirement, it eases the file referencing Add a build.json with release/dev configuration for key...

To view a pdf you can download Adobe reader for free . You can create pdfs programmatically with the help of, e.g by using iTextSharp, jsPDF or PDFSharp (there are other libraries available)

This code writes the string to a file. It is important to close the writer, so this is done in a finally block. public void writeLineToFile(String str) throws IOException { File file = new File("file.txt"); BufferedWriter bw = null; try { bw = new BufferedWriter(ne...

Early Bound (with a reference to Microsoft Scripting Runtime) Sub EnumerateFilesAndFolders( _ FolderPath As String, _ Optional MaxDepth As Long = -1, _ Optional CurrentDepth As Long = 0, _ Optional Indentation As Long = 2) Dim FSO As Scripting.FileSystemObject Set ...

Declaring an array is very similar to declaring a variable, except you need to declare the dimension of the Array right after its name: Dim myArray(9) As String 'Declaring an array that will contain up to 10 strings By default, Arrays in VBA are indexed from ZERO, thus, the number inside the par...

Split Function returns a zero-based, one dimensional array containing a specified number of substrings. Syntax Split(expression [, delimiter [, limit [, compare]]]) PartDescriptionexpressionRequired. String expression containing substrings and delimiters. If expression is a zero-length string(&q...

Inside parent-component.hbs {{yield (hash child=( component 'child-component' onaction=(action 'parentAction') ) )}} Inside parent-component.js export default Ember.Component.extend({ actions: { // We pass this action to the child to call at it's discretion par...

Meteor.call(name, [arg1, arg2...], [asyncCallback]) (1) name String (2) Name of method to invoke (3) arg1, arg2... EJSON-able Object [Optional] (4) asyncCallback Function [Optional] On one hand, you can do : (via Session variable, or via ReactiveVar) var syncCall = Meteor.call("my...

When using non-lazy translation, strings are translated immediately. >>> from django.utils.translation import activate, ugettext as _ >>> month = _("June") >>> month 'June' >>> activate('fr') >>> _("June") 'juin' >>> a...

Prefer dict.get method if you are not sure if the key is present. It allows you to return a default value if key is not found. The traditional method dict[key] would raise a KeyError exception. Rather than doing def add_student(): try: students['count'] += 1 except KeyError: ...

First, add Mongoid to your Gemfile: gem "mongoid", "~> 4.0.0" and then run bundle install. Or just run: $ gem install mongoid After installation, run the generator to create the config file: $ rails g mongoid:config which will create the file (myapp)/config/mongoid...

Create a model (lets call it User) by running: $ rails g model User which will generate the file app/models/user.rb: class User include Mongoid::Document end This is all you need to have a model (albeit nothing but an id field). Unlike ActiveRecord, there is no migration files. All the...