More umd

pages/Basic Types.md

@@ -190,6 +190,27 @@ Declaring variables of type `void` is not useful because you can only assign `un
 let unusable: void = undefined;
 ```
 
+# Null and Undefined
+
+In TypeScript, both `undefined` and `null` actually have their own types named `undefined` and `null` respectively.
+Much like `void`, they're not extremely useful on their own:
+
+```ts
+// Not much else we can assign to these variables!
+let u: undefined = undefined;
+let n: null = null;
+```
+
+By default `null` and `undefined` are subtypes of all other types.
+That means you can assign `null` and `undefined` to something like `number`.
+
+However, when using the `--strictNullChecks` flag, `null` and `undefined` are only assignable to `void` and their respective types.
+This helps avoid *many* common errors.
+In cases where you want to pass in either a `string` or `null` or `undefined`, you can use the union type `string | null | undefined`.
+Once again, more on union types later on.
+
+> As a note: we encourage the use of `--strictNullChecks` when possible, but for the purposes of this handbook, we will assume it is turned off.
+
 # Type assertions
 
 Sometimes you'll end up in a situation where you'll know more about a value than TypeScript does.

pages/Classes.md

@@ -189,27 +189,70 @@ console.log(howard.name); // error
 
 Notice that while we can't use `name` from outside of `Person`, we can still use it from within an instance method of `Employee` because `Employee` derives from `Person`.
 
+A constructor may also be marked `protected`.
+This means that the class cannot be instantiated outside of its containing class, but can be extended. For example,
+
+```ts
+class Person {
+    protected name: string;
+    protected constructor(theName: string) { this.name = theName; }
+}
+
+// Employee can extend Person
+class Employee extends Person {
+    private department: string;
+
+    constructor(name: string, department: string) {
+        super(name);
+        this.department = department;
+    }
+
+    public getElevatorPitch() {
+        return `Hello, my name is ${this.name} and I work in ${this.department}.`;
+    }
+}
+
+let howard = new Employee("Howard", "Sales");
+let john = new Person("John"); // Error: The 'Person' constructor is protected
+```
+
+# Readonly modifier
+
+You can make properties readonly by using the `readonly` keyword.
+Readonly properties must be initialized at their declaration or in the constructor.
+
+```ts
+class Octopus {
+    readonly name: string;
+    readonly numberOfLegs: number = 8;
+    constructor (theName: string) {
+        this.name = theName;
+    }
+}
+let dad = new Octopus("Man with the 8 strong legs");
+dad.name = "Man with the 3-piece suit"; // error! name is readonly.
+```
+
 ## Parameter properties
 
-In our last example, we had to declare a private member `name` and a constructor parameter `theName`, and we then immediately set `name` to `theName`.
+In our last example, we had to declare a readonly member `name` and a constructor parameter `theName` in the `Octopus` class, and we then immediately set `name` to `theName`.
 This turns out to be a very common practice.
 *Parameter properties* let you create and initialize a member in one place.
-Here's a further revision of the previous `Animal` class using a parameter property:
+Here's a further revision of the previous `Octopus` class using a parameter property:
 
 ```ts
-class Animal {
-    constructor(private name: string) { }
-    move(distanceInMeters: number) {
-        console.log(`${this.name} moved ${distanceInMeters}m.`);
+class Octopus {
+    readonly numberOfLegs: number = 8;
+    constructor(readonly name: string) {
     }
 }
 ```
 
-Notice how we dropped `theName` altogether and just use the shortened `private name: string` parameter on the constructor to create and initialize the `name` member.
+Notice how we dropped `theName` altogether and just use the shortened `readonly name: string` parameter on the constructor to create and initialize the `name` member.
 We've consolidated the declarations and assignment into one location.
 
-Parameter properties are declared by prefixing a constructor parameter with an accessibility modifier.
-Using `private` for a parameter property declares and initializes a private member; likewise, the same is done for `public` and `protected`.
+Parameter properties are declared by prefixing a constructor parameter with an accessibility modifier or `readonly`, or both.
+Using `private` for a parameter property declares and initializes a private member; likewise, the same is done for `public`, `protected`, and `readonly`.
 
 # Accessors
 
@@ -266,7 +309,12 @@ if (employee.fullName) {
 
 To prove to ourselves that our accessor is now checking the passcode, we can modify the passcode and see that when it doesn't match we instead get the message warning us we don't have access to update the employee.
 
-Note: Accessors require you to set the compiler to output ECMAScript 5 or higher.
+A couple of things to note about accessors:
+
+First, accessors require you to set the compiler to output ECMAScript 5 or higher.
+Downlevelling to ECMAScript 3 is not supported.
+Second, accessors with a `get` and no `set` are automatically inferred to be `readonly`.
+This is helpful when generating a `.d.ts` file from your code, because users of your property can see that they can't change it.
 
 # Static Properties
 

pages/Compiler Options in MSBuild.md

@@ -22,52 +22,68 @@ Compiler options can be specified using MSBuild properties within an MSBuild pro
 
 Compiler Option                              | MSBuild Property Name                      | Allowed Values
 ---------------------------------------------|--------------------------------------------|-----------------
-`--declaration`                              | TypeScriptGeneratesDeclarations            | boolean
-`--module`                                   | TypeScriptModuleKind                       | `AMD`, `CommonJs`, `UMD`, or `System`
-`--target`                                   | TypeScriptTarget                           | `ES3`, `ES5`, or `ES6`
+`--allowJs`                                  | *Not supported in MSBuild*                 |
+`--allowSyntheticDefaultImports`             | TypeScriptAllowSyntheticDefaultImports     | boolean
+`--allowUnreachableCode`                     | TypeScriptAllowUnreachableCode             | boolean
+`--allowUnusedLabels`                        | TypeScriptAllowUnusedLabels                | boolean
+`--baseUrl`                                  | TypeScriptBaseUrl                          | File path
 `--charset`                                  | TypeScriptCharset                          |
+`--declaration`                              | TypeScriptGeneratesDeclarations            | boolean
+`--declarationDir`                           | TypeScriptDeclarationDir                   | File path
+`--diagnostics`                              | *Not supported in MSBuild*                 |
 `--emitBOM`                                  | TypeScriptEmitBOM                          | boolean
 `--emitDecoratorMetadata`                    | TypeScriptEmitDecoratorMetadata            | boolean
+`--experimentalAsyncFunctions`               | TypeScriptExperimentalAsyncFunctions       | boolean
 `--experimentalDecorators`                   | TypeScriptExperimentalDecorators           | boolean
+`--forceConsistentCasingInFileNames`         | TypeScriptForceConsistentCasingInFileNames | boolean
+`--help`                                     | *Not supported in MSBuild*                 |
 `--inlineSourceMap`                          | TypeScriptInlineSourceMap                  | boolean
 `--inlineSources`                            | TypeScriptInlineSources                    | boolean
+`--init`                                     | *Not supported in MSBuild*                 |
+`--isolatedModules`                          | TypeScriptIsolatedModules                  | boolean
+`--jsx`                                      | TypeScriptJSXEmit                          | `React` or `Preserve`
+`--lib`                                      | TypeScriptLib                              | Comma-separated list of strings
+`--listEmittedFiles`                         | *Not supported in MSBuild*                 |
+`--listFiles`                                | *Not supported in MSBuild*                 |
 `--locale`                                   | *automatic*                                | Automatically set to PreferredUILang value
 `--mapRoot`                                  | TypeScriptMapRoot                          | File path
+`--module`                                   | TypeScriptModuleKind                       | `AMD`, `CommonJs`, `UMD`, `System` or `ES6`
+`--moduleResolution`                         | TypeScriptModuleResolution                 | `Classic` or `Node`
 `--newLine`                                  | TypeScriptNewLine                          | `CRLF` or `LF`
-`--noEmitOnError`                            | TypeScriptNoEmitOnError                    | boolean
+`--noEmit`                                   | *Not supported in MSBuild*                 |
 `--noEmitHelpers`                            | TypeScriptNoEmitHelpers                    | boolean
+`--noEmitOnError`                            | TypeScriptNoEmitOnError                    | boolean
+`--noFallthroughCasesInSwitch`               | TypeScriptNoFallthroughCasesInSwitch       | boolean
 `--noImplicitAny`                            | TypeScriptNoImplicitAny                    | boolean
+`--noImplicitReturns`                        | TypeScriptNoImplicitReturns                | boolean
+`--noImplicitThis`                           | TypeScriptNoImplicitThis                   | boolean
+`--noImplicitUseStrict`                      | TypeScriptNoImplicitUseStrict              | boolean
 `--noLib`                                    | TypeScriptNoLib                            | boolean
 `--noResolve`                                | TypeScriptNoResolve                        | boolean
 `--out`                                      | TypeScriptOutFile                          | File path
 `--outDir`                                   | TypeScriptOutDir                           | File path
+`--outFile`                                  | TypeScriptOutFile                          | File path
+`--paths`                                    | *Not supported in MSBuild*                 |
 `--preserveConstEnums`                       | TypeScriptPreserveConstEnums               | boolean
+`--listEmittedFiles`                         | *Not supported in MSBuild*                 |
+`--pretty`                                   | *Not supported in MSBuild*                 |
+`--reactNamespace`                           | TypeScriptReactNamespace                   | string
 `--removeComments`                           | TypeScriptRemoveComments                   | boolean
 `--rootDir`                                  | TypeScriptRootDir                          | File path
-`--isolatedModules`                          | TypeScriptIsolatedModules                  | boolean
+`--rootDirs`                                 | *Not supported in MSBuild*                 |
+`--skipLibCheck`                             | TypeScriptSkipLibCheck                     | boolean
+`--skipDefaultLibCheck`                      | TypeScriptSkipDefaultLibCheck              | boolean
 `--sourceMap`                                | TypeScriptSourceMap                        | File path
 `--sourceRoot`                               | TypeScriptSourceRoot                       | File path
-`--suppressImplicitAnyIndexErrors`           | TypeScriptSuppressImplicitAnyIndexErrors   | boolean
+`--strictNullChecks`                         | TypeScriptStrictNullChecks                 | File path
 `--suppressExcessPropertyErrors`             |  TypeScriptSuppressExcessPropertyErrors    | boolean
-`--moduleResolution`                         | TypeScriptModuleResolution                 | `Classic` or `Node`
-`--experimentalAsyncFunctions`               | TypeScriptExperimentalAsyncFunctions       | boolean
-`--jsx`                                      | TypeScriptJSXEmit                          | `React` or `Preserve`
-`--reactNamespace`                           | TypeScriptReactNamespace                   | string
-`--skipDefaultLibCheck`                      | TypeScriptSkipDefaultLibCheck              | boolean
-`--allowUnusedLabels`                        | TypeScriptAllowUnusedLabels                | boolean
-`--noImplicitReturns`                        | TypeScriptNoImplicitReturns                | boolean
-`--noFallthroughCasesInSwitch`               | TypeScriptNoFallthroughCasesInSwitch       | boolean
-`--allowUnreachableCode`                     | TypeScriptAllowUnreachableCode             | boolean
-`--forceConsistentCasingInFileNames`         | TypeScriptForceConsistentCasingInFileNames | boolean
-`--allowSyntheticDefaultImports`             | TypeScriptAllowSyntheticDefaultImports     | boolean
-`--noImplicitUseStrict`                      | TypeScriptNoImplicitUseStrict              | boolean
-`--project`                                  | *Not supported in VS*                      |
-`--watch`                                    | *Not supported in VS*                      |
-`--diagnostics`                              | *Not supported in VS*                      |
-`--listFiles`                                | *Not supported in VS*                      |
-`--noEmit`                                   | *Not supported in VS*                      |
-`--allowJs`                                  | *Not supported in VS*                      |
-*VS only option*                             | TypeScriptAdditionalFlags                  | *Any compiler option*
+`--suppressImplicitAnyIndexErrors`           | TypeScriptSuppressImplicitAnyIndexErrors   | boolean
+`--target`                                   | TypeScriptTarget                           | `ES3`, `ES5`, or `ES6`
+`--traceResolution`                          | *Not supported in MSBuild*                 |
+`--types`                                    | *Not supported in MSBuild*                 |
+`--typeRoots`                                | *Not supported in MSBuild*                 |
+`--watch`                                    | *Not supported in MSBuild*                 |
+*MSBuild only option*                        | TypeScriptAdditionalFlags                  | *Any compiler option*
 
 ## What is supported in my version of Visual Studio?
 
@@ -86,4 +102,4 @@ Users using newer versions of TS, will see a prompt to upgrade their project on
 ## TypeScriptCompileBlocked
 
 If you are using a different build tool to build your project (e.g. gulp, grunt , etc.) and VS for the development and debugging experience, set `<TypeScriptCompileBlocked>true</TypeScriptCompileBlocked>` in your project.
-This should give you all the editing support, but not the build when you hit F5.
+This should give you all the editing support, but not the build when you hit F5.