JavaScript Basics

Slides for an internal talk I gave while at MintDigital

Transcript

1. JavaScript at Mint and Beyond
2. var we = “so so so excited”; Variables
3. we = “so so so excited”; Global Variable
4. function sit(seat){ sitting = ‘sitting in the ’+seat+‘ seat’; alert(sitting); } sit(‘front’); alert(sitting); sitting was set globally
5. function parting(chant){ var location = ‘Back Seat’, mood = ‘happy’, over; } multiple variable declaration
6. (we == “so so so excited”) // true
7. (we === “so so so excited”) // more true
8. for(var i=0; i < 10; i++){ // ... }
9. while ( true ) { // for ever and ever }
10. for(var node in object){ // ... }
11. Everything is an Object
12. function Car(seats){ // code } Car.prototype.mood = function(){ return ‘exciting’; } var partyVenue = new Car();
13. var weekDays = [ ‘monday’, ‘tuesday’ ... ]; var weekDays = new Array(‘monday’, ‘tuesday’ ... ); creating arrays
14. var seat = { position: ‘front’, activity: ‘kicking’ }; var seat = new Object(); seat.position = ‘front’; seat.activity = ‘kicking’; creating objects
15. var App = { inlineSearch: function(){ ... }, ajaxPannels: function(){ ... } }; namespacing
16. for(var node in object){ // ... }
17. typeof friday === “undefined” // true BB.isDef(friday) existence
18. if( thursday ){ // } undefined variables cause exceptions
19. var friday = {}; if( friday.now ) { // } undefined attributes don’t
20. function friday(){ return ‘party’; } method
21. function (){ return ‘party’; } anonymous
22. (function (){ return ‘party’; }()); self executing anonymous
23. (function($){ // code that uses jQuery $ here }(jQuery)); pass through variables into anonymous functions
24. elm.addEventListener(‘click’, function(e){ // event code }, false); native events
25. jQuery
28. $(‘div.car p.front-seat’); css selectors
29. $(‘div.car p[rel=“empty”]’); advanced selectors
30. var $car = $(‘div.car’), $frontSeat = $(‘p.front-seat’, $car); or $frontSeat = $car.children(‘p.front-seat’); scoped selectors
31. $(function(){ // execute on DOMReady }); DOMReady Loader
32. $.each( ... ); object with methods
33. $(‘<div id=“friday”>partying</ div>’); create nodes
34. var $seats = $(‘div.seat’); use a $variable name for jQuery objects
35. $(‘div.seat’); // [ node1, node2, node3 ... ] jQuery object is an array of matched nodes
36. $(‘div.seat’).css(‘background’); get css value
37. $(‘div.seat’) .css(‘background’, ‘#bada55’); set value
38. $(‘div.seat’) .css(‘color’, ‘#bada55’) .addClass(‘party’) modifiers return a jQuery object
39. $friday.bind(‘click’, function(e){ e.preventDefault(); // parting }); jQuery events
40. BB.bodyID(‘users-index’, function(){ ... }); BB.bodyClass(‘users’, function(){ ... }); restricting execution
41. <body id=“search-index”> <form method=“get” action=“” id=“search”> <input type=“text” name=“q”> <button type=“submit”>Search!</button> </form> <div id=“results”> </div> </body> a search page
42. BB.bodyID(‘search-index’, function(){ var $form = $(‘form#search’); BB.submitInline($form, { success: function(){ // success code here } } });
43. { results: [ { title: ‘fun’, url: ‘/fun’ }, { title: ‘excited’, url: ‘/excited’ }, ... ] } json response
44. <body id=“search-index”> <form method=“get” action=“” id=“search”> <input type=“text” name=“q”> <button type=“submit”>Search!</button> </form> <div id=“results”> </div> </body> recap search page
45. BB.bodyID(‘search-index’, function(){ var $form = $(‘form#search’), $results = $(‘div#results’); BB.submitInline($form, { success: function(json){ $.each(json.results, function(i, data){ $results.append(‘<a href=“’+data.url +‘”>’+data.title+‘</a>’); }); } } });
46. Browser Development
47. function whichSeatShouldITake(){ var seats = [ ‘Front Left’, ‘Front Right’, ‘Back Left’, ‘Back Right’, ‘Back Middle’], random = Math.round(Math.random()*seats.length)); return “Just sit in the ” + seats[random] + “ seat and shut up”; }