Creating Single Page Web App using Backbone JS
Download as PPTX, PDF6 likes5,932 views
The document outlines the process of creating a single-page web application using Backbone.js, covering foundational technologies such as HTML, CSS, JavaScript, and jQuery. It explains the structure provided by Backbone.js for organizing models, views, and routers, and delves into event handling, data manipulation, and template rendering. Additionally, it discusses best practices for managing model collections and synchronizing data with the server, culminating in examples of rendering venue details from an API response.
![Google Map
• In page view, create Google Map object and render it in the div
created for that
• Register event handler for Google Map click event
@map = new google.maps.Map(
$(’#map-canvas’)[0]),
map_options)
google.maps.event.addListener @map,
'click', (ev) =>
@get_venues(
ev.latLng.lat(),
ev.latLng.lng())
@akshaymathu
48](https://image.slidesharecdn.com/creatingsinglepagewebapp-backbone-140303004806-phpapp01/85/Creating-Single-Page-Web-App-using-Backbone-JS-48-320.jpg)
Creating Single Page Web App using Backbone JS
- 1. Creating Single Page Web App using Akshay Mathur
- 2. Akshay Mathur • Founding Team Member of – ShopSocially (Enabling “social” for retailers) – AirTight Neworks (Global leader of WIPS) • 15+ years in IT industry – Currently Principal Architect at ShopSocially – Mostly worked with Startups • From Conceptualization to Stabilization • At different functions i.e. development, testing, release • With multiple technologies @akshaymathu 2
- 3. What have we learnt • Creating basic web pages – HTML tags – CSS • Basic JavaScript and jQuery – – – – Reading and writing DOM Getting data using AJAX calls Responding to browser events jQuery templates • CoffeeScript • Object Oriented JavaScript – JS Classes – Extending classes using prototypes
- 4. BackboneJS • Provides MVC structure for JavaScript • Built on top of UnderscoreJS • Other than Model, View and Controller (Router) also provides Event and Collection objects – Using custom events help writing good code and eliminates use of global variables – Array of Models with same structure can be combined into Collection for ease of handling @akshaymathu 4
- 5. UnderscoreJS • Has nothing to do with MVC • Provides many useful functions on – Arrays – Objects – Array of Objects • BackboneJS directly extends a few functions for its objects (Classes) @akshaymathu 5
- 6. BackboneJS code class LoginModel extends Backbone.Model class LoginView extends Backbone.View initialize: => @template = $(’#login_template').template() @render() render: => $(@el).html $.tmpl(@template, @model.toJSON()) events: => 'click #login_btn' : ’login_handler’ login_handler: (ev) => window.mpq_track ’Login Click’ class LoginController extends Backbone.Router initialize: => @l_model = new LoginModel window.app_info @l_view = new LoginView model: model, el: ’#login_div’ @akshaymathu 6
- 7. Backbone View • A View is created by extending a Backbone’s view class • A View always have 2 properties: – el: An HTML element that is in the root of the View – model: Model that powers data to the View @akshaymathu 7
- 8. Creating View class LoginView extends Backbone.View initialize: => @template = $.template( $(’#login_template’)) @render() render: => $(@el).html $.tmpl(@template, @model.toJSON()) class LoginController extends Backbone.Router initialize: => @l_model = new LoginModel window.app_info @l_view = new LoginView model: @l_model, el: ’#login_div’ @akshaymathu 8
- 9. Rendering HTML • Typically a view has a template • In the render method, the template should be filled with data and inserted into el – The el can be attached to DOM before or after filling HTML class LoginView extends Backbone.View initialize: => @template = $.template $(’#login_template’) render: => $(@el).html $.tmpl(@template, @model.toJSON()) @akshaymathu 9
- 10. Browser Events • Defining events object within a view automatically connects functions to event handlers class LoginView extends Backbone.View events: 'click #login_btn' : ’login_handler’ login_handler: (ev) => window.mpq_track ’Login Click’ @akshaymathu 10
- 11. Design Views for • http://explore-venues.appspot.com/ @akshaymathu 11
- 12. Thinking of Views • Create a view for whole page – Base view that can handle anything as needed – It may be rendered by server • A view for each unit that is logically different – Event handling is needed within • Keep separate model for each view @akshaymathu 12
- 13. Zombie Views • When new views are created from a view class and attached to DOM in a way that it replaces HTML of an old view – The old view object and its events remain attached and create issues $(“#button”).click -> @view = new SomeView Class SomeView extends backbone.View render: => $(“container”).html template_html @akshaymathu 13
- 14. Handling Zombies • Don’t let zombies create • Use .destroy() on the View instance • Cleanup associated model if needed $(“#button”).click -> @view = new SomeView $(“#close_button”).click -> @view.destroy() @akshaymathu 14
- 15. @akshaymathu 15
- 16. Backbone Model • Model is defined extending the Backbone’s Model Class • The Model object can be created with the data coming from the server (database) • The data can be read later using .get() and set using .set() methods • Transient data (not intended to be synced with server) can be stored separately @akshaymathu 16
- 17. Creating Model app_info = {type: 4, name: ‘Internal Application’, protected: true } class LoginModel extends Backbone.Model initialize: => @is_changed = false class LoginRouter extends Backbone.Router initialize: => @l_model = new LoginModel app_info @akshaymathu 17
- 18. Data Manipulation • Read old_name = @model.get ‘name’ • Write new_name = old_name.toLower() @model.set ‘name’, new_name @model.is_changed = true @akshaymathu 18
- 19. Model Events • Model object raises events on change in data – changed – remove • These events may be captured (by view) and acted upon accordingly – A few properties are also set within the Model – Old and new values of the Model are also available @akshaymathu 19
- 20. Keeping UI Up-to-Date class LoginView extends Backbone.View initialize: => @model.bind(‘change’, @render) @render() render: => $(@el).html $.tmpl(@template, @model.toJSON()) class LoginRouter extends Backbone.Router initialize: => @l_model = new LoginModel app_info @l_view = new LoginView model:@l_model @akshaymathu 20
- 21. Syncing with Server • For having better control over data, one should collect data from the Model and make an AJAX call • One can also attach a URL to the Model and RESTful AJAX calls are automatically done @akshaymathu 21
- 22. Collections • Simple data structure for storing many instances of same model – Array of Model objects • Provides methods and properties for managing the list • Can be created by extending Collection class of Backbone @akshaymathu 22
- 23. Creating Collection class VenueModel extends Backbone.Model class VenueCollection extends Backbone.Collection model: VenueModel class VenueListModel extends Backbone.Model initialize: => @e_list = new VenueCollection class VenueListView extends Backbone.View initialize: => @model.e_list.bind('add', @add_venue) add_venue: (venue_model) => @akshaymathu 23
- 24. @akshaymathu 24
- 25. Backbone Router • It routes URLs to respective methods • A Router is created by extending a Backbone’s router class • Route configuration can be passed while creating the router object instance @akshaymathu 25
- 26. Creating Router class LoginController extends Backbone.Router initialize: => @l_model = new LoginModel window.app_info @l_view = new LoginView model: model, el: ’#login_div’ routes: “help”: “help” $(document).ready -> l_router = new LoginController() @akshaymathu 26
- 27. Route Configuration • Rout configuration is a JavaScript object mapping URLs to functions – URL patterns may be used as key – Data can be read from URLs and passed to functions as parameters @akshaymathu 27
- 28. Routes at Work routes: "help": "help” // #help "search/:query": "search", // #search/kiwis "search/:query/p:page": "search" // #search/kiwis/p7 help: -> search: (query, page)-> @akshaymathu 28
- 29. Catch All • Router is sometimes used for putting methods not belonging to any other Model or View • Router also acts as a glue for all other objects – Typically all basic views are initialized in router so any cross-view functionality can be implemented in router @akshaymathu 29
- 30. @akshaymathu 30
- 31. Events • Events facilitate communication amongst different objects – Data can be passed along with events • Browser raises events on user actions • Publish-Subscribe architecture avoids tight coupling between objects @akshaymathu 31
- 32. Backbone Events • Backbone objects also raise events on various actions – add: when a model is added to a collection. – remove: when a model is removed from a collection. – reset: when the collection's entire contents have been replaced. – change: when a model's attributes have changed. – change: when a specific attribute has been updated. – destroy: when a model is destroyed. @akshaymathu 32
- 33. Custom Events • Backbone’s event module can be mixed with an object – The the objects gets the ability to raise events programmatically – The object also gets the ability to listen to the events @akshaymathu 33
- 34. Defining Custom Events EventDispatcher = SHOW_VENUE: 'show_venue' CLEAN: 'clean' _.extend(EventDispatcher, Backbone.Events) @akshaymathu 34
- 35. Using Custom Events ED = EventDispatcher class VenuetView extends Backbone.View initialize: => ED.bind ED.CLEAN, @remove_self class VenueListView extends Backbone.View initialize: => @model.e_list.bind('add', @add_venue) ED.bind ED.CLEAN, @reset_col clean_old_list: => @venue_list_model.e_list.reset() ED.trigger ED.CLEAN @akshaymathu 35
- 36. @akshaymathu 36
- 37. Go Hands-on Explore FourSquare Venues http://explore-venues.appspot.com/
- 38. @akshaymathu 38
- 39. Design Views • Page view – Accordion – Google Map • Venue list view – All venue tiles • Venue view – Single venue tile • Venue details view (do later) – Popup with details of the venue @akshaymathu 39
- 40. Design Models • As a thumb rule, a model can be kept for each view – Page model – Venue list model – Venue model – Venue details model (do later) @akshaymathu 40
- 41. Create Base HTML • Head – Include Bootstrap CSS – Include JS • Google Map API, jQuery’s , jQuery template • Bootstrap, Underscore, Backbone, App’s custom • Top bar – Use navbar’s HTML from Bootstrap • Accordion – Use Bootstrap jQuery plugin’s HTML – Create accordion headers – Keep accordion bodies blank @akshaymathu 41
- 42. Create jQuery Templates • No template for Google Map – Map UI is completely rendered by Google APIs • Venue template – Each venue tile • Venue details template (do later) – Venue details popup – Use Bootstrap modal jQuery plugin’s HTML @akshaymathu 42
- 43. @akshaymathu 43
- 45. Basic Skeleton class VenueModel extends Backbone.Model class VenueCollection extends Backbone.Collection model: VenueModel class VenueListModel extends Backbone.Model initialize: => @e_list = new VenueCollection class VenueListView extends Backbone.View initialize: => @model.e_list.bind('add', @add_venue) class VenueView extends Backbone.View class PageModel extends Backbone.Model class PageView extends Backbone.View class VenueController extends Backbone.Router @akshaymathu 45
- 46. Start Execution • On DOM ready event, instantiate the router $(document).ready -> venue_controller = new VenueController • Create an instance of page model and view in initialize routine of router class VenueController extends Backbone.Router initialize: => @page_model = new PageModel @page_view = new PageView ( el: $("#maindiv"), model: @page_model) @akshaymathu 46
- 47. Initialize Page View • Page view initializes automatically when its instance gets created in router • Initialize venue list class PageView extends Backbone.View initialize: => @venue_list_model = new VenueListModel @venue_list_view = new VenueListView( el: $("#venue_list"), model: @venue_list_model ) @akshaymathu 47
- 48. Google Map • In page view, create Google Map object and render it in the div created for that • Register event handler for Google Map click event @map = new google.maps.Map( $(’#map-canvas’)[0]), map_options) google.maps.event.addListener @map, 'click', (ev) => @get_venues( ev.latLng.lat(), ev.latLng.lng()) @akshaymathu 48
- 49. Get Venues • Make a JSONP AJAX call to FourSquare for getting venues near the clicked location • Create a model from each venue in result and add to collection venue_model = new VenueModel item.venue @venue_list_model.e_list.add venue_model @akshaymathu 49
- 50. Render Venue Tile • As venue model adds into collection, the add event handler on collection is fired in venue list view @model.e_list.bind('add', @add_venue) • Handlers gets the venue view rendered and attaches it to the DOM add_venue: (venue_model) => venue_view = new VenueView( model: venue_model) tile_html = venue_view.render() $("#venue_col).append tile_html @akshaymathu 50
- 51. Click on Venue Tile • Venue view registers click handler by defining event map class VenueView extends Backbone.View events: "click" : 'show_details’ • Venue detail popup is to be shown outside base element (el) of the venue view so it raises an event show_details: => ED.trigger ED.SHOW_VENUE, @model @akshaymathu 51
- 52. Showing Details Popup • Page view listens to the event and renders details popup class PageView extends Backbone.View initialize: => ED.bind ED.SHOW_VENUE, @show_popup show_popup: (venue_model) => @detail_view = new VenueDetailView model: venue_model $(@el).append @detail_view.render() @akshaymathu 52
- 53. @akshaymathu 53
- 54. Optimization • Venue model and Venue detail model represent exactly same entity – There is always 1-1 relation • Same model may be used for both – First render should not be slow for bringing details @akshaymathu 54