Underscore and Backbone Models
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The document discusses Underscore.js and Backbone.js, highlighting Underscore's utility functions for JavaScript and Backbone's model structure for handling JSON data, often sourced from REST APIs. Key features include methods for binding context, chaining methods, and CRUD operations on models. Additionally, Backbone allows for defining default values and supports various back-end sync methods.
![bind and bindAll
bind makes 'this' useful again
_.bind(function, context, [*args])
Returns a function that has a consistent 'this'
context.
_.bindAll(object) will bind all object's
properties with object as the context](https://image.slidesharecdn.com/2012-01-underscoreandbackbonemodels-130125103606-phpapp01/85/Underscore-and-Backbone-Models-6-320.jpg)
![Chain, Tap and Value
_.chain(value) returns a wrapped value,
which will stay wrapped until _.value() is
called
_([42, 43]).chain()
.first() // 42
.take(function(val) { return val * 2 }) // 42 * 2
.value() // 84
_.tap() let's you temporarily unwrap the value
inside the chain](https://image.slidesharecdn.com/2012-01-underscoreandbackbonemodels-130125103606-phpapp01/85/Underscore-and-Backbone-Models-7-320.jpg)
Underscore and Backbone Models
- 2. Underscore Underscore is a utility belt for Javascript
- 3. Supports Functional Programming Accessed as the '_' object _.is_NaN(...) _.extend(...) _.each(...) Uses standard Javascript objects
- 4. Better Tests ● _.isNaN() - returns false with undefined ● _.isEqual() - full deep-compare, very efficient ● Standard form - _.isFunction, _. isString, _.isUndefined.
- 5. Extend for Mixins _.extend(object, mixins) ● Works on any Javascript object ● Mixins are just standard JS objects too { addon_function: function().... another_addon: function() ... }
- 6. bind and bindAll bind makes 'this' useful again _.bind(function, context, [*args]) Returns a function that has a consistent 'this' context. _.bindAll(object) will bind all object's properties with object as the context
- 7. Chain, Tap and Value _.chain(value) returns a wrapped value, which will stay wrapped until _.value() is called _([42, 43]).chain() .first() // 42 .take(function(val) { return val * 2 }) // 42 * 2 .value() // 84 _.tap() let's you temporarily unwrap the value inside the chain
- 8. So Much More ● Safer keys, values, lastIndexOf, hasOwnProperty ● Array math (union, difference, sorting) ● Lightweight Templating ● All Under 4kb
- 9. Backbone Models Backbone Models hold JSON data, typically fetched from an external REST API Backbone Models are defined with Underscore's extend method Backbone.Model.extend({ ... model definition ... });
- 10. Defaults Backbone Models can define defaults which it also borrows from Underscore var Meal = Backbone.Model.extend({ defaults: { "appetizer": "caesar salad", "entree": "ravioli", "dessert": "cheesecake" } });
- 11. fetch/save Calling fetch() on a Backbone Model is analogous to a "GET" of that resource. Calling save() is analogous to a "PUT" model.fetch(); // make changes to model data model.save();
- 12. Backbone.sync All I/O on Backbone Models is done with Backbone.sync By default, Backbone.sync implements it's CRUD methods on an AJAX backend. There exist alternate implementations, such as backbone.localStorage and backbone. mongodb Or you can write your own ...