61 lines
1.5 KiB
JavaScript
61 lines
1.5 KiB
JavaScript
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//
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// One promise with multiple consumers
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//
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// The getProfile method creates a promise that is resolved with
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// a mock profile. The user is then passed to navbar.showUsername()
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// and account.showProfile().
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//
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// Remember that a promise serves as a placeholder for the result
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// of an operation. Here, the user.profilePromise is a placeholder
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// used by the showUsername and show Profile functions.
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// These functions can be safely called at anytime before or after
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// the profile data is available. The callbacks they use to print
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// the data to the console will only be invoked once the profile
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// is loaded.
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//
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var user = {
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profilePromise: null,
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getProfile: function () {
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if (!this.profilePromise) {
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// This code would request the profile from the server
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var mockProfile = {
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name: 'Samantha',
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subscribedToSpam: false
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}
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this.profilePromise = new Promise(function (resolve, reject) {
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setTimeout(()=>resolve(mockProfile), 1000)
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})
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}
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return this.profilePromise
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}
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}
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var navbar = {
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showUsername: function (user) {
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user.getProfile().then(function (profile) {
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console.log('*** Navbar ***')
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console.log('Name: ' + profile.name)
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})
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}
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}
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var account = {
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showProfile: function (user) {
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user.getProfile().then(function (profile) {
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console.log('*** User Profile ***')
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console.log('Name: ' + profile.name)
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console.log('Send lots of email? ' + profile.subscribedToSpam)
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})
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}
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}
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navbar.showUsername(user)
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account.showProfile(user)
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