Building Data-Driven Web Apps with Flask and SQLAlchemy Transcripts
Chapter: Client and server-side validation
Lecture: Simplified view methods
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We saw that the real value of these view models
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is they let us write simpler view methods
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or action methods.
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Here's our register story that we were working with.
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Notice how simple git is.
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No matter the data that has to be exchanged
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like we have a country dropdown
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we got a populated country list
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out of our database.
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It doesn't matter.
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The view model is going to take care of that.
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All we do is create the view model, send it along.
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For the post one, there's a little
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bit more going on and we got to
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get the data from the form, do the validation
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and so on. But still, it's much simpler.
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So we're going to create this view model.
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We're going to ask it to validate.
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And if it sets some error, well
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we need to show that error to the user.
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What data has to be exchanged?
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It doesn't matter how big the form is
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or how complicated, the view model
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knows how to exchange that data.
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So we just say hey, send that data back.
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Return vm.togit.
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And it takes care of all that.
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Now, if you make it through here
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all that rich validation you've
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added has passed.
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You're probably good to go.
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So here we're going to say, if we were unable
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to register with their email and password
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that the vm got ahold of, we might still
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need to send a message, so we're going to set
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like an error and send it back.
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Otherwise we just do a redirect
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over to either / or /account.
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Wherever we want to send them to we've done it.
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Now isn't this clean and concise?
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Imagine how complicated a realistic
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registration method here would be
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in actual code.
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Well, using view models, it doesn't get
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much worse than this.
