Building Data-Driven Web Apps with Pyramid and SQLAlchemy Transcripts
Chapter: User input and HTML forms
Lecture: Concept: One source of data

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0:00 Let's review this concept
0:01 of having just one source of data
0:03 rather than four or five being passed in
0:05 from these different sources on request.
0:08 So we saw that if we just create just a few lines of code
0:11 the simple create function that takes your request
0:14 and returns this thing we created
0:15 called a request dictionary
0:17 which is really a fancy dictionary
0:19 that lets you do sort of arbitrary dynamic access
0:22 into its keys as if they were fields or attributes
0:25 rather than dictionary style with .get
0:28 or square brackets and things like that.
0:30 Then what we're going to do is we're going to
0:32 pass in the request and we're going to say
0:33 "Let's go and get the query string
0:35 and the headers and the Post and the matchdict
0:38 and all of that stuff and merge it
0:39 into one super dictionary."
0:41 And if there's data that is in both
0:43 like say in the matchdict and the Get
0:46 the last one wins.
0:47 So in this case anything in matchdict
0:49 is going to override anything in the query string.
0:52 And then if we just use this in our action methods
0:55 it gets so much simpler.
0:56 So over here in our registered post
0:59 we say create us one of these dictionaries
1:01 when we say d.email_address d.password
1:03 where email_address and password
1:06 these were the named input elements in our form.
1:10 This is certainly an optional design pattern
1:12 but it's very very useful to help just centralize
1:16 where all this data is coming from.