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Request Variables
2:58Our views won't always know everything. Sometimes we'll need to provide them with new arguments to get them to work like we want. One of the most common ways is through the query string part of the URL.
Lots of times, we want to let users send
in arguments and values through the URL.
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The most common way of doing this is by
using what's call the query string.
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You've seen them before, they're the bit
in the URL after the question mark.
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In Flask, we can get to this pretty
easily, let's find out how.
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>> All right, so before we can get to the
request object which we need in order to
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get to our arguments there.
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We have to actually have their request
object.
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Which is flask is a, it's a simple import
emphasis global object.
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The Python programmer in me kind of
cringes at it being this global object,
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but that's what it is, that's, we're gonna
use it so it's fine.
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This is kind of cool though it being a
global object because it means the request
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is available every where.
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It's always available.
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So that's great, but the only place that
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we're really gonna deal with it is inside
of our views because requests go to views.
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So inside of our index view we're gonna
add a couple of things.
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Here in the function declaration right
here, let's add a key word argument of
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name and we're gonna give it, not Kenneth,
let's give it treehouse.
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So then what we want to do is we want to
take treehouse out of here,
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and we want to put something in here.
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.format name.
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Okay.
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So, let's let's test that and see if that
works.
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Yeah, we still get Hello from Treehouse.
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Now, you know, that, or you notice that I,
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I changed this, but I didn't have to do
anything down here.
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I can just leave it running.
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That's because we have this debug true.
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That makes it reload whenever this code
changes.
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Pretty handy.
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Okay.
So
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now let's make sure that we can set this
new value.
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In the request object there's an attribute
called args that holds all of
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the arguments in the request.
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If you're familiar with web development
this would be things like the get or
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post values.
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Or rather they get and post keywords and
their values.
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It's like a dictionary so we're gonna use
the .get method.
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If the name key isn't there then we're
just gonna use the default name so
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let's do name equals request.args.get name
or just the name that was already set.
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All right.
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So if we get a name great.
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If we don't.
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Use this name.
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Okay?
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Okay.
So, we'll refresh.
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Hello from Treehouse still, and
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then let's add we add question mark which
is what specifies our query values,
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and then we do name and we're gonna say
name equals Kenneth.
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And now it's named Hello from Kenneth.
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So that's pretty cool.
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We get a different name.
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Accessing get variables is a good way to
let users pass in values.
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But query strings are often pretty ugly.
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In fact they're so ugly I'd rather show
you a better way.
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Let's clean up our URLs in the next video.
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