- Forms 6:51
- Forms 3 questions
- Cookies 7:27
- Cookies 4 questions
- Set a Cookie 3 objectives
- Starting the Builder 6:02
- Create a JSON String 2 objectives
- Parse a JSON string 1 objective
- Items 6:27
- Looping Through Items 1 objective
- Drawing the Bear 4:32
- Loop Nested Items 2 objectives
- Flash Messages 5:28
- Flash a Message 3 objectives
- Outro 0:26
- Review: Flask Basics 8 questions
Preview
Video Player
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Forms
6:51Most web apps use forms for gathering data. Ours will be no different, so we need to figure out how to get to the form data easily and cleanly.
[MUSIC]
0:00
[SOUND] To build our web app,
0:03
we need a few more pieces of Flask's
provided functionality.
0:05
Also, we're gonna be using several images
and some pre-built CSS.
0:09
So make sure you start with the work space
associated with this video.
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Something pretty much every web app uses
are forms.
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There are a lot ways out there for
handling forms in Flask, but
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we're just going to use them directly for
this course.
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Let's check them out.
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We're gonna start a new project.
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So I'm gonna go ahead and create a new
app.py, and you
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can see that we already have a templates
directory and a static directory.
0:34
This is thanks to you know the magic of
editing and
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our awesome designers here at Treehouse.
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so don't worry about what's in there we're
gonna modify some of
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what's inside templates but not what's
inside static.
0:49
And the options are something I set up for
us.
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already so we don't have to build it.
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while we're building the app.
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It basically just.
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Kind of defines what our options are,
hence it being called options.
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So let's go ahead and create our Flask app
which means to import flask, and
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we need to make our app, and we need to
run our app.
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And again we have to specify our host, and
our port.
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All right, so let's go ahead and actually
get this running.
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Python app.py and then I'm gonna open that
up.
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[BLANK_AUDIO]
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There we go, we've got that.
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Off to the side, awesome.
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All right.
So there we go.
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We get the not found, cuz there's nothing
there's no routes yet.
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So we should probably add an app, add a
route, right?
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So let's render a template.
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Let's, @app.route for that home page
there.
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Index, return render, template index.html.
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Okay, so let see what that does.
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Render template is not defined.
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That's because I forgot to import it.
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So let's import that.
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[BLANK_AUDIO]
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All right.
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[BLANK_AUDIO]
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All right.
There we go.
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So we've got this cute little bear.
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We gotta form.
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But that form is probably not going to do
anything.
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Lets, lets look at our template.
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And yeah that form's not going to do
anything.
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It's just going to post right back to
itself.
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So what that means is that we have to tell
this where to send its information to.
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What I want to do is I'm going to write.
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I'm gonna write a new method or a new
function rather.
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Let's go over here, and let's make a new
one that's called save.
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And I want this to only be accessible, if
you post to it.
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'Kay.
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So since I only want you to post to it.
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What I want to do is you know right now
we're gonna call this save.
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Let's just have it return Saved.
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All right.
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And over here we're gonna add a new item.
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We need to tell it.
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To print out the URL for a method or for a
function rather, which is called save.
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So it goes and looks at save.
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Figures out what the route it and goes,
oh, it's save.
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Okay.
Cool.
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So, that's where we're going to send it.
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All right.
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Refresh this and
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we're gonna name the bear, I'm gonna name
I'm gonna name the bear Mike.
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Let's build it.
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Yea!
I hit Save.
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So, that's fairly straight forward.
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Let's actually make it to were we, we
don't do this we just get redirected back
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we need to import a new thing so from
flask import redirect
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and from flask import url_for.
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We can actually do all these together, so
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let's just do render_template, redirect,
url_for.
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That way we can have them all down there.
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And what we want to return is a redirect.
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We want it to redirect to the url_for
index.
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All right?
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So, let's go back.
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There's Mike.
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Build it.
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Brings us right back.
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All right.
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So that's pretty cool.
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We handled it, it redirected back to us.
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You know, let's actually let's see what's
happening,
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when we do the redirect, like let's see
what comes in from this form.
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The easiest way to do that, is to go in
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here and bring our own old friend pdb.
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So, we're gonna set a trace right there.
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Make this a little bigger.
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That should give you a hint of what's
going to happen.
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All right.
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And you know what, just to make sure that
we have the information let's
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import request up there.
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Okay.
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So we do this.
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We have Mike the bear and here, well let's
see what we have.
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We just have PDB.
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Do we have request?
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We do, there is a request, there's a whole
lot of stuff here, so
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luckily I know what it is that we need to
look for.
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What we want to look for is inside
request,
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there's a thing called form which is this
immutable multidict.
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I'm really not sure what it means by
multidict, but
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immutable means that we can't change it.
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And so what this tells us is that we have
name as a key and Mike is a value.
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So that's pretty cool.
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I'm gonna go ahead and let the view
continue.
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And then I'm gonna take PDB out of my
view,
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cuz I don't wanna have that just hanging
around.
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[SOUND] Great, we have a form and
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we've seen how to read data from it.
6:42
In our next video, we're going to look at
using cookies to store and retrieve data.
6:47