83 lines
2.9 KiB
Markdown
83 lines
2.9 KiB
Markdown
|
---
|
||
|
|
title: Bottle
|
||
|
|
---
|
||
|
|
|
||
|
|
|
||
|
|
The bottle framework allows us to very quickly and easily get up and running with a basic web application.
|
||
|
|
|
||
|
|
The following details how to write and run a simple greeting web app where we can enter our name in a form, press submit and get back a greeting.
|
||
|
|
|
||
|
|
|
||
|
|
1. Use `pip` to install the bottle package.
|
||
|
|
```
|
||
|
|
pip install bottle
|
||
|
|
```
|
||
|
|
|
||
|
|
2. Create a `html` file to be served when loading the site. For example `index.html`.
|
||
|
|
|
||
|
|
Let's add a heading and a basic form to this page.
|
||
|
|
|
||
|
|
```html
|
||
|
|
<h3>Say Hello</h3>
|
||
|
|
|
||
|
|
<form action="/hello" method="get">
|
||
|
|
Name:
|
||
|
|
<input type="text" name="name"><br><br>
|
||
|
|
<input type="submit">
|
||
|
|
</form>
|
||
|
|
```
|
||
|
|
|
||
|
|
3. Create a new python file, example `main.py`.
|
||
|
|
|
||
|
|
4. In the first line of the file we need to import get, request, and run functions from the bottle module.
|
||
|
|
```python
|
||
|
|
from bottle import get, request, run
|
||
|
|
```
|
||
|
|
|
||
|
|
5. Now we define our function to serve our html file when the root page is accessed.
|
||
|
|
|
||
|
|
Here we use the `@get` decorator, which specifies this function should respond to `HTTP GET` requests and pass in `'/'` as the path that the function will be invoked by.
|
||
|
|
|
||
|
|
Next we define then `index()` function using the `def` keyword.
|
||
|
|
|
||
|
|
To read and return the html file we created in step 2, we use what is called a context manager. This handles opening and closing the file for us, allowing us to read the files and contents and return them with the `return` statement.
|
||
|
|
|
||
|
|
```python
|
||
|
|
@get('/')
|
||
|
|
def index():
|
||
|
|
with open('./index.html') as f:
|
||
|
|
return f.read()
|
||
|
|
```
|
||
|
|
|
||
|
|
6. To get the site to run and listen for requests we need to add a call to the bottle frameworks `run` function as follows.
|
||
|
|
|
||
|
|
Here we pass in the host that the web application will run on, in this case `localhost`, and the port that it should listen for HTTP requests.
|
||
|
|
|
||
|
|
|
||
|
|
7. Run the application and load it up in your browser http://localhost:8080/, you should see the html file we created eariler rendered in the browser.
|
||
|
|
|
||
|
|
If we enter our name and press submit now we will get a `HTTP 404` error though as we have not yet defined the function to respond to this request.
|
||
|
|
|
||
|
|
```python
|
||
|
|
run(host='localhost', port=8080)
|
||
|
|
```
|
||
|
|
|
||
|
|
|
||
|
|
8. Back in our `main.py` file we now need to define the function to respond when sumbitting our form.
|
||
|
|
|
||
|
|
Again we use the `@get` decorator here, however this time we pass in `'/.hello'` as the path. You may notice that this is the same path that we defined in the action attribute of our form in `index.html`.
|
||
|
|
|
||
|
|
Next we retrieve the `name` value from the url, when submitting the form the form data is url encoded like this http://localhost:8080/hello?name=Jon+Snow
|
||
|
|
|
||
|
|
Finally we return our greeting, appending the name entered in our form.
|
||
|
|
|
||
|
|
```python
|
||
|
|
@get('/hello')
|
||
|
|
def hello():
|
||
|
|
name = request.query['name']
|
||
|
|
return f'Hello {name}'
|
||
|
|
```
|
||
|
|
|
||
|
|
### Sources
|
||
|
|
https://bottlepy.org/docs/dev/
|