摘要：而其他的引擎，例如能夠幫我們進(jìn)行驗證登錄自此，官網(wǎng)的我們已經(jīng)大致有了了解后續(xù)我們可以選擇運用該框架實現(xiàn)一些簡單的應(yīng)用，或者可以深入研究其源碼，提升自身的編程水平

在初識Bottle（一）中，我們了解了Bottle的基本用法
在Bottle源碼閱讀（一）和Bottle源碼閱讀（二）可以查看個人對bottle源碼的相關(guān)閱讀筆記

下面繼續(xù)閱讀Bottle的官方文檔https://bottlepy.org/docs/dev...

在bottle中例如css等的文件是不會被自動加載的，因此需要自己定義callback函數(shù)，通過調(diào)用使用

from bottle import static_file
@route("/static/")
def server_static(filename):
    return static_file(filename, root="/path/to/your/static/files")

通過error裝飾器可以對相應(yīng)的錯誤碼自定義對應(yīng)的應(yīng)用函數(shù)

from bottle import error
@error(404)
def error404(error):
    return "Nothing here, sorry"

Bottl框架允許應(yīng)用函數(shù)返回如下類型的結(jié)果

Dictionaries字典：
python的字典通過框架被轉(zhuǎn)換為json字符串，而header中的Content-Type則會被設(shè)置為application/json

Empty Strings, False, None or other non-true values：
header中的Content-Length被設(shè)置為0

Unicode strings
Byte strings
Instances of HTTPError or HTTPResponse
File objects
Iterables and generators

通過在應(yīng)用函數(shù)中改變response的屬性可以自定義

from bottle import response
@route("/iso")
def get_iso():
    response.charset = "ISO-8859-15"
    return u"This will be sent with ISO-8859-15 encoding."

@route("/latin9")
def get_latin():
    response.content_type = "text/html; charset=latin9"
    return u"ISO-8859-15 is also known as latin9."

通過static_file接口，我們可以實現(xiàn)調(diào)用和下載

from bottle import static_file
@route("/images/")
def send_image(filename):
    return static_file(filename, root="/path/to/image/files", mimetype="image/png")

@route("/static/")
def send_static(filename):
    return static_file(filename, root="/path/to/static/files")
    
@route("/download/")
def download(filename):
    return static_file(filename, root="/path/to/static/files", download=filename)

通過abort可以快速定義錯誤碼相應(yīng)的錯誤頁內(nèi)容
redirect實現(xiàn)重定向

from bottle import route, abort
@route("/restricted")
def restricted():
    abort(401, "Sorry, access denied.")
    
from bottle import redirect
@route("/wrong/url")
def wrong():
    redirect("/right/url")

response對象包括了響應(yīng)的metadata例如狀態(tài)碼，headers，cookie等

response的狀態(tài)碼控制瀏覽器的行為，默認(rèn)200ok
response的header可以通過set_header()來設(shè)置，對同一個header項，還可以通過add_header添加額外內(nèi)容
cookie是保留在用戶瀏覽器的一些數(shù)據(jù)，可以通過get_cookie和set_cookie來操作

@route("/hello")
def hello_again():
    if request.get_cookie("visited"):
        return "Welcome back! Nice to see you again"
    else:
        response.set_cookie("visited", "yes")
        return "Hello there! Nice to meet you"

cookie是容易被偽造的，所以Bottle框架提供了cookie的簽名機(jī)制，只需要提供一個secret的參數(shù)作為密鑰
Bottle會自動持久化和去持久化保存在cookie中的數(shù)據(jù)，cookie不超過4k。
此時cookie仍然能從瀏覽器中查看到，而且是可以被復(fù)制的，所以最好不要將密鑰的信息放在用戶客戶端

@route("/login")
def do_login():
    username = request.forms.get("username")
    password = request.forms.get("password")
    if check_login(username, password):
        response.set_cookie("account", username, secret="some-secret-key")
        return template("
Welcome {{name}}! You are now logged in.
", name=username)
    else:
        return "
Login failed.
"

@route("/restricted")
def restricted_area():
    username = request.get_cookie("account", secret="some-secret-key")
    if username:
        return template("Hello {{name}}. Welcome back.", name=username)
    else:
        return "You are not logged in. Access denied."

request 對象包括了Cookies, HTTP header, HTML

from bottle import request, route, template

@route("/hello")
def hello():
    name = request.cookies.username or "Guest"
    return template("Hello {{name}}", name=name)

name = request.cookies.name

# is a shortcut for:

name = request.cookies.getunicode("name") # encoding="utf-8" (default)

# which basically does this:

try:
    name = request.cookies.get("name", "").decode("utf-8")
except UnicodeError:
    name = u""

for choice in request.forms.getall("multiple_choice"):
    do_something(choice)

from bottle import route, request, response, template
@route("/forum")
def display_forum():
    forum_id = request.query.id
    page = request.query.page or "1"
    return template("Forum ID: {{id}} (page {{page}})", id=forum_id, page=page)

  Category:      
  Select a file: 
  

文件上傳到服務(wù)端后

@route("/upload", method="POST")
def do_upload():
    category   = request.forms.get("category")
    upload     = request.files.get("upload")
    name, ext = os.path.splitext(upload.filename)
    if ext not in (".png",".jpg",".jpeg"):
        return "File extension not allowed."

    save_path = get_save_path_for_category(category)
    upload.save(save_path) # appends upload.filename automatically
    return "OK"

通過BaseRequest.body我們可以直接獲取原始的請求體，也可以獲取environ

@route("/my_ip")
def show_ip():
    ip = request.environ.get("REMOTE_ADDR")
    # or ip = request.get("REMOTE_ADDR")
    # or ip = request["REMOTE_ADDR"]
    return template("Your IP is: {{ip}}", ip=ip)

Bottle內(nèi)建了前端模板引擎，在官網(wǎng)給出的這個例子中，會加載./views/中的hello_template.tpl

@route("/hello")
@route("/hello/")
def hello(name="World"):
    return template("hello_template", name=name)
或者
@route("/hello")
@route("/hello/")
@view("hello_template")
def hello(name="World"):
    return dict(name=name)

%if name == "World":
    
Hello {{name}}!
    
This is a test.
%else:
    
Hello {{name.title()}}!
    
How are you?
%end

模板在編譯后會被緩存到內(nèi)存中，修改后需要執(zhí)行bottle.TEMPLATES.clear()清除緩存模板

Bottle提供了一系列的第三方引擎，這些能夠有效地減少重復(fù)性工作
官網(wǎng)使用SQLitePlugin作為例子，在每一次調(diào)用需要與數(shù)據(jù)庫進(jìn)行交互的callback函數(shù)時，該引擎會自動創(chuàng)建連接和關(guān)閉連接。而其他的引擎，例如’auth‘能夠幫我們進(jìn)行驗證登錄

from bottle import route, install, template
from bottle_sqlite import SQLitePlugin

install(SQLitePlugin(dbfile="/tmp/test.db"))

@route("/show/")
def show(db, post_id):
    c = db.execute("SELECT title, content FROM posts WHERE id = ?", (post_id,))
    row = c.fetchone()
    return template("show_post", title=row["title"], text=row["content"])

@route("/contact")
def contact_page():
    """ This callback does not need a db connection. Because the "db"
        keyword argument is missing, the sqlite plugin ignores this callback
        completely. """
    return template("contact")

sqlite_plugin = SQLitePlugin(dbfile="/tmp/test.db")
install(sqlite_plugin)

uninstall(sqlite_plugin) # uninstall a specific plugin
uninstall(SQLitePlugin)  # uninstall all plugins of that type
uninstall("sqlite")      # uninstall all plugins with that name
uninstall(True)          # uninstall all plugins at once

自此，Bottle官網(wǎng)的tutorial我們已經(jīng)大致有了了解
后續(xù)我們可以選擇運用該框架實現(xiàn)一些簡單的應(yīng)用，或者可以深入研究其源碼，提升自身的編程水平