flask之模板html中调用python函数方法

一：html里面可以调用python写的函数

add_template_global（调用函数的引用，"调用函数的名字"）

from common.libs.UrlManager import UrlManager
app.add_template_global(UrlManager.buildStaticUrl,"buildStaticUrl")
app.add_template_global(UrlManager.buildUrl,"buildUrl")
app.add_template_global(UrlManager.buildImageUrl,"buildImageUrl")

作用：这个是为了让前端界面可以通过这个url找到需要的元素

 <img src="{{ buildStaticUrl('/images/common/qrcode.jpg') }}" width="200px">

# -*- coding: utf-8 -*-
import time
from application import app

class UrlManager(object):
    def __init__(self):
        pass

    @staticmethod
    def buildUrl( path ):
        return path

    @staticmethod
    def buildStaticUrl(path):
        release_version = app.config.get( 'RELEASE_VERSION' )
        print("这是什么玩意：",release_version) # 访问login.html一共打印了10次None，源模板7次，本身打印3次
        ver = "%s"%( int( time.time())) if not release_version else release_version
        path =  "/static" + path + "?ver=" + ver
        # 对path进行拼接，路径是静态文件里面的图片和css,js等资源
        return UrlManager.buildUrl( path )

    @staticmethod
    def buildImageUrl( path ):
        app_config = app.config['APP']
        url = app_config['domain'] + app.config['UPLOAD']['prefix_url'] + path
        return url

设计蓝图

from flask import Blueprint,send_from_directory
from application import app

route_static = Blueprint("static",__name__)
@route_static.route("/<path:filename>")
def index(filename):
    # 因为static的位置也改变了，因此使用路由的方式来访问我们静态文件
    return send_from_directory(app.root_path+"/web/static/",filename)

注册蓝图

app.register_blueprint(route_static,url_prefix="/static")

请求成功后，控制台输出

111.18.99.43 - - [04/Apr/2020 20:47:50] "GET /static/css/style.css?ver=1586004470 HTTP/1.1" 200 -
111.18.99.43 - - [04/Apr/2020 20:47:52] "GET /static/plugins/jquery-2.1.1.js?ver=1586004470 HTTP/1.1" 200 -
111.18.99.43 - - [04/Apr/2020 20:47:52] "GET /static/images/common/mini_qrcode.jpg?ver=1586004470 HTTP/1.1" 200 -
111.18.99.43 - - [04/Apr/2020 20:47:53] "GET /static/bootstrap/bootstrap.min.js?ver=1586004470 HTTP/1.1" 200 -
111.18.99.43 - - [04/Apr/2020 20:47:53] "GET /static/plugins/layer/layer.js?ver=1586004470 HTTP/1.1" 200 -
111.18.99.43 - - [04/Apr/2020 20:47:53] "GET /static/images/common/qrcode.jpg?ver=1586004470 HTTP/1.1" 200 -
111.18.99.43 - - [04/Apr/2020 20:47:55] "GET /static/js/common.js?ver=1586004470 HTTP/1.1" 200 -
111.18.99.43 - - [04/Apr/2020 20:47:55] "GET /static/js/user/login.js?ver=1586004470 HTTP/1.1" 200 -

send_from_direcorty（文件所在的文件夹，文件名）的作用：就是帮你找到你的所需要的文件，传入的参数是路径和文件名

 <img src="{{ buildStaticUrl('/images/common/qrcode.jpg') }}" width="200px">

过程：html里面调用了 buildStaticUrl（包含路径），函数的返回值是一个path，给src赋值为这个path，然后就发送了请求，按照这个路径进行寻找，然后触发了route_static这个蓝图，进入index函数，通过send_from_directory方法，找到文件真实的路径，进行展示

# TODO