Niko_Public/checkIn/functions.py

from django.http import HttpResponse, HttpResponseRedirect
from django.shortcuts import render
import json
import datetime
from Niko import settings
import os
from PIL import Image


class DateEncoder(json.JSONEncoder):
    def default(self, obj):
        if isinstance(obj, datetime.datetime):
            return obj.strftime('%Y-%m-%d %H:%M:%S')
        elif isinstance(obj, datetime.date):
            return obj.strftime("%Y-%m-%d")
        else:
            return json.JSONEncoder.default(self, obj)


def qs2json(querySet):
    qdict = []
    for i in querySet:
        qdict.append(i)
    qJson = {}
    qJson = json.dumps(qdict, cls=DateEncoder)
    print(qJson)
    return qJson


def qs2dict(querySet):
    result = []
    for i in querySet:
        result.append(i)
    return result


# 验证用户登录状态
def checkLoginUser(request):
    try:
        request.session['loginID']
        request.session['loginUser']
        request.session['loginNickname']
        return True
    except Exception as e:
        print(e)
        return False


# 获取session
def getSession(request, session):
    try:
        sessionName = request.session[session]
        return sessionName
    except:
        return None


# 检验session id的有效性
def checkSession(request, session):
    try:
        sessionName = request.session[session]
        return True
    except:
        return False


def checkGET(request, GET):
    try:
        result = request.GET[GET]
        return True
    except Exception as e:
        print(e)
        return False


def checkPOST(request, GET):
    try:
        result = request.POST[GET]
        return True
    except:
        return False


# 验证checkIn的组织者是否为登录的用户
def checkCorrectO_ID(request, ID):
    checkSession(request, 'loginID')
    if ID != getSession(request, 'loginID'):
        return False
    else:
        return True


# 上传文件
def upload_file(request, filename, prefix, suffix='', sub_folder='user_upload', max_width=1200):
    try:
        file_name = request.FILES.get(filename)
        ext_file_name = get_ext(file_name)
        save_filename = str(prefix) + suffix + '.' + ext_file_name
        to_path = os.path.join(settings.BASE_DIR, 'checkIn', settings.MEDIA_STORAGE, sub_folder)
        to_file = os.path.join(to_path, save_filename)
        # to_path = to_path.replace('\\', '/')
        # to_file = to_file.replace('\\', '/')
        if not os.path.exists(to_path):
            os.makedirs(to_path)
        destination = open(to_file, 'wb+')
        for chunk in file_name.chunks():
            destination.write(chunk)
        destination.close()

        picture_resize(to_file, max_width)

        return save_filename
    except Exception as e:
        print(e)
        return None


# 图片压缩
# filename 文件名
# max_width 最大宽度，自动计算高度
def picture_resize(filename, max_width=1200):
    image = Image.open(filename)
    w, h = image.size

    if w > max_width:  # 如果宽度大于预定值就缩小比例
        zoom = max_width / w
        resize_h = round(zoom * h)
        resize_image = image.resize((max_width, resize_h), Image.ANTIALIAS)
        resize_image.save(filename)


# 获取文件扩展名
def get_ext(filename):
    filename_2 = str(filename).split('.')
    return filename_2[-1]