Flask的图形化管理界面搭建框架Flask-Admin的使用教程


Posted in Python onJune 13, 2016

Flask-Admin是Flask框架的一个扩展,用它能够快速创建Web管理界面,它实现了比如用户、文件的增删改查等常用的管理功能;如果对它的默认界面不喜欢,可以通过修改模板文件来定制;
Flask-Admin把每一个菜单(超链接)看作一个view,注册后才能显示出来,view本身也有属性来控制其是否可见;因此,利用这个机制可以定制自己的模块化界面,比如让不同权限的用户登录后看到不一样的菜单;

项目地址:https://flask-admin.readthedocs.io/en/latest/

example/simple
这是最简单的一个样例,可以帮助我们快速、直观的了解基本概念,学会定制Flask-Admin的界面
simple.py:

from flask import Flask

from flask.ext import admin


# Create custom admin view
class MyAdminView(admin.BaseView):
  @admin.expose('/')
  def index(self):
    return self.render('myadmin.html')


class AnotherAdminView(admin.BaseView):
  @admin.expose('/')
  def index(self):
    return self.render('anotheradmin.html')

  @admin.expose('/test/')
  def test(self):
    return self.render('test.html')


# Create flask app
app = Flask(__name__, template_folder='templates')
app.debug = True

# Flask views
@app.route('/')
def index():
  return '<a href="/admin/">Click me to get to Admin!</a>'

# Create admin interface
admin = admin.Admin()
admin.add_view(MyAdminView(category='Test'))
admin.add_view(AnotherAdminView(category='Test'))
admin.init_app(app)

if __name__ == '__main__':

  # Start app
  app.run()

在这里可以看到运行效果

BaseView

所有的view都必须继承自BaseView:
class BaseView(name=None, category=None, endpoint=None, url=None, static_folder=None, static_url_path=None)

name: view在页面上表现为一个menu(超链接),menu name == 'name',缺省就用小写的class name
category: 如果多个view有相同的category就全部放到一个dropdown里面(dropdown name=='category')
endpoint: 假设endpoint='xxx',则可以用url_for(xxx.index),也能改变页面URL(/admin/xxx)
url: 页面URL,优先级url > endpoint > class name
static_folder: static目录的路径
static_url_path: static目录的URL
anotheradmin.html:
{% extends 'admin/master.html' %}
{% block body %}
  Hello World from AnotherMyAdmin!<br/>
  <a href="{{ url_for('.test') }}">Click me to go to test view</a>
{% endblock %}

如果AnotherAdminView增加参数endpoint='xxx',那这里就可以写成url_for('xxx.text'),然后页面URL会由/admin/anotheradminview/变成/admin/xxx
如果同时指定参数url='aaa',那页面URL会变成/admin/aaa,url优先级比endpoint高
Admin

class Admin(app=None, name=None, url=None, subdomain=None, index_view=None, translations_path=None, endpoint=None, static_url_path=None, base_template=None)

app: Flask Application Object;本例中可以不写admin.init_app(app),直接用admin = admin.Admin(app=app)是一样的
name: Application name,缺省'Admin';会显示为main menu name('Home'左边的'Admin')和page title
subdomain: ???
index_view: 'Home'那个menu对应的就叫index view,缺省AdminIndexView
base_template: 基础模板,缺省admin/base.html,该模板在Flask-Admin的源码目录里面
部分Admin代码如下:
class MenuItem(object):
  """
    Simple menu tree hierarchy.
  """
  def __init__(self, name, view=None):
    self.name = name
    self._view = view
    self._children = []
    self._children_urls = set()
    self._cached_url = None
    self.url = None
    if view is not None:
      self.url = view.url

  def add_child(self, view):
    self._children.append(view)
    self._children_urls.add(view.url)

class Admin(object):

  def __init__(self, app=None, name=None,
         url=None, subdomain=None,
         index_view=None,
         translations_path=None,
         endpoint=None,
         static_url_path=None,
         base_template=None):

    self.app = app

    self.translations_path = translations_path

    self._views = []
    self._menu = []
    self._menu_categories = dict()
    self._menu_links = []

    if name is None:
      name = 'Admin'
    self.name = name

    self.index_view = index_view or AdminIndexView(endpoint=endpoint, url=url)
    self.endpoint = endpoint or self.index_view.endpoint
    self.url = url or self.index_view.url
    self.static_url_path = static_url_path
    self.subdomain = subdomain
    self.base_template = base_template or 'admin/base.html'

    # Add predefined index view
    self.add_view(self.index_view)

    # Register with application
    if app is not None:
      self._init_extension()

  def add_view(self, view):

    # Add to views
    self._views.append(view)

    # If app was provided in constructor, register view with Flask app
    if self.app is not None:
      self.app.register_blueprint(view.create_blueprint(self))
      self._add_view_to_menu(view)

  def _add_view_to_menu(self, view):

    if view.category:
      category = self._menu_categories.get(view.category)

      if category is None:
        category = MenuItem(view.category)
        self._menu_categories[view.category] = category
        self._menu.append(category)

      category.add_child(MenuItem(view.name, view))
    else:
      self._menu.append(MenuItem(view.name, view))

  def init_app(self, app):

    self.app = app

    self._init_extension()

    # Register views
    for view in self._views:
      app.register_blueprint(view.create_blueprint(self))
      self._add_view_to_menu(view)

从上面的代码可以看出init_app(app)和Admin(app=app)是一样的:
将每个view注册为blueprint(Flask里的概念,可以简单理解为模块)
记录所有view,以及所属的category和url
AdminIndexView

class AdminIndexView(name=None, category=None, endpoint=None, url=None, template='admin/index.html')

name: 缺省'Home'
endpoint: 缺省'admin'
url: 缺省'/admin'
如果要封装出自己的view,可以参照AdminIndexView的写法:
class AdminIndexView(BaseView):

  def __init__(self, name=None, category=None,
         endpoint=None, url=None,
         template='admin/index.html'):
    super(AdminIndexView, self).__init__(name or babel.lazy_gettext('Home'),
                       category,
                       endpoint or 'admin',
                       url or '/admin',
                       'static')
    self._template = template

  @expose()
  def index(self):
    return self.render(self._template)
base_template

base_template缺省是/admin/base.html,是页面的主要代码(基于bootstrap),它里面又import admin/layout.html;
layout是一些宏,主要用于展开、显示menu;
在模板中使用一些变量来取出之前注册view时保存的信息(如menu name和url等):
# admin/layout.html (部分)

{% macro menu() %}
 {% for item in admin_view.admin.menu() %}
  {% if item.is_category() %}
   {% set children = item.get_children() %}
   {% if children %}
    {% if item.is_active(admin_view) %}<li class="active dropdown">{% else %}<li class="dropdown">{% endif %}
     <a class="dropdown-toggle" data-toggle="dropdown" href="javascript:void(0)">{{ item.name }}<b class="caret"></b></a>
     <ul class="dropdown-menu">
      {% for child in children %}
       {% if child.is_active(admin_view) %}<li class="active">{% else %}<li>{% endif %}
        <a href="{{ child.get_url() }}">{{ child.name }}</a>
       </li>
      {% endfor %}
     </ul>
    </li>
   {% endif %}
  {% else %}
   {% if item.is_accessible() and item.is_visible() %}
    {% if item.is_active(admin_view) %}<li class="active">{% else %}<li>{% endif %}
     <a href="{{ item.get_url() }}">{{ item.name }}</a>
    </li>
   {% endif %}
  {% endif %}
 {% endfor %}
{% endmacro %}

example/file
这个样例能帮助我们快速搭建起文件管理界面,但我们的重点是学习使用ActionsMixin模块
file.py:

import os
import os.path as op

from flask import Flask

from flask.ext import admin
from flask.ext.admin.contrib import fileadmin

# Create flask app
app = Flask(__name__, template_folder='templates', static_folder='files')

# Create dummy secrey key so we can use flash
app.config['SECRET_KEY'] = '123456790'


# Flask views
@app.route('/')
def index():
  return '<a href="/admin/">Click me to get to Admin!</a>'


if __name__ == '__main__':
  # Create directory
  path = op.join(op.dirname(__file__), 'files')
  try:
    os.mkdir(path)
  except OSError:
    pass

  # Create admin interface
  admin = admin.Admin(app)
  admin.add_view(fileadmin.FileAdmin(path, '/files/', name='Files'))

  # Start app
  app.run(debug=True)

FileAdmin是已经写好的的一个view,直接用即可:

class FileAdmin(base_path, base_url, name=None, category=None, endpoint=None, url=None, verify_path=True)

base_path: 文件存放的相对路径
base_url: 文件目录的URL
FileAdmin中和ActionsMixin相关代码如下:
class FileAdmin(BaseView, ActionsMixin):
def __init__(self, base_path, base_url,
         name=None, category=None, endpoint=None, url=None,
         verify_path=True):

    self.init_actions()

@expose('/action/', methods=('POST',))
def action_view(self):
  return self.handle_action()

# Actions
@action('delete',
    lazy_gettext('Delete'),
    lazy_gettext('Are you sure you want to delete these files?'))
def action_delete(self, items):
  if not self.can_delete:
    flash(gettext('File deletion is disabled.'), 'error')
    return

  for path in items:
    base_path, full_path, path = self._normalize_path(path)

    if self.is_accessible_path(path):
      try:
        os.remove(full_path)
        flash(gettext('File "%(name)s" was successfully deleted.', name=path))
      except Exception as ex:
        flash(gettext('Failed to delete file: %(name)s', name=ex), 'error')

@action('edit', lazy_gettext('Edit'))
def action_edit(self, items):
  return redirect(url_for('.edit', path=items))
@action()用于wrap跟在后面的函数,这里的作用就是把参数保存起来:
def action(name, text, confirmation=None)
  def wrap(f):
    f._action = (name, text, confirmation)
    return f

  return wrap

name: action name
text: 可用于按钮名称
confirmation: 弹框确认信息
init_actions()把所有action的信息保存到ActionsMixin里面:

# 调试信息
_actions = [('delete', lu'Delete'), ('edit', lu'Edit')]
_actions_data = {'edit': (<bound method FileAdmin.action_edit of <flask_admin.contrib.fileadmin.FileAdmin object at 0x1aafc50>>, lu'Edit', None), 'delete': (<bound method FileAdmin.action_delete of <flask_admin.contrib.fileadmin.FileAdmin object at 0x1aafc50>>, lu'Delete', lu'Are you sure you want to delete these files?')}

action_view()用于处理POST给/action/的请求,然后调用handle_action(),它再调用不同的action处理,最后返回当前页面:

# 省略无关代码
def handle_action(self, return_view=None):

  action = request.form.get('action')
  ids = request.form.getlist('rowid')

  handler = self._actions_data.get(action)

  if handler and self.is_action_allowed(action):
    response = handler[0](ids)

    if response is not None:
      return response

  if not return_view:
    url = url_for('.' + self._default_view)
  else:
    url = url_for('.' + return_view)

  return redirect(url)

ids是一个文件清单,作为参数传给action处理函数(参数items):

# 调试信息
ids: [u'1.png', u'2.png']

再分析页面代码,Files页面对应文件为admin/file/list.html,重点看With selected下拉菜单相关代码:
{% import 'admin/actions.html' as actionslib with context %}

{% if actions %}
  <div class="btn-group">
    {{ actionslib.dropdown(actions, 'dropdown-toggle btn btn-large') }}
  </div>
{% endif %}

{% block actions %}
  {{ actionslib.form(actions, url_for('.action_view')) }}
{% endblock %}

{% block tail %}
  {{ actionslib.script(_gettext('Please select at least one file.'),
           actions,
           actions_confirmation) }}
{% endblock %}

上面用到的三个宏在actions.html:

{% macro dropdown(actions, btn_class='dropdown-toggle') -%}
  <a class="{{ btn_class }}" data-toggle="dropdown" href="javascript:void(0)">{{ _gettext('With selected') }}<b class="caret"></b></a>
  <ul class="dropdown-menu">
    {% for p in actions %}
    <li>
      <a href="javascript:void(0)" onclick="return modelActions.execute('{{ p[0] }}');">{{ _gettext(p[1]) }}</a>
    </li>
    {% endfor %}
  </ul>
{% endmacro %}

{% macro form(actions, url) %}
  {% if actions %}
  <form id="action_form" action="{{ url }}" method="POST" style="display: none">
    {% if csrf_token %}
    <input type="hidden" name="csrf_token" value="{{ csrf_token() }}"/>
    {% endif %}
    <input type="hidden" id="action" name="action" />
  </form>
  {% endif %}
{% endmacro %}

{% macro script(message, actions, actions_confirmation) %}
  {% if actions %}
  <script src="{{ admin_static.url(filename='admin/js/actions.js') }}"></script>
  <script language="javascript">
    var modelActions = new AdminModelActions({{ message|tojson|safe }}, {{ actions_confirmation|tojson|safe }});
  </script>
  {% endif %}
{% endmacro %}

最终生成的页面(部分):

<div class="btn-group">
  <a class="dropdown-toggle btn btn-large" href="javascript:void(0)" data-toggle="dropdown">
    With selected
    <b class="caret"></b>
  </a>

  <ul class="dropdown-menu">
    <li>
      <a onclick="return modelActions.execute('delete');" href="javascript:void(0)">Delete</a>
    </li>
    <li>
      <a onclick="return modelActions.execute('edit');" href="javascript:void(0)">Edit</a>
    </li>
  </ul>
</div>

<form id="action_form" action="/admin/fileadmin/action/" method="POST" style="display: none">
  <input type="hidden" id="action" name="action" />
</form>

<script src="/admin/static/admin/js/actions.js"></script>
<script language="javascript">
  var modelActions = new AdminModelActions("Please select at least one file.", {"delete": "Are you sure you want to delete these files?"});
</script>

选择菜单后的处理方法在actions.js:

var AdminModelActions = function(actionErrorMessage, actionConfirmations) {
  // Actions helpers. TODO: Move to separate file
  this.execute = function(name) {
    var selected = $('input.action-checkbox:checked').size();

    if (selected === 0) {
      alert(actionErrorMessage);
      return false;
    }

    var msg = actionConfirmations[name];

    if (!!msg)
      if (!confirm(msg))
        return false;

    // Update hidden form and submit it
    var form = $('#action_form');
    $('#action', form).val(name);

    $('input.action-checkbox', form).remove();
    $('input.action-checkbox:checked').each(function() {
      form.append($(this).clone());
    });

    form.submit();

    return false;
  };

  $(function() {
    $('.action-rowtoggle').change(function() {
      $('input.action-checkbox').attr('checked', this.checked);
    });
  });
};

对比一下修改前后的表单:

# 初始化
<form id="action_form" style="display: none" method="POST" action="/admin/fileadmin/action/">
  <input id="action" type="hidden" name="action">
</form>

# 'Delete'选中的三个文件
<form id="action_form" style="display: none" method="POST" action="/admin/fileadmin/action/">
  <input id="action" type="hidden" name="action" value="delete">
  <input class="action-checkbox" type="checkbox" value="1.png" name="rowid">
  <input class="action-checkbox" type="checkbox" value="2.png" name="rowid">
  <input class="action-checkbox" type="checkbox" value="3.png" name="rowid">
</form>

# 'Edit'选中的一个文件
<form id="action_form" style="display: none" method="POST" action="/admin/fileadmin/action/">
  <input id="action" type="hidden" name="action" value="edit">
  <input class="action-checkbox" type="checkbox" value="1.png" name="rowid">
</form>

总结一下,当我们点击下拉菜单中的菜单项(Delete,Edit),本地JavaScript代码会弹出确认框(假设有确认信息),然后提交一个表单给/admin/fileadmin/action/,请求处理函数action_view()根据表单类型再调用不同的action处理函数,最后返回一个页面。

Flask-Admin字段(列)格式化
在某些情况下,我们需要对模型的某个属性进行格式化。比如,默认情况下,日期时间显示出来会比较长,这时可能需要只显示月和日,这时候,列格式化就派上用场了。

比如,如果你要显示双倍的价格,你可以这样做:

class MyModelView(BaseModelView):
  column_formatters = dict(price=lambda v, c, m, p: m.price*2)

或者在Jinja2模板中使用宏:

from flask.ext.admin.model.template import macro

class MyModelView(BaseModelView):
  column_formatters = dict(price=macro('render_price'))

# in template
{% macro render_price(model, column) %}
  {{ model.price * 2 }}
{% endmacro %}

回调函数模型:

def formatter(view, context, model, name):
  # `view` is current administrative view
  # `context` is instance of jinja2.runtime.Context
  # `model` is model instance
  # `name` is property name
  pass

正好和上面的v, c, m, p相对应。

Python 相关文章推荐
python遍历数组的方法小结
Apr 30 Python
python实现web方式logview的方法
Aug 10 Python
Python 性能优化技巧总结
Nov 01 Python
Python测试人员需要掌握的知识
Feb 08 Python
Tensorflow 利用tf.contrib.learn建立输入函数的方法
Feb 08 Python
详解Django之auth模块(用户认证)
Apr 17 Python
python得到一个excel的全部sheet标签值方法
Dec 10 Python
Python 获取主机ip与hostname的方法
Dec 17 Python
对python模块中多个类的用法详解
Jan 10 Python
tornado+celery的简单使用详解
Dec 21 Python
python pip如何手动安装二进制包
Sep 30 Python
python实现三次密码验证的示例
Apr 29 Python
Python的Flask框架中集成CKeditor富文本编辑器的教程
Jun 13 #Python
Linux中安装Python的交互式解释器IPython的教程
Jun 13 #Python
浅谈python中的面向对象和类的基本语法
Jun 13 #Python
深入理解python多进程编程
Jun 12 #Python
python中根据字符串调用函数的实现方法
Jun 12 #Python
python中函数总结之装饰器闭包详解
Jun 12 #Python
Python备份目录及目录下的全部内容的实现方法
Jun 12 #Python
You might like
深入for,while,foreach遍历时间比较的详解
2013/06/08 PHP
通过curl模拟post和get方式提交的表单类
2014/04/23 PHP
PHP生成自定义长度随机字符串的函数分享
2014/05/04 PHP
php中strstr、strrchr、substr、stristr四个函数的区别总结
2014/09/22 PHP
PHP通过内置函数memory_get_usage()获取内存使用情况
2014/11/20 PHP
如何通过Linux命令行使用和运行PHP脚本
2015/07/29 PHP
Yii2 如何在modules中添加验证码的方法
2017/06/19 PHP
PHP使用SMTP邮件服务器发送邮件示例
2018/08/28 PHP
将string解析为json的几种方式小结
2010/11/11 Javascript
jQuery+ajax实现动态执行脚本的方法
2015/01/27 Javascript
jQuery简单tab切换效果实现方法
2015/04/08 Javascript
Node.js本地文件操作之文件拷贝与目录遍历的方法
2016/02/16 Javascript
总结十个Angular.js由浅入深的面试问题
2016/08/26 Javascript
jQuery实现的自动加载页面功能示例
2016/09/04 Javascript
AngularJS过滤器filter用法实例分析
2016/11/04 Javascript
快速搭建Node.js(Express)用户注册、登录以及授权的方法
2019/05/09 Javascript
vue弹出框组件封装实例代码
2019/10/31 Javascript
vue实现下载文件流完整前后端代码
2020/11/17 Vue.js
Python修改Excel数据的实例代码
2013/11/01 Python
Python实现模拟登录及表单提交的方法
2015/07/25 Python
Python探索之静态方法和类方法的区别详解
2017/10/27 Python
浅谈python实现Google翻译PDF,解决换行的问题
2018/11/28 Python
Python列表list排列组合操作示例
2018/12/18 Python
树莓派采用socket方式文件传输(python)
2019/06/22 Python
Python paramiko 模块浅谈与SSH主要功能模拟解析
2020/02/29 Python
Python类的动态绑定实现原理
2020/03/21 Python
CSS3动画效果回调处理详解
2014/12/10 HTML / CSS
Bugatchi官方网站:男士服装在线
2019/04/10 全球购物
什么是Smart Navigation?
2016/07/03 面试题
计算机网络专业推荐信
2013/11/24 职场文书
党校学习思想汇报
2014/01/06 职场文书
商场拾金不昧表扬信
2014/01/13 职场文书
计算机专业自荐信
2014/05/24 职场文书
岗位说明书怎么写
2014/07/30 职场文书
捐款感谢信
2015/01/20 职场文书
医院保洁员管理制度
2015/08/05 职场文书