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 \'Click me to get to Admin!\'

# 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：

复制代码 代码如下:
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!

  Click me to go to test view
{% 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

复制代码 代码如下:
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

复制代码 代码如下:
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) %}
  • {% else %}
  • {% endif %}
     {{ item.name }}
     
      
      {% for child in children %}
       {% if child.is_active(admin_view) %}
    • {% else %}
    • {% endif %}
        {{ child.name }}
       
      • 
      {% endfor %}
     
    
    
    • 
   {% endif %}
  {% else %}
   {% if item.is_accessible() and item.is_visible() %}
    {% if item.is_active(admin_view) %}
  • {% else %}
  • {% endif %}
     {{ item.name }}
    
    • 
   {% 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 \'Click me to get to Admin!\'


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：

    复制代码 代码如下:
    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\': (>, lu\'Edit\', None), \'delete\': (>, 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 %}
  
    
    {{ actionslib.dropdown(actions, \'dropdown-toggle btn btn-large\') }}
  
    
{% 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\') -%}
  {{ _gettext(\'With selected\') }}
  
{% endmacro %}

{% macro form(actions, url) %}
  {% if actions %}
  
    
    {% if csrf_token %}
    
    {% endif %}
    
  
    
  {% endif %}
{% endmacro %}

{% macro script(message, actions, actions_confirmation) %}
  {% if actions %}
  
  
  {% endif %}
{% endmacro %}

    最终生成的页面（部分）： 

    
  
    With selected

    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

    
  

    

# \'Delete\'选中的三个文件

    
  
  
  
  

    

# \'Edit\'选中的一个文件

    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。