Flask的图形化管理界面搭建框架Flask-Admin的使用教程

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()

{% 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 %}

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)

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

{% 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 %}

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)

  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"%(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

# 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"htmlcode">

# 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="/UploadFiles/2021-04-08/actions.js') }}">

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="/UploadFiles/2021-04-08/actions.js">

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。

            
           
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