flask-admin:如何根据其他列的值使列只读？

Question

我已经构建了一个允许用户申请代码审查并等待经理批准的系统.

现在我想要实现的目标如下:

1. 如果它被批准, 然后所有字段都变为只读(我手动将项目名称设置为只读):

2. 如果被拒绝,

   

   然后所有字段都可以编辑.当然,在创建新项目时,所有字段都应该是可编辑的.
   

   类的代码Project和ProjectView是如下:

    from flask_sqlalchemy import SQLAlchemy
    from flask_admin.contrib import sqla
    from flask_security import current_user
   
    # Create Flask application
    app = Flask(__name__)
    app.config.from_pyfile('config.py')
    db = SQLAlchemy(app)
   
    class Project(db.Model):
   
           id = db.Column(db.Integer, primary_key=True)
           project_name = db.Column(db.Unicode(128))
           version = db.Column(db.Unicode(128))
           SVN = db.Column(db.UnicodeText)
           approve = db.Column(db.Boolean())
   
           def __unicode__(self):
               return self.name
   
    class ProjectView(sqla.ModelView):
        def is_accessible(self):
            if not current_user.is_active or not current_user.is_authenticated:
                return False
            return False
   
        @property
        def _form_edit_rules(self):
            return rules.RuleSet(self, self.form_rules)
   
        @_form_edit_rules.setter
        def _form_edit_rules(self, value):
            pass
   
        @property
        def _form_create_rules(self):
            return rules.RuleSet(self, self.form_rules)
   
        @_form_create_rules.setter
        def _form_create_rules(self, value):
            pass
   
        @property
        def form_rules(self):
        form_rules = [
            rules.Field('project_name'),
            rules.Field('version'),
            rules.Field('SVN'),
        ]
        if not has_app_context() or current_user.has_role('superuser'):
            form_rules.append('approve')
   

   在我看来,由于approve是一个布尔变量,因此应该有条件判断来判断它是0还是1,然后该字段变为只读或相应的可编辑.

   感谢您提前提出建议.

Answer 1

正如您已经注意到的那样readonly，为字段设置属性相当简单，但使其动态化有点棘手。

首先，您需要一个自定义字段类：

from wtforms.fields import StringField

class ReadOnlyStringField(StringField):
    @staticmethod
    def readonly_condition():
        # Dummy readonly condition
        return False

    def __call__(self, *args, **kwargs):
        # Adding `readonly` property to `input` field
        if self.readonly_condition():
            kwargs.setdefault('readonly', True)
        return super(ReadOnlyStringField, self).__call__(*args, **kwargs)

    def populate_obj(self, obj, name):
        # Preventing application from updating field value
        # (user can modify web page and update the field)
        if not self.readonly_condition():
            super(ReadOnlyStringField, self).populate_obj(obj, name)

为您的视图设置form_overrides属性：

class ProjectView(sqla.ModelView):
    form_overrides = {
        'project_name': ReadOnlyStringField
    }

您需要将自定义readonly_condition函数传递给ReadOnlyStringField实例。我发现的最简单的方法是覆盖edit_form方法：

class ProjectView(sqla.ModelView):
    def edit_form(self, obj=None):
        def readonly_condition():
            if obj is None:
                return False
            return obj.approve
        form = super(ProjectView, self).edit_form(obj)
        form.project_name.readonly_condition = readonly_condition
        return form

快乐编码！