在烧瓶管理员中使用“短语搜索”

Question

我正在使用 Flask-Admin，我对此非常满意。

docs 显示了几个可用于搜索预定义字段的选项。我想让我的用户使用引号进行搜索，例如：

"some phrase of which the order should be intact"

如何使用 Flask-Admin 做到这一点？

Answer 1

在 Flask-Admin 1.3.0 中，您可以在管理视图类中覆盖 _apply_search 方法。请参阅下面非常简单的代码示例 - 主要取自 Flask-Admin sqla 示例 app.py。

本质上，您希望为您的 column_searchable_list 中的列生成类似于 %Your Phrase Here% 的 SQL。 _apply_search 的标准行为是将搜索输入文本拆分为空格，并为结果数组中的每个术语生成类似 SQL 的片段。

相反，您可以使用正则表达式查看是否输入了带引号的字符串，提取引号内的短语，创建适当的 SQL 类片段，然后将其传递给生成查询的代码。

您也可以执行类似的操作来实现短语过滤 - 请参阅下面代码中的类 FilterPhrase 以及它在 column_filters 列表定义中的使用方式。

对于更复杂的短语搜索，您可以使用 Whoosh 之类的东西，Postgres 的内置短语搜索功能 text searching（可能与 SQLAlchemy-Searchable 结合使用）甚至是 Elasticsearch。

# coding: utf-8
__author__ = 'Paul'

from flask import Flask
from flask.ext.sqlalchemy import SQLAlchemy
from sqlalchemy import or_
from flask.ext.admin import Admin
from flask.ext.admin.contrib.sqla import ModelView
from flask.ext.admin.babel import lazy_gettext
from flask.ext.admin.contrib.sqla.filters import BaseSQLAFilter
import re

app = Flask(__name__)

app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///:memory:'
app.config['SQLALCHEMY_ECHO'] = True
db = SQLAlchemy(app)


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


class Post(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    title = db.Column(db.String(255))
    content = db.Column(db.Text, nullable=False)

    def __unicode__(self):
        return self.title


class FilterPhrase(BaseSQLAFilter):
    def apply(self, query, value, alias=None):
        stmt = "%{phrase}%".format(phrase=value)
        return query.filter(self.get_column(alias).ilike(stmt))

    def operation(self):
        return lazy_gettext('phrase')


class PostAdmin(ModelView):
    column_searchable_list = ['title', 'content']

    column_filters = (
        FilterPhrase(Post.title, "Title"),
        FilterPhrase(Post.content, "Content"),
    )

    def _apply_search(self, query, count_query, joins, count_joins, search):

        phrases = re.findall(r'"([^"]*)"', search)

        if len(phrases) == 0:
            return super(PostAdmin, self)._apply_search(query, count_query, joins, count_joins, search)

        stmt = "%{phrase}%".format(phrase=phrases[0])

        # The code below is taken directly from the base _apply_search
        filter_stmt = []
        count_filter_stmt = []

        for field, path in self._search_fields:
            query, joins, alias = self._apply_path_joins(query, joins, path, inner_join=False)

            count_alias = None

            if count_query is not None:
                count_query, count_joins, count_alias = self._apply_path_joins(count_query,
                                                                               count_joins,
                                                                               path,
                                                                               inner_join=False)

            column = field if alias is None else getattr(alias, field.key)
            filter_stmt.append(column.ilike(stmt))

            if count_filter_stmt is not None:
                column = field if count_alias is None else getattr(count_alias, field.key)
                count_filter_stmt.append(column.ilike(stmt))

        query = query.filter(or_(*filter_stmt))

        if count_query is not None:
            count_query = count_query.filter(or_(*count_filter_stmt))

        return query, count_query, joins, count_joins


# Create admin
admin = Admin(app, name='Phrase Searching')
admin.add_view(PostAdmin(model=Post, session=db.session, category='Blog', name='Posts'))


def build_db():
    sample_posts = [
        {
            'title': "de Finibus Bonorum et Malorum - Part I",
            'content': "Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut"
        },
        {
            'title': "de Finibus Bonorum et Malorum - Part II",
            'content': "Sed ut perspiciatis unde omnis iste natus error sit voluptatem accusantium doloremque"
        },
        {
            'title': "de Finibus Bonorum et Malorum - Part III",
            'content': "At vero eos et accusamus et iusto odio dignissimos ducimus qui blanditiis praesentium"
        }
    ]

    db.drop_all()
    db.create_all()

    for row in sample_posts:
        post = Post(**row)
        db.session.add(post)

    db.session.commit()


if __name__ == '__main__':
    build_db()
    app.run()