BootStrap-Flask是《Flask Web 开发实战》作者李辉维护的一个小工具，旨在提供Bootstrap和Flask集成的宏，可以快速构建自己的Web项目。这里简单介绍一下使用方法。
1.安装和初始化
$ pip install bootstrap-flask
初始化和其他组件一样
from flask_bootstrap import Bootstrap
from flask import Flask
app = Flask(__name__)
bootstrap = Bootstrap(app)
db = SQLAlchemy(app)
app.config['SECRET_KEY'] = os.getenv('SECRET_KEY', 'secret string')
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///' + os.path.join(app.root_path, 'data.db')
2. 宏定义
BootStrap-Flask主要提供的宏有如下几个：
1578409827787.jpg
下面挑几个常用的介绍一下，其他的可以参考其文档。
2.1 导航栏
使用方法：
render_nav_item(endpoint, text, badge='', use_li=False, **kwargs)
- endpoint – The endpoint used to generate URL.
- text – The text that will displayed on the item.
- badge – Badge text.
- use_li – Default to generate <a></a>, if set to True, it will generate <li><a></a></li>.
- kwargs – Additional keyword arguments pass to url_for().
demo:
{% extends 'base.html' %}
{% from 'bootstrap/nav.html' import render_nav_item %}
{% block title %} BootStrap-Flask nav {% endblock title%}
{% block content %}
<nav class="navbar navbar-expand-lg navbar-light bg-light">
<div class="navbar-nav mr-auto">
{{ render_nav_item('index', 'Home') }}
{{ render_nav_item('breadcrumb', 'Breadcrumb') }}
{{ render_nav_item('field', 'Field') }}
{{ render_nav_item('form', 'Form') }}
{{ render_nav_item('form_row', 'Form_Row') }}
{{ render_nav_item('message', 'Flash') }}
{{ render_nav_item('pager', 'Pager') }}
</div>
</nav>
{% endblock content %}
效果:
1578567031904.jpg
2.2 表单1
使用方法：
render_form(form, action="", method="post", extra_classes=None, role="form", form_type="basic", horizontal_columns=('lg', 2, 10), enctype=None, button_map={}, id="", novalidate=False, render_kw={})
- form – The form to output.
- action – The URL to receive form data.
- method – <form> method attribute.
- extra_classes – The classes to add to the <form>.
- role – <form> role attribute.
- form_type – One of basic, inline or horizontal. See the Bootstrap docs for details on different form layouts.
- horizontal_columns – When using the horizontal layout, layout forms like this. Must be a 3-tuple of (column-type, left-column-size, right-column-size).
- enctype – <form> enctype attribute. If None, will automatically be set to multipart/form-data if a FileField is present in the form.
- button_map – A dictionary, mapping button field names to names such as primary, danger or success. For example, {'submit': 'success'}. Buttons not found in the button_map will use the default type of button.
- id – The <form> id attribute.
- novalidate – Flag that decide whether add novalidate class in <form>.
- render_kw – A dictionary, specifying custom attributes for the <form> tag.
demo:
class Login(FlaskForm):
username = StringField('Name', validators=[DataRequired(), Length(1, 20)])
password = PasswordField('Password', validators=[DataRequired(), Length(8, 128)])
submit = SubmitField('Submit')
@app.route('/form')
def form():
form = Login()
return render_template('form.html', form=form)
{% extends 'base.html' %}
{% from 'bootstrap/form.html' import render_form %}
{% block title %} BootStrap-Flask Form {% endblock title%}
{% block content %}
<div style="margin: 100px">
<h3>render_form example</h3>
<div >
{{ render_form(form, button_map={'submit': 'success'}) }}
</div>
</div>
{% endblock content %}
效果：
1578567431266.jpg
2.3 表单2
使用方法：
render_form_row(fields, row_class='form-row', col_class_default='col', col_map={})
-
fields – An iterable of fields to render in a row.
-
row_class – Class to apply to the div intended to represent the row, like form-row or row
-
col_class_default – The default class to apply to the div that represents a column if nothing more specific is said for the div column of the rendered field.
-
col_map – A dictionary, mapping field.name to a class definition that should be applied to the div column that contains the field. For example: col_map={'username': 'col-md-2'})
demo:
class Login2(FlaskForm):
username = StringField('Name', validators=[DataRequired(), Length(1, 20)])
password = PasswordField('Password', validators=[DataRequired(), Length(8, 128)])
email = StringField('Email', validators=[DataRequired(), email()])
remember = BooleanField('Remember', default=True)
submit = SubmitField('Submit')
@app.route('/form_row')
def form_row():
form = Login2()
return render_template('form_row.html', form=form)
{% extends 'base.html' %}
{% from 'bootstrap/form.html' import render_form_row %}
{% block title %} BootStrap-Flask {% endblock title%}
{% block content %}
<div style="margin: 100px">
<h3>render_form_row example</h3>
<form method="post">
{{ form.csrf_token() }}
{{ render_form_row([form.username, form.password], col_map={'username': 'col-md-4'}) }}
{{ render_form_row([form.email]) }}
{{ render_form_row([form.remember]) }}
{{ render_form_row([form.submit]) }}
</form>
</div>
{% endblock content %}
效果：
1578568397001.jpg
2.4 分页符
使用方法：
render_pager(pagination, fragment='', prev=('<span aria-hidden="true">←</span> Previous')|safe, next=('Next <span aria-hidden="true">→</span>')|safe, align='', **kwargs)
- pagination – Pagination instance.
- fragment – Add url fragment into link, such as #comment.
- prev – Symbol/text to use for the “previous page” button.
- next – Symbol/text to use for the “next page” button.
- align – Can be ‘left’, ‘center’ or ‘right’, default to ‘left’.
- kwargs – Additional arguments passed to url_for.
demo：
app.config['STUDENT_PER_PAGE'] = 5
class Student(db.Model):
id = db.Column(db.Integer, primary_key=True)
username = db.Column(db.String(30))
@app.route('/pager')
def pager():
page = request.args.get('page', 1, type=int)
per_page = app.config['STUDENT_PER_PAGE']
pagination = Student.query.order_by(Student.id.asc()).paginate(page, per_page=per_page)
students = pagination.items
return render_template('pager.html', pagination=pagination, students=students)
{% extends 'base.html' %}
{% from 'bootstrap/pagination.html' import render_pager %}
{% block title %} BootStrap-Flask Pager {% endblock title%}
{% block content %}
<div style="margin: 100px">
<h3>render_pager example</h3>
<div>
{% if students %}
{% for student in students %}
<h3 class="text-primary"><p>{{ student.username }}</p></h3>
{% endfor %}
{% endif %}
</div>
{{ render_pager(pagination, prev='上一页', next='下一页', align='center') }}
</div>
{% endblock content %}
效果：
1578568611135.jpg
3. 总结
总体使用还是比较方便的，主要是对于不想花过多时间投入到前端Web开发来说，是比较好的工具。详细的信息可以参阅其文档：https://bootstrap-flask.readthedocs.io/en/latest/
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