1 form表单如何生成多选框（包含了多选框可选择内容）
- Form设置班级输入框为 select多选
- 多选
class TeacherForm(Form):
name = fields.CharField(max_length=,
widget=widgets.TextInput(attrs={'class': 'form-control'})
)
cls = fields.MultipleChoiceField(
choices=models.Classes.objects.values_list('id', 'title'),
widget=widgets.SelectMultiple(attrs={'class': 'form-control'})
)
2 上面存在bug:刷新页面无法动态刷新数据库数据
# BUG:页面刷新时，无法动态显示数据库内容
分别打开添加老师（或者学生）的页面，和添加班级的页面， 然后再添加班级页面新添加一个班级。
刷选添加老师（或者学生）页面，发现班级下拉框并没有动态增加刚才新增加的班级。 原因分析：出现在class TeacherForm和StudentForm定义上，以TeacherForm为例
class TeacherForm(Form):
name = fields.CharField(max_length=,
widget=widgets.TextInput(attrs={'class': 'form-control'})
)
cls = fields.MultipleChoiceField(
choices=models.Classes.objects.values_list('id', 'title'),
widget=widgets.SelectMultiple(attrs={'class': 'form-control'})
) 在实例化一个TeacherForm对象时，由于name, cls为类变量，所以这两个类变量只要第一次生成后，
后面实例化对象时，这两个变量是不会改变的。
在调用父类init函数时，会将cls, name放到父类的self.fields里面
self.fields = {'name': name, 'cls': cls} 因此解决办法出来了，在每一次实例化对象时，再获取数据库的值给cls，
重新刷新self.fields里面的cls字段内容
class TeacherForm(Form):
name = fields.CharField(max_length=,
widget=widgets.TextInput(attrs={'class': 'form-control'})
)
cls = fields.MultipleChoiceField(
choices=models.Classes.objects.values_list('id', 'title'),
# 多选这个可不能删，因为下面的init修改的不是这里
widget=widgets.SelectMultiple(attrs={'class': 'form-control'})
) def __init__(self, *args, **kwargs):
super(TeacherForm, self).__init__(*args, **kwargs)
self.fields['cls'].widget.choices = models.Classes.objects.values_list('id', 'title')
3 多选框的内容如何插入数据库
obj = TeacherForm(request.POST)
if obj.is_valid():
print(obj.cleaned_data)
# 多对多关系插入数据库，主要是插入teacher表，和第三张表
class_list = obj.cleaned_data.pop('cls')
print(class_list)
teacher = models.Teacher.objects.create(**obj.cleaned_data)
teacher.cls.add(*class_list)
4 多选框的默认显示
initial中的多选框key的value必须是列表
def edit_teacher(request, nid):
if request.method == "GET":
row = models.Teacher.objects.filter(id=nid).first()
class_ids = row.cls.values_list('id')
class_id_list = list(zip(*class_ids))[0] if list(zip(*class_ids)) else []
obj = TeacherForm(initial={'name': row.name, 'cls': class_id_list})
# obj = TeacherForm(initial={'name': row.name, 'cls': [1,2]})
return render(request, 'app01_edit_teacher.html', {'obj': obj, 'nid': nid})
5 多选框数据更改到数据库
obj = TeacherForm(request.POST)
if obj.is_valid():
print(obj.cleaned_data)
models.Teacher.objects.filter(id=nid).update(name=obj.cleaned_data['name'])
teacher = models.Teacher.objects.filter(id=nid).first()
teacher.cls.set(obj.cleaned_data['cls'])
6 老师管理
6.1 查看老师列表
6.1.1 前端
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<link rel="stylesheet" href="/static/plugins/bootstrap-3.3.7-dist/css/bootstrap.css">
<link rel="stylesheet" href="/static/plugins/font-awesome-4.7.0/css/font-awesome.css">
</head>
<body>
<h4>老师管理</h4>
<p>
<a href="/app01/add_teacher" class="btn btn-primary">添加</a>
</p>
<table class="table table-striped table-bordered table-hover table-condensed">
<thead>
<tr>
<th>ID</th>
<th>姓名</th>
<th>班级</th>
<th>操作</th>
</tr>
</thead>
<tbody>
{% for item in teacher_list %}
<tr>
<td>{{ item.id }}</td>
<td>{{ item.name }}</td>
<td>
{% for x in item.cls.values_list %}
{{ x.1}}
{% endfor %}
</td>
<td>
<a href="/app01/edit_teacher/nid={{ item.id }}" class="glyphicon glyphicon-pencil">编辑</a>|
<a href="/app01/del_teacher/nid={{ item.id }}" class="glyphicon glyphicon-trash">删除</a>
</td>
{#点击删除是一个get请求，要想告诉服务器id，可以通过url get请求获取，或者url匹配到传递给视图#}
</tr>
{% endfor %} </tbody>
</table>
<nav aria-label="Page navigation">
<ul class="pagination">
{{ page_info.pager|safe }}
</ul>
</nav>
</body>
</html>
6.1.2 视图
def teachers(request):
teacher_list = models.Teacher.objects.all()
return render(request, 'app01_teacher_list.html', {'teacher_list': teacher_list})
6.2 增加老师
6.2.1 前端
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<link rel="stylesheet" href="/static/plugins/bootstrap-3.3.7-dist/css/bootstrap.css">
<link rel="stylesheet" href="/static/plugins/font-awesome-4.7.0/css/font-awesome.css">
</head>
<body>
<div style="width:500px;margin:0 auto">
<h4 style="margin-left: 25px;">添加老师</h4>
<form class="form-horizontal" action="/app01/add_teacher" method="POST">
{% csrf_token %}
<div class="form-group">
<label class="col-sm-2 control-label">姓名:</label>
<div class="col-sm-10">
{{ obj.name }}{{ obj.errors.name.0 }}
</div>
</div> <div class="form-group">
<label class="col-sm-2 control-label">班级:</label>
<div class="col-sm-10">
{{ obj.cls }} {{ obj.errors.cls.0 }}
</div>
</div> <div class="form-group">
<div class="col-sm-offset-2 col-sm-10">
<input type="submit" class="btn btn-default" value="提交"/>
</div>
</div>
</form>
</div> </body>
</html>
6.2.2 视图
def add_teacher(request):
if request.method == "GET":
obj = TeacherForm()
return render(request, 'app01_add_teacher.html', {'obj': obj})
else:
obj = TeacherForm(request.POST)
if obj.is_valid():
print(obj.cleaned_data)
# 多对多关系插入数据库，主要是插入teacher表，和第三张表
class_list = obj.cleaned_data.pop('cls')
print(class_list)
teacher = models.Teacher.objects.create(**obj.cleaned_data)
teacher.cls.add(*class_list)
return redirect('/app01/teachers')
else:
print('POST=', request.POST)
print('errors=', obj.errors)
return render(request, 'app01_teacher_list.html', {'obj': obj})
6.3 编辑老师
6.3.1 前端
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<form action="/app01/edit_teacher/nid={{ nid }}" method="POST">
{% csrf_token %}
{{ obj.name }}
{{ obj.cls }}
<p><input type="submit" value="提交"></p>
</form>
</body>
</html>
6.3.2 视图
def edit_teacher(request, nid):
if request.method == "GET":
row = models.Teacher.objects.filter(id=nid).first()
class_ids = row.cls.values_list('id')
class_id_list = list(zip(*class_ids))[0] if list(zip(*class_ids)) else []
obj = TeacherForm(initial={'name': row.name, 'cls': class_id_list})
# obj = TeacherForm(initial={'name': row.name, 'cls': [1,2]})
return render(request, 'app01_edit_teacher.html', {'obj': obj, 'nid': nid})
else:
print('hello')
obj = TeacherForm(request.POST)
if obj.is_valid():
print(obj.cleaned_data)
models.Teacher.objects.filter(id=nid).update(name=obj.cleaned_data['name'])
teacher = models.Teacher.objects.filter(id=nid).first()
teacher.cls.set(obj.cleaned_data['cls'])
return redirect('/app01/teachers')
else:
return render(request, 'app01_edit_teacher.html', {'obj': obj, 'nid': nid})