用数据填充 WTForms FormField FieldList 会在字段中生成 HTML
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【中文标题】用数据填充 WTForms FormField FieldList 会在字段中生成 HTML【英文标题】：Filling WTForms FormField FieldList with data results in HTML in fields 【发布时间】：2015-06-13 10:04:38 【问题描述】：我有一个 Flask 应用程序，我可以在其中通过上传 CSV 文件来填充表单数据，然后读取该文件。我想用从 CSV 读取的数据填充一个 FieldList。但是，当我尝试填充数据时，它会将原始 html 输入到 TextFields 中，而不仅仅是我想要的值。我做错了什么？
app.py
from flask import Flask, render_template, request, url_for
from flask.ext.wtf import Form
from wtforms import StringField, FieldList, FormField, SelectField
from wtforms.validators import DataRequired
from werkzeug.datastructures import MultiDict
app = Flask(__name__)
app.config['SECRET_KEY']='asdfjlkghdsf'
# normally student data is read in from a file uploaded, but for this demo we use dummy data
student_info=[("123","Bob Jones"),("234","Peter Johnson"),("345","Carly Everett"),
("456","Josephine Edgewood"),("567","Pat White"),("678","Jesse Black")]
class FileUploadForm(Form):
pass
class StudentForm(Form):
student_id = StringField('Student ID', validators = [DataRequired()])
student_name = StringField('Student Name', validators = [DataRequired()])
class AddClassForm(Form):
name = StringField('classname', validators=[DataRequired()])
day = SelectField('classday',
choices=[(1,"Monday"),(2,"Tuesday"),(3,"Wednesday"),(4,"Thursday"),(5,"Friday")],
coerce=int)
students = FieldList(FormField(StudentForm), min_entries = 5) # show at least 5 blank fields by default
@app.route('/', methods=['GET', 'POST'])
def addclass():
fileform = FileUploadForm()
classform = AddClassForm()
# Check which 'submit' button was called to validate the correct form
if 'addclass' in request.form and classform.validate_on_submit():
# Add class to DB - not relevant for this example.
return redirect(url_for('addclass'))
if 'upload' in request.form and fileform.validate_on_submit():
# get the data file from the post - not relevant for this example.
# overwrite the classform by populating it with values read from file
classform = PopulateFormFromFile()
return render_template('addclass.html', classform=classform)
return render_template('addclass.html', fileform=fileform, classform=classform)
def PopulateFormFromFile():
classform = AddClassForm()
# normally we would read the file passed in as an argument and pull data out,
# but let's just use the dummy data from the top of this file, and some hardcoded values
classform.name.data = "Super Awesome Class"
classform.day.data = 4 # Thursday
# pop off any blank fields already in student info
while len(classform.students) > 0:
classform.students.pop_entry()
for student_id, name in student_info:
# either of these ways have the same end result.
#
# studentform = StudentForm()
# studentform.student_id.data = student_id
# studentform.student_name.data = name
#
# OR
student_data = MultiDict([('student_id',student_id), ('student_name',name)])
studentform = StudentForm(student_data)
classform.students.append_entry(studentform)
return classform
if __name__ == '__main__':
app.run(debug=True, port=5001)
templates/addclass.html
<html>
<head>
<title>Flask FieldList Demo</title>
</head>
<body>
<h1>Add Class</h1>
% if fileform %
<div>
<p>Add class from file:</p>
<form action="" method="post" enctype="multipart/form-data" name="fileform">
fileform.hidden_tag()
<p><input type="submit" name="upload" value="Upload"></p>
</form>
</div>
<hr>
% endif %
<div>
<form action="" method="post" name="classform">
classform.hidden_tag()
Class Name: classform.name <br>
Day: classform.day <br>
<br>
<div>
<table>
<tr>
<th> Student Number </th>
<th> Name </th>
</tr>
% for student in classform.students %
<tr>
<td> student.student_id </td>
<td> student.student_name </td>
</tr>
% endfor %
</table>
</div>
<p><input type="submit" name="addclass" value="Add Class"></p>
</form>
</div>
</body>
</html>
有问题的代码 sn-p 发生在 classform.students.append_entry(studentform) 行。
如果需要，我可以发布输出 HTML。我期望的是这样的：
我得到的是：
【问题讨论】：
【参考方案1】：好的，我花了好几个小时在这上面，最后它只是一个微不足道的代码更改。
大多数字段都允许您通过修改data 属性来更改它们的值（就像我在上面所做的那样）。事实上，在我的代码中，我有这样的评论：
### either of these ways have the same end result.
#
# studentform = StudentForm()
# studentform.student_id.data = student_id
# studentform.student_name.data = name
#
### OR
#
# student_data = MultiDict([('student_id',student_id), ('student_name',name)])
# studentform = StudentForm(student_data)
但是，对于 FormFields 的 FieldList，我们不应编辑 data 属性，而应编辑字段本身。以下代码按预期工作：
for student_id, name in student_info:
studentform = StudentForm()
studentform.student_id = student_id # not student_id.data
studentform.student_name = name
classform.students.append_entry(studentform)
我希望这可以帮助遇到同样问题的人。
【讨论】：
我不认为你对完整的独立工作示例有一个要点？ 此工作示例的要点是here。 太棒了，我以错误的方式实现了这个，并且很难从数据库中填充以进行编辑。感谢发帖！【参考方案2】：响应接受的答案： append_entry 函数需要数据，而不是表单。 因此，如果您像这样处理它，您的代码也可以按您的预期工作。额外的好处是更易于维护
# First remap your list of tuples to a list of dicts
students = [dict(zip(["student_id","student_name"], student)) for student in student_info]
for student in students:
# Tell the form to add a new entry with the data we supply
classform.students.append_entry(student)
【讨论】：
有趣的是，WTForms 文档说 append_entry([data]) 说 [data] 是可选的，但没有明确说明它应该是字典 - wtforms.readthedocs.io/en/2.2.1/fields/…以上是关于用数据填充 WTForms FormField FieldList 会在字段中生成 HTML的主要内容，如果未能解决你的问题，请参考以下文章
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