在 Flask 中使用 WTForms 更新记录时遇到问题

Question

我正在用 Flask 编写一个应用程序，该应用程序应该用作计时的虚拟打卡钟，但我在更新记录时遇到了问题。

对于现有的打卡或打卡记录（称为打卡），我希望能够允许具有“经理”权限的用户编辑某些属性。这是我到目前为止所拥有的：

观点：

@app.route('/punch/<punchid>', methods=['GET', 'POST'])
@login_required
def punch(punchid):
    if g.user.is_manager:
        punch = Punch.query.get(punchid)
        form = PunchForm()
        form.notes.data = punch.notes
        form.timestamp.data = punch.timestamp
    else:
        flash('You are not authorized to access this function.')
        return redirect(url_for('user', nickname=g.user.nickname))
    if form.validate_on_submit():
        punch.notes = form.notes.data
        punch.timestamp = form.timestamp.data
        print(form.errors)
        db.session.commit()
        flash('Your changes have been saved.')
        return render_template('report.html', punches=Punch.query.order_by(desc(Punch.timestamp)).all())
    else:
        flash('Please check to see that you have entered information correctly.')
    return render_template('punch.html', form=form, punch=punch)

表格：

class PunchForm(Form):
    notes = StringField('notes', validators=[DataRequired()])
    timestamp = DateTimeField('timestamp', format="%Y-%m-%d %H:%M")

模板：

<h1>Edit this Clock-Punch:</h1>
  <form action="" method="post" name="punch">
      {{form.hidden_tag()}}
      <table>
          <tr>
              <td>Employee:</td>
              <td>{{punch.author.nickname}}</td>
          </tr>
          <tr>
              <td>Employee Number:</td>
              <td>{{punch.author.employee_number}}</td>
          </tr>
          <tr>
              <td>In or Out:</td>
              <td>{{punch.in_or_out}}</td>
          </tr>
          <tr>
              <td>Timestamp:</td>
              <td>{{ form.timestamp(size=48) }}</td>
          </tr>
          <tr>
              <td>Notes:</td>
              <td>{{ form.notes(size=128) }}</td>
          </tr>
          <tr>
              <td></td>
              <td><input type="submit" value="Save Changes"></td>
          </tr>
      </table>
  </form>

问题： 当我点击提交按钮时，一切似乎都正常。我的服务器甚至在 POST 上给了我一个 HTTP 200 响应。然而，当我再次查看打孔时，数据保持不变。我在这里是一个完全的 n00b 并且被困在一些微不足道的事情上吗？

Answer 1

你很接近，在请求处理程序中，表单的前几行中填充了数据库中Punch 行的上一个版本的数据，试试这样：

@app.route('/punch/<punchid>', methods=['GET', 'POST'])
@login_required
def punch(punchid):
    if not g.user.is_manager:
        flash('You are not authorized to access this function.')
        return redirect(url_for('user', nickname=g.user.nickname))

    # only for the initial GET request do you want to load
    # the original data from the model into the form
    punch = Punch.query.get(punchid)
    # should throw in a check to make sure this exists, and abort(404) if not...
    if request.method == 'GET':
        form = PunchForm()
        form.notes.data = punch.notes
        form.timestamp.data = punch.timestamp
    if form.validate_on_submit():
        punch.notes = form.notes.data
        punch.timestamp = form.timestamp.data
        print(form.errors)            
        db.session.commit()
        flash('Your changes have been saved.')
        return render_template('report.html', punches=Punch.query.order_by(desc(Punch.timestamp)).all())
    else:
        flash('Please check to see that you have entered information correctly.')
    return render_template('punch.html', form=form, punch=punch)

另外，在validate_on_submit 调用中，您可能应该使用烧瓶重定向到在同一网址上呈现模板的不同路由。