仅当字段错误时如何从字段更新jinja2 html_params答案

【问题标题】：how to update jinja2 html_params from field only when field error仅当字段错误时如何从字段更新jinja2 html_params
【发布时间】：2021-03-31 13:32:17
【问题描述】：

我也使用 bs4 实现了烧瓶安全的客户模板。流程是当用户登录和错误的电子邮件/密码时，我将向用户显示无效反馈。我为每个字段都实现了宏，这是我的 sc：

login_form.html

{% extends "security/layout.html" %}
{% from "security/macro/auth_message.html" import auth_message as am %}
{% from "security/macro/forms.html" import render_field_with_errors, render_field, render_field_errors,
render_field_with_errors_no_labels, render_field_with_errors_no_labels_without_input_group %}
{% block title %}{{ 'login page' | title }}{% endblock title %}

{% block content %}
{{ am("Login Form") }}
{% include "security/macro/alert.html" %}
<form class="form-signin" action="{{ url_for_security('login') }}" method="POST" name="login_user_form">
    {{ login_user_form.hidden_tag() }}
    {{ render_field_with_errors_no_labels(login_user_form.email, class_="form-control", id="email", placeholder="Email
    address") }}
    {{ render_field_with_errors_no_labels(login_user_form.password,class_="form-control", id="password",
    placeholder="Password") }}
    <div class="row">
        <div class="col-8">
            <div class="icheck-primary">
                {{ render_field_with_errors_no_labels_without_input_group(login_user_form.remember, id="remember") }}
                <label for="remember">
                    Remember Me
                </label>
            </div>
        </div>
        <!-- /.col -->
        <div class="col-4">
            {{ render_field(login_user_form.submit,class="btn btn-primary btn-block" ) }}
        </div>
        <!-- /.col -->
    </div>
    <hr>
    {{ render_field_errors(login_user_form.csrf_token) }}
</form>
{% endblock %}

security/macro/forms.html

{% macro render_field_with_errors_no_labels(field) %}
<div class="input-group mb-3">
    {{ field(**kwargs)|safe }}
    {% if field.errors %}
    {# this section i have trouble #}
    {% set field = field.html_params({'class_':'is-invalid', 'aria-describedby':'{{ field.id }}-error'}) %}
    <span id="{{ field.id }}-error" class="invalid-feedback">
        {% for error in field.errors %}
        {{ error }}
        {% endfor %}
    </span>
    {% endif %}
</div>
{% endmacro %}

但结果是

jinja2.exceptions.UndefinedError: 'wtforms.fields.simple.PasswordField object' has no attribute 'html_params'

那么，如何使用 **kwargs 更新字段以添加指定的类和属性？

谢谢

【问题讨论】：

标签： flask jinja2 wtforms

【解决方案1】：

我已经解决了这个问题，阅读 wtforms 文档here后基本解决

这是我的修改代码

security/macro/forms.html

{% macro render_field_with_errors_no_labels(field) %}
<div class="input-group mb-3">
    {% if field.errors %}
    {% set update_aria = kwargs.update({'aria_describedby': field.id~'-error'}) %}
    {% set update_css = kwargs.update({'class' :'form-control is-invalid'}) %}
    {{ field(class=update_class, aria_describedby=update_aria, **kwargs) }}
    <span id="{{ field.id }}-error" class="invalid-feedback">
        {% for error in field.errors %}
        {{ error }}
        {% endfor %}
    </span>
    {% else %}
    {{ field(**kwargs)|safe }}
    {% endif %}
</div>
{% endmacro %}

【讨论】：