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Redis记录历史表单数据，之后读取填充选择表单

需求，在创建博客时，对于表单中的选择框每次都需要重新选，如果是发布同一类型的文章，分类、专题、标签都是一样，那么如何记录上次该浏览器的选择呢？

image.png

1. 创建博客时将浏览器选择的历史记录在Redis中；
2. 视图中尝试读取该值，并在前端selected选中。

新建博客视图

创建验证form_valid(self, form)成功后将选择项保存到redis数据库中，并设置过期时间为12小时

对于多选框，需要将结果值转换为以_连接的字符串，'_'.join(map(lambda tag: str(tag.id), form.cleaned_data.get('tags')))

存储到Redis中。

当再次创建时，获取Redis中的值，对于多选，需要字符串分解了int型的列表select_tags = list(int(tag_id) for tag_id in last_select_tags.split('_'))

前端option中通过tag.id in select_tags判断是否是选中状态。

# 文章创建
@method_decorator(login_required, name='dispatch')
class BlogCreate(CreateView):
    model = Article
    template_name = 'rearend/blog-edit.html'
    form_class = ArticleForm

    from utils.project_config import get_redis_db
    redis_db = get_redis_db()

    # success_url = 'xxx'  # 可以设置创建成功后跳转地址，也可以使用下面的函数

    def get_success_url(self):
        # print(self.object.id)  # 可以得到新创建的博客id
        # return reverse('blog:blog_list')
        return reverse('blog_admin:blog_detail', kwargs={'article_id': self.object.id})

    # 表单验证通过，修改一些字段的值
    def form_valid(self, form):
        if self.request.user:
            form.instance.author = self.request.user
            from django.contrib.auth.models import Group
            # 如果用户在已注册的组中，当发布了一篇文章后，将用户移动到作者的组（id=4）中
            if self.request.user in Group.objects.get(id=5).user_set.all():
                Group.objects.get(id=5).user_set.remove(self.request.user)
                Group.objects.get(id=4).user_set.add(self.request.user)

        # 博客创建保留上次创建的记录在表单中
        csrftoken = self.request.COOKIES.get('csrftoken', None)
        if csrftoken:
            # 保存记录到redis
            self.redis_db.set('{}:create:article:select:category'.format(csrftoken), form.cleaned_data.get('category').id, ex=43200)  # 12小时过期
            select_feature = form.cleaned_data.get('feature').id if form.cleaned_data.get('feature') else 0
            self.redis_db.set('{}:create:article:select:feature'.format(csrftoken), select_feature, ex=43200)
            self.redis_db.set('{}:create:article:select:tags'.format(csrftoken), '_'.join(map(lambda tag: str(tag.id), form.cleaned_data.get('tags'))), ex=43200)  # 转为"1_3_5"字符串
        return super(BlogCreate, self).form_valid(form)

    def get_context_data(self, **kwargs):
        context = super(BlogCreate, self).get_context_data(**kwargs)
        context['status_choices'] = list(map(lambda x: {'status_code': x[0], 'status_value': x[1]}, Article.STATUS_CHOICES))
        context['categories'] = Category.objects.all()
        context['features'] = Feature.objects.all()
        context['tags'] = Tag.objects.all()
        context['select_category'] = context['select_feature'] = ''
        context['select_tags'] = []
        if self.request.path == reverse('blog_admin:blog_create'):
            csrftoken = self.request.COOKIES.get('csrftoken', None)
            last_select_category = self.redis_db.get('{}:create:article:select:category'.format(csrftoken))
            last_select_feature = self.redis_db.get('{}:create:article:select:feature'.format(csrftoken))
            last_select_tags = self.redis_db.get('{}:create:article:select:tags'.format(csrftoken))
            # print(last_select_tags.split('_'))
            if last_select_category and last_select_feature and last_select_tags:
                context['select_category'] = int(last_select_category)
                context['select_feature'] = int(last_select_feature)
                context['select_tags'] = list(int(tag_id) for tag_id in last_select_tags.split('_'))  # 只能用int类型
        return context

创建表单前端模板

<div class="form-group">
    <label for="{{ form.category.id_for_label }}">{{ form.category.label_tag }}</label>
    <select class="form-control select2" name="category" id="{{ form.category.id_for_label }}" style="width: 100%">
        {% for category in categories %}
            <option value="{{ category.id }}" {% if form.category.value == category.id or category.id == select_category %} selected {% endif %}
                    style="height: 30px">{{ category.name }}</option>
        {% endfor %}
    </select>
</div>
<div class="form-group">
    <label for="{{ form.feature.id_for_label }}">{{ form.feature.label_tag }}</label>
    <select class="form-control select2" name="feature" id="{{ form.feature.id_for_label }}" style="width: 100%">
        <option value="" {% if not form.feature.value %} selected {% endif %} style="height: 30px">---------------</option>
        {% for feature in features %}
            <option value="{{ feature.id }}" {% if form.feature.value == feature.id or feature.id == select_feature %} selected {% endif %}
                    style="height: 30px">{{ feature.name }}</option>
        {% endfor %}
    </select>
</div>
<div class="form-group">
    <label for="{{ form.tags.id_for_label }}">{{ form.tags.label_tag }}</label>
    <select class="select2 select2-hidden-accessible" name="tags" id="{{ form.tags.id_for_label }}" multiple="" data-placeholder="可选择多个标签" aria-hidden="true"
            style="width: 100%;">
        {% for tag in tags %}
            <option value="{{ tag.id }}" {% if tag.id in form.tags.value or tag.id in select_tags %} selected {% endif %}>{{ tag.name }}</option>
        {% endfor %}
    </select>
</div>