Question

在我正在处理的项目中，默认情况下我需要select标记位于特定的option。我试图让它做到这一点，如果我将变量设置为某个数字，页面加载时将选择相应的选项。出于某种原因，我用来判断该选项是否与变量相同的代码总是返回false。

View.py

@login_required
def display_work(request, id, chapter = 1):
    info = dict()
    work = Work.objects.get(id = id)
    chapters = Chapter.objects.filter(work = id).order_by("order_number")
    info['title'] = work.title
    info['summery'] = work.summery
    info['current_chapter'] = chapter # the number the options are compared to
    print chapter
    info['id'] = id
    num_chapters = 0
    chapter_list = []
    for c in chapters:
        temp = (c.title, c.order_number) # where the numbering for the options is set (see template code)
        chapter_list.append(temp)
        num_chapters += 1
    info['total_chapter'] = num_chapters
    content = chapters[int(chapter)-1].content
    return render_to_response("SubMain/display_work.html", {'STATIC_URL':STATIC_URL, "info":info, "chapters": chapter_list, "content": content})

模板：模板在列表中运行，检查其创建的选项是否是当前章节。如果是这样，它应该“选择”它。

{% for t, o in chapters %}
<option value="/work/{{ info.id }}/{{ o }}" {% if o == info.current_chapter %} selected="selected" {% endif %}>Chapter {{ o }}: {{ t }}</option>
{% endfor %}

然而，每当我运行代码时，都没有被选中（if标签中有什么）。通过我已完成的调试，我确认o为2，info.current_chapter为2。

Answer 1

在模板中尝试使用单个'='操作而不是'=='。

<option value="/work/{{ info.id }}/{{ o }}" {% if o = info.current_chapter %} selected="selected" {% endif %}>Chapter {{ o }}: {{ t }}</option>

Answer 2

尝试ifequal

 {% for t, o in chapters %}
    <option value="/work/{{ info.id }}/{{ o }}" {% ifequal o info.current_chapter %} selected="selected" {% endifequal %}>Chapter {{ o }}: {{ t }}</option>
    {% endfor %}

Django：模板语言比较总是返回false

2 个答案: