How to control content conditional judgment and loop display in AnQiCMS with Django template engine syntax?

Use Django template syntax to make AnQiCMS content display more flexible conditional judgment and loop

The strength of AnQiCMS lies not only in its efficient and stable backend architecture, but also in the great flexibility it provides for front-end content display for content operators.Among them, deeply integrating the Django template engine syntax allows us to build like a child's blocks, easily control the display of website content through simple conditional judgments and loops, creating more intelligent and user-friendly dynamic pages.

This article, let's delve into how to skillfully use Django template engine conditional judgment in AnQiCMS{% if %}) and loop display({% for %}Function, brings vitality to the website content.

Understand conditional judgment: Let the content 'taste the dish according to the person.'

Imagine, you want certain content to appear only under specific conditions, such as only displaying to VIP users, or highlighting articles with a 'recommended' tag, or showing exclusive promotional information on a particular holiday. At this point,{% if %}The tag becomes our helpful assistant, it can decide whether to render a section of HTML code according to the conditions you set.

In AnQiCMS templates, the syntax of conditional judgments is very intuitive, usually starting with{% if 条件 %}and ends with{% endif %}end.

Basic usage: single condition judgment

The simplest conditional judgment is based on a boolean value (True or False). For example, we want to determine whether an article has a thumbnail, and if it does, display it:

{% if archive.Thumb %}
    <img src="{{ archive.Thumb }}" alt="{{ archive.Title }}" />
{% endif %}

here,archive.ThumbIf there is a value (non-empty), the condition is true, and the image will be displayed.

Multiple choices:{% else %}and{% elif %}

If you want to provide an alternative solution when the condition is not met, we can introduce{% else %}For example, when an article does not have a thumbnail, a default placeholder image is displayed:

{% if archive.Thumb %}
    <img src="{{ archive.Thumb }}" alt="{{ archive.Title }}" />
{% else %}
    <img src="/static/images/default-thumb.png" alt="默认缩略图" />
{% endif %}

When the situation is more complex and it is necessary to judge multiple mutually exclusive conditions,{% elif %}(else if abbreviation) can be used. For example, based on the recommended attributes of the article(Flag) show different prompts:

{% if archive.Flag == "h" %}
    <span class="badge badge-hot">头条</span>
{% elif archive.Flag == "c" %}
    <span class="badge badge-recommend">推荐</span>
{% else %}
    <!-- 其他情况，不显示标签 -->
{% endif %}

Here, we comparearchive.FlagThe value determines whether to display the label 'Headlines' or 'Recommendations.' It is worth noting that conditional judgments support various comparison operators, such as==(equals,)!=(not equal,)>(greater than,)<(less than,)>=(greater than or equal to,)<=(less than or equal to), as well asin(inclusive) andnot(Not) logical operators, which allow us to build very complex judgment logic. For example, determining whether an ID is in a certain list:{% if item.Id in selectedIds %}.

Master the cyclic display: Efficiently present a large amount of information

When we need to display a series of contents, such as the latest article list, product categories, or image gallery, it is obviously unrealistic and inefficient to write them individually. At this time,{% for %}The loop tag becomes our helpful assistant, it can traverse the array or list data obtained by AnQiCMS through various tags (such asarchiveList,categoryList,navListetc) and display them one by one.

Basic Usage: Traverse list data

In AnQiCMS, we usually use a tag to get the data list first, then use{% for %}The tag to iterate over. For example, get the latest 10 articles and display their titles and links:

{% archiveList articles with type="list" limit="10" %}
    <ul>
        {% for article in articles %}
            <li>
                <a href="{{ article.Link }}">{{ article.Title }}</a>
            </li>
        {% endfor %}
    </ul>
{% endarchiveList %}

here,articlesIsarchiveListThe article list returned by the tag,articleIs the variable for the current article in each loop.

Handle empty list:{% empty %}

When processing list data, we often encounter the situation where the list is empty. To avoid the page from appearing blank or unfriendly prompts,{% empty %}tags provide an elegant solution. When{% for %}When the loop data is empty,{% empty %}the content in it will be rendered:

{% archiveList products with type="list" categoryId=currentCategory.Id limit="8" %}
    <ul>
        {% for product in products %}
            <li>
                <a href="{{ product.Link }}">{{ product.Title }}</a>
            </li>
        {% empty %}
            <li>抱歉，该分类下暂无产品。</li>
        {% endfor %}
    </ul>
{% endarchiveList %}

Enhanced loop control:forloopVariables,reversedandcycle

{% for %}Some special tags are provided inside the loop.forloopA variable that can help us better control the loop:

• forloop.Counter: The current loop iteration number, starting from 1.
• forloop.Revcounter: The reverse sequence number of the current loop, starting from the total count.
• forloop.First: A boolean value, which is True if it is the first item in the loop.
• forloop.Last: Boolean value, if the current is the last item in the loop, it is True.

Using these variables, we can achieve many practical effects, such as adding numbers to list items or highlighting the first article:

{% archiveList articles with type="list" limit="5" %}
    <ol>
        {% for article in articles %}
            <li {% if forloop.First %}class="highlight-first"{% endif %}>
                {{ forloop.Counter }}. <a href="{{ article.Link }}">{{ article.Title }}</a>
            </li>
        {% endfor %}
    </ol>
{% endarchiveList %}

In addition, we can also use{% for item in list reversed %}Reverse iterate through the list, or utilize{% cycle 'odd' 'even' %}Tags to alternate the odd and even row styles of list items.

Combine to build a smarter dynamic page.

The real strength lies in combining conditional judgment and loop display to build highly dynamic and intelligent pages.

For example, when building a multi-level navigation menu, you can first iterate through the first-level categories, and then use{% if item.HasChildren %}to determine if there are subcategories, if there are, continue to iterate through the subcategories:

{% navList mainNavs %}
    <ul class="main-menu">
        {% for item in mainNavs %}
            <li {% if item.IsCurrent %}class="active"{% endif %}>
                <a href="{{ item.Link }}">{{ item.Title }}</a>
                {% if item.NavList %} {# 判断是否有下级导航 #}
                    <ul class="sub-menu">
                        {% for subItem in item.NavList %}
                            <li {% if subItem.IsCurrent %}class="active"{% endif %}>
                                <a href="{{ subItem.Link }}">{{ subItem.Title }}</a>
                            </li>
                        {% endfor %}
                    </ul>
                {% endif %}
            </li>
        {% endfor %}
    </ul>
{% endnavList %}

In this example, we not only displayed the main navigation in a loop, but also through{% if item.NavList %}Determined if there was a child navigation and performed a nested loop. This greatly improved the flexibility and maintainability of the navigation.

For example, show related recommendations on the article detail page and decide whether to display the image based on whether the article has a cover image:

`twig

<h3>相关推荐</h3>
{% archiveList relatedArticles with type="related" limit="5" %}
    <ul>
        {% for article in relatedArticles %}
            <li>
                {% if article.Thumb %}
                    <img src="{{ article.Thumb }}" alt="{{ article.Title }}" class="related-thumb">
                {% endif