As an experienced website operations expert, I am well aware of the importance of data processing and precise calculation in website display and business logic in my daily work.AnQiCMS (AnQiCMS) provides great convenience for us content operators with its efficient and flexible features.Today, let's talk about a practical problem often encountered in template development - how to elegantly handle floating-point number operations with decimal points in the Anqi CMS template.

The template engine of Anqi CMS adopts a syntax similar to Django, which allows operators familiar with web development to quickly get started.Its strength lies in its ability to not only easily display data but also to perform certain data processing at the template level, including the floating-point arithmetic we are discussing today.Understanding and mastering these techniques will help us build dynamic pages more flexibly, such as calculating product prices, displaying discounts, and even presenting simple statistics.

Core Function: Direct Arithmetic Operations

Performing floating-point arithmetic in the AnQi CMS template is far from as complex as you might imagine. Its template engine allows us to directly use double curly braces{{ }}Using common mathematical operators, it's as natural as writing a simple equation.Whether it is addition, subtraction, multiplication, division, or more advanced power operations and modulus operations, AnQiCMS can directly recognize and calculate.

For example, suppose you have a product priceitem.Pricewhich is a floating-point number (like)99.99), and the quantity purchased by the useritem.Quantityis an integer (like)2You want to calculate the total price and display it? You can simply implement it like this:)

{{ item.Price * item.Quantity }}

If you need to add shipping costsshippingFee(For example)10.50), and calculate a discount (for example)0.8），the entire expression can be written together continuously:)

商品总价：{{ (item.Price * item.Quantity + shippingFee) * 0.8 }} 元

Here are theitem.PriceandshippingFeeIf it is already a floating-point number type, the template engine will automatically perform floating-point arithmetic. In addition, you can also use comparison operators (==,!=,<,>,<=,>=Compare floating-point numbers using this:

{% if (item.Price * item.Quantity) > 100 %}
    <p>恭喜，订单金额已超过100元！</p>
{% endif %}

Ensure the correct data type: Type conversion filter

In the actual template development, the data we get from the backend may not always be the type we expect.For example, the price field stored in the database may be read as a string, or the numeric value submitted through a form may also be of string type.In this case, performing mathematical operations directly may lead to unexpected results, even errors.

To ensure the accuracy of the calculation, AnQiCMS template providesfloatandintegera filter to force variables to be converted to floating-point or integer types.

  • floatFilter:When you are sure a variable represents a floating-point number but its current type is a string or another incompatible type, usefloata filter to convert it to a floating-point number.

    {% set priceString = "99.99" %}
{% set quantityString = "2" %}
总金额：{{ priceString|float * quantityString|float }}

    In this way, even though priceStringandquantityStringAt first they are strings, they will also be correctly converted to floating-point numbers for multiplication. If the conversion fails,floatThe filter will return0.0.

  • integerFilter:Similarly, if you need to convert a variable to an integer for calculation (for example, product inventory is usually an integer), you can useintegerFilter.

    {% set stockString = "10.5" %} {# 假设某个字段被误存为浮点数形式的字符串 #}
当前库存：{{ stockString|integer }}

    HerestockStringit will be converted to an integer10. If the conversion fails,integerThe filter will return0.

By reasonably utilizing these type conversion filters, the robustness of template code can be greatly improved, thus avoiding calculation errors caused by mismatched data types.

Beautiful and Precise Control: Floating-point Number Formatting Display

After floating-point arithmetic, it is usually necessary to display the result in a user-friendly manner, such as displaying currency in two decimal places.The AnQiCMS template provides various filters to help us finely control the display format of floating-point numbers.

  • floatformatFilter:This is the most commonly used floating-point number formatting tool, which can retain the specified decimal places of a floating-point number.

    • If no parameter is specified, it will default to retaining one decimal place and will automatically handle trailing zeros (if the decimal part is.0It will display as an integer). It will also round to the third decimal place.
      
{{ 34.23234|floatformat }} {# 显示 34.2 #}
{{ 34.00000|floatformat }} {# 显示 34 #}
{{ 34.26000|floatformat }} {# 显示 34.3 #}
    • If you want to keep more or fewer decimal places, you can pass a number as a parameter. For example, to keep three decimal places:
      
{{ 34.23234|floatformat:3 }} {# 显示 34.232 #}
{{ 34.00000|floatformat:3 }} {# 显示 34.000 #}
      floatformatThe filter is very useful in handling scenarios where fixed decimal places are required, such as currency.

  • stringformatFilter:For more complex formatting needs, such as adding a currency symbol before a number, or displaying in a specific alignment style,stringformatthe filter provides powerfulfmt.Sprintf()formatting capabilities of style.

    {% set totalPrice = 123.456 %}
最终价格：{{ totalPrice|stringformat:"¥%.2f" }} {# 显示 ¥123.46 #}
百分比：{{ 0.55555|stringformat:"%.2f%%" }} {# 显示 55.56% #}

    stringformatProvided extremely high flexibility, capable of meeting almost all formatting needs from numbers to strings, especially when combining special symbols with numbers.

By combiningfloatformatandstringformatYou can ensure that the floating-point arithmetic results are not only accurate but also presented on the page in the most user-friendly and business-demand-oriented manner.

Examples of practical application scenarios

In the actual operation of AnQi CMS, floating-point arithmetic is ubiquitous:

  1. Product price and total order amount:Calculate the unit price of the product multiplied by the quantity, subtract the discount of the voucher, and finally add the shipping fee to get the final payment amount.

    {% set itemPrice = 50.75 %}
{% set quantity = 3 %}
{% set discount = 0.9 %} {# 9折 #}
{% set shippingFee = 8.00 %}
{% set finalAmount = (itemPrice * quantity * discount + shippingFee)|floatformat:2 %}
<p>商品单价：{{ itemPrice }} 元</p>
<p>购买数量：{{ quantity }} 件</p>
<p>折扣：{{ (1 - discount)*100 }}%</p>
<p>运费：{{ shippingFee }} 元</p>
<p>最终支付：{{ finalAmount }} 元</p>

  2. Percentage display:Calculate percentage data such as product discounts, tax rates, and sales growth rates.

    {% set salesThisMonth = 15000.00 %}
{% set salesLastMonth = 12000.00 %}
{% set growthRate = (salesThisMonth - salesLastMonth) / salesLastMonth * 100 %}
<p>本月销售额：{{ salesThisMonth }} 元</p>
<p>上月销售额：{{ salesLastMonth }} 元</p>
<p>增长率：{{ growthRate|floatformat:2 }}%</p>

  3. Data statistics display:Calculate average values and ranking scores.

    {% set totalScore = 85.5 + 92.0 + 78.5 %}
{% set numberOfStudents = 3 %}
{% set averageScore = totalScore / numberOfStudents %}
<p>总分：{{ totalScore }}</p>
<p>平均分：{{ averageScore|floatformat:1 }}</p>

These examples all demonstrate how to perform basic floating-point arithmetic in the Anqi CMS template and use filters for formatting to meet various content display requirements.

Summary