Guide data: The mystery of converting string numbers to integers in AnQi CMS template （integerFilter details)

In modern website operation, dynamically handling and displaying data is one of the core values of content management systems.AnQiCMS (AnQiCMS) boasts a high-performance architecture based on the Go language and a flexible Django-style template engine, providing powerful tools for content operators.However, data is often stored in databases or entered by users in the form of strings.When we need to perform precise numerical calculations on these string-type numbers, such as adding and subtracting product prices, counting inventory quantities, or performing points calculations, directly manipulating strings can lead to errors or unexpected results.

At this moment, how to elegantly and efficiently convert string-type numbers to integers for calculation in AnQi CMS templates has become an indispensable skill. AnQi CMS provides a special solution for this—integerfilter.

The necessity of data type conversion

The flexible content model of AnQi CMS allows us to customize rich fields for articles, products, etc.For example, you may have set fields such as "priceImagine if your template tries to add two string type prices directly, for example, "10" plus "5This is the fundamental difference between string concatenation and numerical calculation.In order to perform correct mathematical operations, we must ensure that the operands are of true numeric type, and that is the value of data type conversion.

integerThe role and usage of filters

The Anqi CMS template engine has followed the Django-style filter mechanism, allowing you to use simple pipe symbols|Pass the data to a function for processing.integerThe filter is one of them, and its core function is:Convert a string representation of a number to an integer type..

When this filter encounters non-numeric characters, null values, or strings that do not match the format during the conversion process, it will safely return0To avoid errors during template rendering. This error-tolerant mechanism is particularly important for handling uncontrollable user input or external data sources.

It is worth noting that if you are dealing with a numeric string that may contain decimals (such as "99.5"), and you want to convert it to an integer (for example, rounding to 99), you would usually first usefloatThe filter converts it to a floating-point number and then passes throughintegerThe filter rounds off. This ensures that the decimal part is parsed correctly, for example, "50.5" will first become 50.500000, and then be converted to 50.

We will understand its usage through some practical examples:

1. Simple string to integer conversion

Assuming you have a variablecount_strStoring the string "123", do you want to convert it to an integer?

{% set count_str = "123" %}
<p>原始字符串: {{ count_str }}</p>
<p>转换为整数: {{ count_str|integer }}</p>
{# 输出:
   原始字符串: 123
   转换为整数: 123
#}

2. Handle strings with decimals and take the integer part

If your data may contain decimals, such as '99.5', and you want to get the integer 99.

{% set price_str = "99.5" %}
<p>原始字符串 (含小数): {{ price_str }}</p>
<p>先转浮点再转整数: {{ price_str|float|integer }}</p>
{# 输出:
   原始字符串 (含小数): 99.5
   先转浮点再转整数: 99
#}

By this two-step conversion, you can ensure99.5is correctly identified as a floating-point number99.5, thenintegerThe filter rounds it to99.

3. Calculate in the actual content model

Assuming you have a product document (archiveobject), which contains custom fieldsOriginalPriceandDiscountThey can all be stored as strings. You want to calculate the final price.

{% archiveDetail product_archive with name="archive" %} {# 假设这里获取了当前产品的文档数据 #}

{# 从自定义字段获取字符串值，并提供默认值以防为空 #}
{% set original_price_str = product_archive.OriginalPrice|default:"0" %}
{% set discount_str = product_archive.Discount|default:"0" %}

{# 将字符串转换为整数进行计算 #}
{% set original_price = original_price_str|float|integer %}
{% set discount = discount_str|float|integer %}

<p>产品原价（字符串形式）: {{ original_price_str }}</p>
<p>产品折扣（字符串形式）: {{ discount_str }}</p>
<p>转换后的原价（整数）: {{ original_price }}</p>
<p>转换后的折扣（整数）: {{ discount }}</p>
<p>最终计算价格: {{ original_price - discount }}</p> {# 直接进行整数减法运算 #}

{% endarchiveDetail %}
{# 假设 OriginalPrice 是 "150" 和 Discount 是 "25.5" #}
{# 输出:
   产品原价（字符串形式）: 150
   产品折扣（字符串形式）: 25.5
   转换后的原价（整数）: 150
   转换后的折扣（整数）: 25
   最终计算价格: 125
#}

This example shows how to safely extract string data from the content model byfloatandintegerThe filter performs the conversion and then performs precise mathematical operations.default:"0"Its use also reflects good programming practices, preventing conversion failure when the field is empty.

Extended application: besidesintegerother than

The template filter function of AnQi CMS is not justinteger. Besides converting strings to integers, you will also find many other indispensable tools in data processing:

  • floatFilterIt is specifically used to convert strings to floating-point numbers, and it is your preferred choice when you need to retain decimal parts for calculation.
  • floatformatFilterAfter floating-point calculations, if you need to control the number of decimal places displayed, such as rounding or fixing the number of decimal places,floatformatprovides powerful formatting capabilities.
  • addFilterHowever, basic arithmetic operations such as addition, subtraction, multiplication, and division can be performed directly, butaddFilters can handle the concatenation or addition of different types of data (numbers, strings) more flexibly.
  • **stringformatFilter