What advanced formatting options does the AnQiCMS `stringformat` filter support (such as outputting percentages, scientific notation)?

In AnQiCMS template development, the flexibility of data display is often a key factor in determining user experience and the professionalism of content presentation. Among them,stringformatFilter is undoubtedly a powerful tool that allows us to finely format various data types, meeting from simple precision control of numbers to complex percentages, scientific notation, and other advanced requirements.

stringformatFilter: The data formatter in the template

stringformatThe filter is like a data formatter in the template, its core function is to mimic the built-in Go languagefmt.Sprintf()Function, which converts numbers, strings, and even more complex data types into strings according to a predefined format.This means that, regardless of whether your data is an integer, a floating-point number, or plain text, you can customize the final display style through it.

It includes the most basic application of controlling the display accuracy of floating-point numbers, for example, if you have a floating-point number3.141592653and you want it to display only two decimal places, you can use it like this:

{{ 3.141592653|stringformat:"%.2f" }} {# 输出：3.14 #}

here,%.2fTell the filter to format numbers as floating-point numbers and retain two decimal places. Similarly, it handles integers or embedded strings with ease:

{{ 99|stringformat:"数值：%d" }} {# 输出：数值：99 #}
{{ "AnQiCMS"|stringformat:"系统名称：%s" }} {# 输出：系统名称：AnQiCMS #}

These basic usages provide convenience for data display, butstringformatits true power lies in its support for advanced formatting options.

Advanced formatting options: Let the data 'speak'.

In many business scenarios, we need to present data in a more expressive way, such as percentages in financial statements, scientific notation in scientific research, or precise control of text alignment.stringformatThe filter provides various advanced options to help us achieve these goals.

Output percentage

Directly outputting a decimal as a percentage often does not conform to people's reading habits. For example,0.15Generally displayed as15%. With the help ofstringformat, we can easily achieve:

First, multiply the original decimal by 100, then use%.0f(a floating point number without decimal places) or%.2f(Format as a floating-point number with two decimal places and then manually concatenate the percentage sign.)

{% set discount = 0.15 %}
产品折扣：{{ (discount * 100)|stringformat:"%.0f" }}% {# 输出：产品折扣：15% #}

{% set completion_rate = 0.9876 %}
完成率：{{ (completion_rate * 100)|stringformat:"%.2f" }}% {# 输出：完成率：98.76% #}

After this process, the originally dull numbers are transformed into intuitive percentage forms, greatly enhancing the readability of the information.

Scientific notation

When dealing with very large or very small numbers, scientific notation is a standard and concise way of representation.stringformatBy%eand%EThese formatting verbs support scientific notation:

• %eConvert numbers to scientific notation using lowercase letterseIndicates the exponent.
• %EConvert numbers to scientific notation using uppercase lettersEIndicates the exponent.

{% set large_number = 123456789.12345 %}
宇宙距离：{{ large_number|stringformat:"%e" }} 米 {# 输出：宇宙距离：1.234568e+08 米 #}

{% set small_number = 0.00000012345 %}
粒子大小：{{ small_number|stringformat:"%E" }} 毫米 {# 输出：粒子大小：1.234500E-07 毫米 #}

In this way, even facing extreme values, we can maintain clear and professional presentation in the template.

Width and alignment

Sometimes you need to control the width and alignment of the output result to achieve a neat table or report layout.stringformatAllow you to specify the minimum width of the output field and decide whether to align left or right:

• %[width]s: Right-align the string and fill it with spaces on the left until it reaches the specified width.
• %-[width]sLeft-align a string and fill with spaces on the right until the specified width is reached.
• %[width]dRight-align an integer and fill with spaces on the left.

{% set product_name = "高端服务器" %}
{% set price = 12345 %}
商品列表：
- 名称：{{ product_name|stringformat:"%-15s" }} 价格：{{ price|stringformat:"%8d" }} 元
{% set product_name_b = "入门主机" %}
{% set price_b = 899 %}
- 名称：{{ product_name_b|stringformat:"%-15s" }} 价格：{{ price_b|stringformat:"%8d" }} 元
{# 示例输出：
- 名称：高端服务器     价格：   12345 元
- 名称：入门主机       价格：     899 元
#}

This alignment is very useful when generating structured output (such as reports, receipts).

Other useful number formats

stringformatIt supports some other number formatting options, although not commonly used, they can be very practical in certain scenarios:

• %b: Converts an integer to binary representation.
• %x/%XConvert integer to hexadecimal representation (lowercase/uppercase).
• %cConvert integer to corresponding Unicode character.

{% set decimal_value = 99 %}
二进制：{{ decimal_value|stringformat:"%b" }} {# 输出：二进制：1100011 #}
十六进制：{{ decimal_value|stringformat:"%x" }} {# 输出：十六进制：63 #}
字符：{{ decimal_value|stringformat:"%c" }} {# 输出：字符：c #}

These options provide flexible solutions for lower-level or specific data display requirements.

View data types and structures

When debugging or unsure of variable content,%v/%+v/%#vand%TThese formatting verbs can help us better understand the data:

• %v: The default format for outputting values.
• %+v: When the value is a struct, it will output the field names and values.
• %#vOutput the Go language syntax representation of the value (i.e., the source code snippet).
• %TOutput the Go language type of the value.

{% set my_variable = {"key": "value", "number": 123} %}
普通输出：{{ my_variable|stringformat:"%v" }}
带字段名：{{ my_variable|stringformat:"%+v" }}
Go语法：{{ my_variable|stringformat:"%#v" }}
类型：{{ my_variable|stringformat:"%T" }}
{# 实际输出会因变量的具体结构而异，但能提供丰富的调试信息 #}

Summary

stringformatThe filter brings powerful data formatting capabilities to the AnQiCMS template.From controlling decimal places to outputting percentages, scientific notation, and fine text alignment and type checking, it allows content managers and developers to present data in a highly customized and professional manner.Mastery of these advanced formatting options can greatly enhance the presentation of website content and provide a more accurate, user-friendly experience.