如何高效拆分两个字符串并生成所有值的组合（MediaWiki模板）

问题场景 #

我在MediaWiki模板里有两个参数location和locality_subjects，每个参数都支持多个用分号分隔的值，示例如下：

|location=Bucks County, Pennsylvania;Chester County, Pennsylvania
|locality_subjects=Court records;Probate records;Vital records

需要为这两个参数的所有值组合生成分类链接，预期输出如下：

[[Category:Bucks County, Pennsylvania, court records]]
[[Category:Bucks County, Pennsylvania, probate records]]
[[Category:Bucks County, Pennsylvania, vital records]]
[[Category:Chester County, Pennsylvania, court records]]
[[Category:Chester County, Pennsylvania, probate records]]
[[Category:Chester County, Pennsylvania, vital records]]

目前我假设每个参数最多包含4个值，用硬编码的方式逐个写出所有组合，代码非常冗余：

[[Category:{{#explode:{{{location|}}}|;|0}}, {{#explode:{{lc:{{{locality_subjects|}}}|;|0}}]]
[[Category:{{#explode:{{{location|}}}|;|0}}, {{#explode:{{lc:{{{locality_subjects|}}}|;|1}}]]
[[Category:{{#explode:{{{location|}}}|;|0}}, {{#explode:{{lc:{{{locality_subjects|}}}|;|2}}]]
[[Category:{{#explode:{{{location|}}}|;|0}}, {{#explode:{{lc:{{{locality_subjects|}}}|;|3}}]]
[[Category:{{#explode:{{{location|}}}|;|1}}, {{#explode:{{lc:{{{locality_subjects|}}}|;|0}}]]
[[Category:{{#explode:{{{location|}}}|;|1}}, {{#explode:{{lc:{{{locality_subjects|}}}|;|1}}]]
[[Category:{{#explode:{{{location|}}}|;|1}}, {{#explode:{{lc:{{{locality_subjects|}}}|;|2}}]]
[[Category:{{#explode:{{{location|}}}|;|1}}, {{#explode:{{lc:{{{locality_subjects|}}}|;|3}}]]
[[Category:{{#explode:{{{location|}}}|;|2}}, {{#explode:{{lc:{{{locality_subjects|}}}|;|0}}]]
[[Category:{{#explode:{{{location|}}}|;|2}}, {{#explode:{{lc:{{{locality_subjects|}}}|;|1}}]]
[[Category:{{#explode:{{{location|}}}|;|2}}, {{#explode:{{lc:{{{locality_subjects|}}}|;|2}}]]
[[Category:{{#explode:{{{location|}}}|;|2}}, {{#explode:{{lc:{{{locality_subjects|}}}|;|3}}]]
[[Category:{{#explode:{{{location|}}}|;|3}}, {{#explode:{{lc:{{{locality_subjects|}}}|;|0}}]]
[[Category:{{#explode:{{{location|}}}|;|3}}, {{#explode:{{lc:{{{locality_subjects|}}}|;|1}}]]
[[Category:{{#explode:{{{location|}}}|;|3}}, {{#explode:{{lc:{{{locality_subjects|}}}|;|2}}]]
[[Category:{{#explode:{{{location|}}}|;|3}}, {{#explode:{{lc:{{{locality_subjects|}}}|;|3}}]]

想问有没有更高效的实现方式？

高效实现方案 #

可以利用MediaWiki的ParserFunctions扩展提供的#arraymap函数，实现自动遍历两个参数的所有值并生成组合分类，代码如下：

{{#arraymap:{{{location|}}}|;|$loc|
  {{#arraymap:{{lc:{{{locality_subjects|}}}}}|;|$subj|
    [[Category:$loc, $subj]]
  }}
}}

代码说明 #

• 外层#arraymap：将location参数按分号;拆分为数组，把每个元素赋值给变量$loc
• 内层#arraymap：将转小写后的locality_subjects参数按分号拆分，把每个元素赋值给变量$subj
• 内层自动生成[[Category:$loc, $subj]]格式的分类链接，最终输出所有值的组合

优势 #

• 无需硬编码值的数量，自动适配任意数量的分号分隔值（只要参数格式正确）
• 代码简洁易维护，避免冗余的重复代码
• 保留了原实现中{{lc:...}}转小写的逻辑，和预期输出一致

注意：确保你的MediaWiki站点已安装并启用了ParserFunctions扩展（绝大多数维基站点默认已配置）

内容的提问来源于stack exchange，提问作者redheadkelly