Useful Jinja macros

macros.html

{% macro plural(num, unit) -%}
    {{ num }} {% if num == 1 %}{{ unit }}{% else %}{{ unit }}s{% endif -%}
{%- endmacro %}

{% macro ordinal(number) -%}
    {%- if number % 100 > 3 and number % 100 < 21 -%}{{ number }}th
    {%- elif number % 10 == 1 -%}{{ number }}st
    {%- elif number % 10 == 2 -%}{{ number }}nd
    {%- elif number % 10 == 3 -%}{{ number }}rd
    {%- else -%}{{ number }}th{%- endif -%}
{%- endmacro %}

{% macro readTime(wordCount,wpm=200) -%}
    {% if (wordCount/wpm)>=1 %}
        {{ plural((wordCount//wpm), "minute") }}
    {% else %}
        {{ plural((wordCount//wpm)*60, "second") }}
    {% endif %}
{%- endmacro %}

{% macro age(time) -%}
    {%- set now = time.now(tz=time.tzinfo) -%}
    {%- set offset = now - time -%}
    {%- if offset.days > 600 -%}
        {{ plural(now.year - time.year, "year") }}
    {%- elif offset.days > 69 -%}
        {{ plural((now.year - time.year) * 12 + now.month - time.month, "month") }}
    {%- elif offset.days > 6 -%}
        {{ plural(offset.days // 7, "week") }}
    {%- elif offset.days > 0 -%}
        {{ plural(offset.days, "day") }}
    {%- elif offset.seconds > 3600 -%}
        {{ plural(offset.seconds // 3600, "hour") }}
    {%- elif offset.seconds > 3600 -%}
        {{ plural(offset.seconds // 60, "minute") }}
    {%- else -%}
        {{ plural(offset.seconds, "second") }}
    {%- endif -%}
{%- endmacro %}