Enabled performing mathematical operations in templates using layout:set:math tag, :math variable modifier and exp:math module

[intoeetive]

Enabled performing mathematical operations in templates using layout:set:math tag
Added :math modifiers on variables and exp:math module

This PR is allowing to perform mathematical operations prior to assigning the result to layout variable. To achieve that, use {layout:set:math} tag

The following code will produce something like 1409.24202

{exp:channel:entries channel_id="1" entry_id="1"}
{layout:set:math name="math"}{entry_date}/1000000{/layout:set:math}
{/exp:channel:entries}

Under the hood, it's using EvalMath library, which is the same one that mx_calc is using.

Another two options are using variable modifier and module

Variable modifier takes the variable (e.g. segment_1) as first part of expression and optional expression parameter as its second part. Additionally, function can be applied to the result. So if we want to divide to entry date by by 10, add 5 to the result and then take square root of it we can do the following

{entry_date:math expression="/10+5" function="sqrt"}

Module tag works the same as variable modifier, but it expects complete expression. It can be used as single tag as a tag pair. When used as tag pair, the result is in result variable

{exp:math expression="/10+5" function="sqrt"}
{result}
{/exp:math}

Both modifier and tag return the result formatted. They accept same parameters as :number_format modifier

The documentation is here: ExpressionEngine/ExpressionEngine-User-Guide#994