Ember-math-helpers

HTMLBars template helpers for doing basic arithmetic operations

Installation

ember install ember-math-helpers

Usage

Basic Arithmetic

Helper	JavaScript	HTMLBars
add	a + b	{{add a b}}
div	a / b	{{div a b}}
mod	a % b	{{mod a b}}
mult	a * b	{{mult a b}}
sub	a - b	{{sub a b}}

Math

We decided we should support the entirety of the JS Math methods, so this list will be quite long.

Helper	JavaScript	HTMLBars
abs	Math.abs(a)	{{abs a}}
acos	Math.acos(a)	{{acos a}}
acosh	Math.acosh(a)	{{acosh a}}
asin	Math.asin(a)	{{asin a}}
asinh	Math.asinh(a)	{{asinh a}}
atan	Math.atan(a)	{{atan a}}
atanh	Math.atanh(a)	{{atanh a}}
atan2	Math.atan2(a, b)	{{atan2 a b}}
cbrt	Math.cbrt(a)	{{cbrt a}}
ceil	Math.ceil(a)	{{ceil a}}
clz32	Math.clz32(a)	{{clz32 a}}
cos	Math.cos(a)	{{cos a}}
cosh	Math.cosh(a)	{{cosh a}}
exp	Math.exp(a)	{{exp a}}
expm1	Math.expm1(a)	{{expm1 a}}
floor	Math.floor(a)	{{floor a}}
fround	Math.fround(a)	{{fround a}}
hypot	Math.hypot([a, b, c...])	{{hypot a b c}}
imul	Math.imul(a, b)	{{imul a b}}
log-e	Math.log(a)	{{log-e a}}
log1p	Math.log1p(a)	{{log1p a}}
log10	Math.log10(a)	{{log10 a}}
log2	Math.log2(a)	{{log2 a}}
max	Math.max([a, b, c...])	{{max a b c}}
min	Math.min([a, b, c...])	{{min a b c}}
pow	Math.pow(a, b)	{{pow a b}}
round	Math.round(a)	{{round a}}
sign	Math.round(a)	{{sign a}}
sin	Math.sin(a)	{{sin a}}
sqrt	Math.sqrt(a)	{{sqrt a}}
tan	Math.tan(a)	{{tan a}}
tanh	Math.tanh(a)	{{tanh a}}
trunc	Math.trunc(a)	{{trunc a}}

Random

Helper	JavaScript	HTMLBars
random (No Args) [, decimals]	Math.random(), decimals sets precision from 0-20 (default: 0)	{{random}} or {{random decimals=4}}
random (Upper Bound) [, round]	capped Math.random(), decimals sets precision from 0-20 (default: 0)	{{random 42}} or {{random 42 decimals=4}}
random (Upper Bound, Lower Bound) [, round])	bounded Math.random(), decimals sets precision from 0-20 (default: 0)	{{random 21 1797}} or {{random 21 1797 decimals=4}}

You can pass as many arguments as you would like to the helpers. For something like 10 - 1 - 2 - 3 you could do:

{{sub 10 1 2 3}}

You can also use these helpers to do math inside other HTMLBars markup like so:

<span class="nav-marker color-{{if multiColor (add selectedIndex 1) 1}}"></span>

Composable Helpers

There is full support for using all of the helpers together, to do complex math, even though complex calculations may be better left to JS.

For something like (15 + 5) / 2 * 10 you could do:

{{mult (div (add 15 5) 2) 10}}