At some point, while working on the MontageJS framework, the question came up what CSS naming convention we should start using. After a long discussion we settled on using the BEM methodology, but changed the syntax a bit. To keep this post short, I won’t go into detail why using BEM is a good idea, but rather explain why we chose a different syntax. Here some examples:

.digit-Progress          /* org-Component */
.digit-Progress-bar      /* org-Component-childElement */
.digit-Progress--small   /* org-Component--variation */

Note: The org- (digit-) prefix is used as a name-space so it wouldn’t conflict with other packages/libraries/frameworks.

Now let’s take a look at the reasons for choosing such a syntax.

Hyphens (-)

The main reason why we’re using a hyphen (-) instead of underscores (_), has to do with the fact that their behavior is different when double-clicking to select text. Try for yourself:

component__element /* underscores */
component-element  /* hyphen */

See how when you’re using underscores it selects the part before and after, in this case the whole component__element. But with hyphens it let’s you select only the part you double-clicked. component OR element. This let’s you quickly edit only the parts you want:

camelCase

Now, what if the component or child element consists of multiple words? We could use underscores like component_name-element_name. It would still be double-clickable, but readability suffers since it’s harder to see what belongs together. Better to use camelCase which groups each part visually: componentName-elementName.

MainComponent

OK, I think we’re getting closer. As a last rule, for the “main” component we use PascalCase. The reason for it is to add emphasis and make it easier to distinguish the main component from a child element. Also when using a namespace, the component moves to the second position, which makes it even more important to have it stick out: org-Component-childElement

–variation

We kept the more commonly used double hyphens (–) for variations. digit-Progress--small. It makes sense, because it pulls the variation (–small) visually more apart and makes it look like it’s something “different” than the default component.

So that’s about it. For more details about this naming convention, take a look at the SUIT framework, which also started to use the same syntax and documented it really well.

In the end, whatever Shade of BEM you choose to cook with probably depends on your personal taste, but thinking about a great UX by improving usability and readability won’t hurt either.

Rotch Library - NE538.N5 W49 2019

Rotch Library - N6537.C329 A4 2019

Rotch Library - N6260.K87 2019

Rotch Library - N7280.R888 2018

Rotch Library - N8251.S555 A48 2018

Rotch Library - N6659.M55 A4 2018

Rotch Library - N6546.N6 F64 2019

Rotch Library - NK1175.M53 2019

Rotch Library - N6488.I8 V433 2019 R6

Rotch Library - ND673.B73 B46 2018

Rotch Library - N6537.C663 A4 2018

Rotch Library - ND723.K53 A4 2018

Rotch Library - N8214.5.F8 C539 2019

Rotch Library - N7274.S76 2019

Rotch Library - N7433.4.F73 F67 2019

Online Resource

Online Resource

Dewey Library - NC1766.U52 P38 2019

Rotch Library - ND1460.E95 I57 2019

Rotch Library - N6260.S56 2019

Rotch Library - N7433.8.M67 2019

Rotch Library - N8354.A3513 2019

Online Resource

Rotch Library - NK2087.75.A1 B35 2019

Rotch Library - N7265.3.A733 2019

Rotch Library - TR647.N4454 2019

Rotch Library - NK1505.B38 2019

Rotch Library - N8520.A53 2018