Derby supports creating JavaScript literals in templates. The syntax is identical to JavaScript, except that identifiers within literals are parsed as view paths instead of JavaScript variables. Derby parses template expressions with Esprima, so its coverage of JavaScript expression syntax is comprehensive. Technically, undefined is an unmodifiable global property and not a literal value. For simplicity, Derby treats it as a literal.

ANCHORSimple literals

<!-- Numbers -->
<!-- Booleans -->
<!-- Strings -->
<!-- Regular expressions -->
<!-- null -->
<!-- undefined -->
<!-- Arrays -->
{{ [0, 1, 2] }}
<!-- Objects -->
{{ {name: 'Jim'} }}

For greater efficiency, simple literals are instantiated at the time of parsing. Object literals created at parse time will be passed by reference to controller functions, so be careful not to modify them.

<!-- CAUTION: This array will be the same object on each function call -->
<button on-click="doStuff([1, 2, 3])"></button>

It is possible to iterate over object literals in template expressions. In most cases, it makes more sense to define constants in the controller or use HTML, but this can be handy when prototyping and debugging.

  {{each ['A', 'B', 'C']}}

{{with {name: 'Jim', age: 23} as #user}}

ANCHORLiterals containing paths

Literals containing paths are created at render time and populated with the appropriate values from the model.

  {{each [first, 1, 2, 3]}}

<button on-click="addNew({userId:})"></button>
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