Template Syntax

Syntax

Templates are a string containing a sequence of plain strings and expressions.
Expressions are wrapped by a pair of {}'s and come in two types:
1. Value Expression
  Places a value at a specific point in a string template.
```
This is a template {%someVariable} with value expressions {$someFunction()}
```
2. Conditional Expression
  Evaluates a condition, then conditionally places one of two template strings using ternary (?:) syntax.
  A conditional expression is "truthy" when it's value is not false, NaN, undefined, null, or an empty string ''. Because it is a renderable value in a string, the number 0 is treated as a truthy value.
  If the condition is truthy, the expression will resolve to the string after the ?. Otherwise, it will resolve to the string after the :. The : is optional and if excluded, an empty string '' will be placed if the condition is falsey.
```
{%someVar?truthy string:falsey string} {$someFn(%someVar,foo)?truthy string only}
```
  Additional expressions can be nested inside of the truthy/falsey case.
```
Welcome, {%firstName?{%firstName}{%lastName? {%lastName}}:Guest}!
```
Value expressions and the condition of a conditional expression contain either a Variable Accessor or a Function Call.
- Variable Accessors are indicated by a % followed by a property name or a chain of .-separated property names. They retrieve values from the dictionary of variables passed to the template at the time of execution.
```
%variableName
%some.deepValue
%some.deeper.value
%someArray.3.name
```
  If a value is not found, a variable accessor will resolve to an empty string ''.
- Function Calls are indicated by a $ followed by a function name and a pair of parenthesis () which may optionally contain a list of ,-separated arguments.
  Valid arguments for function calls are variable accessors, plain strings, and nested function calls. Functions may accept any number of arguments.
```
$functionName()
$functionName(%arg1,plain string)
$fnOne(%var,$fnTwo(%otherVar,foo))
```
White space is always preserved and is interpretted as being part of a plain string.
Reserved characters ({}?:)%$) can be escaped with a \ prefix. Reserved characters are context-aware. For example, a } that is not within an expression does not need to be escaped.

Syntax​

Syntax