Interface TemplateParameter

The literal its first default(…) filter gives, or null.

Every filter name applied to it, in order of first appearance.

The type its SQL filters imply (the last SQL filter of each use), or array for a loop's iterable. <name>.length implies no type of its own (an array and a string both have a length); a number or boolean use beside it is reported as a type conflict.

Whether the template needs a value: true when at least one use sits outside every {% if %} block and every inline if, and has no default(…). A parameter used only inside conditional blocks, only in conditions, or only inside inline ifs, is optional.