DefineParser

= gives a value a name. Every later tag with that name renders the value. Use it to pick a random number once and mention it three times, or to keep a long piece of text out of the middle of a sentence.

For template authors

Syntax

{=(name):value}

The tag itself renders nothing. Reference the name afterwards with {name}.

Examples

{=(prefix):!}The prefix here is `{prefix}`.
# The prefix here is `!`.

Define once, use many times. Without this, each {range} would roll a different number:

{=(roll):{range:1-6}}You rolled {roll}. {if({roll}==6):Nice!|Try again.}
# You rolled 6. Nice!

Aliases

=, assign, let, var

For developers

Register the parser

import { Interpreter, DefineParser, StrictVarsParser } from 'tagscript';
const ts = new Interpreter(new DefineParser(), new StrictVarsParser());

You need a variable parser as well. DefineParser writes the variable, and StrictVarsParser reads it back.

Behaviour

The parameter is required and holds the name. The payload holds the value and is optional, so {=(name)} defines an empty string.

parse wraps the payload in a StringTransformer and stores it on ctx.response.variables, then returns an empty string. Definitions are visible to any tag that comes after them in the template, and they show up on response.variables once the render finishes.

A definition overwrites a variable your app seeded under the same name. Seed anything the template must not be able to shadow under a name you also check after the render.

API reference

DefineParser