match

Used within a template function to specify the shape of the target facts.

static match<T>(
    template: Partial<T>
): Specification<T>;

Parameters

• template - A JSON object with the desired type and predecessors

Returns

• A specification that can be used by query or watch

Examples

This function can be used either as a static or an instance function. If you already have an instance j of the Jinaga object, you can call j.match.

However, if you are defining a library of template functions, you usually do not have the instance j in scope. In this situation, you can alias the Jinaga class to call j.match as a static function.

import { Jinaga as j } from 'jinaga';

function postsByAuthor(a) {
    return j.match({
        type: 'Blog.Post',
        author: a
    });
}

Call suchThat to attach a condition to the template.

function messagesInChannel(c) {
    return j.match({
        type: 'Chat.Message',
        channel: c
    }).suchThat(j.not(messageIsRedacted));
}

function messageIsRedacted(m) {
    return j.exists({
        type: 'Chat.Message.Redacted',
        message: m
    });
}