test-body-template.html

<template id="test-template">
    <div>
        <span>test-template</span>
        <span>{{content}}</span>
    </div>
</template>

<script>
    kiwi.plugin('test-body-template', function (kiwi, log) {
        const testTemplate = {
            template: '#test-template',
            props: ['content', 'buffer', 'message'],
            data() {
                return {
                    show: true,
                };
            },
            mounted() {
                console.log('test-template mounted', this);
            },
        };

        const testTemplateComponent = kiwi.Vue.extend(testTemplate);

        kiwi.state.$on('message.blocks', function (event, blocks) {
            console.log('message.blocks', JSON.stringify(event), JSON.stringify(blocks));
        });

        kiwi.state.$on('message.poststyle', function (event) {
            if (!event.message || event.message.type !== 'privmsg') {
                return;
            }

            const content = event.message.message;

            if (!content) {
                console.log('no content');
                return;
            }

            console.log('adding template', content, event);
            // event.message.bodyTemplate = new testTemplateComponent({
            //     data: {
            //         content: content,
            //     },
            // });
            // event.message.bodyTemplate.$mount();

            event.message.bodyTemplate = testTemplateComponent;
            event.message.bodyTemplateProps = { content: content};
            event.message.embed = { type: 'url', payload: null };
            event.message.html = '';
        });
    });
</script>