Obsidian.md templater script to update the link chain of Daily Notes

fixdailylinks.js

const PREV_PROPERTY = "prev-log"
const NEXT_PROPERTY = "next-log"
const LOG_PATH = "Log/";

/*
This will set the prev-log and next-log properties of the current file to the previous and next daily log files.
It also updates the properties of the previous and next files to point correctly.
Requires the file title to be the date, and nothing else.

The script requires access to tp, so call it with
<% await tp.user.fixdailylinks(tp) %>


With dynamic previous and next pointer using Dataview:
`$= "<<" + (dv.current()["prev-log"]||"None") +" | " + (dv.current()["next-log"]||"None") + ">>"` <%* await tp.user.fixdailylinks(tp) %>
*/

async function fix_daily_links(tp) {

    const today = new Date(tp.file.title)
    const this_link = `[[${tp.config.target_file.path}]]`

    const log_files = app.vault.getMarkdownFiles().filter(file => {
        if (!file.path.startsWith(LOG_PATH)) return false;
        return true
    });
    log_files.sort((a,b) => {
        if (a.name < b.name) return -1;
        if (a.name > b.name) return 1;
        return 0;
    })

    const older_files = log_files.filter(file => {
        const fileDate = new Date(file.basename)
        if (fileDate >= today) return false;
        return true
    })
    const prev_file = older_files?.[older_files.length-1];

    const newer_files = log_files.filter(file => {
        const fileDate = new Date(file.basename)
        if (fileDate <= today) return false;
        return true
    })
    const next_file = newer_files?.[0];

    setTimeout(async () => {
        if(prev_file)
            await app.fileManager.processFrontMatter(prev_file, fm => {
                fm[NEXT_PROPERTY]= this_link;
                return fm;
            });
        if(next_file)
            await app.fileManager.processFrontMatter(next_file, fm => {
                fm[PREV_PROPERTY]= this_link;
                return fm;
            });
        await app.fileManager.processFrontMatter(tp.config.target_file, fm => {
            fm[NEXT_PROPERTY] = next_file ? `[[${next_file.path}]]` : "";
            fm[PREV_PROPERTY] = prev_file ? `[[${prev_file.path}]]` : "";
            return fm;
        })
    }, 300);

    return "";
}

module.exports = fix_daily_links;