zulip/static/js/message_edit_history.js

import render_message_edit_history from "../templates/message_edit_history.hbs";

import * as people from "./people";

const {format, isSameDay} = require("date-fns");

export function fetch_and_render_message_history(message) {
    channel.get({
        url: "/json/messages/" + message.id + "/history",
        data: {message_id: JSON.stringify(message.id)},
        success(data) {
            const content_edit_history = [];
            let prev_time = null;

            for (const [index, msg] of data.message_history.entries()) {
                // Format times and dates nicely for display
                const time = new Date(msg.timestamp * 1000);
                const item = {
                    timestamp: timerender.stringify_time(time),
                    display_date: format(time, "MMMM d, yyyy"),
                    show_date_row: prev_time === null || !isSameDay(time, prev_time),
                };

                if (msg.user_id) {
                    const person = people.get_by_user_id(msg.user_id);
                    item.edited_by = person.full_name;
                }

                if (index === 0) {
                    item.posted_or_edited = "Posted by";
                    item.body_to_render = msg.rendered_content;
                } else if (msg.prev_topic && msg.prev_content) {
                    item.posted_or_edited = "Edited by";
                    item.body_to_render = msg.content_html_diff;
                    item.topic_edited = true;
                    item.prev_topic = msg.prev_topic;
                    item.new_topic = msg.topic;
                } else if (msg.prev_topic) {
                    item.posted_or_edited = "Topic edited by";
                    item.topic_edited = true;
                    item.prev_topic = msg.prev_topic;
                    item.new_topic = msg.topic;
                } else {
                    // just a content edit
                    item.posted_or_edited = "Edited by";
                    item.body_to_render = msg.content_html_diff;
                }

                content_edit_history.push(item);

                prev_time = time;
            }
            $("#message-history").attr("data-message-id", message.id);
            $("#message-history").html(
                render_message_edit_history({
                    edited_messages: content_edit_history,
                }),
            );
        },
        error(xhr) {
            ui_report.error(
                i18n.t("Error fetching message edit history"),
                xhr,
                $("#message-history-error"),
            );
        },
    });
}

export function show_history(message) {
    $("#message-history").html("");
    $("#message-edit-history").modal("show");
    fetch_and_render_message_history(message);
}