zulip/static/js/rendered_markdown.js

function get_user_id_for_mention_button(elem) {
    const user_id_string = $(elem).attr('data-user-id');
    // Handle legacy markdown that was rendered before we cut
    // over to using data-user-id.
    const email = $(elem).attr('data-user-email');

    if (user_id_string === "*" || email === "*") {
        return "*";
    }

    if (user_id_string) {
        return parseInt(user_id_string, 10);
    }

    if (email) {
        // Will return undefined if there's no match
        const user = people.get_by_email(email);
        if (user) {
            return user.user_id;
        }
        return;
    }
    return;
}

function get_user_group_id_for_mention_button(elem) {
    const user_group_id = $(elem).attr('data-user-group-id');

    if (user_group_id) {
        return parseInt(user_group_id, 10);
    }

    return;
}

exports.update_elements = (content) => {
    // Set the rtl class if the text has an rtl direction
    if (rtl.get_direction(content.text()) === 'rtl') {
        content.addClass('rtl');
    }

    content.find('.user-mention').each(function () {
        const user_id = get_user_id_for_mention_button(this);
        // We give special highlights to the mention buttons
        // that refer to the current user.
        if (user_id === "*" || people.is_my_user_id(user_id)) {
            // Either a wildcard mention or us, so mark it.
            $(this).addClass('user-mention-me');
        }
        if (user_id && user_id !== "*" && !$(this).find(".highlight").length) {
            // If it's a mention of a specific user, edit the
            // mention text to show the user's current name,
            // assuming that you're not searching for text
            // inside the highlight.
            const person = people.get_by_user_id(user_id, true);
            if (person !== undefined) {
                // Note that person might be undefined in some
                // unpleasant corner cases involving data import.
                markdown.set_name_in_mention_element(this, person.full_name);
            }
        }
    });

    content.find('.user-group-mention').each(function () {
        const user_group_id = get_user_group_id_for_mention_button(this);
        const user_group = user_groups.get_user_group_from_id(user_group_id, true);
        if (user_group === undefined) {
            // This is a user group the current user doesn't have
            // data on.  This can happen when user groups are
            // deleted.
            blueslip.info("Rendered unexpected user group " + user_group_id);
            return;
        }

        const my_user_id = people.my_current_user_id();
        // Mark user group you're a member of.
        if (user_groups.is_member_of(user_group_id, my_user_id)) {
            $(this).addClass('user-mention-me');
        }

        if (user_group_id && !$(this).find(".highlight").length) {
            // Edit the mention to show the current name for the
            // user group, if its not in search.
            $(this).text("@" + user_group.name);
        }
    });

    content.find('a.stream').each(function () {
        const stream_id = parseInt($(this).attr('data-stream-id'), 10);
        if (stream_id && !$(this).find(".highlight").length) {
            // Display the current name for stream if it is not
            // being displayed in search highlight.
            const stream_name = stream_data.maybe_get_stream_name(stream_id);
            if (stream_name !== undefined) {
                // If the stream has been deleted,
                // stream_data.maybe_get_stream_name might return
                // undefined.  Otherwise, display the current stream name.
                $(this).text("#" + stream_name);
            }
        }
    });

    content.find('a.stream-topic').each(function () {
        const stream_id = parseInt($(this).attr('data-stream-id'), 10);
        if (stream_id && !$(this).find(".highlight").length) {
            // Display the current name for stream if it is not
            // being displayed in search highlight.
            const text = $(this).text();
            const topic = text.split('>', 2)[1];
            const stream_name = stream_data.maybe_get_stream_name(stream_id);
            if (stream_name !== undefined) {
                // If the stream has been deleted,
                // stream_data.maybe_get_stream_name might return
                // undefined.  Otherwise, display the current stream name.
                $(this).text("#" + stream_name + ' > ' + topic);
            }
        }
    });

    // Display emoji (including realm emoji) as text if
    // page_params.emojiset is 'text'.
    if (page_params.emojiset === 'text') {
        content.find(".emoji").replaceWith(function () {
            const text = $(this).attr("title");
            return ":" + text + ":";
        });
    }
};