zulip/zephyr/static/js/setup.js

// Miscellaneous early setup.
// This is the first of our Javascript files to be included.

var templates = {};
var csrf_token;
$(function () {
    // Display loading indicator.  This disappears after the first
    // get_updates completes.
    if (have_initial_messages) {
        util.make_loading_indicator($('#page_loading_indicator'), 'Loading...');
    } else {
        try {
            tutorial.run_when_ready();
        } catch (e) {
            util.show_first_run_message();
        }
    }

    // Compile Handlebars templates.
    $.each(['message', 'subscription',
            'actions_popover_title', 'actions_popover_content',
            'invite_subscription', 'new_stream_users'],
        function (index, name) {
            templates[name] = Handlebars.compile($('#template_'+name).html());
        }
    );

    // This requires that we used Django's {% csrf_token %} somewhere on the page.
    csrf_token = $('input[name="csrfmiddlewaretoken"]').attr('value');

    $.ajaxSetup({
        beforeSend: function (xhr, settings) {
            if (!(/^http:.*/.test(settings.url) || /^https:.*/.test(settings.url))) {
                // Only send the token to relative URLs i.e. locally.
                xhr.setRequestHeader("X-CSRFToken", csrf_token);
            }
        }
    });

    // For some reason, jQuery wants this to be attached to an element.
    $('body').ajaxError(function (event, xhr) {
        if (xhr.status === 401) {
            // We got logged out somehow, perhaps from another window or a session timeout.
            // We could display an error message, but jumping right to the login page seems
            // smoother and conveys the same information.
            window.location.replace('/accounts/login');
        }
    });
});