Jam.py documentation

Client-side report programmingΒΆ

To print a report on the client use the print method.

As a result of calling this function, the client calls create_param_form method to create a form for editing the report parameters, based on the html template defined in the index.html file (see Forms).

This method, after creating the form, triggers the following events:

The default code has the on_param_form_created event handler, defined for the task. In this event, the click on the Print button is connected to the report’s process_report method.

function on_param_form_created(item) {
    item.param_form.find("#ok-btn").on('click.task', function() {
    item.param_form.find("#cancel-btn").on('click.task', function() {

In its turn the process_report method triggers

In this event handlers developer can define some common (report group event handler) or specific (report event handler) attributes of the report.

For example, in the default code, there is the on_before_print_report event handler of the report group, in which report’s extension attribute is defined:

function on_before_print_report(report) {
    var select;
    report.extension = 'pdf';
    if (report.param_form) {
        select = report.param_form.find('select');
        if (select && select.val()) {
            report.extension = select.val();

In the following event handler, defined in the client module of the invoice report of the Demo application, the value of the report id parameter is set:

function on_before_print_report(report) {
    report.id.value = report.task.invoices.id.value;

After that the process_report method sends asynchronous request to the server to generate the report (see Server-side programming).

The server returns to the method an url to a file with generated report.

The method then checks if the on_open_report event handler of the report group is defined. If this events handler if defined calls it, otherwise checks the on_open_report of the report. If it is defined then calls it.

If none of this events are defined, it (depending on the report extension attribute) opens the report in the browser or saves it to disc.