A computer network environment for modifying application data and updating application components of an offline application, the environment comprising: a web client (102, 202) and a web server (106, 204); a computer network connecting the web client and the web server (106, 204); the web server (106, 204) operable for: receiving a request from the web client (102, 202) to generate a downloadable file representing an offline version of a web-based application hosted by the web server (106, 204), wherein the request includes a selection of data to be edited or used in the offline version of the web-based application; packaging application components and data used by the web-based application into the downloadable file; transmitting the downloadable file to the requesting web client (102, 202); locking (216, 508) portions of the web-based application to prevent access to the web-based application corresponding to the data being edited or operated on in the downloaded offline version of the web-based application; receiving an upload of a revised downloadable file, the revised downloadable file including changes to the application components and/or changes to the data, wherein the changes include modifications performed to the web-based application functionality or data; updating at least one of the application components and the data used by the web-based application with the changes to the at least one of the application components and the data contained in the revised downloadable file; responsive to the updating, unlocking the web-based application; and responsive to the unlocking, locking the downloadable file in order to prevent future use. a web client (102, 202) and a web server (106, 204); a computer network connecting the web client and the web server (106, 204); the web server (106, 204) operable for: receiving a request from the web client (102, 202) to generate a downloadable file representing an offline version of a web-based application hosted by the web server (106, 204), wherein the request includes a selection of data to be edited or used in the offline version of the web-based application; packaging application components and data used by the web-based application into the downloadable file; transmitting the downloadable file to the requesting web client (102, 202); locking (216, 508) portions of the web-based application to prevent access to the web-based application corresponding to the data being edited or operated on in the downloaded offline version of the web-based application; receiving an upload of a revised downloadable file, the revised downloadable file including changes to the application components and/or changes to the data, wherein the changes include modifications performed to the web-based application functionality or data; updating at least one of the application components and the data used by the web-based application with the changes to the at least one of the application components and the data contained in the revised downloadable file; responsive to the updating, unlocking the web-based application; and responsive to the unlocking, locking the downloadable file in order to prevent future use. receiving a request from the web client (102, 202) to generate a downloadable file representing an offline version of a web-based application hosted by the web server (106, 204), wherein the request includes a selection of data to be edited or used in the offline version of the web-based application; packaging application components and data used by the web-based application into the downloadable file; transmitting the downloadable file to the requesting web client (102, 202); locking (216, 508) portions of the web-based application to prevent access to the web-based application corresponding to the data being edited or operated on in the downloaded offline version of the web-based application; receiving an upload of a revised downloadable file, the revised downloadable file including changes to the application components and/or changes to the data, wherein the changes include modifications performed to the web-based application functionality or data; updating at least one of the application components and the data used by the web-based application with the changes to the at least one of the application components and the data contained in the revised downloadable file; responsive to the updating, unlocking the web-based application; and responsive to the unlocking, locking the downloadable file in order to prevent future use.