4. The method of claim 1 , further comprising: receiving a modification to the preview from the first client device; applying the modification to the native document to produce a modified document; generating an updated preview document from the modified native document; and sending the updated preview document to the first client device.
4. The method of claim 1 , further comprising: receiving a modification to the preview from the first client device; applying the modification to the native document to produce a modified document; generating an updated preview document from the modified native document; and sending the updated preview document to the first client device. 7. The method of claim 4 , wherein the native document includes a chart referencing a field modified by the modification; and applying the modification further comprises modifying the chart.