12. A method comprising: generating a preview document of a native document comprising a preview code including table elements corresponding to fields in the native document, the native document stored on a client device, the generating comprising: generating field dimensions for the fields in the native document; generating a field mapping of fields in the native document to table elements in the preview code; generating a formula listing designating, for each formula of a set of formulas in the native document, one or more fields associated with the formula in the native document; and displaying the preview document on a display by executing the preview code; generating an updated preview document in response to a change to the native document; swapping the updated preview document with the displayed preview document; and applying a current user interaction context to the swapped updated preview document.
12. A method comprising: generating a preview document of a native document comprising a preview code including table elements corresponding to fields in the native document, the native document stored on a client device, the generating comprising: generating field dimensions for the fields in the native document; generating a field mapping of fields in the native document to table elements in the preview code; generating a formula listing designating, for each formula of a set of formulas in the native document, one or more fields associated with the formula in the native document; and displaying the preview document on a display by executing the preview code; generating an updated preview document in response to a change to the native document; swapping the updated preview document with the displayed preview document; and applying a current user interaction context to the swapped updated preview document. 22. The method of claim 12 , further comprising: receiving a modification to the preview specifying a modification version; identifying a document version associated with the native document; determining that a version conflict exists by comparing the document version differs from the modification version; and when the document version differs from the modification version, reconciling the conflict.