24. A non-transitory computer-readable storage medium storing executable computer instructions that, when executed by a processor, cause the processor to perform steps 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.
26. The non-transitory computer-readable storage medium of claim 24 , wherein the executable computer instructions is further configured to cause the processor to: receive a modification of a table element from the user; determine a target field associated with the modification using the field mapping; and modify the target field in the native document with the modification.