6. A method comprising: receiving a request from a client device for a preview of a native document, the preview representing the native document in a file format other than the file format of the native document; inserting, by a document mapping module in the native document prior to rendering a preview, a set of unique links comprising a uniform resource locator (URL) and each unique link associated with a different word in the native document, the native object comprising a renderable portion of the native document; rendering, by a document rendering module, the native document into a preview of the native document and thereby generating a bounding area for each of the unique links in the set of unique links, the bounding area mapping a page and pixel location on the preview to the native object associated with the unique link; and providing the preview to the client device for display.
8. The method of claim 6 , further comprising: receiving a request to add a comment to the preview indicating a selected portion of the preview for the comment; identifying a location on the preview of the selected portion of the preview; identifying a set of native objects corresponding to the location by matching the location to bounding areas for one or more unique links associated with the identified set of native objects; and inserting the comment in the native document at the location of the identified set of native objects.