Copying document content through a hosted system

1. A computer-implemented method of sharing data between composite documents, the method comprising:

receiving, at a server system from a remote computing device, an identification of a first composite document, wherein:

the first composite document comprises a spreadsheet workbook stored as a data structure on the server system, and

the first composite document contains a plurality of distinct sub-documents, wherein one or more of the sub-documents comprises a worksheet of the spreadsheet workbook;

receiving at the server system an indication of user intent to copy one of the sub-documents to a second composite document, the indication resulting from a user selection of a name of the one of the sub-documents for copying to the second composite document, wherein the second composite document comprises a spreadsheet workbook stored as a data structure on the server system;

identifying one or more composite documents stored on the server system to which a user associated with the remote computing device has access;

receiving an indication of a user selection of the second composite document from among the one or more composite documents; and

causing the indicated one of the sub-documents to be copied from the first composite document to the second composite document.

2. The method of claim 1 , wherein receiving the identification of the first composite document comprises receiving a user request to serve the first composite document to the remote computing device for editing of the first composite document on the computing device.

3. The method of claim 1 , wherein identifying one or more documents to which the user has access comprises analyzing a document-directed access control list that associates particular registered users of a public server system with particular documents based on whether the particular registered users are authorized to access the particular documents.

4. The method of claim 1 , further comprising serving to the remote computing device a control that, when selected by a user of the remote computing device, causes the second composite document to be automatically served for display and manipulation on the remote computing device.

5. The method of claim 1 , further comprising maintaining absolute references in the indicated one of the sub-documents to other sub-documents in the first composite document, after causing the indicated one of the sub-documents to be copied to the second composite document.

6. The method of claim 5 , further comprising serving to the remote computing device information that indicates locations in the indicated one of the sub-documents in which references to other sub-documents may have been broken.

7. The method of claim 1 , wherein the second composite document is not open on a computer for any user of the system when the indicated one of the sub-documents is copied into it.

8. The method of claim 1 , wherein:

each distinct sub-document of the plurality of distinct sub-documents is a standalone sheet of the first composite document; and

causing the indicated one of the sub-documents to be copied to the second composite document comprises causing the standalone sheet of the first composite document corresponding to the indicated one of the sub-documents to be copied to the second composite document without the user opening the second composite document.

9. The method of claim 8 , wherein each distinct sub-document of the plurality of distinct sub-documents is a spreadsheet sheet of a first workbook comprised in the first composite document, wherein causing the indicated one of the sub-documents to be copied to the second composite document comprises causing the spreadsheet sheet of the first workbook corresponding to the indicated one of the sub-documents to be copied as a new spreadsheet sheet into a second workbook comprised in the second composite document.

10. The method of claim 1 , further comprising:

identifying, at the server, content of the first composite document corresponding to the indicated one of the sub-documents; and

causing the copying of the identified content from the first composite document to the second composite document.

11. One or more non-transitory computer-readable media having recorded thereon instructions, that when executed by one or more computer processors, perform operations comprising:

receiving an identification of a first composite document, wherein:

the first composite document comprises a spreadsheet workbook stored as a data structure on the server system, and

the first composite document contains a plurality of distinct sub-documents, wherein one or more of the sub-documents comprises a worksheet of the spreadsheet workbook;

receiving at the server system an indication of user intent to copy one of the sub-documents to a second composite document, the indication resulting from a user selection of a name of the one of the sub-documents for copying to the second composite document, wherein the second composite document comprises a spreadsheet workbook stored as a data structure on the server system;

identifying one or more composite documents stored on the server system to which a user associated with the remote computing device has access;

receiving an indication of a user selection of the second composite document from among the one or more composite documents; and

causing the indicated one of the sub-documents to be copied from the first composite document to the second composite document.

12. The non-transitory recordable media of claim 11 , wherein receiving the identification of the first composite document comprises receiving a user request to serve the first composite document to the remote computing device for editing of the first composite document on the computing device.

13. The non-transitory recordable media of claim 11 , wherein identifying one or more documents to which the user has access comprises analyzing a document-directed access control list that associates particular registered users of a public server system with particular documents based on whether the particular registered users are authorized to access the particular documents.

14. The non-transitory recordable media of claim 11 , wherein the operations further comprise serving to the remote computing device a control that, when selected by a user of the remote computing device, causes the second composite document to be automatically served for display and manipulation on the remote computing device.

15. The non-transitory recordable media of claim 11 , wherein the operations further comprise maintaining absolute references in the indicated one of the sub-documents to other sub-documents in the first composite document, after causing the indicated one of the sub-documents to be copied to the second composite document.

16. The non-transitory recordable media of claim 15 , wherein the operations further comprise serving to the remote computing device information that indicates locations in the indicated one of the sub-documents in which references to other sub-documents may have been broken.

17. The non-transitory recordable media of claim 11 , wherein the operations further comprise transforming references in the indicated one of the sub-documents to other sub-documents in the first composite document, so as to aim the references to sub-documents in the second composite document.