Corda Spreadsheets

Web Server API

GET /get-all-spreadsheets gets all existing spreadsheets' linear IDs
GET /get-spreadsheet&id=<SPREADSHEET_ID> gets spreadsheet in form of list of lists of pairs (VALUE, FORMULA)
GET /create-spreadsheet creates new spreadsheet
GET /set-data?id=<SPREADSHEET_ID>&d=<VALUE>&f=<FORMULA>&row=<ROW>&col=<COLUMN>&version=<VERSION> set's data in spreadsheet under id

Building it:

./gradlew build
./gradlew buildDependents
./gradlew deployNodes

Running it:

build/nodes/runnodes

and then launch the web server / RPC client:

./gradlew runPartyAServer

And navigate to the port, typically http://localhost:10007

Debugging The Webserver

Run it as described above. It uses React Bootstrap, so use Chrome, install the React web extension, and then open the developer console (ctrl+shift+I).

About the front end

User guide

Click on a cell to edit
Formula should be prefixed with =
Grey background cells are not editable.

Start up

The web front end starts by sending a REST request get-all-spreadsheets which returns all the linear ids of the sheets in Corda
These are rendered in the drop down.
If there is one, the data for that sheet is retrieved via get-spreadsheet(id), otherwise the user selects one.

Internals

Formula calculations are on the server side (i.e. calculated in the Corda nodes).
The table is a sparse array of cells with row and column ids.
Each cell contains either a formula or a display value, or both, for rendering and editing.
Editing a cell, if owned by the node serving the sheet, triggers a REST set-data` call with the row, and column index and either the display value or the formula.
Multiple views on the spreadsheet are updated by short-polling though push notification via web socket is trivial to implement.

Implementation

Using react and boostrap
State is stored in the App and passed down to all controls as properties. Speak to your friendly neighbourhood web dev about this kind of thing.

dimosr/corda-spreadsheet