is it possible to write custom functions

[cleesmith]

Is it possible to write custom functions for ethercalc ?
If yes, how?

I would like to add functions similar to google spreadsheets, such as:
=importxml(A1, "//p[@class='myforecast-current-lrg']")

... or:

=ImportData("http://gmaps-samples.googlecode.com/svn/trunk/articles-csvtokml/google-addresses.csv")

[ghost]

If not, is there a plugin architecture? Not seen in docs yet.

[audreyt]

There is one in 001c277 but I'd suggest using Ajax in the browser to retrieve JSON or CSV, and then use the REST API (http://docs.ethercalc.apiary.io/) to fill in data.

You can e.g. have another server get a HTTP request from the client and put it into a certain cell using the set A1 text t sometext command (use the Audit tab to see the command syntax corresponding to operations).

Or you can have the button retrieve the value over Ajax and run a

window.spreadsheet.context.sheetobj.ScheduleSheetCommands("...")

Where the … is the same set command.

[Pegbiter]

@audreyt do you have a simple example of implementing a custom server this way? Even if UDF Excel is impossible, I would like to store an expression in a cell and evaluate the result and update the sheet.

[audreyt]

Sorry I have no examples of such a periodically-update-certain-cell server at hand — folks please feel free to chime in.

[eddyparkinson]

@Pegbiter what do you want the UDF to do?

Update with value
To update the sheet with the result of an expression
http://sheet.cellmaster.com.au/example_command

other example
http://sheet.cellmaster.com.au/examples