publishWebService without executing "fun" locally

[ckarras]

In many of my tests with publishWebService, it failed because it's trying to execute locally the function to publish, using a subset of the data (hard coded to head(inputSchema)). This subset is often inappropriate (5 rows could be insufficient to execute some functions, not cover enough data to cover all cases, etc)

Question: Why exactly does the function need to be executed locally before publishing the service?
Would it be possible to allow bypassing this execution by specifying explicitly anything that is discovered dynamically by invoking the function?

[andrie]

The function runs only to make a best guess on the schema that the webservice should use for returning results.

You can define this schema by hand and pass it as the argument to the outputSchema.

[ckarras]

I already specified outputSchema, but the function is still invoked locally. Is there another option I need to set?

Example:
ep <- publishWebService(ws, fun = testAzureMLWebService, name = "test azureml web service",
inputSchema = inputSchema,
data.frame = TRUE,
outputSchema = outputSchema,
packages = c("zoo","reshape")
)