Adding data mapper when no previous output shape is provided

This is a…

[ ] Feature request
[ ] Regression (a behavior that used to work and stopped working in a new release)
[ ] Bug report  
[x] Documentation issue or request

Description

It seems to me that a data mapper step is only selectable when a previous step in the integration provides some supported output data shape? Why is that? I can imagine a data mapper to be required also when no previous step provides an output shape.

Users may need to map from constant values or properties only, too. When no output data shape has been found in previous steps the data mapping is not displayed even though a mapping is mandatory for the integration to work.

Example Integration: Timer -> SQL invoke -> Log

Even in case the SQL invocation specifies placeholders that should be mapped (insert into todo (task, completed) values (:#task, 0)) the data mapper is not offered to the user.

I think data mapping step should be available all the time.

[gashcrumb]

@zregvart I actually only changed this in the react impl as it so happened the discussion was happening right when we were bringing some of this code over, here’s the commit.

[zregvart]

I’ve tried this on a Timer to SQL integration, I can’t add the mapper in between those. I can see that the SQL connector has an inputDataShape. Was this case covered/considered with this issue?