API questions

[David Goodenough]

I notice when looking at the API pages that a method is defined as starting
at a given line, and then the code below always starts on the next line, i.e.
missing out the prototype.  For example:-

Definition at line 116 of file print-session.c.

  117 {
  118     return print_settings;
  119 }

Would it not be possible to show line 116 as well?  This seems to be a
consistent problem throughout the docs.

The reason I was looking was to generate customer reports via the API.
I would like to be able to generate a report for each customer who either
has a non-zero balance or where some transaction (invoice or receipt of
payment) happened last month (or since rather since I last ran the program).
I then want to export the report as a PDF.  I have looked my way through
the API docs but could not see how to generate reports, or to check for
the balance or the presence of transactions since a date.

I found docs on how to create invoices, but also need to be able to 
export them as PDFs and could not locate the API for that either.  I notice
in the gnucash XML files that the last direcorty to which invoices ( and I 
guess customer reports ) were exported is stored, is this available from
the API.

What I want to be able to write is a program that will generate reports
for all relevant customers, and then send an email to each customer who
has either an invoice and/or a report containing both.

Any pointers gratefully received.

David