Custom Reports Using Eguile
Contents
What is eguile?
eguile is a way of processing a template file to create a guile script.
More specifically, within GnuCash, guile is used to combine HTML and guile code to create a report, such as an invoice or balance sheet.
The GnuCash version of eguile is eguile-gnc.scm, written in early 2009 by Chris Dennis, and based on Neale Pickett's eguile.scm.
For example,
<h3><?scm:d coyname ?></h3> <h2><?scm:d reportname ?> as at <?scm:d (gnc-print-date opt-date-tp) ?></h2>
would become
(display "<h3>")(display "Acme Tools Ltd.")(display "</h3> <h2>)(display "Balance Sheet")(display " as at ") (display "05/04/2009")(display "<h2">)
which is then evaluated as guile code to create the text of the report.
How to install an eguile report
To try out eguile-based reports, you first need to download eguile-gnc.scm and put it into the report folder. On my system -- Ubuntu -- that's /usr/share/gnucash/guile-modules/gnucash/report/eguile-gnc.scm. In general, it should go into the same folder as files such as fancy-invoice.scm.
Note: GnuCash 2.3/2.4 already includes eguile-gnc.scm.
Install the report and its associated files in the usual way (see the "From a user account" section of the Custom Reports page). The easiest way is to put all the files for a report into your .gnucash folder, and then add a line to .gnucash/config.user like this:
(load-from-path "/path/to/my/.gnucash/report.scm")
If .gnucash/config.user does not already exist, just create it and add the new line.
For example, on a Linux system, for a user called 'chris', the Tax Invoice report can be installed by:
- Downloading taxinvoice.scm and taxinvoice.eguile.scm, and putting them into the /home/chris/.gnucash/ folder.
- Adding this line to /home/chris/.gnucash/config.user:
(load-from-path "/home/chris/.gnucash/taxinvoice.scm")
Restart GnuCash, and the report should then show up somewhere in the reports menu, depending on the menu-path option in the report. The Tax Invoice and Balance Sheet reports (see below) put themselves into the Reports/Business sub-menu.
How to create an eguile report
...
eguile syntax
Within what is otherwise an HTML source file, Guile/Scheme code is wrapped in '<?scm ... ?>' (whitespace is required after '<?scm' and before '?>')
'<?scm ... ?>' pairs can NOT be nested.
The optional :d modifier (i.e. '<?scm:d' ) is just a shortcut for '(display ... )', so '<?scm:d x ?>' is the same as '<?scm (display x) ?>'
Note that s-expressions can be spread across more than one '<?scm ... ?>', for example:
<?scm (if (> x 3) (begin ?>Bigger<?scm ) (begin ?>Smaller<?scm )) ?>
Each chunk of text outside a '<?scm ... ?>' pair ends up wrapped in a (display ... ), after having had double quotes etc. escaped.
The processing happens in two passes. Initially the input file is converted to a Guile script, and then that script is evaluated to produce the final result (as a string which is passed back to the report-displaying part of GnuCash).
For example, if the input file contained these lines:
<h1 align="center">Invoice <?scm:d invoiceid ?></h1> <?scm (for-each (lambda (entry) ?> <p>Date: <?scm:d (entry date) ?>, description: <?scm:d (entry desc) ?> <?scm ) entries) ?>
the resulting script would look like:
(display "<h1 align=\"center\">Invoice ")(display invoiceid)(display "</h1>") (for-each (lambda (entry) (display "<p>Date: ")(display (entry date)) (display ", description: ")(display (entry desc)) ) entries)
and the final result might be this:
<h1 align="center">Invoice 002345</h1> <p>Date: 04/03/2009, description: Widgets <p>Date: 05/03/2009, description: Modified widgets
...
...the rest of this page will be here very soon
Internationalisation
Always use _ rather than N_ in the template file. N_ can be used for report option names, help text, and default values.
Available Reports
The following eguile-based reports are available. More will be contributed soon (hopefully).
Tax Invoice
| Report file: | taxinvoice.scm |
| Template file: | taxinvoice-eguile.scm |
| CSS file: | none |
| Sample output: | |
| Author: | ChrisDennis |
| Version: | 0.01 |
| Last update: | June 2009 |
Features
- Automatically includes only relevant columns. For example, if none of the items on the invoice have discounts applied, then the discount columns will be omitted.
Issues
- taxinvoice.scm includes code to display individual taxes on a per-entry basis, i.e. on each line of the invoice. This relies on a fix to the Swig encoding that is currently in the pipeline as bug #573645, but it includes a work-around so that it simply misses out the extra columns if that fix hasn't been applied. This bug has been fixed in 2.3/2.4.
- Doesn't have a separate CSS file (yet).
Balance Sheet
| Report file: | balsheet-eg.scm |
| Template file: | balsheet-eg.eguile.scm |
| CSS file: | balsheet-eg.css |
| Sample output: | |
| Author: | ChrisDennis |
| Version: | 0.01 |
| Last update: | June 2009 |
Features
- Displays the balance sheet in a 'text book' style with rules under columns etc.
- Uses the 'Assets = Equity + Liabilities' model. If there is demand for an 'Assets - Liabilities = Equity' version, then that could be done as a separate report, or by adding an option and some extra code to this one.
- One- or two-column layout.
- Negative values can be shown as, for example, '-£100.00' or '(£100.00)'.
- Deliberately has fewer options than the standard balance sheet. It makes 'intelligent' decisions about what to display. For example, parent accounts that are marked as placeholders and have a zero balance do not have their balance shown at all.
- Handles commodities/currencies in a basic way -- exchange rates are calculated as at the date of the balance sheet.
- A balancing entry (labelled 'Retained Earnings' by default) is calculated so that the sheet always balances.
Issues
- Needs people to test it and comment on it.
- To do: option to put the currency symbol at the top of each column, rather than on every value.
