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excerpts: Database excerpts

The lino_xl.lib.excerpts plugin adds the notion of database excerpts.

We assume that you have read The excerpts plugin and printing : Basic printing functionality.

Lines starting with >>> in this document are code snippets that get tested as part of our development workflow.

>>> from lino import startup
>>> startup('lino_book.projects.min9.settings')
>>> from lino.api.shell import *
>>> from lino.api.doctest import *


  • add lino_xl.lib.excerpts to your lino.core.Site.get_installed_plugins().

  • Add the virtual field printed to your layout

Lino does not automatically add an action per model to make the excerpt history visible from a model. If you want this, add yourself your preferred variant.

This can be either using a ShowSlaveTable button in the toolbar:

show_excerpts = dd.ShowSlaveTable('excerpts.ExcerptsByOwner')
show_excerpts = dd.ShowSlaveTable('excerpts.ExcerptsByProject')

Or by adding excerpts.ExcerptsByOwner or excerpts.ExcerptsByProject (or both, or your own subclass of one of them) to the detail_layout.


In addition to the main template, excerpt types can specify a body template.

body template

When the main template is being rendered, it has a context variable body, which is itself rendered from a template.

As a site manager (and when lino.modlib.davlink is installed) you can easily modify the main template that has been used to print a given excerpt using the Edit Template button in the detail window of that Excerpt object.

If you want to configure which document to use as main template, then you must use the Configuration menu:

  • Configuration ‣ Excerpt types

class lino_xl.lib.excerpts.Excerpt

A printable document that describes some aspect of the current situation.


The type of this excerpt (ForeignKey to ExcerptType).


The object being printed by this excerpt. See Controllable.owner.


The optional company of the recipient of this excerpt. See ContactRelated.company.


The optional contact person of the recipient of this excerpt. See ContactRelated.contact_person.


The recipient of this excerpt. See ContactRelated.recipient


The language used for printing this excerpt.


See lino_xl.lib.contacts.mixins.ContactRelated.get_address_html().

Return the address of the recipient of this excerpt.

class lino_xl.lib.excerpts.ExcerptDetail
class lino_xl.lib.excerpts.Excerpts

Base class for all tables on Excerpt.

class lino_xl.lib.excerpts.AllExcerpts
class lino_xl.lib.excerpts.MyExcerpts
class lino_xl.lib.excerpts.ExcerptsByType
class lino_xl.lib.excerpts.ExcerptsByOwner

Shows all excerpts whose owner field is this.

class lino_xl.lib.excerpts.ExcerptsByProject

Only used if lino.core.site.Site.project_model is set.

Excerpt types

class lino_xl.lib.excerpts.ExcerptType

The type of an excerpt. Every excerpt has a mandatory field Excerpt.excerpt_type which points to an ExcerptType instance.


The designation of this excerpt type. One field for every language.


The database model for which this excerpt type is to be used.


See lino.modlib.printing.mixins.PrintableType.build_method.


The main template to be used when printing an excerpt of this type.


The body template to use when printing an excerpt of this type.


The template to use when sending this an excerpt of this type by email.


Optional pointer to a shortcut field. If this is not empty, then the given shortcut field will manage excerpts of this type.

See also Shortcuts. See also lino_xl.lib.excerpts.choicelists.Shortcuts.

class lino_xl.lib.excerpts.ExcerptTypes

Displays all rows of ExcerptType.

Model mixins

class lino_xl.lib.excerpts.Certifiable

Any model that inherits from this mixin becomes “certifiable”.

That is:

  • it has a printed_by field and a corresponding virtual field printed which point to the excerpt that is the “definitive” (“Certifying”) printout of this object.

  • It may define a list of “certifiable” fields by providing a get_certifiable_fields() method.

Usage example:

from lino_xl.lib.excerpts.mixins import Certifiable

class MyModel(dd.UserAuthored, Certifiable, dd.Duplicable):

The lino_xl.lib.excerpts.fixtures.std fixture automatically creates a certifying ExcerptType instance for every model which inherits from Certifiable.


Displays information about when this database row has been printed.

Clicking on it will display the database excerpt that certifies this database row.


Pointer to the database excerpt that certifies this database row.

A Certifiable is considered “certified” when this field is not None.

Note that this field is a nullable ForeignKey with on_delete set to SET_NULL.

on_duplicate(self, ar, master)

After duplicating e.g. a budget that had been printed, we don’t want the duplicate point to the same excerpt.

Extends lino.mixins.duplicable.Duplicable.on_duplicate().


A class method. Expected to return a string with a space-separated list of field names. These files will automaticaly become disabled (readonly) when the document is “certified”. The default implementation returns an empty string, which means that no field will become disabled when the row is “certified”.

For example:

def get_certifiable_fields(cls):
    return 'date user title'
def get_excerpt_title(self)

A string to be used in templates as the title of the certifying document.

get_excerpt_templates(self, bm)

Return either None or a list of template names to be used when printing an excerpt controlled by this object.

class lino_xl.lib.excerpts.ExcerptTitle

Mixin for models like lino_welfare.modlib.aids.AidType and lino_xl.lib.courses.Line.


The designation of this row as seen by the user e.g. when selecting an instance of this model.

One field for every language.


The text to print as title in confirmations. One field for every language. If this is empty, then name is used.


excerpt shortcut field

A virtual display field with actions for quickly managing, for a given database object, its excerpt of a given type.

class lino_xl.lib.excerpts.Shortcut
class lino_xl.lib.excerpts.Shortcuts

A choicelists of excerpt shortcut fields.

These virtual fields are being installed during pre_analyze by set_excerpts_actions().



This template is the default value, used by many excerpt types in their template field. It is designed to be locally overridden by local site managers in order to match their letter paper.


class lino_xl.lib.excerpts.BodyTemplateContentField


class lino_xl.lib.excerpts.CreateExcerpt

Create an excerpt in order to print this data record.

class lino_xl.lib.excerpts.ClearPrinted

Clear any previously generated printable document. Mark this object as not printed. A subsequent call to print will generate a new cache file.

Signal handlers


A receiver for the lino.core.signals.pre_analyze signal.

Installs (1) print management actions on models for which there is an excerpt type and (2) the excerpt shortcut fields defined in lino_xl.lib.excerpts.choicelists.Shortcuts.

Note that excerpt types for a model with has MTI children, the action will be installed on children as well. For example a lino_avanti.lib.avanti.Client in lino_book.projects.adg can get printed either as a TermsConditions.odt or as a final report.body.html.

When the database does not yet exist (e.g. during pm prep), it simply ignores that situation silently and does not define the print actions.


This is called for every new Excerpt object and it sets certain default values.

For the default language, note that the owner overrides the recipient. This rule is important e.g. for printing aid confirmations in Lino Welfare.