DeveloperGuidelines

How to add a new module?

Copy an existing module, paste & edit. Good modules to look at to start with are or & cr as these are simplest & standard.

Model

Add module to db.module:

• ​http://127.0.0.1:8000/sahana/appadmin/select/db?query=db.module.id%3E0

This makes it visible on the front page & the left-hand navigation menu

Create a file /models/module.py

This needs a table to store the module's menu options in:

module='name'

# Menu Options
db.define_table('%s_menu_option' % module,
                SQLField('name'),
                SQLField('function'),
                SQLField('description',length=256),
                SQLField('priority','integer'),
                SQLField('enabled','boolean',default='True'))
db['%s_menu_option' % module].name.requires=[IS_NOT_EMPTY(),IS_NOT_IN_DB(db,'%s_menu_option.name' % module)]
db['%s_menu_option' % module].name.requires=IS_NOT_EMPTY()
db['%s_menu_option' % module].priority.requires=[IS_NOT_EMPTY(),IS_NOT_IN_DB(db,'%s_menu_option.priority' % module)]

Populate this table with the functions that you wish to expose to the module's front page & left-hand navigation bar:

if not len(db().select(db['%s' % table].ALL)):
	db['%s' % table].insert(
        name="Home",
	function="index",
	priority=0,
	description="Home",
	enabled='True'
	)
	db['%s' % table].insert(
        name="Add Vehicle",
	function="vehicle/create",
	priority=1,
	description="Add a vehicle to the database",
	enabled='True'
	)
	db['%s' % table].insert(
        name="List Vehicles",
	function="vehicle",
	priority=2,
	description="List information of all vehicles",
	enabled='True'
	)

Add additional tables to this file, as-required for your resources.
To avoid namespace clashes, use the format: db.module_table

e.g. if building a Vehicle Management System, create db.veh_vehicle:

module='veh'
resource='vehicle'
table=module+'_'+resource
db.define_table(table,
                SQLField('modified_on','datetime',default=now),
                SQLField('uuid',length=64,default=uuid.uuid4()),
                SQLField('name'))
db['%s' % table].represent=lambda table:shn_list_item(table,resource='vehicle',action='display')
db.veh_vehicle.name.requires=IS_NOT_EMPTY()
db.veh_vehicle.name.comment=SPAN("*",_class="req")

Also add the messages for your resources:

title_create=T('Add Vehicle')
title_display=T('Vehicle Details')
title_list=T('List Vehicles')
title_update=T('Edit Vehicle')
subtitle_create=T('Add New Vehicle')
subtitle_list=T('Vehicles')
label_list_button=T('List Vehicles')
label_create_button=T('Add Vehicle')
msg_record_created=T('Vehicle added')
msg_record_modified=T('Vehicle updated')
msg_record_deleted=T('Vehicle deleted')
msg_list_empty=T('No Vehicles currently registered')
exec('crud_strings.%s=Storage(title_create=title_create, title_display=title_display, title_list=title_list, title_update=title_update, subtitle_create=subtitle_create, subtitle_list=subtitle_list, label_list_button=label_list_button, label_create_button=label_create_button, msg_record_created=msg_record_created, msg_record_modified=msg_record_modified, msg_record_deleted=msg_record_deleted, msg_list_empty=msg_list_empty)' % resource)

Controller

Create a file: /controllers/module.py

Add the T2 framework functions:

# T2 framework functions
def login(): redirect(URL(r=request,c='default',f='login'))
def logout(): t2.logout(next='login')
def register(): redirect(URL(r=request,c='default',f='register'))
def profile(): redirect(URL(r=request,c='default',f='profile'))

Add CRUD functions for your tables:

def vehicle():
    "RESTful CRUD controller"
    return shn_rest_controller(module,'vehicle')

Manual method for if/when you need more control: DeveloperGuidelinesCreateReadUpdateDelete

Views

Add HTML templates for any custom functions: /views/module/function.html

NB Only index.html is required to start with since the RESTful controller re-uses standard views

DeveloperGuidelines