Changes between Initial Version and Version 1 of DeveloperGuidelines

Timestamp:

12/20/08 02:51:43 (16 years ago)

Author:

Fran Boon

Comment:

--

DeveloperGuidelines

@@ +1 @@
+Web2Py:
+* http://mdp.cti.depaul.edu/examples/static/cookbook.pdf
+* http://mdp.cti.depaul.edu/examples/static/web2py_cheatsheet.pdf
+
+MVC (like Rails)
+
+  Model
+   Defines databases in: /models/db.py   (equivalent of inst/mysql-dbcreate.sql)
+
+  Controller
+   Python functions in /controllers/module.py
+   e.g.
+   def list_records():
+       list=t2.itemize(table)
+       return dict (list=list)
+    
+  View
+   HTML/Javascript templates in /views/module/function.html
+   - these are normal HTML/JS files with the ability to add in Python code (e.g. variables) surrounded by brackets: {{ interpreted python here }}
+   - there should be an .html file available for each function in the module (name normally being the same as the function)
+   - if there is no view defined then a default view will be displayed, which will show the values of all the data it can see, but not be formatted nicely
+
+   CSS/Javascript files are stored in /static      (equivalent of www/res)
+
+Python:
+* Slow start
+ - http://openbookproject.net/thinkcs/python/english2e/
+* Quick start
+ - http://diveintopython.org/
+* v.Quick start!
+    Indentation matters (use 4 spaces instead of Tabs)
+    OOP - everything is an object
+
+T2 is used for AAA & simplified CRUD (inc Conflict Detection)
+http://mdp.cti.depaul.edu/examples/static/t2.pdf
+We extend the T2 class in modules/sahana.py
+
+CRUD
+Create Record:
+  Controller
+   def add_record():
+       form=t2.create(db.table)
+       return dict(form=form)
+  View
+    views/module/add_record.html
+     {{=form}}
+Display Record:
+  Controller
+   def display_record():
+       item=t2.display(db.table)
+       return dict(item=item)
+  View
+    views/module/display_record.html
+     {{=item}}
+Update Record:
+  Controller
+   def display_record():
+       form=t2.update(db.table)
+       return dict(form=form)
+  View
+    views/module/add_record.html
+     {{=form}}
+Delete Record:
+  Controller
+   def delete_record():
+   db(db.table.id==t2.id).delete()
+   response.confirmation=T("Record deleted")
+   response.view="module/list_records.html"
+  View
+    normally not used (reuse existing list_records view)
+
+
+Populate the side navigation Menus by adding this to each controller:
+module='module'
+# Current Module (for sidebar title)
+module_name=db(db.module.name==module).select()[0].name_nice
+# List Modules (from which to build Menu of Modules)
+modules=db(db.module.enabled=='Yes').select(db.module.ALL,orderby=db.module.menu_priority)
+# List Options (from which to build Menu for this Module)
+options=db(db['%s_menu_option' % module].enabled=='Yes').select(db['%s_menu_option' % module].ALL,orderby=db['%s_menu_option' % module].priority)
+
+Each function needs to return these values to the view:
+  return dict(module_name=module_name,modules=modules,options=options)
+
+List output can be made more functional by adding this to your table definitions in models/db.py:
+   db.table.represent=lambda table: A(table.display_field,_href=t2.action('display_table',table.id))
+Form labels can be set in a translatable manner using:
+   db.table.field.label=T("label")
+Form field can be made to use a TEXTAREA by marking the field as being type 'text':
+   SQLField('field','text'),
+Form field can be made to use a SELECT dropdown by setting the field as a lookup to another table:
+   SQLField('field',db.othertable),
+Set this to use a different field than 'id' in the views (e.g. 'name') using:
+   db.table.field.requires=IS_NULL_OR(IS_IN_DB(db,'othertable.id','othertable.name'))
+Form field being required can be marked using:
+   db.table.field.comment=SPAN("*",_class="req")
+Help for a form field can be set using:
+   A(SPAN("[Help]"),_class="popupLink",_id="tooltip",_title=T("Help|This is what this field is for."))
+
+Conflict Detection:
+Add this field to each table which needs protecting (in models/db.py):
+SQLField('modified_on','datetime'), # Used by T2 to do edit conflict-detection
+
+AAA
+ Controller
+  Each controller which incldues protected functions needs this:
+   def login():
+       response.view='login.html'
+           return dict(form=t2.login())
+   def logout(): t2.logout(next='login')
+   def register():
+           response.view='register.html'
+           return dict(form=t2.register())
+  Each protected function needs this:
+   @t2.requires_login('login')
+   def function():
+
+
+How to add a new module?
+- copy existing & edit!
+  Model
+   Add module to db.module:
+    http://127.0.0.1:8000/sahana/appadmin/select/db?query=db.module.id%3E0
+   Create a table to store the module's menu options to /models/db.py
+    db.module_menu_option
+   Add tables to /models/db.py
+  Controller
+   Add CRUD functions for these tables to /views/module.py
+  View
+   Add HTML templates for these functions: /views/module/function.html
+
+How to do Options fields?
+Sahana2 has a generic 'field_options' table for storing Options fields/.
+Sahana3 uses a separate table for each lookup list
+
+
+Advanced Tricks:
+* Python debugging
+- use Web2Py shell: http://www.vimeo.com/879939
+- http://docs.python.org/library/doctest.html
+- http://docs.python.org/library/bdb.html
+* CSS & Javascript debugging
+- use Firebug: http://code.google.com/support/bin/answer.py?answer=77412&topic=12044
+* jQuery:
+- http://www.tvidesign.co.uk/blog/improve-your-jquery-25-excellent-tips.aspx
+* Ext:
+- http://extjs.com/learn/Tutorial:Introduction_to_Ext_2.0
+- http://extjs.com/learn/Manual:Basic_Application_Design
+- http://extjs.com/forum/showthread.php?t=26728
+- http://extjs.com/learn/Ext_FAQ_Debugging