Creating Moodle modules

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Creating Moodle modules

• sam marshall

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Contents

• Introduction to Moodle system
• Introduction to modules
• Versions and database tables
• Capabilities
• Language files and help files
• Forms
• view.php

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Introduction to Moodle system

• PHP ?
• Database-driven
• Library of simplifying database access
  functions
• Every table has auto-increment id field
• Little persistent state
• Session data exists, not heavily used
• Mainly functions, not object-oriented
• Independent PHP scripts

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Introduction to modules

• Activities
• Appear on front page of course
• Add using dropdown
• Update settings
• Link goes to modules own PHP files
• Whats in a module?

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mod/name

• db
• install.xml
• access.php
• update.php
• version.php
• lang
• en_utf8
• name.php
• help
• mods.html
• lib.php
• mod_form.php
• styles.php
• view.php

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Database structure

• prefix_course_modules
• An instance of a module in a particular course
• prefix_name
• Your table. Must have id, name, course
• And index on course
• cm-gtinstance name-gtid
• Variables
• cm, name, course

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Versions and database tables

• install.xml
• Used when installing for first time
• Create with horrible editor (not by hand!)
• update.php
• Used after code update on existing database
• Code in PHP
• version.php
• Module version e.g. 2007031600

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Capabilities

• Define capabilities for your module
• Array in access.php
• Specifies available capabilities and who has them
  by default
• mod/nameedit, mod/nameview,
• Check capabilities
• Get context object for current module instance
• has_capability(mod/nameedit,context)

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Language files

• All strings taken out into language files
• Except system errors
• But not except user errors!
• Why? Now or future contribution to community
• Language file goes in lang/en_utf8/name.php
• stringfrogscanjumpFrogs can jump
• stringhowhighHow high? a metres!
• A couple standard strings (module name)

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Help files

• In lang/en_utf8/help
• Basic XHTML content
• One standard file mods.html
• Add other files
• Link to them with standard help button
• For example, in forms

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Forms

• In case youve forgotten

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Forms

• mod_form.php
• PHP QuickForm Moodle extensions
• mform-gtaddElement('text', 'name',
  get_string('name'))
• Various types provided
• Easy to add help buttons
• Does formatting for you
• And accessibility (hopefully)

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view.php

• Your own PHP code
• Can do anything
• Should use Moodle standard functions where
  appropriate
• Header, footer, tabs, etc.
• Other PHP scripts too (as needed)
• view.php is just where the link goes

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Conclusion

• Standard platform features need to be used
• Maintaining
• Administration (capabilities)
• Community sharing
• Initial design is important
• Skills needed
• Database
• PHP
• And

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Bonus scare slide

• Security!!!!1!!1!!eleventy-one
• Public Web application
• Easy to make mistakes
• Check permission on action as well as when
  showing link
• Avoid SQL injection
• Be careful!

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To end on a positive note

• ?