Implement employee-absence widget

See also: http://wiki.civicrm.org/confluence/display/HR/Absence+-+Employee+Perspective

Tasks:

T1. Implement skeletal/placeholder page

• Use Backbone Marionette
• Define data classes – AbsenceModel, and AbsenceCollection, and AbsenceCriteria
• Add tabs, routes, and placeholder implementations of ListView, CalendarView, and StatisticsView
• Add events to refresh content whenever the filter criteria changes

T2. Change the filter widgets from single-selects to checkbox multi-selects

• Probably use https://github.com/ehynds/jquery-ui-multiselect-widget
• Possibly use http://ivaynberg.github.io/select2/

T3. Add styling

• Use vertical-tab layout like the mockup
• Ensure that spacing holds up reasonable in different browsers/resolutions

T4. Load real data

• Load real list of absence-related activity types (CRM_HRAbsence_Page_EmployeeAbsencePage::registerResources)
• Load real list of absence periods (CRM_HRAbsence_Page_EmployeeAbsencePage::registerResources)
• Implement API (either update/enhance the Activity API or add a new API) to fetch absence-activities; must support filters:
• period_id: accepts or int or (ideally) array of ints
• activity_type_id: accepts or int or (ideally) array of ints
• target_contact_id: int (note: be sure to respect ACLs)

T5. Implement ListView which displays the first tab. Notes:

• The raw data should be available in this.options.collection (AbsenceCollection).
• The raw filter criteria should be available in this.options.criteria (AbsenceCriteria).
• Write qunit tests for the functions which compute totals.
• If multiple periods are selected, note that the table will display subsection for each period.

T6. Implement CalendarView which displays the second tab. Notes:

• The raw data should be available in this.options.collection (AbsenceCollection).
• The raw filter criteria should be available in this.options.criteria (AbsenceCriteria).
• Write qunit tests for functions or classes which which get activities by date

T7. Implement StatisticsView which displays the third tab. Notes:

• The raw data should be available in this.options.collection (AbsenceCollection).
• The raw filter criteria should be available in this.options.criteria (AbsenceCriteria).
• Write qunit tests for functions or classes which compute the statistics

T8. Implement "New Absence" behavior

• ie choose an item from a dropdown, and it redirects to the Absence Request screen in create mode (HR-227)

T9. Embed in standalone "My Absences" page (/civicrm/absences")

T10. Embed in "View Contact" page (as tab – maybe /civicrm/absences?cid=<contact>&snippet=<foo>)