LiquidFeedback Core (Backend)

This page is dedicated to the backend of LiquidFeedback (“the core”). You may also want to visit the main page of LiquidFeedback.

The core consists of a database scheme for the PostgreSQL database, including the algorithms for delegations, feedback and the voting procedure implemented as SQL views and database procedures written in PL/pgSQL. As it is licensed under the liberal MIT/X11-License you can include it in any software project you like, as long as there is PostgreSQL support for your programming language available.

Dependencies

• PostgreSQL 8.3 or higher

Repository

• mercurial repository

Download official releases

• liquid_feedback_core-v1.2.7.tar.gz
• liquid_feedback_core-v1.2.6.tar.gz (If you use PostgreSQL 8.3, use update script contained in liquid_feedback_core-v1.2.7.tar.gz)
• liquid_feedback_core-v1.2.5.tar.gz
• liquid_feedback_core-v1.2.4.tar.gz
• liquid_feedback_core-v1.2.3.tar.gz
• liquid_feedback_core-v1.2.2.tar.gz
• liquid_feedback_core-v1.2.1.tar.gz
• liquid_feedback_core-v1.2.0.tar.gz
• liquid_feedback_core-v1.1.0.tar.gz
• liquid_feedback_core-v1.0.3.tar.gz
• liquid_feedback_core-v1.0.2.tar.gz
• liquid_feedback_core-v1.0.1.tar.gz
• liquid_feedback_core-v1.0.0.tar.gz
• liquid_feedback_core-beta26.tar.gz
• liquid_feedback_core-beta25.tar.gz
• liquid_feedback_core-beta24.tar.gz
• liquid_feedback_core-beta23.tar.gz
• liquid_feedback_core-beta22.tar.gz
• liquid_feedback_core-beta21.tar.gz
• liquid_feedback_core-beta20.tar.gz
• liquid_feedback_core-beta19.tar.gz
• liquid_feedback_core-beta18.tar.gz
• liquid_feedback_core-beta17.tar.gz
• liquid_feedback_core-beta16.tar.gz
• liquid_feedback_core-beta15.tar.gz
• liquid_feedback_core-beta14.tar.gz
• liquid_feedback_core-beta13.tar.gz
• liquid_feedback_core-beta12.tar.gz
• liquid_feedback_core-beta11.tar.gz
• liquid_feedback_core-beta10.tar.gz
• liquid_feedback_core-beta9.tar.gz
• liquid_feedback_core-beta8.tar.gz
• liquid_feedback_core-beta7.tar.gz
• liquid_feedback_core-beta6.tar.gz
• liquid_feedback_core-beta5.tar.gz
• liquid_feedback_core-beta4.tar.gz
• liquid_feedback_core-beta3.tar.gz
• liquid_feedback_core-beta2.tar.gz
• liquid_feedback_core-beta1.tar.gz

Changes

• 2010-08-30: Version 1.2.7 released
  • Removed unintentionally inserted extra columns in view global_delegation from previous update
  • Changed update script from v1.2.5 to v1.2.6 to work with PostgreSQL 8.3
• 2010-08-30: Version 1.2.6 released
  • Important bugfix, affecting correct counting of supporters/votes (delegations of inactive members were still counted)
• 2010-08-16: Version 1.2.5 released
  • Improved locking to avoid unneccessary delays and possible deadlocks
• 2010-08-15: Version 1.2.4 released
  • lf_update continues on error (but still reports errors)
• 2010-07-24: Version 1.2.3 released
  • Added rendered_draft table for caching
• 2010-07-20: Version 1.2.2 released
  • Save battle data from calls of function clean_issue(issue.id) by materializing battle view
• 2010-07-19: Version 1.2.1 released
  • New function clean_issue(issue.id), which deletes all discussion data and votes of an issue
• 2010-07-14: Version 1.2.0 released
  • Removed "login" name history
  • Deletion functions delete_member(...) and delete_private_data() delete more data
    • Fields last_login and notify_email_lock_expiry of table member
    • Final votes on open issues are deleted by delete_member(...) function as well
• 2010-07-08: Version 1.1.0 released
  • Removed column interest_exists from table direct_population_snapshot
  • Replaced function delete_member_data(...) by function delete_member(...)
  • Added column notify_email_lock_expiry
  • Bugfix: Corrected comment for function manual_freeze(...)
• 2010-06-17: Version 1.0.3 released
  • Bugfix: Corrected table for index delegating_voter_member_id_idx
• 2010-04-21: Version 1.0.2 released
  • Function delete_member_data(...) also deletes area memberships now
  • Bug introduced in v1.0.1 fixed: Function delete_private_data() used by lf_export does not delete delegations anymore
• 2010-04-20: Version 1.0.1 released
  • Function delete_member_data(...) also deletes outgoing delegations now
• 2010-04-20: Tarball for Version 1.0.0 recreated
  • The .tar.gz-file was replaced, due to a wrong directory prefix in the old archive.
• 2010-04-15: Version 1.0.0 released
  • New function delete_member_data(...)
  • Added missing index for table member_history
  • Some references fixed to restrict updates
• 2010-03-26: Version beta26 released
  • Save timestamp of last login
  • Save timestamps of member activation/deactivation
  • Deletion of suggestions with attached opinions is now possible (changed reference to ON DELETE CASCADE)
• 2010-03-08: Version beta25 released
  • Changes in lf_export: Use pg_dump and psql instead of createdb to copy database
• 2010-03-08: Version beta24 released
  • Added missing DELETEs in function delete_private_data()
  • Fixed wrong COMMENT statement for table member_relation_setting
• 2010-03-04: Version beta23 released
  • Critical bugfix in function "create_snapshot"(...): Fixed incorrect calculation of opinion count for suggestions
• 2010-02-22: Version beta22 released
  • Bugfix: Added missing states in "valid_state" constraint of table "issue"
• 2010-02-21: Version beta21 released
  • Bug in "forbid_changes_on_closed_issue_trigger"() fixed, which caused errors when closing issues under certain circumstances
• 2010-02-20: Version beta20 released
  • Better handling of ties in final voting (changes rankings and final winners in certain cases)
    • Calculate strengths of pairwise defeats primarily by absolute number of votes for winner and secondarily by absolute number of votes for loser (as recommended in this paper, section 6)
    • Treatment of edge cases in function "vote_ratio"(...)
• 2010-02-09: Version beta19 released
  • Triggers ensure that votes can't be modified by a broken frontend after issues have been frozen
  • New snapshot event 'half_freeze' and renamed event 'start_of_voting' to 'full_freeze'
  • Policy values admission_, discussion_, verification_ and voting_time get copied into issue, and each issue uses its own values
  • Added tables allowing frontends to store member-relation, area, issue and suggestion settings
  • Close issues when verification time elapsed after revoking last initiative
  • Moved core-update files to update directory; Added BEGIN and COMMIT to core-update.beta16-beta17.sql
  • Changed year in LICENSE to "2009-2010"
• 2010-01-23: Version beta18 released
  • Bug fixed, which caused issue_voting_started events in timeline to be shown only after an issue had been closed
• 2010-01-22: Version beta17 released
  • New view timeline
  • More indicies (for timeline)
  • New table setting_map to store more complicated frontend user settings
• 2010-01-13: Version beta16 released
  • Critical bug related to revoked initiatives fixed, which caused lf_update or check_everything() to exit with an error instead of performing the neccessary tasks
• 2010-01-10: Version beta15 released
  • Bugfix: Revoked initiatives will never be admitted
  • Possibility to recommend another initiative to support when revoking an initiative
  • Allow "initiator"."accepted" to be NULL (NULL means "no answer yet", while FALSE means "rejected")
• 2010-01-04: Version beta14 released
  • Function delete_private_data() deletes now all member contacts, including private ones, to protect users privacy when database dumps are published
  • New table member_history logging changes of names and logins
• 2010-01-02: Version beta13 released
  • Function delete_private_data() deletes now all invite codes again, due to privacy reasons when using unencrypted channels for sending the invite codes
• 2010-01-02: Version beta12 released
  • Changed function delete_private_data() to delete more data, including tables setting and member_image, for better data protection
  • Bugfix related to linux-sh in shell script lf_export
  • New fields password_reset_secret and password_reset_secret_expiry in member table
  • UNIQUE constraint for notify_email_secret and password_reset_secret fields in member table
  • Database constraint forbids adding yourself as a contact
• 2009-12-25: Version beta11 released
  • Support is now automatically deleted, when interest is deleted
  • All tables dealing with delegations now contain a column scope (including table delegation)
  • Changes in fields related to notify_email of member
  • Policies can now specify larger majorities to be reached (e.g. 2/3)
  • New column agreed in table initiative to mark, if initiative has reached majority specified by policy
  • Minor bugfix in constraint non_admitted_initiatives_cant_contain_voting_results of initiative table
  • Function delete_private_data() no longer deletes invite codes, which have been already used
  • Removed view battle_participant
  • Added index on opinion (member_id, initiative_id)
• 2009-12-10: Version beta10 released
  • Voting will be skipped, if no initiative is admitted for voting
  • Invite code feature allows people having an invite code to create one account
  • Contingent system to limit the number of initiatives or text entries to be submitted by each member within a given time
  • Ability to store a formatting engine for each draft, which can be used to allow initiatives to choose between available wiki parsers
  • New table setting storing user settings for the frontend (replaced hidden_hints column of beta9)
  • Better policy support
    • New table allowed_policy to select which policies can be used in each area
    • Policies are now ordered by an index field
  • Bugfixes
    • In function close_voting(...): If there were no voters, this resulted in a NULL value as positive and negative vote counts
    • In delete_private_data() function: Secret fields of member table are now deleted too
    • Major bug fixed in lf_export, which caused data loss on execution
• 2009-11-30: Version beta9 released
  • Added missing indicies on TSVECTOR fields
  • New field latest_snapshot_event in table issue specifying the type of the latest snapshot taken
  • Added weight field also for (intermediate) delegating members in snapshot and voter tables
  • Possibility for an initiative to specify a URL where an external discussion takes place (discussion_url)
  • Export concept for creating a database dump, without some non-public information (e.g. private contact data)
    • Shell script lf_export
    • Database function delete_private_data()
  • Field in member table to be used by a frontend to store information about hints being hidden by the user
  • Minor cleanup / New comments
• 2009-11-23: Version beta8 released
  • More attibutes in member table
  • Renamed column ident_number of member table to identification
  • Images of members are now stored in extra table member_image
  • Minor bugfix in init.sql: Added missing verification_time column
  • Full text index search support using PostgreSQL's TSVECTOR and TSQUERY datatypes
  • New function highlight(...), which helps to highlight matching words in search results
• 2009-11-18: Version beta7 released
  • Fixed bug in function close_voting(...) leading to wrong voter_count values in issue table
  • Added avatar column to member table for storing a small picture of the member
• 2009-11-17: Version beta6 released
  • Added function for printing delegation chains
  • Replaced column member_count of table area by 3 new columns:
    • direct_member_count
    • member_weight (regarding delegations)
    • autoreject_weight
  • Added calculated field to member_count table, storing the time of computation of the total member count and area member counts
  • Added view liquid_feedback_version
  • Code cleanup
• 2009-11-15: Version beta5 released
  • Precalculation of certain values to increase performance:
    • Count of active members per area
    • Count of active members altogether
    • Count of people involved in the voting process for an issue
  • Minor bugfix in function close_voting(...) related to initiatives having no positive or negative votes
• 2009-11-15: Version beta4 released
  • Introduced half-freeze feature: Policies can cause issues to become half-frozen for a given amount of time before becoming fully frozen for voting. When an issue is half-frozen initiatives may not modify their drafts, but creating a new initiative or removing/adding support and opinions is still possible.
  • Bugfix: end_of_admission snapshots are now created for accepted issues.
• 2009-11-07: Version beta3 released
  • Minor bugfix: Autocreated entries in supporter table refer to the current draft of the initiative instead of throwing an error
• 2009-11-03: Version beta2 released
  • Serious bugfix in SQL function create_snapshot(...), which caused wrong counting of opinions on suggestions
  • lf_update now deletes expired sessions
  • Redundancy in SQL function check_everything() removed by using existent views
• 2009-10-27: Version beta1 released