mdbelma / budburst-android-client Goto Github PK

Project Budburst

Cameron Ketcham

UCLA CENS project to write an android app to interface with http://budburst.ucar.edu/ to allow people to easily take images and make observations.

I tried to make a model abstraction for the sqlite3 database since the database was so unruly to begin with. I copied ideas I learned when using ruby on rails and appengine. I tried to apply those ideas to this problem. Here is an overview of how it works. I am not sure I succeeded in making something extremely useful but I hope I did.

First there are different databases which you can instantiate which act on different kinds of models.
	1. StaticDatabase - this database just holds data which it imports from and sql file which can be placed in the res/raw folder.
	2. WritableDatabase - this database is the same as a StaticDatabase however you have the ability to insert data using the function insertRow, you pass a model to this function.
	3. SyncableDatabase - this database allows syncing down and up using json encodings.

There are different kinds of models you can then use with these databases.
	1. The base class is Row. It includes the default column _id.
	2. RelationRow. this is a row which maps data from two tables (HasMany). If you name the database species_phenophase, it means species has many phenophases.
	3. Syncable row. this is the row which should be used for the syncable database. it includes a field which tells if it is synced with the server or not.

to make a new model you should extend the appropriate base model.  Any public fields will be saved to the database. you can also make functions which can be called on a model to get more information such as plant.species() will give me the SpeciesRow for the current plant.

to query the database I use a databaseManager which keeps references to the datbases I created. If I want access to all the entries in the plant database I just use the databaseManager to find it. ex. myDatabaseManager.getDatabase("plant") will return the plant database. I can perform queries like all() which will return all the rows, find(id) which will find the row with the give id, and find("where clause") which will filter the query by the specified where clause.
You create databases using the databaseManager as well. You can use either createDatabase, or createSyncableDatabase which specifies whether or not you have data that you wish to sync with a server or not.

If you have any suggestions on how to make this better, please let me know. thanks.