it.polimi.dima.mediatracker.controllers

Class CategoriesController

java.lang.Object

it.polimi.dima.mediatracker.controllers.CategoriesController

public class CategoriesController
extends java.lang.Object

Controller for categories that allows to query the database to retrieve data

Constructor Summary

Constructors

Constructor and Description
CategoriesController()

Method Summary

Modifier and Type	Method and Description
void	addDefaultCategoriesIfEmpty(Context context) If the categories table is empty, adds the default categories (i.e.
void	deleteCategory(Category category) Removes a category from the database (together with all media items associated to it)
java.util.Iterator<Category>	getAllCategories() Getter
Category	getCategoryById(java.lang.Long categoryId) Getter
static CategoriesController	getInstance() Singleton pattern
void	saveCategory(Category category) Inserts or updates a category in the database
java.lang.String	validateCategory(Context context, Category category) Validates a category, possibly fixing what is wrong or, if impossible, returning an error string
java.lang.String	validateCategoryDbRow(Context context, java.util.HashMap<java.lang.String,java.lang.Object> values) Like validateCategory(Context, Category) but with actual DB values

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CategoriesController

public CategoriesController()

Method Detail

getInstance

public static CategoriesController getInstance()

Singleton pattern

getAllCategories

public java.util.Iterator<Category> getAllCategories()

Getter

Returns:

an iterator containing all categories

getCategoryById

public Category getCategoryById(java.lang.Long categoryId)

Getter

Parameters:

categoryId - the ID of the category

Returns:

the category with the given ID or null if not found

addDefaultCategoriesIfEmpty

public void addDefaultCategoriesIfEmpty(Context context)

If the categories table is empty, adds the default categories (i.e. those corresponding to all media types)

Parameters:

context - the context

saveCategory

public void saveCategory(Category category)

Inserts or updates a category in the database

Parameters:

category - the category to update/insert

deleteCategory

public void deleteCategory(Category category)

Removes a category from the database (together with all media items associated to it)

Parameters:

category - the category to remove

validateCategory

public java.lang.String validateCategory(Context context,
                                         Category category)

Validates a category, possibly fixing what is wrong or, if impossible, returning an error string

Parameters:

context - the context

category - the category to validate

Returns:

null if no error (or errors were fixed by this method), a string containing the error otherwise

validateCategoryDbRow

public java.lang.String validateCategoryDbRow(Context context,
                                              java.util.HashMap<java.lang.String,java.lang.Object> values)

Like validateCategory(Context, Category) but with actual DB values

Parameters:

context - the context

values - hash column name => value

Returns:

null if no error (or errors were fixed by this method), a string containing the error otherwise