net.zer0bandwidth.android.lib.database.sqlitehouse.refractor

Interface Refractor<T>

All Known Implementing Classes:

BooleanLens, CalendarLens, CharacterLens, CommaDelimStringsListLens, DateLens, DoubleLens, FloatLens, FormFeedDelimStringsListLens, GregorianCalendarLens, IntegerLens, Lens, LongLens, NullRefractor, ShortLens, SQLDateLens, StringCollectionLens, StringLens

public interface Refractor<T>

Defines how data is moved between a Java data type and its corresponding SQLite data type. This library defines several default refractors, some of which are simple, and others of which exhibit varying degrees of magic hackery. Apps may also define their own custom Refractor implementations and register them in their SQLiteHouse descendants, after initialization but before opening a connection. The package name is a reference to the Fresnel lens of a lighthouse; a set of implementation classes metaphorically define the rings of a Fresnel lens through which the data is refracted.

Since:

zer0bandwidth-net/android 0.1.4 (#26)

See Also:

Lens

Method Summary

Modifier and Type	Method and Description
Refractor<T>	addToBundle(android.os.Bundle bndl, java.lang.String sKey, T val) Determines the correct method in Bundle to be used to add the specified value to an existing bundle.
Refractor<T>	addToContentValues(android.content.ContentValues vals, java.lang.String sKey, T val) Determines the correct method in ContentValues to be used to add the specified value to a set of content values.
T	fromBundle(android.os.Bundle bndl, java.lang.String sKey) Determines the correct method in Bundle to be used to fetch the specified column, then returns that value.
T	fromCursor(android.database.Cursor crs, java.lang.String sKey) Determines the correct method in Cursor to be used to fetch the specified column, then returns that value.
java.lang.String	getSQLiteDataType() Defines the SQLite data type to be used when writing a value into the database.
java.lang.String	getSQLiteDefaultString() Returns a string representation of the column type's default value, for use in an SQLite statement.
T	getSQLiteDefaultValue() Returns a reasonable non-null default value for a column of this data type in SQLite, particularly for cases in which the value cannot be null.
T	getValueFrom(SQLightable o, java.lang.reflect.Field fld) Gets the value of a field which would be appropriate for this refractor.
java.lang.String	toSQLiteString(T o) Converts a Java thing's value into a string to be used in a SQLite query, for example, in a WHERE clause filter.

Method Detail

getSQLiteDataType

java.lang.String getSQLiteDataType()

Defines the SQLite data type to be used when writing a value into the database. This is used to create the column definition.

Returns:

the SQLite data type string for this Java data type

getSQLiteDefaultValue

T getSQLiteDefaultValue()

Returns a reasonable non-null default value for a column of this data type in SQLite, particularly for cases in which the value cannot be null. Examples would be 0 for integer types, an empty string for string types, false for Boolean types, etc.

Returns:

a reasonable non-null default value for the data type

toSQLiteString

java.lang.String toSQLiteString(T o)

Converts a Java thing's value into a string to be used in a SQLite query, for example, in a WHERE clause filter.

Parameters:

o - the Java thing to be converted

Returns:

a string serialization for use in an SQLite statement

getSQLiteDefaultString

java.lang.String getSQLiteDefaultString()

Returns a string representation of the column type's default value, for use in an SQLite statement. The Lens abstract class provides a canonical implementation of this method:

     return this.toSQLiteString( this.getSQLiteDefaultValue() ) ;
 

Returns:

the string representation of the column type's default value

getValueFrom

T getValueFrom(SQLightable o,
               java.lang.reflect.Field fld)
        throws java.lang.IllegalAccessException

Gets the value of a field which would be appropriate for this refractor.

Parameters:

o - the object instance from which the value will be extracted

fld - the field from which the value will be extracted

Returns:

the value

Throws:

java.lang.IllegalAccessException

addToContentValues

Refractor<T> addToContentValues(android.content.ContentValues vals,
                                java.lang.String sKey,
                                T val)

Determines the correct method in ContentValues to be used to add the specified value to a set of content values.

Parameters:

vals - the set of content values

sKey - the content value key

val - the value to be stored

Returns:

(fluid)

addToBundle

Refractor<T> addToBundle(android.os.Bundle bndl,
                         java.lang.String sKey,
                         T val)

Determines the correct method in Bundle to be used to add the specified value to an existing bundle.

Parameters:

bndl - the bundle

sKey - the field's key

val - the value to be stored

Returns:

(fluid)

Since:

zer0bandwidth-net/android 0.1.7 (#50)

fromCursor

T fromCursor(android.database.Cursor crs,
             java.lang.String sKey)

Determines the correct method in Cursor to be used to fetch the specified column, then returns that value.

Parameters:

crs - the cursor from which data should be fetched

sKey - the data column name

Returns:

the value from the cursor

fromBundle

T fromBundle(android.os.Bundle bndl,
             java.lang.String sKey)

Determines the correct method in Bundle to be used to fetch the specified column, then returns that value.

Parameters:

bndl - the bundle from which data should be fetched

sKey - the data column name

Returns:

the value from the bundle

Since:

zer0bandwidth-net/android 0.1.7 (#50)