com.bea.ld.filter
Class FilterXQuery

java.lang.Object
  com.bea.ld.filter.FilterXQuery

All Implemented Interfaces:

java.io.Serializable

public class FilterXQuery
extends java.lang.Object
implements java.io.Serializable

This class enables client-side control of data service function results through filtering and ordering without having to use complex XQuery syntax. A filter object is passed to Liquid Data (along with the name of a function in a data service), which processes the filters/orderby list and generates the XQuery. This capability is helpful in cases where a data service returns results that contain nested objects and you want to get different views of the objects based on certain conditions.

For example, if the returned document is CUSTOMERS/CUSTOMER/ORDER, where:

• CUSTOMERS: the top-level document element.
• CUSTOMER: a repeatable sequence inside CUSTOMERS.
• ORDER: a repeatable sequence inside CUSTOMER.

There are four possible ways to view large orders (say CUSTOMER/ORDER/ORDER_AMOUNT > 1000)

1. All CUSTOMER objects but only large ORDER objects
2. Only CUSTOMER object which has at least one large order and view all ORDER objects for such CUSTOMER
3. Only CUSTOMER object which has at least one large order and view only Large ORDER objects (basically 1 & 2)
4. Only CUSTOMER object which has all the ORDER as large order (i.e., ORDER_AMOUNT > 1000)

Instead of writing XQuery for all these cases you just pass this object as parameter when executing the data service function.

1. All CUSTOMER objects but Only Large ORDER objects
FilterXQuery filter = new FilterXQuery();
filter.addFilter("CUSTOMERS/CUSTOMER/ORDER","CUSTOMERS/CUSTOMER/ORDER/ORDER_AMOUNT",">","1000");


2. Only CUSTOMER object which has at least one large order and view All ORDER objects for such CUSTOMER

FilterXQuery filter = new FilterXQuery();
filter.addFilter("CUSTOMERS/CUSTOMER","CUSTOMERS/CUSTOMER/ORDER/ORDER_AMOUNT",">","1000");


3. Only CUSTOMER object which has at least one large order and view only Large ORDER objects ( basically 1 & 2)

FilterXQuery filter = new FilterXQuery();
filter.addFilter("CUSTOMERS/CUSTOMER","CUSTOMERS/CUSTOMER/ORDER/ORDER_AMOUNT",">","1000");
filter.addFilter("CUSTOMERS/CUSTOMER/ORDER","CUSTOMERS/CUSTOMER/ORDER/ORDER_AMOUNT",">","1000");


4. Only CUSTOMER object which has all the ORDER as large order (i.e. ORDER_AMOUNT > 1000)

FilterXQuery filter = new FilterXQuery();
filter.addFilter("CUSTOMERS/CUSTOMER","CUSTOMERS/CUSTOMER/ORDER/ORDER_AMOUNT",">","1000",true);


See Also:

addFilter(String appliesTo, String field, String operator, String value), createFilter(String field, String operator, String value, boolean everyChild), Serialized Form

Field Summary

static java.lang.String	AND
static java.lang.String	ANY_TYPE_LIMIT
static java.lang.String	ASCENDING
static java.lang.String	BEA_SQL_LIKE
static java.lang.String	DESCENDING
static java.lang.String	EQUAL
static java.lang.String	GREATER_THAN
static java.lang.String	GREATER_THAN_EQUAL
static java.lang.String	LESS_THAN
static java.lang.String	LESS_THAN_EQUAL
static java.lang.String	MATCHES
static java.lang.String	NOT
static java.lang.String	NOT_EQUAL
static java.lang.String	OR

Constructor Summary

FilterXQuery()

Method Summary

void	addFilter(java.lang.String appliesTo, Filter filter)
void	addFilter(java.lang.String appliesTo, Filter f1, Filter f2, java.lang.String op)
void	addFilter(java.lang.String appliesTo, java.lang.String field, java.lang.String operator, java.lang.String value) Creates a filter and adds it to the list of filters.
void	addFilter(java.lang.String appliesTo, java.lang.String field, java.lang.String operator, java.lang.String value, boolean everyChild)
void	addOrderBy(java.lang.String appliesTo, java.lang.String field, java.lang.String sort) Adds the sort crieteria to the object specified by the appliesTo argument.
Filter	createFilter(Filter f1, Filter f2, java.lang.String operator) This method will create a compound filter.
Filter	createFilter(java.lang.String field, java.lang.String operator, java.lang.String value) Creates a filter that can be later applied to any of the objects in the hierarchy of the field path, e.g., either to CUSTOMER or ORDER if the field is CUSTOMER/ORDER/TOTAL_ORDER_AMOUNT.
Filter	createFilter(java.lang.String field, java.lang.String operator, java.lang.String value, boolean everyChild)
ExternalVariables	getExternalVariables() gets the ExternalVariables
void	setExternalVariables(ExternalVariables v) set the ExternalVariables containing the list of external variables which can be used in filter/limit.
void	setLimit(java.lang.String appliesTo, java.lang.String max) Associates the maximum number of entries to return of the element specified by the appliesTo argument.
org.openuri.www.FilterXQuery	toProxy()

Methods inherited from class java.lang.Object

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

Field Detail

LESS_THAN

public static final java.lang.String LESS_THAN

See Also:

Constant Field Values

GREATER_THAN

public static final java.lang.String GREATER_THAN

See Also:

Constant Field Values

LESS_THAN_EQUAL

public static final java.lang.String LESS_THAN_EQUAL

See Also:

Constant Field Values

GREATER_THAN_EQUAL

public static final java.lang.String GREATER_THAN_EQUAL

See Also:

Constant Field Values

EQUAL

public static final java.lang.String EQUAL

See Also:

Constant Field Values

NOT_EQUAL

public static final java.lang.String NOT_EQUAL

See Also:

Constant Field Values

AND

public static final java.lang.String AND

See Also:

Constant Field Values

OR

public static final java.lang.String OR

See Also:

Constant Field Values

NOT

public static final java.lang.String NOT

See Also:

Constant Field Values

BEA_SQL_LIKE

public static final java.lang.String BEA_SQL_LIKE

See Also:

Constant Field Values

MATCHES

public static final java.lang.String MATCHES

See Also:

Constant Field Values

ASCENDING

public static final java.lang.String ASCENDING

See Also:

Constant Field Values

DESCENDING

public static final java.lang.String DESCENDING

See Also:

Constant Field Values

ANY_TYPE_LIMIT

public static final java.lang.String ANY_TYPE_LIMIT

See Also:

Constant Field Values

Constructor Detail

FilterXQuery

public FilterXQuery()

Method Detail

createFilter

public Filter createFilter(java.lang.String field,
                           java.lang.String operator,
                           java.lang.String value)

Creates a filter that can be later applied to any of the objects in the hierarchy of the field path, e.g., either to CUSTOMER or ORDER if the field is CUSTOMER/ORDER/TOTAL_ORDER_AMOUNT.

Parameters:

field - Path relative to document element.

operator - This is an operator ( <,<=,>,>=,=,!=) supported by XQuery directly on field (XAPTH).

value - Value against which the field will be compared. Provide necessary quotes if required.

Returns:

return the filter object. This filter can be applied to any of the object in the hierarchy of the field.

createFilter

public Filter createFilter(java.lang.String field,
                           java.lang.String operator,
                           java.lang.String value,
                           boolean everyChild)

Parameters:

everyChild - This flag is false by default. This is applicable only if the field belongs to one of the child objects in the hierarchy and this filter is applied to the parent object. If this flag is true it will return parent object only if the filter condition is satisfied by all the children of the parent object.

See Also:

createFilter(String field, String operator, String value)

createFilter

public Filter createFilter(Filter f1,
                           Filter f2,
                           java.lang.String operator)

This method will create a compound filter.

Parameters:

f1 - Filter object created by any of the createFilter Method.

f2 - Filter object created by any of the createFilter Method.

operator - Logical operator (and, or, not). For not operator, f2 will not be used and can be set to null.

Returns:

- A Filter Object.

addFilter

public void addFilter(java.lang.String appliesTo,
                      java.lang.String field,
                      java.lang.String operator,
                      java.lang.String value)

Creates a filter and adds it to the list of filters.

Parameters:

appliesTo - String XPath (relative to document element) to which the filter is applied.

See Also:

for details

addFilter

public void addFilter(java.lang.String appliesTo,
                      java.lang.String field,
                      java.lang.String operator,
                      java.lang.String value,
                      boolean everyChild)

See Also:

addFilter(String appliesTo, String field, String operator, String value), createFilter(String field, String operator, String value, boolean everyChild)

addFilter

public void addFilter(java.lang.String appliesTo,
                      Filter f1,
                      Filter f2,
                      java.lang.String op)

See Also:

addFilter(String appliesTo, String field, String operator, String value), createFilter(Filter f1, Filter f2, String operator)

addFilter

public void addFilter(java.lang.String appliesTo,
                      Filter filter)

See Also:

addFilter(String appliesTo, String field, String operator, String value), createFilter(Filter f1, Filter f2, String operator)

addOrderBy

public void addOrderBy(java.lang.String appliesTo,
                       java.lang.String field,
                       java.lang.String sort)

Adds the sort crieteria to the object specified by the appliesTo argument.

Parameters:

appliesTo - String XPath relative to document Element

field - String fieldName (relative (not the full path) to 'appliesTo' object)

sort - sort criteria (ascending/descending)

setLimit

public void setLimit(java.lang.String appliesTo,
                     java.lang.String max)

Associates the maximum number of entries to return of the element specified by the appliesTo argument.

Parameters:

appliesTo - String XPath ( relative to document element) to which the filter is applied.

max - $variable declared in ExternalVariables OR int value specified in string e.g. "2"

setExternalVariables

public void setExternalVariables(ExternalVariables v)

set the ExternalVariables containing the list of external variables which can be used in filter/limit.

Parameters:

v - ExternalVariables

getExternalVariables

public ExternalVariables getExternalVariables()

gets the ExternalVariables

Returns:

the ExternalVariables object

toProxy

public org.openuri.www.FilterXQuery toProxy()