Package org.zkoss.zk.xel.impl

Class Utils

java.lang.Object

org.zkoss.zk.xel.impl.Utils

public class Utils
extends Object

Utilities to handle the metainfo.

Since:

3.0.6

Author:

tomyeh

Field Summary

Fields

Modifier and Type	Field	Description
static final int	LIST	Used with parseComposite(java.lang.String, java.lang.Class, int) to indicate the expression is a vector, i.e., a list separated with comma.
static final int	MAP	Used with parseComposite(java.lang.String, java.lang.Class, int) to indicate the expression is a map, i.e., a map paired with equal and separated with comma.
static final int	SCALAR	Used with parseComposite(java.lang.String, java.lang.Class, int) to indicate the expression is a scalar value.

Constructor Summary

Constructors

Constructor	Description
Utils()

Method Summary

Modifier and Type	Method	Description
static Object	evaluateComposite(Evaluator eval, Component comp, Object expr)	Evaluates the composite expression parsed by parseComposite(java.lang.String, java.lang.Class, int) against a component.
static Object	evaluateComposite(Evaluator eval, Page page, Object expr)	Evaluates the composite expression parsed by parseComposite(java.lang.String, java.lang.Class, int) against a page.
static Object	parseComposite(String expr, Class expcls, int type)	Parses an expression which could a scalar, vector or map, depending on the specified type.
static ExValue[]	parseList(String expr, Class expcls, boolean ignoreEmpty)	Parses a list of expressions that is separated by comma.

Methods inherited from class java.lang.Object

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

Field Details

SCALAR

public static final int SCALAR

Used with parseComposite(java.lang.String, java.lang.Class, int) to indicate the expression is a scalar value. In other words, it won't handle it specially. If a

See Also:

• Constant Field Values

LIST

public static final int LIST

Used with parseComposite(java.lang.String, java.lang.Class, int) to indicate the expression is a vector, i.e., a list separated with comma. Example: "first, ${second}".

See Also:

• Constant Field Values

MAP

public static final int MAP

Used with parseComposite(java.lang.String, java.lang.Class, int) to indicate the expression is a map, i.e., a map paired with equal and separated with comma. Example: "one=first, two=${second}".

See Also:

• Constant Field Values

Constructor Details

Utils

public Utils()

Method Details

parseList

public static ExValue[] parseList(String expr,
 Class expcls,
 boolean ignoreEmpty)

Parses a list of expressions that is separated by comma. For example, parseList("${a}, b, ${c}", Object.class) will return a three-element array.

Parameters:

ignoreEmpty - whether to return null if expr is an empty expression.

Returns:

an array of the parsed expressions (at least with one element), or null if expr is null.

See Also:

• parseComposite(java.lang.String, java.lang.Class, int)

parseComposite

public static Object parseComposite(String expr,
 Class expcls,
 int type)

Parses an expression which could a scalar, vector or map, depending on the specified type.

If type is SCALAR, it is a simple expression and no special parsing happens. For example, "a, ${b}" will be evaluated to "a, boy" if b is "boy" if evaluateComposite(org.zkoss.zk.xel.Evaluator, org.zkoss.zk.ui.Component, java.lang.Object) is called.

If type is LIST, the expression is a list separated with comma. For example, "a, ${b}" will be evaluated to a list with two elements: "a" and "boy". It is similar to parseList(java.lang.String, java.lang.Class, boolean).

If type is MAP, the expression is a list of paired entries. For example, "a=apple, b=${b}" will be evaluated to a map with two entries, ("a", "apple") and ("b", "boy").

Parameters:

type - one of SCALAR, LIST and MAP.

Returns:

ExValue if SCALAR, ExValue[] if LIST, Map(String, ExValue) if MAP, or null if expr is null. To evaluate it, invoke evaluateComposite(org.zkoss.zk.xel.Evaluator, org.zkoss.zk.ui.Component, java.lang.Object) by passing the returned value as its expr argument.

evaluateComposite

public static Object evaluateComposite(Evaluator eval,
 Component comp,
 Object expr)

Evaluates the composite expression parsed by parseComposite(java.lang.String, java.lang.Class, int) against a component.

evaluateComposite

public static Object evaluateComposite(Evaluator eval,
 Page page,
 Object expr)

Evaluates the composite expression parsed by parseComposite(java.lang.String, java.lang.Class, int) against a page.