Eclipse Plug-in Developer Guide
Previous Page	Home	Next Page

Platform Plug-in Developer Guide Reference Extension Points Reference

Property Pages

Identifier:

org.eclipse.ui.propertyPages

Description:

This extension point is used to add additional property page for objects of a given type. Once defined, these property pages will appear in the Properties Dialog for objects of that type.

A property page is a user friendly way to interact with the properties of an object. Unlike the Properties view, which restricts the space available for editing an object property, a property page may benefit from the freedom to define larger, more complex controls with labels, icons, etc. Properties which logically go together may also be clustered in a page, rather than scattered in the property sheet. However, in most applications it will be appropriate to expose some properties of an object via the property sheet and some via the property pages.

Property pages are shown in a dialog box that is normally visible when the "Properties" menu item is selected on a pop-up menu for an object. In addition to the object class, the name filter can optionally be supplied to register property pages only for specific object types.

If these filtering mechanisms are inadequate a property page may use the filter mechanism. In this case the attributes of the target object are described in a series of key value pairs. The attributes which apply to the selection are type specific and beyond the domain of the workbench itself, so the workbench will delegate filtering at this level to the actual selection.

Configuration Markup:

<!ELEMENT extension ( page*)>

<!ATTLIST extension

point CDATA #REQUIRED

id CDATA #IMPLIED

name CDATA #IMPLIED

point - a fully qualified identifier of the target extension point
id - an optional identifier of the extension instance
name - an optional name of the extension instance

<!ELEMENT page ( filter* , keywordReference* , enabledWhen?)>

<!ATTLIST page

id CDATA #REQUIRED

name CDATA #REQUIRED

icon CDATA #IMPLIED

objectClass CDATA #IMPLIED

class CDATA #REQUIRED

nameFilter CDATA #IMPLIED

adaptable (true | false)

category IDREF #IMPLIED

The page is the specification of the implementation and appearance of the page.

id - a unique name that will be used to identify this page
name - a translatable name that will be used in the UI for this page
icon - a relative path to an icon that will be used in the UI in addition to the page name
Deprecated objectClass - a fully qualified name of the class for which the page is registered. This class does not need to implement IAdaptable. Objects that are not an instance of IAdaptable will be wrappered in an IAdaptable before being sent to the property page's instance (an org.eclipse.ui.IWorkbenchPropertyPage).
Deprecated in Eclipse 3.3. Use the instanceOf or adapt element of the enabledWhen element instead. If duplicate page definitions were previously used to register the page for multiple objectClass types, these should be combined into one page definition using multiple instanceOf elements combined inside an or element
class - a fully qualified name of the class that implements org.eclipse.ui.IWorkbenchPropertyPage.
nameFilter - an optional attribute that allows registration conditional on wild card match applied to the target object name.
Deprecated adaptable - a flag that indicates if types that adapt to IResource should use this property page. This flag is used if objectClass adapts to IResource. Default value is false.
Deprecated in Eclipse 3.3. Use adapt sub element of the enabledWhen element instead
NOTE: The adaptable attribute will attempt adapt an object to org.eclipse.core.resources.IResource before referencing the types registered in Platform#getAdaptorManager. The enabledWhen element has no special case tests for org.eclipse.core.resources.IResource and uses Platform#getAdaptorManager to look up adaptable types. These can be registered using the org.eclipse.core.runtime.adaptors extension point.
category - A path indicating the location of the page in the properties tree. The path may either be a parent node ID or a sequence of IDs separated by '/', representing the full path from the root node.

<!ELEMENT filter EMPTY>

<!ATTLIST filter

name CDATA #REQUIRED

value CDATA #REQUIRED

This element is used to evaluate the attribute state of each object in the current selection. A match only if each object in the selection has the specified attribute state. Each object in the selection must implement, or adapt to, org.eclipse.ui.IActionFilter.

name - the name of an object attribute.
value - the value of an object attribute. In combination with the name attribute, the name value pair is used to define the target object for a property page.

<!ELEMENT keywordReference EMPTY>

<!ATTLIST keywordReference

id IDREF #IMPLIED

A reference by a property page to a keyword. See the keywords extension point.

id - The id of the keyword being referred to.

The enabled when element specifies the conditions under which this property page will be added to the properties dialog.

<!ELEMENT enablement ( not , and , or , instanceof , test , systemTest , equals , count , with , resolve , adapt , iterate , reference)*>

A generic root element. The element can be used inside an extension point to define its enablement expression. The children of an enablement expression are combined using the and operator.

This element represent a NOT operation on the result of evaluating it's sub-element expression.

<!ELEMENT and ( not , and , or , instanceof , test , systemTest , equals , count , with , resolve , adapt , iterate , reference)*>

This element represent an AND operation on the result of evaluating all it's sub-elements expressions.

<!ELEMENT or ( not , and , or , instanceof , test , systemTest , equals , count , with , resolve , adapt , iterate , reference)*>

This element represent an OR operation on the result of evaluating all it's sub-element expressions.

<!ELEMENT instanceof EMPTY>

<!ATTLIST instanceof

value CDATA #REQUIRED

This element is used to perform an instanceof check of the object in focus. The expression returns EvaluationResult.TRUE if the object's type is a sub type of the type specified by the attribute value. Otherwise EvaluationResult.FALSE is returned.

value - a fully qualified name of a class or interface.

<!ELEMENT test EMPTY>

<!ATTLIST test

property CDATA #REQUIRED

args CDATA #IMPLIED

value CDATA #IMPLIED

forcePluginActivation (true | false)

This element is used to evaluate the property state of the object in focus. The set of testable properties can be extended using the propery tester extension point. The test expression returns EvaluationResult.NOT_LOADED if the property tester doing the actual testing isn't loaded yet and the attribute forcePluginActivation is set to false. If forcePluginActivation is set to true and the evaluation context used to evaluate this expression support plug-in activation then evaluating the property will result in activating the plug-in defining the tester.

property - the name of an object's property to test.
args - additional arguments passed to the property tester. Multiple arguments are separated by commas. Each individual argument is converted into a Java base type using the same rules as defined for the value attribute of the test expression.
value - the expected value of the property. Can be omitted if the property is a boolean property. The test expression is supposed to return EvaluationResult.TRUE if the property matches the value and EvaluationResult.FALSE otherwise. The value attribute is converted into a Java base type using the following rules:
- the string "true" is converted into Boolean.TRUE
- the string "false" is converted into Boolean.FALSE
- if the string contains a dot then the interpreter tries to convert the value into a Float object. If this fails the string is treated as a java.lang.String
- if the string only consists of numbers then the interpreter converts the value in an Integer object.
- in all other cases the string is treated as a java.lang.String
- the conversion of the string into a Boolean, Float, or Integer can be suppressed by surrounding the string with single quotes. For example, the attribute value="'true'" is converted into the string "true"
forcePluginActivation - a flag indicating whether the plug-in contributing the property tester should be loaded if necessary. As such, this flag should be used judiciously, in order to avoid unnecessary plug-in activations. Most clients should avoid setting this flag to true. This flag is only honored if the evaluation context used to evaluate this expression allows plug-in activation. Otherwise the flag is ignored and no plug-in loading takes place.

<!ELEMENT systemTest EMPTY>

<!ATTLIST systemTest

property CDATA #REQUIRED

value CDATA #REQUIRED

Tests a system property by calling the System.getProperty method and compares the result with the value specified through the value attribute.

property - the name of an system property to test.
value - the expected value of the property. The value is interpreted as a string value.

<!ELEMENT equals EMPTY>

<!ATTLIST equals

value CDATA #REQUIRED

This element is used to perform an equals check of the object in focus. The expression returns EvaluationResult.TRUE if the object is equal to the value provided by the attribute value. Otherwise EvaluationResult.FALSE is returned.

value - the expected value. The value provided as a string is converted into a Java base type using the same rules as for the value attribute of the test expression.

<!ELEMENT count EMPTY>

<!ATTLIST count

value CDATA #REQUIRED

This element is used to test the number of elements in a collection.

value - an expression to specify the number of elements in a list. Following wildcard characters can be used:

*

any number of elements

?

no elements or one element

+

one or more elements

!

no elements

-N)

less than N elements

(N-

greater than N elements

integer value

the list must contain the exact number of elements

<!ELEMENT with ( not , and , or , instanceof , test , systemTest , equals , count , with , resolve , adapt , iterate , reference)*>

<!ATTLIST with

variable CDATA #REQUIRED

This element changes the object to be inspected for all its child element to the object referenced by the given variable. If the variable can not be resolved then the expression will throw an ExpressionException when evaluating it. The children of a with expression are combined using the and operator.

variable - the name of the variable to be used for further inspection. It is up to the evaluator of an extension point to provide the variable in the variable pool.

<!ELEMENT resolve ( not , and , or , instanceof , test , systemTest , equals , count , with , resolve , adapt , iterate , reference)*>

<!ATTLIST resolve

variable CDATA #REQUIRED

args CDATA #IMPLIED

This element changes the object to be inspected for all its child element to the object referenced by the given variable. If the variable can not be resolved then the expression will throw an ExpressionException when evaluating it. The children of a resolve expression are combined using the and operator.

variable - the name of the variable to be resolved. This variable is then used as the object in focus for child element evaluation. It is up to the evaluator of an extension point to provide a corresponding variable resolver (see IVariableResolver) through the evaluation context passed to the root expression element when evaluating the expression.
args - additional arguments passed to the variable resolver. Multiple arguments are separated by commas. Each individual argument is converted into a Java base type using the same rules as defined for the value attribute of the test expression.

<!ELEMENT adapt ( not , and , or , instanceof , test , systemTest , equals , count , with , resolve , adapt , iterate , reference)*>

<!ATTLIST adapt

type CDATA #REQUIRED

This element is used to adapt the object in focus to the type specified by the attribute type. The expression returns not loaded if either the adapter or the type referenced isn't loaded yet. It throws an ExpressionException during evaluation if the type name doesn't exist at all. The children of an adapt expression are combined using the and operator.

type - the type to which the object in focus is to be adapted.

<!ELEMENT iterate ( not , and , or , instanceof , test , systemTest , equals , count , with , resolve , adapt , iterate , reference)*>

<!ATTLIST iterate

operator (or|and)

ifEmpty (true | false)

This element is used to iterate over a variable that is of type java.util.Collection, or a variable that adapts to org.eclipse.core.expressions.IIterable. If the object in focus is not one of the above then a CoreException with an ExpressionStatus will be thrown while evaluating the expression. The child expressions of an iterate expression are combined using the and operator.

operator - either "and" or "or". The operator defines how the results of all the child expressions applied to each child of the Collection or IIterable will be combined and what (if any) short circuit evaluation will be used. If not specified, "and" will be used.
ifEmpty - the value return from the iterate expression if the collection is empty. If not specified then true is returned when the operator equals "and" and false is return if the operator equals "or".

<!ELEMENT reference EMPTY>

<!ATTLIST reference

definitionId IDREF #REQUIRED

This element is used to reference an expression from the org.eclipse.core.expressions.definitions extension point. The expression definition will be evaluated within the current expression element using the current evaluation context.

definitionId - The unique id of an expression from org.eclipse.core.expressions.definitions.

Examples:

The following is an example of the property page definition:


   <extension point=
"org.eclipse.ui.propertyPages"
> 
        <page 
            id=
"com.xyz.projectPage"
 
            name=
"XYZ Java Properties"
 
            class=
"com.xyz.ppages.JavaPropertyPage"
 
            nameFilter=
"*.java"
> 
            <enabledWhen>
             <instanceof
                  value=
"org.eclipse.core.resources.IFile"
>
             </instanceof>
          </enabledWhen>
            <filter name=
"readOnly"
 value=
"true"
/> 
        </page> 
    </extension>

Supplied Implementation:

Some objects provided by the workbench may have property pages registered. Plug-ins are allowed to add more property pages for these objects. Property pages are not limited to workbench resources: all objects showing up in the workbench (even domain specific objects created by the plug-ins) may have property pages and other plug-ins are allowed to register property pages for them.

Copyright (c) 2002, 2006 IBM Corporation and others.
All rights reserved. This program and the accompanying materials are made available under the terms of the Eclipse Public License v1.0 which accompanies this distribution, and is available at https://www.eclipse.org/legal/epl-v10.html