Refactoring Status Context Viewers
Identifier:
org.eclipse.ltk.ui.refactoring.statusContextViewers
Since:
3.0
Description:
This extension point is used to define a special viewer capable to present the context of a refactoring status entry to the user. The reader of the extension point provides the following predefined variables which can be accessed during expression evaluation using the <with variable="..."/> tag:
- context
- the context object managed by the refactoring status entry that is to be presented
in the user interface.
Variables can be accessed using the <with variable="..."/> expression. The default variable used during expression evaluation is bound to the context variable.
Configuration Markup:
<!ELEMENT extension (
statusContextViewer*)>
<!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 statusContextViewer (
enablement)>
<!ATTLIST statusContextViewer
id CDATA #REQUIRED
class CDATA #REQUIRED
>
-
id - unique identifier for the status context viewer.
-
class - the name of the class that provides the implementation.
<!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.
<!ELEMENT not (
not |
and |
or |
instanceof |
test |
systemTest |
equals |
count |
with |
resolve |
adapt |
iterate |
reference)>
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 example below contributes a status context viewer for FileStatusContext objects.
<extension point=
"org.eclipse.ltk.ui.refactoring.statusContextViewers"
>
<statusContextViewer
class=
"org.eclipse.ltk.internal.ui.refactoring.FileStatusContextViewer"
id=
"org.eclipse.ltk.internal.ui.refactoring.fileStatusContextViewer"
>
<enablement>
<instanceof value=
"org.eclipse.ltk.core.refactoring.FileStatusContext"
/>
</enablement>
</statusContextViewer>
</extension>
Copyright (c) 2001, 2004 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