- From: Toufic Boubez via cvs-syncmail <cvsmail@w3.org>
- Date: Tue, 19 Jun 2007 06:47:50 +0000
- To: public-ws-policy-eds@w3.org
Update of /sources/public/2006/ws/policy
In directory hutz:/tmp/cvs-serv32105
Modified Files:
ws-policy-guidelines.xml ws-policy-guidelines.html
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Implemented place holder for Editors' action 249 to lock the document this week
Index: ws-policy-guidelines.html
===================================================================
RCS file: /sources/public/2006/ws/policy/ws-policy-guidelines.html,v
retrieving revision 1.77
retrieving revision 1.78
diff -u -d -r1.77 -r1.78
--- ws-policy-guidelines.html 19 Jun 2007 03:02:59 -0000 1.77
+++ ws-policy-guidelines.html 19 Jun 2007 06:47:47 -0000 1.78
@@ -139,9 +139,9 @@
5.5.1 <a href="#doc-ignorable-assertions">Assertions and Ignorable Behavior</a><br>
5.5.2 <a href="#XML-ignorable-assertions">XML Outline for Ignorable </a><br>
5.6 <a href="#optional-policy-assertion">Designating Optional Behaviors</a><br>
- 5.6.1 <a href="#d3e768">Optional behavior in Compact authoring</a><br>
- 5.6.2 <a href="#d3e808">Optional behavior at runtime</a><br>
- 5.6.2.1 <a href="#d3e853">Example</a><br>
+ 5.6.1 <a href="#d3e783">Optional behavior in Compact authoring</a><br>
+ 5.6.2 <a href="#d3e823">Optional behavior at runtime</a><br>
+ 5.6.2.1 <a href="#d3e868">Example</a><br>
5.7 <a href="#levels-of-abstraction">Considerations for Policy Attachment in WSDL </a><br>
5.8 <a href="#interrelated-domains">Interrelated domains</a><br>
6. <a href="#versioning-policy-assertions">Versioning Policy Assertions</a><br>
@@ -209,8 +209,8 @@
the question.
</p></div><div class="div1">
<h2><a name="best-practices-list" id="best-practices-list"></a>2. List of Best Practice Statements</h2><p>The following Best Practices appear in this document with discussion and examples, and are summarized here for quick reference:</p><ul><li><p><a href="#bp-assertion-semantics"><b>1. Semantics Independent of
- Attachment Mechanisms</b></a></p></li><li><p><a href="#bp-semantics-and-form"><b>2. Semantics Independent of the Form</b></a></p></li><li><p><a href="#bp-assertion-start"><b>3. Start with Simple Assertion</b></a></p></li><li><p><a href="#bp-unique-qnames"><b>4. Use Unique QNames</b></a></p></li><li><p><a href="#XMLOutline"><b>5. Provide an XML Outline</b></a></p></li><li><p><a href="#AssertionDefinitions"><b>6. Specify Semantics Clearly</b></a></p></li><li><p><a href="#bp-not-necessary-to-understand-a-message"><b>7. Not Necessary to Understand a Message</b></a></p></li><li><p><a href="#bp-assertion-duplication"><b>8. Avoid Duplication of Assertions</b></a></p></li><li><p><a href="#bp-assertion-parameters"><b>9. Use Parameters for Useful
- Information</b></a></p></li><li><p><a href="#bp-dependent-behaviors"><b>10. Use Nested Assertions for Dependent Behaviors</b></a></p></li><li><p><a href="#bp-declare-nested-assertions"><b>11. Enumerate Nested Assertions</b></a></p></li><li><p><a href="#bp-discourage-domain-specific-intersection"><b>12. Discourage Domain Specific Intersection</b></a></p></li><li><p><a href="#DefineIgnorable"><b>13. Assertions Document Ignorable Behavior</b></a></p></li><li><p><a href="#ignorableAssertions"><b>14. Ignorable Attribute in XML</b></a></p></li><li><p><a href="#bp-assertion-xml-allow-optional"><b>15. Assertion XML should allow use of wsp:Optional attribute</b></a></p></li><li><p><a href="#bp-assertion-description-explicitly-allow-optional"><b>16. Use the wsp:Optional attribute to indicate optional</b></a></p></li><li><p><a href="#bp-limit-optional-assertions"><b>17. Limit use of Optional Assertions</b></a></p></li><li><p><a href="#bp-entire-mep-for-optional"><b>18. Consider entire message exchange pattern whn specifying Assertions that may be optional</b></a></p></li><li><p><a href="#bp-indicate-optional-assertion-use"><b>19. Indicate use of an Optional Assertion</b></a></p></li><li><p><a href="#bp-WSDL-policy-subject"><b>20. Assertion Authors Should Specify Policy Subject(s)</b></a></p></li><li><p><a href="#bp-WSDL-policy-subject-Granularity"><b>21. Choose the Most Granular Policy Subject</b></a></p></li><li><p><a href="#bp-WSDL-multiple-policy-subjects"><b>22. Define Semantics of Attachment to Multiple Policy Subjects</b></a></p></li><li><p><a href="#bp-WSDL-preferred-attachment-point"><b>23. Specify Preferred Attachment Point for an Assertion</b></a></p></li><li><p><a href="#bp-WSDL-policy-multiple-instance-semantics"><b>24. Describe Semantics of Multiple Assertions of Same Type</b></a></p></li><li><p><a href="#bp-specify-composition"><b>25. Specify Composition with Related Assertions</b></a></p></li><li><p><a href="#bp-independent-assertions"><b>26. Use Independent Assertions for Different Versions of a Bhavior</b></a></p></li><li><p><a href="#bp-policy-subject-change"><b>27. Change of the Policy Subject Over Time</b></a></p></li></ul></div><div class="div1">
+ Attachment Mechanisms</b></a></p></li><li><p><a href="#bp-compatibility-tests"><b>2. Behaviors Relevant to Compatibility Tests</b></a></p></li><li><p><a href="#bp-semantics-and-form"><b>3. Semantics Independent of the Form</b></a></p></li><li><p><a href="#bp-assertion-start"><b>4. Start with Simple Assertion</b></a></p></li><li><p><a href="#bp-unique-qnames"><b>5. Use Unique QNames</b></a></p></li><li><p><a href="#XMLOutline"><b>6. Provide an XML Outline</b></a></p></li><li><p><a href="#AssertionDefinitions"><b>7. Specify Semantics Clearly</b></a></p></li><li><p><a href="#bp-not-necessary-to-understand-a-message"><b>8. Not Necessary to Understand a Message</b></a></p></li><li><p><a href="#bp-assertion-duplication"><b>9. Avoid Duplication of Assertions</b></a></p></li><li><p><a href="#bp-assertion-parameters"><b>10. Use Parameters for Useful
+ Information</b></a></p></li><li><p><a href="#bp-dependent-behaviors"><b>11. Use Nested Assertions for Dependent Behaviors</b></a></p></li><li><p><a href="#bp-declare-nested-assertions"><b>12. Enumerate Nested Assertions</b></a></p></li><li><p><a href="#bp-discourage-domain-specific-intersection"><b>13. Discourage Domain Specific Intersection</b></a></p></li><li><p><a href="#DefineIgnorable"><b>14. Assertions Document Ignorable Behavior</b></a></p></li><li><p><a href="#ignorableAssertions"><b>15. Ignorable Attribute in XML</b></a></p></li><li><p><a href="#bp-assertion-xml-allow-optional"><b>16. Assertion XML should allow use of wsp:Optional attribute</b></a></p></li><li><p><a href="#bp-assertion-description-explicitly-allow-optional"><b>17. Use the wsp:Optional attribute to indicate optional</b></a></p></li><li><p><a href="#bp-limit-optional-assertions"><b>18. Limit use of Optional Assertions</b></a></p></li><li><p><a href="#bp-entire-mep-for-optional"><b>19. Consider entire message exchange pattern whn specifying Assertions that may be optional</b></a></p></li><li><p><a href="#bp-indicate-optional-assertion-use"><b>20. Indicate use of an Optional Assertion</b></a></p></li><li><p><a href="#bp-WSDL-policy-subject"><b>21. Assertion Authors Should Specify Policy Subject(s)</b></a></p></li><li><p><a href="#bp-WSDL-policy-subject-Granularity"><b>22. Choose the Most Granular Policy Subject</b></a></p></li><li><p><a href="#bp-WSDL-multiple-policy-subjects"><b>23. Define Semantics of Attachment to Multiple Policy Subjects</b></a></p></li><li><p><a href="#bp-WSDL-preferred-attachment-point"><b>24. Specify Preferred Attachment Point for an Assertion</b></a></p></li><li><p><a href="#bp-WSDL-policy-multiple-instance-semantics"><b>25. Describe Semantics of Multiple Assertions of Same Type</b></a></p></li><li><p><a href="#bp-specify-composition"><b>26. Specify Composition with Related Assertions</b></a></p></li><li><p><a href="#bp-independent-assertions"><b>27. Use Independent Assertions for Different Versions of a Bhavior</b></a></p></li><li><p><a href="#bp-policy-subject-change"><b>28. Change of the Policy Subject Over Time</b></a></p></li></ul></div><div class="div1">
<h2><a name="Assertions" id="Assertions"></a>3. What is an Assertion? </h2><p>An assertion is a piece of metadata that describes a
capability related to a specific WS-Policy domain. Sets of domain-specific assertions
are typically defined in a dedicated specification that describes
@@ -395,12 +395,12 @@
assertion specification:
</p><p>
<ul><li><p>The definition of the assertion's semantic
- (See best practice <a href="#AssertionDefinitions"><b>6. Specify Semantics Clearly</b></a>).</p></li><li><p>The specification of the set of valid policy subjects to which an
+ (See best practice <a href="#AssertionDefinitions"><b>7. Specify Semantics Clearly</b></a>).</p></li><li><p>The specification of the set of valid policy subjects to which an
assertion may be attached
- (See best practice <a href="#bp-WSDL-policy-subject"><b>20. Assertion Authors Should Specify Policy Subject(s)</b></a>).</p></li><li><p>The scope of the assertion in the context of a particular policy
+ (See best practice <a href="#bp-WSDL-policy-subject"><b>21. Assertion Authors Should Specify Policy Subject(s)</b></a>).</p></li><li><p>The scope of the assertion in the context of a particular policy
subject (See best practices in Section <a href="#levels-of-abstraction"><b>5.7 Considerations for Policy Attachment in WSDL </b></a>).</p></li><li><p>Any composition considerations if the assertion is used with
other assertions in a context
- (See best practice <a href="#bp-specify-composition"><b>25. Specify Composition with Related Assertions</b></a>).</p></li></ul>
+ (See best practice <a href="#bp-specify-composition"><b>26. Specify Composition with Related Assertions</b></a>).</p></li></ul>
</p><p>
The WS-Policy Attachment specification defines a number of different
policy subjects to which an assertion can be attached. For attaching to
@@ -429,7 +429,12 @@
such as web service protocols that manifest on the wire." - to Section 5.1.
May 9th 07, an issue was opened against G2 - issue
<a href="http://www.w3.org/Bugs/Public/show_bug.cgi?id=4566">4566</a>.
- </td></tr></table></div><div class="div2">
+ </td></tr></table><div class="boxedtext"><p><a name="bp-compatibility-tests" id="bp-compatibility-tests"></a><span class="practicelab">Best
+Practice 2: Behaviors Relevant to Compatibility Tests</span></p><p class="practice">
+ Whenever possible, Assertion Authors should define policy asswertions
+ for behaviors that are relevant to compatibility tests, such as web service
+ protocols that manifest on the wire.
+ </p></div><table border="1" summary="Editorial note"><tr><td align="left" valign="top" width="50%"><b>Editorial note</b></td><td align="right" valign="top" width="50%"> </td></tr><tr><td colspan="2" align="left" valign="top">Place holder.</td></tr></table></div><div class="div2">
<h3><a name="compact-full" id="compact-full"></a>5.2 Authoring Styles </h3><p>WS-Policy supports two different authoring styles, compact form and
normal form. A compact form is one in which an expression consists of
three constructs: an attribute to decorate an assertion (to indicate
@@ -451,7 +456,7 @@
description for a policy assertion should not depend on the style used
to author a policy expression that contains the assertion.
</p><div class="boxedtext"><p><a name="bp-semantics-and-form" id="bp-semantics-and-form"></a><span class="practicelab">Best
-Practice 2: Semantics Independent of the Form</span></p><p class="practice">The semantics of an assertion should be independent of
+Practice 3: Semantics Independent of the Form</span></p><p class="practice">The semantics of an assertion should be independent of
the form (compact or normal form) of policy expressions that contain the
assertion.</p></div><p>
In the example below, the policy expression is shown in its two forms,
@@ -548,7 +553,7 @@
work progresses, one may add more parameters or nested policy assertions
to meet one's interoperability needs.
</p><div class="boxedtext"><p><a name="bp-assertion-start" id="bp-assertion-start"></a><span class="practicelab">Best
-Practice 3: Start with Simple Assertion</span></p><p class="practice">Assertion Authors should start with a simple working assertion
+Practice 4: Start with Simple Assertion</span></p><p class="practice">Assertion Authors should start with a simple working assertion
that allows assertion parameter extensibility. </p></div><p>New Assertion Authors are encouraged to look at <cite><a href="#WS-RM-Policy">Web Services Reliable Messaging Policy</a></cite> to see an example of a
relatively simple domain that has defined three assertions. Assertion Authors are encouraged to look at <cite><a href="#WS-SecurityPolicy">WS-SecurityPolicy</a></cite> to see an example of a complex domain that has been decomposed into a set of policy expressions.
</p></div><div class="div3">
@@ -559,9 +564,9 @@
represent an assertion parameter as a child element (by leveraging natural XML nesting)
or an attribute of an assertion. The general guidelines on when to use XML elements
versus attributes apply is: Use a unique QName to identify a distinct behavior </p><div class="boxedtext"><p><a name="bp-unique-qnames" id="bp-unique-qnames"></a><span class="practicelab">Best
-Practice 4: Use Unique QNames</span></p><p class="practice">Assertion Authors should use a unique QName to identify a distinct behavior.</p></div><p> and provide
+Practice 5: Use Unique QNames</span></p><p class="practice">Assertion Authors should use a unique QName to identify a distinct behavior.</p></div><p> and provide
an XML outline (plus an XML schema document) to specify the syntax of an assertion. </p><div class="boxedtext"><p><a name="XMLOutline" id="XMLOutline"></a><span class="practicelab">Best
-Practice 5: Provide an XML Outline</span></p><p class="practice">Assertion authors should provide an XML outline plus an XML schema to
+Practice 6: Provide an XML Outline</span></p><p class="practice">Assertion authors should provide an XML outline plus an XML schema to
specify the syntax of an assertion.
</p></div><p> An example of this method (below) is given in the Web Services Reliable Messaging Policy document. [<cite><a href="#WS-RM-Policy">Web Services Reliable Messaging Policy</a></cite>]
</p><div class="exampleOuter"><div class="exampleInner"><pre>
@@ -598,7 +603,7 @@
</sp:IssuedToken>
</pre></div></div><div class="boxedtext"><p><a name="AssertionDefinitions" id="AssertionDefinitions"></a><span class="practicelab">Best
-Practice 6: Specify Semantics Clearly</span></p><p class="practice"> Assertion authors should clearly and completely specify the
+Practice 7: Specify Semantics Clearly</span></p><p class="practice"> Assertion authors should clearly and completely specify the
semantics of a policy assertion.
</p></div></div><div class="div3">
<h4><a name="self-describing" id="self-describing"></a>5.3.3 Self Describing Messages </h4><p> WS-Policy is intended to communicate the requirements, capabilities and
@@ -631,7 +636,7 @@
their assertions by specifying additional properties, headers,
etc. that must be present in a message as part of their assertion design.
</p><div class="boxedtext"><p><a name="bp-not-necessary-to-understand-a-message" id="bp-not-necessary-to-understand-a-message"></a><span class="practicelab">Best
-Practice 7: Not Necessary to Understand a Message</span></p><p class="practice">Assertion Authors should not define policy assertions to represent information that is necessary to understand a message.</p></div><p>For example, if the details of a message's encryption ( e.g., the cipher used, etc) are expressed
+Practice 8: Not Necessary to Understand a Message</span></p><p class="practice">Assertion Authors should not define policy assertions to represent information that is necessary to understand a message.</p></div><p>For example, if the details of a message's encryption ( e.g., the cipher used, etc) are expressed
in policy that isn't attached to the message, it isn't possible
to later decipher it. This is very different from expressing, in
policy, what ciphers (and so forth) are supported by a particular
@@ -661,7 +666,7 @@
</p><p>It is the responsibility of the Assertion Authors to avoid duplication of assertions.
A review by a broad community is the best way to ensure that the granularity of a set
of domain assertions is appropriate.</p><div class="boxedtext"><p><a name="bp-assertion-duplication" id="bp-assertion-duplication"></a><span class="practicelab">Best
-Practice 8: Avoid Duplication of Assertions</span></p><p class="practice">Assertion Authors should reuse an existing assertion (rather than create a new one) whenever possible.</p></div></div></div><div class="div2">
+Practice 9: Avoid Duplication of Assertions</span></p><p class="practice">Assertion Authors should reuse an existing assertion (rather than create a new one) whenever possible.</p></div></div></div><div class="div2">
<h3><a name="comparison" id="comparison"></a>5.4 Comparison of Nested and Parameterized Assertions</h3><p>There are two different ways to provide additional information in an
assertion beyond its type. We cover these two cases below followed by a
comparison of these approaches targeting when to use either of the approach.
@@ -676,7 +681,7 @@
domain specific processing for policy intersection.</p><p>In the XML representation of a policy assertion, the child elements
and attributes of the assertion excluding child elements and attributes
from the policy language namespace name are the assertion parameters.</p><div class="boxedtext"><p><a name="bp-assertion-parameters" id="bp-assertion-parameters"></a><span class="practicelab">Best
-Practice 9: Use Parameters for Useful
+Practice 10: Use Parameters for Useful
Information</span></p><p class="practice">Assertion Authors should represent useful (or additional)
information necessary for engaging the behavior represented by a policy
assertion as assertion parameters.
@@ -706,10 +711,10 @@
that are allowed. There is one caveat to watch out for: policy assertions
with deeply nested policy can greatly increase the complexity of a policy and should be
avoided when they are not needed.</p><div class="boxedtext"><p><a name="bp-dependent-behaviors" id="bp-dependent-behaviors"></a><span class="practicelab">Best
-Practice 10: Use Nested Assertions for Dependent Behaviors</span></p><p class="practice">Assertion Authors should represent dependent behaviors that are relevant
+Practice 11: Use Nested Assertions for Dependent Behaviors</span></p><p class="practice">Assertion Authors should represent dependent behaviors that are relevant
to a compatibility test and apply to the same policy subject using
nested policy assertions.</p></div><div class="boxedtext"><p><a name="bp-declare-nested-assertions" id="bp-declare-nested-assertions"></a><span class="practicelab">Best
-Practice 11: Enumerate Nested Assertions</span></p><p class="practice">If there is a nested policy expression, then the Assertion Authors
+Practice 12: Enumerate Nested Assertions</span></p><p class="practice">If there is a nested policy expression, then the Assertion Authors
should enumerate the nested policy assertions that are allowed.</p></div><p>The main consideration for selecting parameters or nesting
of assertions is that <em>the framework intersection
algorithm processes nested alternatives, but does not consider
@@ -731,7 +736,7 @@
delegated to the specific domain handlers that are not visible
to the WS-Policy framework. However, domain specific intersection processing reduces
interop and increases the burden to implement an assertion.</p><div class="boxedtext"><p><a name="bp-discourage-domain-specific-intersection" id="bp-discourage-domain-specific-intersection"></a><span class="practicelab">Best
-Practice 12: Discourage Domain Specific Intersection</span></p><p class="practice">Assertion authors should only specify domain specific
+Practice 13: Discourage Domain Specific Intersection</span></p><p class="practice">Assertion authors should only specify domain specific
intersection semantics when policy intersection is insufficient.</p></div><p>We will use the WS-SecurityPolicy to illustrate the use of nested assertions.
</p><p>Securing messages is a complex usage scenario. The WS-SecurityPolicy Assertion Authors have defined the
<code>sp:TransportBinding</code> policy assertion to indicate
@@ -826,15 +831,15 @@
of the ignorable attribute.
</p><div class="div3">
<h4><a name="doc-ignorable-assertions" id="doc-ignorable-assertions"></a>5.5.1 Assertions and Ignorable Behavior</h4><div class="boxedtext"><p><a name="DefineIgnorable" id="DefineIgnorable"></a><span class="practicelab">Best
-Practice 13: Assertions Document Ignorable Behavior</span></p><p class="practice"> An assertion description should use the wsp:Ignorable attribute
+Practice 14: Assertions Document Ignorable Behavior</span></p><p class="practice"> An assertion description should use the wsp:Ignorable attribute
to indicate that the behavior indicated by the QName may be ignored by policy intersection.
</p></div></div><div class="div3">
<h4><a name="XML-ignorable-assertions" id="XML-ignorable-assertions"></a>5.5.2 XML Outline for Ignorable </h4><div class="boxedtext"><p><a name="ignorableAssertions" id="ignorableAssertions"></a><span class="practicelab">Best
-Practice 14: Ignorable Attribute in XML</span></p><p class="practice"> An assertion XML outline should allow for the use of the wsp:Ignorable attribute
+Practice 15: Ignorable Attribute in XML</span></p><p class="practice"> An assertion XML outline should allow for the use of the wsp:Ignorable attribute
to indicate ignorable behavior.
</p></div></div></div><div class="div2">
<h3><a name="optional-policy-assertion" id="optional-policy-assertion"></a>5.6 Designating Optional Behaviors</h3><div class="div3">
-<h4><a name="d3e768" id="d3e768"></a>5.6.1 Optional behavior in Compact authoring</h4><p>Optional behaviors represent behaviors that may be engaged by a consumer. When using the
+<h4><a name="d3e783" id="d3e783"></a>5.6.1 Optional behavior in Compact authoring</h4><p>Optional behaviors represent behaviors that may be engaged by a consumer. When using the
compact authoring form for assertions, such behaviors are marked by
using <code>wsp:Optional</code> attribute with a value of
"true". (In order to simplify reference to such assertions,
@@ -849,7 +854,7 @@
the wsp:Optional attribute. Assertion Authors should clearly indicate in the assertion
definition that it is possible to be optional
and to allow the use of the wsp:Optional attribute in the XML definition. </p><div class="boxedtext"><p><a name="bp-assertion-xml-allow-optional" id="bp-assertion-xml-allow-optional"></a><span class="practicelab">Best
-Practice 15: Assertion XML should allow use of wsp:Optional attribute</span></p><p class="practice">An assertion XML outline should allow the use of the wsp:Optional attribute to
+Practice 16: Assertion XML should allow use of wsp:Optional attribute</span></p><p class="practice">An assertion XML outline should allow the use of the wsp:Optional attribute to
indicate optional behaviors.</p></div><p>To give a general example, the definition of assertion syntax for a hypothetical assertion such as SampleAssertion,
should allow attribute extensibility as part of the XML definition, allowing the wsp:Optional attribute to be used:
</p><div class="exampleOuter">
@@ -857,7 +862,7 @@
This is an extensibility mechanism to allow additional attributes to be added to the element, including wsp:Optional.
</pre></div></div><p>The portion of the assertion definition that describes policy subjects and assertion attachment should indicate
that wsp:Optional can be used to indicate that the behavior is optional for the policy subject.</p><div class="boxedtext"><p><a name="bp-assertion-description-explicitly-allow-optional" id="bp-assertion-description-explicitly-allow-optional"></a><span class="practicelab">Best
-Practice 16: Use the wsp:Optional attribute to indicate optional</span></p><p class="practice">Assertion authors should use the wsp:Optional attribute to indicate that a
+Practice 17: Use the wsp:Optional attribute to indicate optional</span></p><p class="practice">Assertion authors should use the wsp:Optional attribute to indicate that a
behavior indicated by a QName is optional for the associated policy subject.</p></div><p>Continuing the example with the hypothetical SampleAssertion, the section on Assertion Attachment should
include discussion of optionality.
</p><div class="exampleOuter">
@@ -865,14 +870,14 @@
it has an Endpoint Policy Subject and must be attached to a wsdl:binding or wsdl:port.
The assertion may be optional when attached to these subjects, allowing use of wsp:Optional.
</pre></div></div></div><div class="div3">
-<h4><a name="d3e808" id="d3e808"></a>5.6.2 Optional behavior at runtime</h4><p>Since optional behaviors indicate optionality for
+<h4><a name="d3e823" id="d3e823"></a>5.6.2 Optional behavior at runtime</h4><p>Since optional behaviors indicate optionality for
both the provider and the consumer, behaviors that must
always be engaged by a consumer must not be marked as
"optional" with a value "true" since this would allow the
consumer to select the policy alternative that does not contain the assertion,
and thus not engaging the behavior.
</p><div class="boxedtext"><p><a name="bp-limit-optional-assertions" id="bp-limit-optional-assertions"></a><span class="practicelab">Best
-Practice 17: Limit use of Optional Assertions</span></p><p class="practice">Assertion Authors should not use optional assertions for behaviors that must be present
+Practice 18: Limit use of Optional Assertions</span></p><p class="practice">Assertion Authors should not use optional assertions for behaviors that must be present
in compatible policy expressions.</p></div><p> The target scope of an optional assertion is an important factor for
Assertion Authors to consider as it determines the
<em>granularity</em> where the behavior is optionally
@@ -904,7 +909,7 @@
assertions and require the use of endpoint policy subject
when message policy subject is used via attachment.
</p><div class="boxedtext"><p><a name="bp-entire-mep-for-optional" id="bp-entire-mep-for-optional"></a><span class="practicelab">Best
-Practice 18: Consider entire message exchange pattern when specifying Assertions that may be optional</span></p><p class="practice">Assertion Authors should associate optional assertions with the appropriate endpoint and use the smallest
+Practice 19: Consider entire message exchange pattern when specifying Assertions that may be optional</span></p><p class="practice">Assertion Authors should associate optional assertions with the appropriate endpoint and use the smallest
possible granularity to limit the degree to which optionality applies.</p></div><p>
Behaviors must be engaged
with respect to messages that are targeted to the provider
@@ -918,9 +923,9 @@
(Such an out of band mechanism is outside the scope of WS-Policy
Framework).
</p><div class="boxedtext"><p><a name="bp-indicate-optional-assertion-use" id="bp-indicate-optional-assertion-use"></a><span class="practicelab">Best
-Practice 19: Indicate use of an Optional Assertion</span></p><p class="practice">When a given behavior may be optional, it must be possible for both message participants to determine that the assertion is selected by both parties,
+Practice 20: Indicate use of an Optional Assertion</span></p><p class="practice">When a given behavior may be optional, it must be possible for both message participants to determine that the assertion is selected by both parties,
either out of band or as reflected by the message content.</p></div><div class="div4">
-<h5><a name="d3e853" id="d3e853"></a>5.6.2.1 Example</h5><p>
+<h5><a name="d3e868" id="d3e868"></a>5.6.2.1 Example</h5><p>
The <cite><a href="#WS-Policy-Primer">Web Services Policy Primer</a></cite> document contains an example that outlines the
use of
<cite><a href="#MTOM">MTOM</a></cite> as an optional behavior that can be engaged by a consumer.
@@ -957,7 +962,7 @@
made using an endpoint then the subject is the endpoint policy subject. </p></li><li><p>If the behavior applies to any message exchange
defined by an operation then the subject is the operation policy subject. </p></li><li><p>If the behavior applies to an input message then
the subject is the message policy subject - similarly for output and fault message policy subjects.</p></li></ul><div class="boxedtext"><p><a name="bp-WSDL-policy-subject" id="bp-WSDL-policy-subject"></a><span class="practicelab">Best
-Practice 20: Assertion Authors Should Specify Policy Subject(s)</span></p><p class="practice">Assertion Authors should specify the set of relevant policy subjects with which
+Practice 21: Assertion Authors Should Specify Policy Subject(s)</span></p><p class="practice">Assertion Authors should specify the set of relevant policy subjects with which
the assertion may be associated. For instance, if a policy assertion is to be used with
WSDL, the assertion description should specify a WSDL policy subject - such as service,
endpoint, operation and message.
@@ -990,7 +995,7 @@
policy attachments to policy subjects of broader scope and granularity
should be done only after careful evaluation.
</p><div class="boxedtext"><p><a name="bp-WSDL-policy-subject-Granularity" id="bp-WSDL-policy-subject-Granularity"></a><span class="practicelab">Best
-Practice 21: Choose the Most Granular Policy Subject</span></p><p class="practice">Assertion Authors should choose the most granular policy subject
+Practice 22: Choose the Most Granular Policy Subject</span></p><p class="practice">Assertion Authors should choose the most granular policy subject
to which the behavior represented by a policy assertion applies.
</p></div><p>
For authoring convenience, Assertion Authors may allow the
@@ -1001,7 +1006,7 @@
same assertion attached to different policy subjects at the same
time in order to avoid conflicting behavior.
</p><div class="boxedtext"><p><a name="bp-WSDL-multiple-policy-subjects" id="bp-WSDL-multiple-policy-subjects"></a><span class="practicelab">Best
-Practice 22: Define Semantics of Attachment to Multiple Policy Subjects</span></p><p class="practice">If an assertion is allowed to be associated with multiple policy subjects,
+Practice 23: Define Semantics of Attachment to Multiple Policy Subjects</span></p><p class="practice">If an assertion is allowed to be associated with multiple policy subjects,
the assertion author should describe the semantics of multiple instances of
the same assertion attached to multiple policy subjects at the same time.
</p></div><p>If the capability is not really suitable and may imply
@@ -1022,7 +1027,7 @@
when the policy assertions do not target wire-level behaviors but
rather abstract requirements, this technique does not apply.
</p><div class="boxedtext"><p><a name="bp-WSDL-preferred-attachment-point" id="bp-WSDL-preferred-attachment-point"></a><span class="practicelab">Best
-Practice 23: Specify Preferred Attachment Point for an Assertion</span></p><p class="practice">If an assertion can be attached at multiple attachment points
+Practice 24: Specify Preferred Attachment Point for an Assertion</span></p><p class="practice">If an assertion can be attached at multiple attachment points
within a policy subject, Assertion Authors should specify a
preferred attachment point for the chosen policy subject.
</p></div><p>Assertion Authors that utilize WSDL policy subjects need to
@@ -1041,7 +1046,7 @@
same alternative. However, the clear semantics defined by the SignedParts
assertion enable processing of the multiple occurrences properly.
</p><div class="boxedtext"><p><a name="bp-WSDL-policy-multiple-instance-semantics" id="bp-WSDL-policy-multiple-instance-semantics"></a><span class="practicelab">Best
-Practice 24: Describe Semantics of Multiple Assertions of Same Type</span></p><p class="practice">A policy alternative can contain multiple instances of the same
+Practice 25: Describe Semantics of Multiple Assertions of Same Type</span></p><p class="practice">A policy alternative can contain multiple instances of the same
policy assertion type. Assertion authors should specify the semantics of
multiple instances of same policy assertion type in the same policy
alternative and the semantics of parameters and nested policy (if any)
@@ -1060,7 +1065,7 @@
assertions and should also make sure that when adding assertions those new assertions are consistent
with pre-existing assertions of any
interrelated domain. </p><div class="boxedtext"><p><a name="bp-specify-composition" id="bp-specify-composition"></a><span class="practicelab">Best
-Practice 25: Specify Composition with Related Assertions</span></p><p class="practice">Assertion authors should clearly specify how an assertion
+Practice 26: Specify Composition with Related Assertions</span></p><p class="practice">Assertion authors should clearly specify how an assertion
may compose with other related assertions, if any.</p></div></div></div><div class="div1">
<h2><a name="versioning-policy-assertions" id="versioning-policy-assertions"></a>6. Versioning Policy Assertions</h2><p>Assertion Authors need to consider not just the expression of the current set of requirements but
how they anticipate new assertions being added to the set. There are three aspects to versioning policy assetions:</p><ul><li><p> Assertion Extensibility </p></li><li><p> Policy Language Extensibility </p><p>Over time, the Policy WG or third parties can version or extend the Policy Language with new
@@ -1090,7 +1095,7 @@
[<cite><a href="#WS-Addressing">WS-Addressing Core</a></cite>]. These equivalent behaviors
are mutually exclusive for an interaction. Such equivalent
behaviors can be modeled as independent assertions. </p><div class="boxedtext"><p><a name="bp-independent-assertions" id="bp-independent-assertions"></a><span class="practicelab">Best
-Practice 26: Use Independent Assertions for Different Versions of a Behavior</span></p><p class="practice">Assertion Authors should use independent assertions for modeling different
+Practice 27: Use Independent Assertions for Different Versions of a Behavior</span></p><p class="practice">Assertion Authors should use independent assertions for modeling different
versions of a behavior.</p></div><p>The
policy expression in the example below requires the use of
WSS: SOAP Message Security 1.0. </p><div class="exampleOuter">
@@ -1103,7 +1108,7 @@
<sp:Wss11>…</sp:Wss11>
</Policy></pre></div></div></div><div class="div2">
<h3><a name="supporting-new-policy-subjects" id="supporting-new-policy-subjects"></a>6.3 Supporting New Policy Subjects</h3><p>
- The best practice <a href="#bp-WSDL-policy-subject"><b>20. Assertion Authors Should Specify Policy Subject(s)</b></a> specifies that policy authors should
+ The best practice <a href="#bp-WSDL-policy-subject"><b>21. Assertion Authors Should Specify Policy Subject(s)</b></a> specifies that policy authors should
define the set of policy subjects to which policy assertions can be
attached. Over time, new policy subjects may need to be defined. When
this occurs, policy Assertion Authors may update the list of policy
@@ -1119,7 +1124,7 @@
new policy subjects are added it is incumbent on the authors to retain the
semantic of the policy assertion.
</p><div class="boxedtext"><p><a name="bp-policy-subject-change" id="bp-policy-subject-change"></a><span class="practicelab">Best
-Practice 27: Change of the Policy Subject Over Time</span></p><p class="practice">If the policy subjects change over time,
+Practice 28: Change of the Policy Subject Over Time</span></p><p class="practice">If the policy subjects change over time,
the assertion description should also be versioned to reflect this
change.</p></div></div></div><div class="div1">
<h2><a name="best-practices-attachment" id="best-practices-attachment"></a>7. Applying Best Practices for Policy Attachment</h2><div class="div2">
@@ -1665,12 +1670,12 @@
are reflected.
</td></tr><tr><td rowspan="1" colspan="1">20070518</td><td rowspan="1" colspan="1">PY</td><td rowspan="1" colspan="1">Updated Appendix E, Changes in this Version of the Document
(<a href="#change-description"><b>E. Changes in this Version of the Document</b></a>).
- </td></tr><tr><td rowspan="1" colspan="1">20070520</td><td rowspan="1" colspan="1">ASV</td><td rowspan="1" colspan="1">Added Best Practice <a href="#bp-specify-composition"><b>25. Specify Composition with Related Assertions</b></a> (from
+ </td></tr><tr><td rowspan="1" colspan="1">20070520</td><td rowspan="1" colspan="1">ASV</td><td rowspan="1" colspan="1">Added Best Practice <a href="#bp-specify-composition"><b>26. Specify Composition with Related Assertions</b></a> (from
the <a href="http://lists.w3.org/Archives/Public/public-ws-policy/2007Mar/att-0069/good-practices-4-assertion-authors-03-05-2007.pdf">IBM
and MS Contribution</a> to
<a href="#interrelated-domains"><b>5.8 Interrelated domains</b></a>. Added an ed note that
Section <a href="#interrelated-domains"><b>5.8 Interrelated domains</b></a> needs to be re-structured.
- </td></tr><tr><td rowspan="1" colspan="1">20070520</td><td rowspan="1" colspan="1">ASV</td><td rowspan="1" colspan="1">Added Best Practice <a href="#bp-not-necessary-to-understand-a-message"><b>7. Not Necessary to Understand a Message</b></a> (from
+ </td></tr><tr><td rowspan="1" colspan="1">20070520</td><td rowspan="1" colspan="1">ASV</td><td rowspan="1" colspan="1">Added Best Practice <a href="#bp-not-necessary-to-understand-a-message"><b>8. Not Necessary to Understand a Message</b></a> (from
the <a href="http://lists.w3.org/Archives/Public/public-ws-policy/2007Mar/att-0069/good-practices-4-assertion-authors-03-05-2007.pdf">IBM
and MS Contribution</a> to
<a href="#self-describing"><b>5.3.3 Self Describing Messages </b></a>.
@@ -1719,4 +1724,6 @@
<a href="http://www.w3.org/2005/06/tracker/wspolicyeds/actions/286">286</a>.
</td></tr><tr><td rowspan="1" colspan="1">200706018</td><td rowspan="1" colspan="1">ASV</td><td rowspan="1" colspan="1">Implemented Editors' action
<a href="http://www.w3.org/2005/06/tracker/wspolicyeds/actions/295">295</a>.
+ </td></tr><tr><td rowspan="1" colspan="1">200706018</td><td rowspan="1" colspan="1">TIB</td><td rowspan="1" colspan="1">Implemented place holder for Editors' action
+ <a href="http://www.w3.org/2005/06/tracker/wspolicyeds/actions/249">249</a> for locking the document.
</td></tr></tbody></table><br></div></div></body></html>
\ No newline at end of file
Index: ws-policy-guidelines.xml
===================================================================
RCS file: /sources/public/2006/ws/policy/ws-policy-guidelines.xml,v
retrieving revision 1.92
retrieving revision 1.93
diff -u -d -r1.92 -r1.93
--- ws-policy-guidelines.xml 19 Jun 2007 03:02:59 -0000 1.92
+++ ws-policy-guidelines.xml 19 Jun 2007 06:47:47 -0000 1.93
@@ -494,6 +494,18 @@
<loc href="http://www.w3.org/Bugs/Public/show_bug.cgi?id=4566">4566</loc>.
</edtext>
</ednote>
+ <p role="practice" id="bp-compatibility-tests">
+ <quote>Behaviors Relevant to Compatibility Tests</quote>
+ <quote>
+ Whenever possible, Assertion Authors should define policy asswertions
+ for behaviors that are relevant to compatibility tests, such as web service
+ protocols that manifest on the wire.
+ </quote>
+ </p>
+ <ednote>
+ <edtext>Place holder.</edtext>
+ </ednote>
+
</div2>
<div2 id="compact-full">
@@ -2688,6 +2700,13 @@
<loc href="http://www.w3.org/2005/06/tracker/wspolicyeds/actions/295">295</loc>.
</td>
</tr>
+ <tr>
+ <td>200706018</td>
+ <td>TIB</td>
+ <td>Implemented place holder for Editors' action
+ <loc href="http://www.w3.org/2005/06/tracker/wspolicyeds/actions/249">249</loc> for locking the document.
+ </td>
+ </tr>
</tbody>
</table>
</inform-div1>
Received on Tuesday, 19 June 2007 06:47:54 UTC