Question & Answer
Question
The XQuery version 1.0 specifications state that the implementation of certain items must be specified by the implementor. How does the DataPower appliance implement these implementation-defined items?
Cause
The following XQuery specifications require the implementation-defined items to be documented:
Answer
The following tables list the implementation-defined behaviors on the DataPower appliance. For details on each feature, see the specification.
Table 1: XQuery 1.0: An XML Query Language, Appendix D Implementation-Defined Items
| Feature | Description | Documented behavior | |
| 1 | Unicode version | The supported version of Unicode | Unicode, version 6.0 |
| 2 | Statically-known collations | The set of collation URLs that the implementation recognizes. | Statically-known collations: DB2 short-form starts with "name=UCA500R1_". See the Unicode Collation Algorithm based collations topic. "L=" and "S=" options are also supported for human readable collation format. For example, the following collations are supported: |
| 3 | Implicit time zone | The time zone value that is used when a time zone is not specified | The implicit time zone uses the local time zone |
| 4 | Warnings | When are warnings raised, and how are warnings handled | Warnings are raised as normal DataPower appliance warnings |
| 5 | Errors | How are errors reported | Errors are reported as normal DataPower errors |
| 6 | XML and XML Names specifications | Which versions of the XML and XML Names specifications are supported | XML Version: XML 1.0 and XML Names |
| 7 | Static context and dynamic context | Which components of the static context or dynamic context does the implementation overwrite or augment | For dynamic context, the context item is defined by the processing policy input context, as interpreted by the xformng input type. Variable values that are listed as external in the XQuery must be of type xs:string and work like DataPower parameters for XSLT. There is a limitation that they only work for explicitly non-namespaced parameter names (for example, "{}my-param" and not for others, including those that show up without a namespace name in the WebGUI. For ones that do not work at all, they often return the empty string and not an error when they are not found. Even external parameters that are not defined at all often return the empty string and not an error. There are additional built-in functions. The MapUtils conv: functions that are available in XSLT. |
| 8 | Optional axes or Full-Axis Feature support | Which optional axes are supported if the Full-Axis Feature is not supported. | The Full-Axis feature is supported |
| 9 | Handling of empty sequences that are returned by an ordering key | By default, when an ordering key in an order by clause returns an empty sequence, is it handled as empty least or empty greatest | The default order for empty sequences is empty least. |
| 10 | Extension expressions and pragmas | What extension expressions and pragmas are recognized | No pragmas are supported. |
| 11 | Option declarations | What option declarations are recognized | Option declarations recognized: JSONiq: declare option jsoniq-version "0.4.42"; This option declaration activates the JSONiq feature for version 0.4.42 of JSONiq. |
| 12 | Protocols | What protocols are supported to pass parameters to an external function | No protocols are supported for external functions because there are no external functions. |
| 13 | Module import | How are the modules that are imported identified | For Multiple Single Module Import, every module import must have exactly one Location Hint, and the module is entirely loaded from that location. |
| 14 | Static typing feature | What static typing extensions are supported by the static typing feature | The static typing feature is not supported. |
| 15 | Serialization feature | How is serialization invoked | Serialization is always invoked by default with the default serialization parameters. |
| 16 | Default values for certain serialization feature parameters | What are the default values for the following serialization feature parameters:
| The default values for serialization:
|
| 17 | Results of an external function call that is unsuccessful | What is the result of an external function call that is unsuccessful | In the case of an unsuccessful call to an unimplemented external function, the function returns the empty sequence or raises an error. |
| 18 | Data types range limits | What are the ranges of values for data types that are listed in section 5.3 Data Model Conformance of the specification | Data types are limited consistent with the DataPower XML Schema limitations. The xs:decimal function and all of its subtypes are limited to 18 digits. |
| 19 | Syntactic extensions | What are the syntax and semantics of XQuery syntactic extensions as in section 5.4 Syntax Extensions of the specification | The following syntactic extensions are supported:
|
Table 2: XQuery 1.0 and XPath 2.0 Data Model, Appendix F.1, Implementation-Defined Items
| Feature | Description | Documented behavior | |
| 1 | User-defined or implementation-defined types | What are the supported user-defined or implementation-defined types | User-defined types are not allowed. Implementation-defined types from the JSONiq specification are supported. |
| 2 | Accessing an undefined property | What is the behavior when accessing an undefined property | Accessing an undefined property raises a standard DataPower error. |
Table 3: XQuery 1.0 and XPath 2.0 Functions and Operators, Appendix E Checklist of Implementation-Defined Features
| Feature | Description | Documented behavior | |
| 1 | Trace function | What is the destination of the trace output. | Destination of trace output:
|
| 2 | Operators on numeric values, overflow conditions | How do xs:integer operations handle overflow conditions with limited-precision integer operations. | Overflow condition always raise error err:FOAR0002. |
| 3 | Operators on numeric values, precision of returned values | What is the precision for xs:decimal values that are returned by numeric operators | The number of digits of precision is 18. That is, there are 8 digits before the decimal point and 18 digits after the decimal point. |
| 4 | Operators on numeric values, fractional overflow | How do numeric operations handle overflow conditions | The handling of the fractional overflow, whether the result is truncated or rounded, is undefined. The behavior might be different every operation. |
| 5 | Unicode version | The supported version of Unicode | Unicode, version 6.0 |
| 6 | Normalization | Which of the following normalization forms are supported:
| The fn:normalize-unicode function supports the following forms:
|
| 7 | Collation decomposition | The ability to decompose strings into collation units that are suitable for substring matching | The collation decomposition suitability for substring matching provides as much as the International Components for Unicode (ICU). |
| 8 | Number of digits for year values and fractional second precision | How many digits are supported for year values and for fractional second precision. | Year values support 3 digits. Fractional second precision is 1 millisecond or 3 digits. |
| 9 | Casting a string to xs:decimal. | What is the result of casting a string to xs:decimal when the resulting value cannot be accurately represented | Too many decimal digits raises error FOAR0002. |
| 10 | fn:doc configuration options | What external configuration options are supported for fn:doc processing | The fn:doc function provides the following external configuration options:
|
| 11 | Relaxing stability options for fn:collection and fn:doc | How are stability options for fn:collection and fn:doc weakened | Relaxing stability options: None |
Table 4: XSLT 2.0 and XQuery 1.0 Serialization, Appendix D Checklist of Implementation-Defined Features
| Feature | Description | Documented behavior | |
| 1 | Sequence normalization for output methods | For the defined output methods, does sequence normalization take place | When output is XML, sequence normalization always takes place. When the output is JSON, sequence normalization never takes place. |
| 2 | Custom serialization parameters | What custom serialization parameters are supported | A custom serialization parameter provides the ability to set output:method to be JSON as in the following declaration: declare option output:method "json"; |
| 3 | Additional serialization parameters | How additional serialization parameters effect the output of the serializer | No additional serialization parameters are supported. |
| 4 | Encoding phase of serialization | What is the option to skip the encoding phase of serialization | An option to skip the encoding phase is not supported. |
| 5 | CDATA results | What CDATA mechanism is supported | No CDATA result mechanism is supported. |
| 6 | Custom normalization-form form parameter value | What custom normalization-form form parameters are supported | No custom normalization-form form parameters are supported. |
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Document Information
Modified date:
15 June 2018
UID
swg21633591