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XPathFunctionResolver
interface XPathFunctionResolver
XPathFunctionResolver provides access to the set of user defined XPathFunctions.
XPath functions are resolved by name and arity. The resolver is not needed for XPath built-in functions and the resolver cannot be used to override those functions.
In particular, the resolver is only called for functions in an another namespace (functions with an explicit prefix). This means that you cannot use the XPathFunctionResolver to implement specifications like XML-Signature Syntax and Processing which extend the function library of XPath 1.0 in the same namespace. This is a consequence of the design of the resolver.
If you wish to implement additional built-in functions, you will have to extend the underlying implementation directly.
Summary
| Public methods |
| abstract XPathFunction! |
Find a function in the set of available functions.
|
Public methods
resolveFunction
abstract fun resolveFunction(
functionName: QName!,
arity: Int
): XPathFunction!
Find a function in the set of available functions.
If functionName or arity is null, then a NullPointerException is thrown.
| Parameters |
functionName |
QName!: The function name. |
arity |
Int: The number of arguments that the returned function must accept. |
| Return |
XPathFunction! |
The function or null if no function named functionName with arity arguments exists. |
| Exceptions |
java.lang.NullPointerException |
If functionName or arity is null. |
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Last updated 2025-02-10 UTC.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-02-10 UTC."],[],[],null,["# XPathFunctionResolver\n\nAdded in [API level 8](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)\n\nXPathFunctionResolver\n=====================\n\n```\ninterface XPathFunctionResolver\n```\n\n|--------------------------------------------|\n| [javax.xml.xpath.XPathFunctionResolver](#) |\n\n`XPathFunctionResolver` provides access to the set of user defined `XPathFunction`s.\n\nXPath functions are resolved by name and arity. The resolver is not needed for XPath built-in functions and the resolver ***cannot*** be used to override those functions.\n\nIn particular, the resolver is only called for functions in an another namespace (functions with an explicit prefix). This means that you cannot use the `XPathFunctionResolver` to implement specifications like [XML-Signature Syntax and Processing](http://www.w3.org/TR/xmldsig-core/) which extend the function library of XPath 1.0 in the same namespace. This is a consequence of the design of the resolver.\n\nIf you wish to implement additional built-in functions, you will have to extend the underlying implementation directly.\n\nSummary\n-------\n\n| Public methods ||\n|----------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| abstract [XPathFunction](/reference/kotlin/javax/xml/xpath/XPathFunction)! | [resolveFunction](#resolveFunction(javax.xml.namespace.QName,%20kotlin.Int))`(`functionName:` `[QName](../namespace/QName.html#)!`, `arity:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`)` Find a function in the set of available functions. |\n\nPublic methods\n--------------\n\n### resolveFunction\n\nAdded in [API level 8](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) \n\n```\nabstract fun resolveFunction(\n functionName: QName!, \n arity: Int\n): XPathFunction!\n```\n\nFind a function in the set of available functions.\n\nIf `functionName` or `arity` is `null`, then a `NullPointerException` is thrown.\n\n| Parameters ||\n|----------------|---------------------------------------------------------------------------------------------------------------------------------------------|\n| `functionName` | [QName](../namespace/QName.html#)!: The function name. |\n| `arity` | [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html): The number of arguments that the returned function must accept. |\n\n| Return ||\n|-------------------------------------------------------------------|-------------------------------------------------------------------------------------------|\n| [XPathFunction](/reference/kotlin/javax/xml/xpath/XPathFunction)! | The function or `null` if no function named `functionName` with `arity` arguments exists. |\n\n| Exceptions ||\n|----------------------------------|-----------------------------------------|\n| `java.lang.NullPointerException` | If `functionName` or `arity` is `null`. |"]]
