- Qt 5.15
- Qt XML Patterns
- C++ Classes
- QAbstractUriResolver
- Qt 5.15.19 Reference Documentation

# QAbstractUriResolver Class

The QAbstractUriResolver class is a callback interface for resolving Uniform Resource Identifiers. A Uniform Resource Identifier (URI) is a string that uniquely identifies a resource. URIs are versatile global identifiers. It is often useful to transform a URI that identifies something logical into a URI that locates something physical (a URL), or to simply map a URI to a different URI. QAbstractUriResolver::resolve() provides this functionality. More...

Header: | #include <QAbstractUriResolver>
qmake: | QT += xmlpatterns
Since: | Qt 4.4

This class was introduced in Qt 4.4.

- List of all members, including inherited members

Note: All functions in this class are reentrant.

## Public Functions

| QAbstractUriResolver(QObject *parent = nullptr)
virtual | ~QAbstractUriResolver()
virtual QUrl | resolve(const QUrl &relative, const QUrl &baseURI) const = 0

## Detailed Description

For example, one could write a QAbstractUriResolver subclass that rewrites library ISBN number URIs as book title URLs, e.g., urn:isbn:0-345-33973-8 would be rewritten as file:///books/returnOfTheKing.doc. Or a QAbstractUriResolver subclass could be written for a web browser to let the web browser protect the user's private files by mapping incoming requests for them to null URIs.

See also http://en.wikipedia.org/wiki/Uniform_Resource_Identifier.

## Member Function Documentation

### QAbstractUriResolver::QAbstractUriResolver(QObject *parent = nullptr)

Constructs a QAbstractUriResolver with the specified parent.

### `[virtual]` QAbstractUriResolver::~QAbstractUriResolver()

Destructor.

### `[pure virtual]` QUrl QAbstractUriResolver::resolve(const QUrl &relative, const QUrl &baseURI) const

Returns the relative URI resolved using the baseURI.

The caller guarantees that both relative and baseURI are valid, and that baseURI is absolute. relative can be relative, absolute, or empty.

The returned QUrl can be a default constructed QUrl. If it is not a default constructed QUrl, it will be absolute and valid. If a default constructed QUrl is returned, it means the relative URI was not accepted to be resolved.

If the reimplemented resolve() function decides it has nothing to do about resolving the relative URI, it should simply return the relative URI resolved against the baseURI, i.e.:

     return baseURI.resolved(relative);

See also QUrl::isRelative() and QUrl::isValid().