/// <summary>Associates an alias name with an actual name.</summary>
/// <remarks>
/// Associates an alias name with an actual name.
/// <p>
/// Define a alias mapping from one namespace/property to another. Both
/// property names must be simple names. An alias can be a direct mapping,
/// where the alias and actual have the same data type. It is also possible
/// to map a simple alias to an item in an array. This can either be to the
/// first item in the array, or to the 'x-default' item in an alt-text array.
/// Multiple alias names may map to the same actual, as long as the forms
/// match. It is a no-op to reregister an alias in an identical fashion.
/// Note: This method is not locking because only called by registerStandardAliases
/// which is only called by the constructor.
/// Note2: The method is only package-private so that it can be tested with unittests
/// </remarks>
/// <param name="aliasNS">
/// The namespace URI for the alias. Must not be null or the empty
/// string.
/// </param>
/// <param name="aliasProp">
/// The name of the alias. Must be a simple name, not null or the
/// empty string and not a general path expression.
/// </param>
/// <param name="actualNS">
/// The namespace URI for the actual. Must not be null or the
/// empty string.
/// </param>
/// <param name="actualProp">
/// The name of the actual. Must be a simple name, not null or the
/// empty string and not a general path expression.
/// </param>
/// <param name="aliasForm">
/// Provides options for aliases for simple aliases to array
/// items. This is needed to know what kind of array to create if
/// set for the first time via the simple alias. Pass
/// <code>XMP_NoOptions</code>, the default value, for all
/// direct aliases regardless of whether the actual data type is
/// an array or not (see
/// <see cref="Com.Adobe.Xmp.Options.AliasOptions"/>
/// ).
/// </param>
/// <exception cref="Com.Adobe.Xmp.XMPException">for inconsistant aliases.</exception>
internal void RegisterAlias(string aliasNS, string aliasProp, string actualNS, string actualProp, AliasOptions aliasForm)
{
lock (this)
{
ParameterAsserts.AssertSchemaNS(aliasNS);
ParameterAsserts.AssertPropName(aliasProp);
ParameterAsserts.AssertSchemaNS(actualNS);
ParameterAsserts.AssertPropName(actualProp);
// Fix the alias options
AliasOptions aliasOpts = aliasForm != null ? new AliasOptions(XMPNodeUtils.VerifySetOptions(aliasForm.ToPropertyOptions(), null).GetOptions()) : new AliasOptions();
if (p.Matcher(aliasProp).Find() || p.Matcher(actualProp).Find())
{
throw new XMPException("Alias and actual property names must be simple", XMPErrorConstants.Badxpath);
}
// check if both namespaces are registered
string aliasPrefix = GetNamespacePrefix(aliasNS);
string actualPrefix = GetNamespacePrefix(actualNS);
if (aliasPrefix == null)
{
throw new XMPException("Alias namespace is not registered", XMPErrorConstants.Badschema);
}
else
{
if (actualPrefix == null)
{
throw new XMPException("Actual namespace is not registered", XMPErrorConstants.Badschema);
}
}
string key = aliasPrefix + aliasProp;
// check if alias is already existing
if (aliasMap.ContainsKey(key))
{
throw new XMPException("Alias is already existing", XMPErrorConstants.Badparam);
}
else
{
if (aliasMap.ContainsKey(actualPrefix + actualProp))
{
throw new XMPException("Actual property is already an alias, use the base property", XMPErrorConstants.Badparam);
}
}
XMPAliasInfo aliasInfo = new _XMPAliasInfo_390(actualNS, actualPrefix, actualProp, aliasOpts);
aliasMap.Put(key, aliasInfo);
}
}
