/// <summary>
/// Does the location represent a place where an element can be created or replaced by a completion?
/// </summary>
/// <param name="location">
/// The XML location.
/// </param>
/// <param name="replaceElement">
/// The element (if any) that will be replaced by the completion.
/// </param>
/// <param name="parentPath">
/// If specified, the location's node's parent must have the specified <see cref="XSPath"/>.
/// </param>
/// <returns>
/// <c>true</c>, if the location represents an element that can be replaced by completion; otherwise, <c>false</c>.
/// </returns>
/// <remarks>
/// We can replace "<>" and "<<Element />".
/// </remarks>
public static bool CanCompleteElement(this XmlLocation location, out XSElement replaceElement, XSPath parentPath = null)
{
if (location == null)
{
throw new ArgumentNullException(nameof(location));
}
replaceElement = null;
// Simplest case - we're on whitespace so we can simply insert an element without replacing anything.
if (location.IsWhitespace(out XSWhitespace whitespace) && (parentPath == null || whitespace.HasParentPath(parentPath)))
{
return(true);
}
XSElement element;
if (!location.IsElement(out element))
{
return(false);
}
if (location.IsElementBetweenAttributes())
{
return(false);
}
// Check if we need to perform a substition of the element to be replaced (the common case is simply replacing an existing element or partial element).
if (element.IsValid)
{
// Do we have an invalid parent (e.g. "<<Foo />", which yields invalid element named "" with child element named "Foo")?
bool isParentValid = element.ParentElement?.IsValid ?? true;
if (!isParentValid)
{
// We can't handle the case where the parent isn't on the same line as the child (since that's not the case outlined above).
if (element.ParentElement.Start.LineNumber != location.Node.Start.LineNumber)
{
return(false);
}
// But we *can* handle this case by targeting the "parent" element (since that's the element we're actually after anyway).
if (location.Node.Start.ColumnNumber - element.ParentElement.Start.ColumnNumber == 1)
{
element = element.ParentElement;
}
}
}
if (parentPath != null && !element.HasParentPath(parentPath))
{
return(false);
}
replaceElement = element;
return(true);
}
/// <summary>
/// Does the location represent an element's attributes range (but not a specific attribute)?
/// </summary>
/// <param name="location">
/// The XML location.
/// </param>
/// <param name="element">
/// Receives the <see cref="XSElement"/>.
/// </param>
/// <returns>
/// <c>true</c>, if the location represents an element; otherwise, <c>false</c>.
/// </returns>
public static bool IsElementBetweenAttributes(this XmlLocation location, out XSElement element)
{
if (location == null)
{
throw new ArgumentNullException(nameof(location));
}
if (location.IsElementBetweenAttributes())
{
element = (XSElement)location.Node;
return(true);
}
else
{
element = null;
return(false);
}
}
/// <summary>
/// Does the location represent a place where an attribute can be created or replaced by a completion?
/// </summary>
/// <param name="location">
/// The XML location.
/// </param>
/// <param name="element">
/// The element whose attribute will be completed.
/// </param>
/// <param name="replaceAttribute">
/// The attribute (if any) that will be replaced by the completion.
/// </param>
/// <param name="needsPadding">
/// An <see cref="PaddingType"/> value indicating what sort of padding (if any) is required before / after the attribute.
/// </param>
/// <param name="onElementWithPath">
/// If specified, the location's element must have the specified path.
/// </param>
/// <returns>
/// <c>true</c>, if the location represents an element that can be replaced by completion; otherwise, <c>false</c>.
/// </returns>
public static bool CanCompleteAttribute(this XmlLocation location, out XSElement element, out XSAttribute replaceAttribute, out PaddingType needsPadding, XSPath onElementWithPath = null)
{
if (location == null)
{
throw new ArgumentNullException(nameof(location));
}
replaceAttribute = null;
needsPadding = PaddingType.None;
XSAttribute attribute;
if (location.IsAttribute(out attribute) && !location.IsValue())
{
element = attribute.Element;
if (location.Position == attribute.Start)
{
// Since we're on an existing attribute, we'll add a new attribute after it.
attribute = null;
needsPadding = PaddingType.Trailing;
}
}
else if (location.IsElementBetweenAttributes(out element))
{
if (element.Attributes.Count > 0)
{
// Check if we're directly before an attribute.
foreach (XSAttribute currentAttribute in element.Attributes)
{
if (location.Position == currentAttribute.End)
{
needsPadding = PaddingType.Leading;
}
else
{
continue;
}
break;
}
}
else if (location.Position == element.NameRange.End) // We're directly after the name.
{
needsPadding = PaddingType.Leading;
}
}
else if (location.IsElement(out element))
{
// Check if we're directly after the name.
if (location.Position != element.NameRange.End)
{
return(false);
}
needsPadding = PaddingType.Leading;
}
else
{
return(false);
}
if (onElementWithPath != null && !element.Path.Matches(onElementWithPath))
{
return(false);
}
replaceAttribute = attribute;
return(true);
}