/// <summary>
/// Returns a filtered collection of the descendant elements for this document
/// or element, in document order. Only elements that have a matching System.Xml.Linq.XName
/// are included in the collection.
/// </summary>
/// <param name="name">The System.Xml.Linq.XName to match.</param>
/// <returns>
/// An System.Collections.Generic.IEnumerable`1 of System.Xml.Linq.XElement
/// containing the descendant elements of the System.Xml.Linq.XContainer that
/// match the specified System.Xml.Linq.XName.
/// </returns>
public IEnumerable <XElement> Descendants(XName name)
{
//this one is much simpler than Elements since we can call the getElementsByTagName method that does exactly what we want.
object jsNodesForElement = CSHTML5.Interop.ExecuteJavaScript("$0.getElementsByTagName($1)", INTERNAL_jsnode, name.ToString());
if (XDocument.IsNullOrUndefined(jsNodesForElement)) //no children.
{
yield break;
}
int i = 0;
while (true)
{
object nodeAtI = CSHTML5.Interop.ExecuteJavaScript("$0[$1]", jsNodesForElement, i);
if (CSHTML5.Interop.IsUndefined(nodeAtI))
{
break;
}
//note: they have a tagName so they are definitely XElements.
yield return((XElement)XDocument.GetXNodeFromJSNode(nodeAtI));
++i;
}
yield break;
}
/// <summary>
/// Returns a collection of the child elements of this element or document, in
/// document order.
/// </summary>
/// <returns>
/// An System.Collections.Generic.IEnumerable<XElement> of System.Xml.Linq.XElement
/// containing the child elements of this System.Xml.Linq.XContainer, in document
/// order.
/// </returns>
public IEnumerable <XElement> Elements()
{
//Note on the JS below: the filter is to get rid of the XText elements which have no tagName.
//object jsNodesForElement = CSHTML5.Interop.ExecuteJavaScript("Array.from($0.childNodes).filter(node => node.tagName !== undefined)", INTERNAL_jsnode);
//todo: check whether the line above is more efficient than the line below and change accordingly (if IE allows it, see todo in Elements(XName))
object jsNodesForElement = CSHTML5.Interop.ExecuteJavaScript("Array.from($0.childNodes).filter(function(node) { return node.tagName !== undefined})", INTERNAL_jsnode);
if (XDocument.IsNullOrUndefined(jsNodesForElement))
{
yield break; // no children.
}
int i = 0;
while (true)
{
object nodeAtI = CSHTML5.Interop.ExecuteJavaScript("$0[$1]", jsNodesForElement, i);
if (CSHTML5.Interop.IsUndefined(nodeAtI))
{
break;
}
//note: they have a tagName so they are definitely XElements.
yield return((XElement)XDocument.GetXNodeFromJSNode(nodeAtI));
++i;
}
yield break;
}
/// <summary>
/// Gets the first (in document order) child element with the specified System.Xml.Linq.XName.
/// </summary>
/// <param name="name">The System.Xml.Linq.XName to match.</param>
/// <returns>
/// A System.Xml.Linq.XElement that matches the specified System.Xml.Linq.XName,
/// or null.
/// </returns>
public XElement Element(XName name)
{
//note: we couldn't use INTERNAL_jsnode.getElementsByTagName(name) because it returns the children of the children nodes as well (we only want the immediate children).
//Note about the js below: Array.from is to get the possibility to call the filter method:
string nameAsString = name.LocalName;
string namespaceAsString = name.NamespaceName;
// object jsNodeForElement = CSHTML5.Interop.ExecuteJavaScript("Array.from($0.childNodes).filter(node => node.tagName == $1)[0]", INTERNAL_jsnode, name.ToString());
//todo: check whether the line above is more efficient than the line below and change accordingly (if IE allows it, see todo in Elements(XName))
// Note: below, the test ((!$2 && !node.namespaceURI) || node.namespaceURI == $2) can be read as both are null or empty, or they are the same. This way, the case one is null while the other is empty will still be considered a match.
object jsNodeForElement = CSHTML5.Interop.ExecuteJavaScript("Array.from($0.childNodes).filter(function(node) { return (node.localName == $1 && ((!$2 && !node.namespaceURI) || node.namespaceURI == $2))})[0]", INTERNAL_jsnode, nameAsString, namespaceAsString); //}
if (XDocument.IsNullOrUndefined(jsNodeForElement)) //not found, we return null.
{
return(null);
}
XNode node = XDocument.GetXNodeFromJSNode(jsNodeForElement);
if (node is XElement)
{
return((XElement)node);
}
return(null);
}
//todo: handle the comment nodes type XComment in c#
//todo: change the way we determine the type of the nodes (cf. https://developer.mozilla.org/en-US/docs/Web/API/Node/nodeType)
// basically, nodeType = : 1 is XElement, 3 is XText, 8 is XComment, 9 is XDocument but is useless I think
/// <summary>
/// Returns a collection of the child nodes of this element or document, in document
/// order.
/// </summary>
/// <returns>
/// An System.Collections.Generic.IEnumerable<T> of System.Xml.Linq.XNode containing
/// the contents of this System.Xml.Linq.XContainer, in document order.
/// </returns>
public IEnumerable <XNode> Nodes()
{
int i = 0;
while (true)
{
object nodeAtI = CSHTML5.Interop.ExecuteJavaScript("$0.childNodes[$1]", INTERNAL_jsnode, i);
if (CSHTML5.Interop.IsUndefined(nodeAtI))
{
break;
}
yield return(XDocument.GetXNodeFromJSNode(nodeAtI));
++i;
}
yield break;
}
/// <summary>
/// Returns a filtered collection of the child elements of this element or document,
/// in document order. Only elements that have a matching System.Xml.Linq.XName
/// are included in the collection.
/// </summary>
/// <param name="name">The System.Xml.Linq.XName to match.</param>
/// <returns>
/// An System.Collections.Generic.IEnumerable`1 of System.Xml.Linq.XElement
/// containing the children of the System.Xml.Linq.XContainer that have a matching
/// System.Xml.Linq.XName, in document order.
/// </returns>
public IEnumerable <XElement> Elements(XName name)
{
//note: we couldn't use INTERNAL_jsnode.getElementsByTagName(name) because it returns the children of the children nodes as well (we only want the immediate children).
//jsNodesForElement = CSHTML5.Interop.ExecuteJavaScript("Array.from($0.childNodes).filter(node => node.tagName == $1)", INTERNAL_jsnode, name.ToString());
//todo: if IE learns that => isn't a syntax error (which breaks the whole file) and can use it properly, use the line above instead of the following because it seems to be more efficient.
object jsNodesForElement = CSHTML5.Interop.ExecuteJavaScript("Array.from($0.childNodes).filter(document.functionToCompareWordForFilter($1))", INTERNAL_jsnode, name.ToString());
#region explanation of the line above
//note: normal use of filter: myArray.filter( function(node) { return testOnNode; })
//problem here: testOnNode depends on the name than node and we cannot put $1 in there because JSIL changes it to "this.$name", but "this" does not exist where "testOnNode" is.
//solution: document.functionToCompareWordForFilter(name) returns A FUNCTION that takes a node and compares its tagName to name (see in cshtml5.js)
// when calling document.functionToCompareWordForFilter, this.$name exists
// and the created method that is used by filter can use it normally.
//in short: the function created by document.functionToCompareWordForFilter provides the name, filter provides the node.
#endregion
if (XDocument.IsNullOrUndefined(jsNodesForElement)) //nothing fits the request.
{
yield break;
}
int i = 0;
while (true)
{
object nodeAtI = CSHTML5.Interop.ExecuteJavaScript("$0[$1]", jsNodesForElement, i);
if (CSHTML5.Interop.IsUndefined(nodeAtI))
{
break;
}
//note: they have a tagName so they are definitely XElements.
yield return((XElement)XDocument.GetXNodeFromJSNode(nodeAtI));
++i;
}
yield break;
}
/// <summary>
/// Gets the first (in document order) child element with the specified System.Xml.Linq.XName.
/// </summary>
/// <param name="name">The System.Xml.Linq.XName to match.</param>
/// <returns>
/// A System.Xml.Linq.XElement that matches the specified System.Xml.Linq.XName,
/// or null.
/// </returns>
public XElement Element(XName name)
{
//note: we couldn't use INTERNAL_jsnode.getElementsByTagName(name) because it returns the children of the children nodes as well (we only want the immediate children).
//Note about the js below: Array.from is to get the possibility to call the filter method:
string nameAsString = name.LocalName;
// object jsNodeForElement = CSHTML5.Interop.ExecuteJavaScript("Array.from($0.childNodes).filter(node => node.tagName == $1)[0]", INTERNAL_jsnode, name.ToString());
//todo: check whether the line above is more efficient than the line below and change accordingly (if IE allows it, see todo in Elements(XName))
object jsNodeForElement = CSHTML5.Interop.ExecuteJavaScript("Array.from($0.childNodes).filter(function(node) { return node.tagName == $1})[0]", INTERNAL_jsnode, nameAsString); //}
if (XDocument.IsNullOrUndefined(jsNodeForElement)) //not found, we return null.
{
return(null);
}
XNode node = XDocument.GetXNodeFromJSNode(jsNodeForElement);
if (node is XElement)
{
return((XElement)node);
}
return(null);
}
