I have an HtmlDocument that may or may have a proper <head> and <body> section or might just be an html fragment. Either way, I want to run it through a function that will ensure that it has (more) proper html structure.
I know that I can check if it has a body by seeing if
doc.DocumentNode.SelectSingleNode("//body");
is null. If it does not have a body, how would I wrap the contents of doc.DocumentNode in a <body> element and assign it back to the HtmlDocument?
Edit: There seems to be some confusion about what I want to do. In jquery terms:
$doc = $(document);
if( !$doc.has('body') ) {
$doc.wrapInner('body');
}
Basically, if there is no body element, put a body element around everything.
You could do something like this:
HtmlDocument doc = new HtmlDocument();
doc.Load(MyTestHtm);
HtmlNode body = doc.DocumentNode.SelectSingleNode("//body");
if (body == null)
{
HtmlNode html = doc.DocumentNode.SelectSingleNode("//html");
// we presume html exists
body = CloneAsParentNode(html.ChildNodes, "body");
}
static HtmlNode CloneAsParentNode(HtmlNodeCollection nodes, string name)
{
List<HtmlNode> clones = new List<HtmlNode>(nodes);
HtmlNode parent = nodes[0].ParentNode;
// create a new parent with the given name
HtmlNode newParent = nodes[0].OwnerDocument.CreateElement(name);
// insert before the first node in the selection
parent.InsertBefore(newParent, nodes[0]);
// clone all sub nodes
foreach (HtmlNode node in clones)
{
HtmlNode clone = node.CloneNode(true);
newParent.AppendChild(clone);
}
// remove all sub nodes
foreach (HtmlNode node in clones)
{
parent.RemoveChild(node);
}
return newParent;
}
Related
I'm using Html Agility Pack (1.4.9.5) to remove a node within a specified class:
var document = new HtmlDocument();
document.LoadHtml("<p><div class=\"remove-it\"></div></p>");
var nodesToRemove = document.QuerySelectorAll(".remove-it");
if (nodesToRemove != null)
{
foreach (var node in nodesToRemove)
{
node.Remove();
}
}
var res = document.DocumentNode.OuterHtml;
The problem is that at the end res is equal to:
<p>
but it should be:
<p></p>
How can I fix this?
Almost there! You are missing
HtmlNode.ElementsFlags["p"] = HtmlElementFlag.Closed; before document.LoadHtml("<p><div class=\"remove-it\"></div></p>");.
What that does is that the p element will be automatically closed when parsing the document.
I need to get all nodes from a html, then from that nodes I need to get the text and sub-nodes, and the same thing but from that sub-sub-nodes.
For example, I have this HTML:
<p>This <b>is a Link</b> with <b>bold</b></p>
So I need a way to get the p node, then the non-formatted text (this), the only-bold text (is a), the bolded link (Link) and the rest formatted and not formatted text.
I know that with the htmldocument I can select all nodes and sub-nodes, but, how Can I get the text before the sub-node, then the sub-node, and its text/sub-nodes so I can make the rendered version of the html ("This is a Link with bold")?
Please note that the above example is a simple one. The HTML would have more complex things like list, frames, numbered list, triple-formatted text, etc. Also note that the rendered thing is not a problem. I have already done that but in another way. What I need is the part to get the nodes and its content only.
Also, I can't ignore any node, so I can't filter by nothing. And the main node could start as p, div, frame, ul, etc.
After looking in the htmldoc and its properties, and thanks to #HungCao 's observation, I got a working simple way to interpretate a HTML code.
My code is a little more complex to add it as example, so I will post a lite version of it.
First of all, the htmlDoc has to be loaded. It could be on any function:
HtmlDocument htmlDoc = new HtmlDocument();
string html = #"<p>This <b>is a Link</b> with <b>bold</b></p>";
htmlDoc.LoadHtml(html);
Then we need to interpretate each "main" node (p in this case) and, depending its type, we need to load a LoopFunction (InterNode)
HtmlNodeCollection nodes = htmlDoc.DocumentNode.ChildNodes;
foreach (HtmlNode node in nodes)
{
if(node.Name.ToLower() == "p") //Low the typeName just in case
{
Paragraph newPPara = new Paragraph();
foreach(HtmlNode childNode in node.ChildNodes)
{
InterNode(childNode, ref newPPara);
}
richTextBlock.Blocks.Add(newPPara);
}
}
Please note that there is a property called "NodeType", but it will not return the correct type. So, instead use the "Name" property (Also note that the Name property in htmlNode is not the same as the Name attribute in HTML).
Finally, we have the InterNode function that will add inlines to the referred (ref) Paragraph
public bool InterNode(HtmlNode htmlNode, ref Paragraph originalPar)
{
string htmlNodeName = htmlNode.Name.ToLower();
List<string> nodeAttList = new List<string>();
HtmlNode parentNode = htmlNode.ParentNode;
while (parentNode != null) {
nodeAttList.Add(parentNode.Name);
parentNode = parentNode.ParentNode;
} //we need to get it multiple types, because it could be b(old) and i(talic) at the same time.
Inline newRun = new Run();
foreach (string noteAttStr in nodeAttList) //with this we can set all the attributes to the inline
{
switch (noteAttStr)
{
case ("b"):
case ("strong"):
{
newRun.FontWeight = FontWeights.Bold;
break;
}
case ("i"):
case ("em"):
{
newRun.FontStyle = FontStyle.Italic;
break;
}
}
}
if(htmlNodeName == "#text") //the #text means that its a text node. Like <i><#text/></i>. Thanks #HungCao
{
((Run)newRun).Text = htmlNode.InnerText;
} else //if it is not a #text, don't load its innertext, as it's another node and it will always have a #text node as a child (if it has any text)
{
foreach (HtmlNode childNode in htmlNode.ChildNodes)
{
InterNode(childNode, ref originalPar);
}
}
return true;
}
Note: I know that I said that my app need to render the HTML in another way that a webview does, and I know that this example code generate the same thing as a Webview, but, as I said before, this is just a lite version of my final code. In fact, my original/full code is working as I need to and this is just the base.
I use HtmlAgilityPack to parse the html document of a webbrowser control.
I am able to find my desired HtmlNode, but after getting the HtmlNode, I want to retun the corresponding HtmlElement in the WebbrowserControl.Document.
In fact HtmlAgilityPack parse an offline copy of the live document, while I want to access live elements of the webbrowser Control to access some rendered attributes like currentStyle or runtimeStyle
HtmlAgilityPack.HtmlDocument doc = new HtmlAgilityPack.HtmlDocument();
doc.LoadHtml(webBrowser1.Document.Body.InnerHtml);
var some_nodes = doc.DocumentNode.SelectNodes("//p");
// this selection could be more sophisticated
// and the answer shouldn't relay on it.
foreach (HtmlNode node in some_nodes)
{
HtmlElement live_element = CorrespondingElementFromWebBrowserControl(node);
// CorrespondingElementFromWebBrowserControl is what I am searching for
}
If the element had a specific attribute it could be easy but I want a solution which works on any element.
Please help me what can I do about it.
In fact there seems to be no direct possibility to change the document directly in the webbroser control.
But you can extract the html from it, mnipulate it and write it back again like this:
HtmlAgilityPack.HtmlDocument doc = new HtmlAgilityPack.HtmlDocument();
doc.LoadHtml(webBrowser1.DocumentText);
foreach (HtmlAgilityPack.HtmlNode node in doc.DocumentNode.ChildNodes) {
node.Attributes.Add("TEST", "TEST");
}
StringBuilder sb = new StringBuilder();
using (StringWriter sw = new StringWriter(sb)) {
doc.Save(sw);
webBrowser1.DocumentText = sb.ToString();
}
For direct manipulation you can maybe use the unmanaged pointer webBrowser1.Document.DomDocument to the document, but this is outside of my knowledge.
HtmlAgilityPack definitely can't provide access to nodes in live HTML directly. Since you said there is no distinct style/class/id on the element you have to walk through the nodes manually and find matches.
Assuming HTML is reasonably valid (so both browser and HtmlAgilityPack perform normalization similarly) you can walk pairs of elements starting from the root of both trees and selecting the same child node.
Basically you can build "position-based" XPath to node in one tree and select it in another tree. Xpath would look something like (depending you want to pay attention to just positions or position and node name):
"/*[1]/*[4]/*[2]/*[7]"
"/body/div[2]/span[1]/p[3]"
Steps:
In using HtmlNode you've found collect all parent nodes up to the root.
Get root of element of HTML in browser
for each level of children find position of corresponding child on HtmlNodes collection on step 1 in its parent and than find live HtmlElement among children of current live node.
Move to newly found child and go back to 3 till found node you are looking for.
the XPath attribute of the HtmlAgilityPack.HtmlNode shows the nodes on the path from root to the node. For example \div[1]\div[2]\table[0]. You can traverse this path in the live document to find the corresponding live element. However this path may not be precise as HtmlAgilityPack removes some tags like <form> then before using this solution add the omitted tags back using
HtmlNode.ElementsFlags.Remove("form");
struct DocNode
{
public string Name;
public int Pos;
}
///// structure to hold the name and position of each node in the path
The following method finds the live element according to the XPath
static public HtmlElement GetLiveElement(HtmlNode node, HtmlDocument doc)
{
var pattern = #"/(.*?)\[(.*?)\]"; // like div[1]
// Parse the XPath to extract the nodes on the path
var matches = Regex.Matches(node.XPath, pattern);
List<DocNode> PathToNode = new List<DocNode>();
foreach (Match m in matches) // Make a path of nodes
{
DocNode n = new DocNode();
n.Name = n.Name = m.Groups[1].Value;
n.Pos = Convert.ToInt32(m.Groups[2].Value)-1;
PathToNode.Add(n); // add the node to path
}
HtmlElement elem = null; //Traverse to the element using the path
if (PathToNode.Count > 0)
{
elem = doc.Body; //begin from the body
foreach (DocNode n in PathToNode)
{
//Find the corresponding child by its name and position
elem = GetChild(elem, n);
}
}
return elem;
}
the code for GetChild Method used above
public static HtmlElement GetChild(HtmlElement el, DocNode node)
{
// Find corresponding child of the elemnt
// based on the name and position of the node
int childPos = 0;
foreach (HtmlElement child in el.Children)
{
if (child.TagName.Equals(node.Name,
StringComparison.OrdinalIgnoreCase))
{
if (childPos == node.Pos)
{
return child;
}
childPos++;
}
}
return null;
}
I have a problem that my xpath is not working.
I am trying to get the url from Google.com's search result list into a string list.
But i am unable to reach on url using Xpath.
Please help me in correcting my xpath. Also tell me what should be on the place of ??
HtmlWeb hw = new HtmlWeb();
List<string> urls = new List<string>();
HtmlAgilityPack.HtmlDocument doc = hw.Load("http://www.google.com/search?q=" +txtURL.Text.Replace(" " , "+"));
HtmlNodeCollection linkNodes = doc.DocumentNode.SelectNodes("//div[#class='f kv']");
foreach (HtmlNode linkNode in linkNodes)
{
HtmlAttribute link = linkNode.Attributes["?????????"];
urls.Add(link.Value);
}
for (int i = 0; i <= urls.Count - 1; i++)
{
if (urls.ElementAt(i) != null)
{
if (IsValid(urls.ElementAt(i)) != true)
{
grid.Rows.Add(urls.ElementAt(i));
}
}
}
The URLs seem to live in the cite element under that selected divs, so the XPath to select those is //div[#class='f kv']/cite.
Now, since these contain markup but you only want the text, select the InnerText of the selected nodes. Note that these do not begin with http://.
HtmlNodeCollection linkNodes =
doc.DocumentNode.SelectNodes("//div[#class='f kv']/cite");
foreach (HtmlNode linkNode in linkNodes)
{
HtmlAttribute link = linkNode.InnerText;
urls.Add(link.Value);
}
The correct XPath is "//div[#class='kv']/cite". The f class you see in the browser element inspector is (probably) added after the page is rendered using javascript.
Also, the link text is not in an attribute, you can get it using the InnerText property of the <div> element(s) obtained at the earlier step.
I changed these lines and it works:
var linkNodes = doc.DocumentNode.SelectNodes("//div[#class='kv']/cite");
foreach (HtmlNode linkNode in linkNodes)
{
urls.Add(linkNode.InnerText);
}
There's a caveat though: some links are trimmed (you'll see a ... in the middle)
I want to replace inner text of HTML tags with another text.
I am using HtmlAgilityPack
I use this code to extract all texts
HtmlDocument doc = new HtmlDocument();
doc.Load("some path")
foreach (HtmlNode node in doc.DocumentNode.SelectNodes("//text()[normalize-space(.) != '']")) {
// How to replace node.InnerText with some text ?
}
But InnerText is readonly. How can I replace texts with another text and save them to file ?
Try code below. It select all nodes without children and filtered out script nodes. Maybe you need to add some additional filtering. In addition to your XPath expression this one also looking for leaf nodes and filter out text content of <script> tags.
var nodes = doc.DocumentNode.SelectNodes("//body//text()[(normalize-space(.) != '') and not(parent::script) and not(*)]");
foreach (HtmlNode htmlNode in nodes)
{
htmlNode.ParentNode.ReplaceChild(HtmlTextNode.CreateNode(htmlNode.InnerText + "_translated"), htmlNode);
}
Strange, but I found that InnerHtml isn't readonly. And when I tried to set it like that
aElement.InnerHtml = "sometext";
the value of InnerText also changed to "sometext"
The HtmlTextNode class has a Text property* which works perfectly for this purpose.
Here's an example:
var textNodes = doc.DocumentNode.SelectNodes("//body/text()").Cast<HtmlTextNode>();
foreach (var node in textNodes)
{
node.Text = node.Text.Replace("foo", "bar");
}
And if we have an HtmlNode that we want to change its direct text, we can do something like the following:
HtmlNode node = //...
var textNode = (HtmlTextNode)node.SelectSingleNode("text()");
textNode.Text = "new text";
Or we can use node.SelectNodes("text()") in case it has more than one.
* Not to be confused with the readonly InnerText property.