Imagine, you are confronted with a big textfile, for example HTML, and only want to edit one line of code in this file.
The standard approach would be to first read everthing and then write everthing, including the changed text, back to a separate file, which would not be very efficient in this usecase.
I want to use a similar approach to open a file in the Editor, find the line you need and then edit this specific line.
Is there any FileIO that allows actual editing/replacing in stead of plain append or create?
EDIT:
What I have in my mind so far is exactly the example that Rahul Singh gave below.
But as mentioned, if I think about this approach it doesn't seem very efficient if you just want to edit one or even a few lines. In my actual problem where the question came from, the file is a HTML file in which want to insert a additional table row. But I think this use-case also is interesting to all files that contains plain text
You can use HTML Agility Pack.
This is an agile HTML parser that builds a read/write DOM and supports
plain XPATH or XSLT.It is a .NET code library that allows you to parse "out of the web"
HTML files.
For example this code fix all hrefs in HTML file:
HtmlDocument doc = new HtmlDocument();
doc.Load("file.htm");
foreach(HtmlNode link in doc.DocumentElement.SelectNodes("//a[#href"])
{
HtmlAttribute att = link["href"];
att.Value = FixLink(att); //FixLink() is your custom method
}
doc.Save("file.htm");
firstly please share what you have tried so far, as we dont have any idea upon data that your textFile contains,
First read through out the file in streamreader and store it into string then do string.replace and do the editing, you could also use the split options and by check it by contains function do the editing.
and you can always go by XSLT options but for that you need to use XPath to select
Related
I have html code:
<p>Answer1</p>
<h2>Category1</h2>
<p>Answer2</p>
<p>Answer3</p>
I need to do parsing so that each answer (p) belongs to the category(h2) above.
If nothing is above, then the category will be null.
Look like this :
obj1.category = null; obj1.answer = "Answer1";
obj2.category ="Category1"; obj2.answer = "Answer2";
obj3.category ="Category1"; obj3.answer = "Answer3";
I tried to solve this, but it was useless.
Use HTMLAgilityPack. It will parse HTML and allow you do use LINQ to SELECT whatever you need from the DOM structure.
In addition to HTMLAgilityPack, I've also written a light weight HTML parse for C#.
There's no big secret to the technique, but it's sort of detailed work. You just go through the text character by character and pull out HTML elements.
My parser is on Github as HtmlMonkey.
UPDATE:
I just added support for fairly advanced selectors to easily find nodes within a parsed document.
I'm trying to use the OpenXML SDK and the samples on Microsoft's pages to replace placeholders with real content in Word documents.
It used to work as described here, but after editing the template file in Word adding headers and footers it stopped working. I wondered why and some debugging showed me this:
Which is the content of texts in this piece of code:
using (WordprocessingDocument wordDoc = WordprocessingDocument.Open(DocumentFile, true))
{
var texts = wordDoc.MainDocumentPart.Document.Body.Descendants<Text>().ToList();
}
So what I see here is that the body of the document is "fragmented", even though in Word the content looks like this:
Can somebody tell me how I can get around this?
I have been asked what I'm trying to achieve. Basically I want to replace user defined "placeholders" with real content. I want to treat the Word document like a template. The placeholders can be anything. In my above example they look like {var:Template1}, but that's just something I'm playing with. It could basically be any word.
So for example if the document contains the following paragraph:
Do not use the name USER_NAME
The user should be able to replace the USER_NAME placeholder with the word admin for example, keeping the formatting intact. The result should be
Do not use the name admin
The problem I see with working on paragraph level, concatenating the content and then replacing the content of the paragraph, I fear I'm losing the formatting that should be kept as in
Do not use the name admin
Various things can fragment text runs. Most frequently proofing markup (as apparently is the case here, where there are "squigglies") or rsid (used to compare documents and track who edited what, when), as well as the "Go back" bookmark Word sets in the background. These become readily apparent if you view the underlying WordOpenXML (using the Open XML SDK Productivity Tool, for example) in the document.xml "part".
It usually helps to go an element level "higher". In this case, get the list of Paragraph descendants and from there get all the Text descendants and concatenate their InnerText.
OpenXML is indeed fragmenting your text:
I created a library that does exactly this : render a word template with the values from a JSON.
From the documenation of docxtemplater :
Why you should use a library for this
Docx is a zipped format that contains some xml. If you want to build a simple replace {tag} by value system, it can already become complicated, because the {tag} is internally separated into <w:t>{</w:t><w:t>tag</w:t><w:t>}</w:t>. If you want to embed loops to iterate over an array, it becomes a real hassle.
The library basically will do the following to keep formatting :
If the text is :
<w:t>Hello</w:t>
<w:t>{name</w:t>
<w:t>} !</w:t>
<w:t>How are you ?</w:t>
The result would be :
<w:t>Hello</w:t>
<w:t>John !</w:t>
<w:t>How are you ?</w:t>
You also have to replace the tag by <w:t xml:space=\"preserve\"> to ensure that the space is not stripped out if they is any in your variables.
I need to retrieve some info from an html doc since the web service to get a json or an xml is still not ready. Im working with c# and using regular expressions to get the data i need from the html string. I've managed to get the div i want to work with from the whole html string but now i'm having trouble getting the info between the first span tag.
I've attempted to retrieve the data between ; and the first closing span tag but what i really want is the content between the first span tag.
Here's the regular expression i've written so far, but it's not working:
".*;(?<Content>(\r|\n|.)*)</span>"
I also tried this but didnt work either:
"<span class=""type"">(?<Content>(\r|\n|.)*)</span>"
Here is the div i want to retrieve the data from:
<div class="main">ABASASDFÓ 18/06/2014 17:38h Blabla Balbal <span class="type">15.80€ </span>+1.94 % +0.30€ | HOME <SPAN class="type2">11,398.70</span> +0.65 % +74.10</div>
EDIT: I can't use Htmlagilitypack since my client does not want us to use any external library. I've also heard about using the XmlReader but i'm not sure the structure of the html will match an xml one accordingly.
This regex will capture the string:
"<span class=\"type\">(?<Content>([^<]*))</span>"
Although, I agree with other answers, you should use something like Path instead of Regexes for parsing html.
Here's how it is done with a regex in Javascript. You should be able to adapt this for C# pretty easily.
var inner = html.match( /<span class="type"(?:\s+[a-z]+(?:\s*=\s*(?:"[^"]*"|'[^']*'|[^\s>]+)))*\s*>([\S\s]*)<\/span>/i)[1];
Fiddle: http://jsfiddle.net/GarryPas/uk32r8vz/
You want to use XPath for that. Something like this:
div/span/text()
I understand not wanting some external 3rd party library in your solution, the solution to that is to go fetch the source code of the entire library:
https://htmlagilitypack.codeplex.com/
Now you don't have an external library, you have an internal library and you can use the right tool for the job!
XmlReader is a fairly low-level tool, it could technically do the job for you but what you're more after is "use XmlReader to do XPath" which is talked about here: https://msdn.microsoft.com/en-us/library/ms950778.aspx
The XPathReader class is the result of all that, which has been superseded by LINQ to XML: https://msdn.microsoft.com/en-ca/library/bb387098.aspx
So another option here is to try to use some LINQ to process your HTML file, but that might be tricky since HTML isn't good XML. Still, it's another option if you're looking for those.
Hey guys, XDocument is being very finicky with one of the xml feeds I have to parse, and keeps giving me the error
'=' is an unexpected token. The expected token is ';'. Line 1, position 576.
Which is basically XDocument crying about a loose "=" sign in the XML document.
I don't have any control over the source XML document, so I need to either get XDocument to ignore this error, or use some other class. Any ideas on either one?
If the document isn't well-formed XML (and my guess is that you have '&=' in the document or some other entity-looking string) then it's unlikely that any other XML parsers are going to be any happier with it. Have you tried loading the document in, say, IE to see if it parses there or pasted to an XML validator? You can also just try XmlDocument.Load() and see if it parses there, that's the next closest XML parser (aside from XmlReader which takes a little bit of setting up).
It won't make for good XML, but if you need to just load up a bad document then the HTML Agility Pack is a good tool. It can overlook many of the things that make HTML not XHTML and not XML-like, so your erroneous XML input will likely be parsed too. The object model it expresses is similar to XmlDocument. e.g.
HtmlDocument doc = new HtmlDocument();
doc.Load("file.xml");
foreach(HtmlNode link in doc.DocumentElement.SelectNodes("//a[#href"])
{
HtmlAttribute att = link["href"];
att.Value = FixLink(att);
}
doc.Save("file.htm");
Or you can use Agility Pack to clean up the XML and then feed its clean output to a real XML parser for further processing.
This is a quick and dirty trick that I've used for one-time tasks. It's not necessarily recommended over a proper solution.
What I would recommended if time permits is to somehow format/fix the erroneous XML content (e.g. maybe in its string form, or using another tool) before feeding it to an XML parser.
Take a look at the answers of this question: Parsing an XML/XHTML document but ignoring errors in C#
The best option I believe is to parse it in a try/catch block, remove the offending block inside the catch block, and re-parse.
What would be the best way to search through HTML inside a C# string variable to find a specific word/phrase and mark (or wrap) that word/phrase with a highlight?
Thanks,
Jeff
I like using Html Agility Pack very easy to use, although there hasn't been much updates lately, it is still usable. For example grabbing all the links
HtmlWeb client = new HtmlWeb();
HtmlDocument doc = client.Load("http://yoururl.com");
HtmlNodeCollection Nodes = doc.DocumentNode.SelectNodes("//a[#href]");
foreach (var link in Nodes)
{
Console.WriteLine(link.Attributes["href"].Value);
}
Regular Expression would be my way. ;)
If the HTML you're using XHTML compliant, you could load it as an XML document, and then use XPath/XSL - long winded but kind of elegant?
An approach I used in the past is to use HTMLTidy to convert messy HTML to XHTML, and then use XSL/XPath for screen scraping content into a database, to create a reverse content management system.
Regular expressions would do it, but could be complicated once you try stripping out tags, image names etc, to remove false positives.
In simple cases, regular expressions will do.
string input = "ttttttgottttttt";
string output = Regex.Replace(input, "go", "<strong>$0</strong>");
will yield: "tttttt<strong>go</strong>ttttttt"
But when you say HTML, if you're referring to final text rendered, that's a bit of a mess. Say you've got this HTML:
<span class="firstLetter">B</span>ook
To highlight the word 'Book', you would need the help of a proper HTML renderer. To simplify, one can first remove all tags and leave only contents, and then do the usual replace, but it doesn't feel right.
You could look at using Html DOM, an open source project on SourceForge.net.
This way you could programmatically manipulate your text instead of relying regular expressions.
Searching for strings, you'll want to look up regular expressions. As for marking it, once you have the position of the substring it should be simple enough to use that to add in something to wrap around the phrase.