Please tell me how to find and replace particular word in a file using vb.net

Question

i have created a template xml file witch contain some words like {contentname}. i need to replace such a tags with my values. please tell me how to search such a words and replace using filehandling in vb.net my xml templatefile is like this:

<!-- BEGIN: main -->
<?xml version="1.0" encoding="UTF-8"?>
<OTA_HotelSearchRQ xmlns="http://www.opentravel.org/OTA/2003/05" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.opentravel.org/OTA/2003/05OTA_HotelSearchRQ.xsd" EchoToken="{EchoToken}" Target="{Target}" Version="1.006" PrimaryLangID="{PrimaryLangId}" MaxResponses="{MaxResponses}">
<POS>
<!-- BEGIN:Source -->
<Source>
<RequestorID ID="{affiliateId}" MessagePassword="{MessagePassword}" />
</Source>
<!-- END:Source -->
</POS>
<Criteria <!-- BEGIN:AvailableOnlyIndicator -->AvailableOnlyIndicator="    {AvailableOnlyIndicator}"<!-- END:AvailableOnlyIndicator -->>
<Criterion>

Answer 1

If you have a valid XML file as template, you should follow one of two ways:

• Open it as XmlDocument and update your values through DOM
• Create a XSLT and pass your parameters to transform your template

Below I'm talking about first method. I'll write C#, but you can easily translate it to VB.NET:

XmlDocument doc = new XmlDocument();
doc.Load("yourfile.xml");

XmlNamespaceManager nsmgr = new XmlNamespaceManager(doc.NameTable);
nsmgr.AddNamespace("ota", "http://www.opentravel.org/OTA/2003/05")

XmlElement hotelSearch = doc.SelectSingleNode
    ("/ota:OTA_HotelSearchRQ", nsmgr) as XmlElement;
hotelSearch.SetAttribute("EchoToken", "{EchoToken}");
hotelSearch.SetAttribute("Target", "{Target}");
// ... and so on ...

XmlElement requestorId = hotelSearch.SelectSingleNode
    ("ota:POS/ota:Source/ota:RequestorID", nsmgr) as XmlElement;
requestorId.SetAttribute("ID", "{affiliateId}");
requestorId.SetAttribute("MessagePassword", "{MessagePassword}");
// ... and so on ...

Answer 2

For something like this, if the files are small and text based, I would use regular expression Replace, or the simpler String.Replace.

Answer 3

VB.NET version (if someone requires. Its working) of solution provided by Mr. Rubens Farias:

Dim doc As XmlDocument = New XmlDocument()
    doc.Load(HttpContext.Current.Server.MapPath("~\actions\HOTEL_SEARCH.template.xml"))

    Dim nsmgr As XmlNamespaceManager = New XmlNamespaceManager(doc.NameTable)
    nsmgr.AddNamespace("ota", "http://www.opentravel.org/OTA/2003/05")

    Dim hotelSearch As XmlElement = CType(doc.SelectSingleNode("/ota:OTA_HotelSearchRQ", nsmgr), XmlElement)
    hotelSearch.SetAttribute("EchoToken", BLLHotel_Search.EchoToken)
    hotelSearch.SetAttribute("Target", BLLHotel_Search.Target)

    Dim requestorId As XmlElement = CType(hotelSearch.SelectSingleNode("ota:POS/ota:Source/ota:RequestorID", nsmgr), XmlElement)
    hotelSearch.SetAttribute("ID", BLLHotel_Search.affiliateId)
    hotelSearch.SetAttribute("MessagePassword", BLLHotel_Search.MessagePassword)

    doc.Save(HttpContext.Current.Server.MapPath("hello.xml"))

Answer 4

You could use String.Replace.