(C#) Find and Update an XML Attribute Value

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Demonstrates how to find an element in XML with a specified attribute name and then update the attribute value.

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// Let's say you have 2 XML files with identical structures as shown directly below,
// and you wish to update the values in the 1st XML file with those in the 2nd XML file.

// <global>
//     <phrase id="2FADisabled" value="2factor authentication disabled"/>
//     <phrase id="2FAEnabled" value="2factor authentication enabled"/>
//     <phrase id="2FAResetFailed" value="Failed to disable two factor authentication"/>
// </global>

// <global>
//     <phrase id="2FAResetFailed" value="Failed to reset two factor authentication"/>
//     <phrase id="2FADisabled" value="2FA authentication disabled"/>
//     <phrase id="2FAEnabled" value="2FA authentication enabled"/>
// </global>

// First, initialize each of the Chilkat XML objects.
// These could be loaded from files, but we'll just create them manually for this example..

Chilkat.Xml xml1 = new Chilkat.Xml();
xml1.Tag = "global";
xml1.UpdateAttrAt("phrase",true,"id","2FADisabled");
xml1.UpdateAttrAt("phrase",true,"value","2factor authentication disabled");
xml1.UpdateAttrAt("phrase[1]",true,"id","2FAEnabled");
xml1.UpdateAttrAt("phrase[1]",true,"value","2factor authentication enabled");
xml1.UpdateAttrAt("phrase[2]",true,"id","2FAResetFailed");
xml1.UpdateAttrAt("phrase[2]",true,"value","Failed to disable two factor authentication");

Chilkat.Xml xml2 = new Chilkat.Xml();
xml2.Tag = "global";
xml2.UpdateAttrAt("phrase",true,"id","2FAResetFailed");
xml2.UpdateAttrAt("phrase",true,"value","Failed to reset two factor authentication");
xml2.UpdateAttrAt("phrase[1]",true,"id","2FADisabled");
xml2.UpdateAttrAt("phrase[1]",true,"value","2FA authentication disabled");
xml2.UpdateAttrAt("phrase[2]",true,"id","2FAEnabled");
xml2.UpdateAttrAt("phrase[2]",true,"value","2FA authentication enabled");

// Iterate over attribute values in xml2 and update the same in xml1.

string phrase_id;
string phrase_value;

Chilkat.StringBuilder sbPath = new Chilkat.StringBuilder();

int i = 0;
int count_i = xml2.NumChildrenHavingTag("phrase");
while (i < count_i) {
    xml2.I = i;
    phrase_id = xml2.ChilkatPath("phrase[i]|(id)");
    phrase_value = xml2.ChilkatPath("phrase[i]|(value)");

    // Notice how the UpdateAttrAt method's 1st argument is a Chilkat path -- which is an expression
    // to find the location of the XML element to be updated.
    // Here we create a path of the form "/A/tagName,attributeName,attributeValuePattern", which means
    // find the direct descendent of xml2 having tag=tagName, with an attribute=attributeName where the attribute value
    // matches the attributeValuePattern.  If attributeValuePattern does not contain a "*", then it must match directly.
    // We'll build a Chilkat path such as "/A/phrase,id,2FADisabled"
    sbPath.SetString("/A/phrase,id,");
    sbPath.Append(phrase_id);

    // This assumes the corresponding element exists in xml1.
    xml1.UpdateAttrAt(sbPath.GetAsString(),true,"value",phrase_value);

    i = i + 1;
}

// Now see how xml1 has been updated..
Debug.WriteLine(xml1.GetXml());