C
C
Find and Update an XML Attribute Value
See more XML Examples
Demonstrates how to find an element in XML with a specified attribute name and then update the attribute value.Chilkat C Downloads
#include <C_CkXml.h>
#include <C_CkStringBuilder.h>
void ChilkatSample(void)
{
HCkXml xml1;
HCkXml xml2;
const char *phrase_id;
const char *phrase_value;
HCkStringBuilder sbPath;
int i;
int count_i;
// 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..
xml1 = CkXml_Create();
CkXml_putTag(xml1,"global");
CkXml_UpdateAttrAt(xml1,"phrase",TRUE,"id","2FADisabled");
CkXml_UpdateAttrAt(xml1,"phrase",TRUE,"value","2factor authentication disabled");
CkXml_UpdateAttrAt(xml1,"phrase[1]",TRUE,"id","2FAEnabled");
CkXml_UpdateAttrAt(xml1,"phrase[1]",TRUE,"value","2factor authentication enabled");
CkXml_UpdateAttrAt(xml1,"phrase[2]",TRUE,"id","2FAResetFailed");
CkXml_UpdateAttrAt(xml1,"phrase[2]",TRUE,"value","Failed to disable two factor authentication");
xml2 = CkXml_Create();
CkXml_putTag(xml2,"global");
CkXml_UpdateAttrAt(xml2,"phrase",TRUE,"id","2FAResetFailed");
CkXml_UpdateAttrAt(xml2,"phrase",TRUE,"value","Failed to reset two factor authentication");
CkXml_UpdateAttrAt(xml2,"phrase[1]",TRUE,"id","2FADisabled");
CkXml_UpdateAttrAt(xml2,"phrase[1]",TRUE,"value","2FA authentication disabled");
CkXml_UpdateAttrAt(xml2,"phrase[2]",TRUE,"id","2FAEnabled");
CkXml_UpdateAttrAt(xml2,"phrase[2]",TRUE,"value","2FA authentication enabled");
// Iterate over attribute values in xml2 and update the same in xml1.
sbPath = CkStringBuilder_Create();
i = 0;
count_i = CkXml_NumChildrenHavingTag(xml2,"phrase");
while (i < count_i) {
CkXml_putI(xml2,i);
phrase_id = CkXml_chilkatPath(xml2,"phrase[i]|(id)");
phrase_value = CkXml_chilkatPath(xml2,"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"
CkStringBuilder_SetString(sbPath,"/A/phrase,id,");
CkStringBuilder_Append(sbPath,phrase_id);
// This assumes the corresponding element exists in xml1.
CkXml_UpdateAttrAt(xml1,CkStringBuilder_getAsString(sbPath),TRUE,"value",phrase_value);
i = i + 1;
}
// Now see how xml1 has been updated..
printf("%s\n",CkXml_getXml(xml1));
// <global>
// <phrase id="2FADisabled" value="2FA authentication disabled"/>
// <phrase id="2FAEnabled" value="2FA authentication enabled"/>
// <phrase id="2FAResetFailed" value="Failed to reset two factor authentication"/>
// </global>
CkXml_Dispose(xml1);
CkXml_Dispose(xml2);
CkStringBuilder_Dispose(sbPath);
}