Objective-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. Objective-C

#import <CkoXml.h>
#import <NSString.h>
#import <CkoStringBuilder.h>

//  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..

CkoXml *xml1 = [[CkoXml alloc] init];
xml1.Tag = @"global";
[xml1 UpdateAttrAt: @"phrase" autoCreate: YES attrName: @"id" attrValue: @"2FADisabled"];
[xml1 UpdateAttrAt: @"phrase" autoCreate: YES attrName: @"value" attrValue: @"2factor authentication disabled"];
[xml1 UpdateAttrAt: @"phrase[1]" autoCreate: YES attrName: @"id" attrValue: @"2FAEnabled"];
[xml1 UpdateAttrAt: @"phrase[1]" autoCreate: YES attrName: @"value" attrValue: @"2factor authentication enabled"];
[xml1 UpdateAttrAt: @"phrase[2]" autoCreate: YES attrName: @"id" attrValue: @"2FAResetFailed"];
[xml1 UpdateAttrAt: @"phrase[2]" autoCreate: YES attrName: @"value" attrValue: @"Failed to disable two factor authentication"];

CkoXml *xml2 = [[CkoXml alloc] init];
xml2.Tag = @"global";
[xml2 UpdateAttrAt: @"phrase" autoCreate: YES attrName: @"id" attrValue: @"2FAResetFailed"];
[xml2 UpdateAttrAt: @"phrase" autoCreate: YES attrName: @"value" attrValue: @"Failed to reset two factor authentication"];
[xml2 UpdateAttrAt: @"phrase[1]" autoCreate: YES attrName: @"id" attrValue: @"2FADisabled"];
[xml2 UpdateAttrAt: @"phrase[1]" autoCreate: YES attrName: @"value" attrValue: @"2FA authentication disabled"];
[xml2 UpdateAttrAt: @"phrase[2]" autoCreate: YES attrName: @"id" attrValue: @"2FAEnabled"];
[xml2 UpdateAttrAt: @"phrase[2]" autoCreate: YES attrName: @"value" attrValue: @"2FA authentication enabled"];

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

NSString *phrase_id = 0;
NSString *phrase_value = 0;

CkoStringBuilder *sbPath = [[CkoStringBuilder alloc] init];

int i = 0;
int count_i = [[xml2 NumChildrenHavingTag: @"phrase"] intValue];
while (i < count_i) {
    xml2.I = [NSNumber numberWithInt: 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] autoCreate: YES attrName: @"value" attrValue: phrase_value];

    i = i + 1;
}

//  Now see how xml1 has been updated..
NSLog(@"%@",[xml1 GetXml]);

//  <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>