(Objective-C) S3 Get Bucket Objects with CommonPrefixes

Demonstrates how to get a list of bucket objects using the prefix and delimiter query params to get an XML result with CommonPrefixes.

Chilkat Objective-C Library Downloads MAC OS X (Cocoa) Libs iOS Libs

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

// This example assumes the Chilkat HTTP API to have been previously unlocked.
// See Global Unlock Sample for sample code.

CkoHttp *http = [[CkoHttp alloc] init];

// Insert your access key here:
http.AwsAccessKey = @"AWS_ACCESS_KEY";

// Insert your secret key here:
http.AwsSecretKey = @"AWS_SECRET_KEY";

// In this example, my bucket is "chilkat100".
// It contains a number of folders, one of which is named "images".
// I want to get a list of all sub-folders under the "images" folder
NSString *strXml = [http S3_ListBucketObjects: @"chilkat100?prefix=images/&delimiter=/"];
if (http.LastMethodSuccess != YES) {
    NSLog(@"%@",http.LastErrorText);
    return;
}

NSLog(@"%@%d",@"Response status code = ",[http.LastStatus intValue]);

CkoXml *xml = [[CkoXml alloc] init];
BOOL success = [xml LoadXml: strXml];
if (success != YES) {
    NSLog(@"%@",xml.LastErrorText);
    return;
}

// If the response status code was not 200, then the XML response is not a 
// listing of objects, but instead contains error information.
if ([http.LastStatus intValue] != 200) {
    NSLog(@"%@",[xml GetXml]);
    NSLog(@"%@",@"Failed.");
    return;
}

// A sample response is shown below.
NSLog(@"%@",[xml GetXml]);
NSLog(@"%@",@"----");

// Here is the list of sub-folders (i.e. CommonPrefixes)

// <?xml version="1.0" encoding="UTF-8"?>
// <ListBucketResult xmlns="http://s3.amazonaws.com/doc/2006-03-01/">
//     <Name>chilkat100</Name>
//     <Prefix>images/</Prefix>
//     <Marker/>
//     <MaxKeys>1000</MaxKeys>
//     <Delimiter>/</Delimiter>
//     <IsTruncated>false</IsTruncated>
//     <CommonPrefixes>
//         <Prefix>images/africa/</Prefix>
//     </CommonPrefixes>
//     <CommonPrefixes>
//         <Prefix>images/sea_creatures/</Prefix>
//     </CommonPrefixes>
// </ListBucketResult>

NSString *Prefix = 0;

// The XML can be parsed like this:
int i = 0;
int count_i = [[xml NumChildrenHavingTag: @"CommonPrefixes"] intValue];
while (i < count_i) {
    xml.I = [NSNumber numberWithInt: i];
    Prefix = [xml GetChildContent: @"CommonPrefixes[i]|Prefix"];
    NSLog(@"%@%@",@"Prefix = ",Prefix);
    i = i + 1;
}