B4X

S3 Get Bucket Objects with CommonPrefixes

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Demonstrates how to get a list of bucket objects using the prefix and delimiter query params to get an XML result with CommonPrefixes. B4X

Dim success As Boolean = False

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

Dim http As ChilkatHttp
http.Initialize("http")

'  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
Dim strXml As String = http.S3_ListBucketObjects("chilkat100?prefix=images/&delimiter=/")
If http.LastMethodSuccess <> True Then
    Log(http.LastErrorText)
    Return
End If


Log("Response status code = " & http.LastStatus)

Dim xml As ChilkatXml
xml.Initialize
success = xml.LoadXml(strXml)
If success <> True Then
    Log(xml.LastErrorText)
    Return
End If


'  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 <> 200 Then
    Log(xml.GetXml)
    Log("Failed.")
    Return
End If


'  A sample response is shown below.
Log(xml.GetXml)
Log("----")

'  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>

Dim Prefix As String

'  The XML can be parsed like this:
Dim i As Int = 0
Dim count_i As Int = xml.NumChildrenHavingTag("CommonPrefixes")
Do While i < count_i
    xml.I = i
    Prefix = xml.GetChildContent("CommonPrefixes[i]|Prefix")
    Log("Prefix = " & Prefix)
    i = i + 1
Loop