Objective-C

Xero Get Attachment (Download a Xero Attachment)

Demonstrates how to get the content of an attachment in Xero.

Note: This example requires Chilkat v9.5.0.64 or greater.

Objective-C

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

BOOL success = NO;

//  Note: Requires Chilkat v9.5.0.64 or greater.

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

CkoRest *rest = [[CkoRest alloc] init];

//  Before sending REST API calls, the REST object needs to be
//  initialized for OAuth1.
//  See Xero 2-Legged OAuth1 Setup for sample code.

//  Assuming the REST object's OAuth1 authenticator is setup, and the initial
//  connection was made, we may now send REST HTTP requests..

//  --------------------------------------------------------------
//  First get a list of attachments for a given document (in this case a Receipt).

NSString *endPoint = @"Receipts";
NSString *receiptID = @"c4f40e59-c390-0001-caff-ce731c707d00";

CkoStringBuilder *sbPath = [[CkoStringBuilder alloc] init];
[sbPath Append: @"/api.xro/2.0/{Endpoint}/{Guid}/Attachments/"];
int numReplaced = [[sbPath Replace: @"{Endpoint}" replacement: endPoint] intValue];
numReplaced = [[sbPath Replace: @"{Guid}" replacement: receiptID] intValue];

NSString *responseXml = [rest FullRequestNoBody: @"GET" uriPath: [sbPath GetAsString]];
if (rest.LastMethodSuccess != YES) {
    NSLog(@"%@",rest.LastErrorText);
    return;
}

//  A 200 response is expected for actual success.
if ([rest.ResponseStatusCode intValue] != 200) {
    NSLog(@"%@",responseXml);
    return;
}

//  Examine the response.
NSLog(@"%@",responseXml);

//  A sample response looks like this:

//  	<Response xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
//  	  <Id>b235646f-34ac-4b15-90ce-d63267f7cd33</Id>
//  	  <Status>OK</Status>
//  	  <ProviderName>ChilkatPrivate</ProviderName>
//  	  <DateTimeUTC>2016-11-11T14:32:17.0908971Z</DateTimeUTC>
//  	  <Attachments>
//  	    <Attachment>
//  	      <AttachmentID>0edcddc8-325f-40c7-b950-8c71f14afc7c</AttachmentID>
//  	      <FileName>penguins.jpg</FileName>
//  	      <Url>http://api.xero.com/api.xro/2.0/Receipts/c4f40e59-c390-0001-caff-ce731c707d00/Attachments/penguins.jpg</Url>
//  	      <MimeType>image/jpg</MimeType>
//  	      <ContentLength>777835</ContentLength>
//  	    </Attachment>
//  	    <Attachment>
//  	      <AttachmentID>0adffdc8-325f-65c7-b950-4391f14af908</AttachmentID>
//  	      <FileName>starfish.jpg</FileName>
//  	      <Url>http://api.xero.com/api.xro/2.0/Receipts/c4f40e59-c390-0001-caff-ce731c707d00/Attachments/starfish.jpg</Url>
//  	      <MimeType>image/jpg</MimeType>
//  	      <ContentLength>24537</ContentLength>
//  	    </Attachment>
//  	  </Attachments>
//  	</Response>

CkoXml *xml = [[CkoXml alloc] init];
[xml LoadXml: responseXml];

//  Iterate over the attachments and download each.
int numRecords = [[xml NumChildrenAt: @"Attachments"] intValue];
NSLog(@"%@%d",@"Number of Attachments = ",numRecords);

CkoStringBuilder *sbSaveFilePath = [[CkoStringBuilder alloc] init];
CkoStringBuilder *sbAttachmentPath = [[CkoStringBuilder alloc] init];
CkoBinData *attachmentData = [[CkoBinData alloc] init];
int i = 0;
while (i < numRecords) {
    xml.I = [NSNumber numberWithInt: i];
    NSString *attachmentID = [xml GetChildContent: @"Attachments|Attachment[i]|AttachmentID"];
    NSString *filename = [xml GetChildContent: @"Attachments|Attachment[i]|FileName"];

    NSLog(@"%@%@",@"AttachmentID: ",attachmentID);
    NSLog(@"%@%@",@"Filename: ",filename);
    NSLog(@"%@",@"----");

    //  Download this attachment.
    //  First build the path for this particular attachment by appending the FileName to the path used to get the list of attachments.
    [sbAttachmentPath Clear];
    [sbAttachmentPath AppendSb: sbPath];
    [sbAttachmentPath Append: filename];

    //  Send the GET request in one call, and then get the response in the next two.
    success = [rest SendReqNoBody: @"GET" uriPath: [sbAttachmentPath GetAsString]];
    if (success != YES) {
        NSLog(@"%@",rest.LastErrorText);
        return;
    }

    //  Get the response header.  If it's not a 200 success status code, then the response body does NOT contain
    //  the attachment data.
    int statusCode = [[rest ReadResponseHeader] intValue];
    if (statusCode == -1) {
        //  We didn't get any response..
        NSLog(@"%@",rest.LastErrorText);
        return;
    }

    if (statusCode != 200) {
        NSLog(@"%@%d",@"Response Status: ",statusCode);
        NSString *responseBody = [rest ReadRespBodyString];
        if (rest.LastMethodSuccess != YES) {
            NSLog(@"%@",@"Failed to read the response body.");
        }
        else {
            NSLog(@"%@",responseBody);
        }

        NSLog(@"%@",@"Failed.");
        return;
    }

    //  OK, the response header indicates the attachment content is forthcoming...
    //  There are a few ways to get the response body. If it is a very large attachment, it can be streamed directly
    //  to a file.  We'll assume it's not, so we'll get the response into a BinData object, and then save it to a file.
    [attachmentData Clear];
    success = [rest ReadRespBd: attachmentData];
    if (success != YES) {
        NSLog(@"%@",rest.LastErrorText);
        return;
    }

    //  Save the data to the file.
    [sbSaveFilePath SetString: @"qa_output/"];
    [sbSaveFilePath Append: filename];
    success = [attachmentData WriteFile: [sbSaveFilePath GetAsString]];
    if (success != YES) {
        NSLog(@"%@",@"Failed to save to output file.");
    }
    else {
        NSLog(@"%@%@",@"Saved to ",[sbSaveFilePath GetAsString]);
    }

    i = i + 1;
}