(Delphi DLL) Page Through All Contacts

Demonstrates how to page through the entire list of Google Contacts.

Chilkat for Delphi Downloads Chilkat non-ActiveX DLL for Delphi Chilkat ActiveX DLL for Delphi * The examples here use the non-ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, StringBuilder, AuthGoogle, Xml, JsonObject, Rest;

...

procedure TForm1.Button1Click(Sender: TObject);
var
jsonToken: HCkJsonObject;
success: Boolean;
gAuth: HCkAuthGoogle;
rest: HCkRest;
bAutoReconnect: Boolean;
startIndex: Integer;
maxResults: Integer;
totalResults: Integer;
sbMaxResults: HCkStringBuilder;
sbStartIndex: HCkStringBuilder;
loopIteration: Integer;
sbResponseBody: HCkStringBuilder;
xml: HCkXml;
startIndex2: Integer;
itemsPerPage: Integer;
numEntries: Integer;
i: Integer;
idUrl: PWideChar;
fullName: PWideChar;
emailAddress: PWideChar;
xLink: HCkXml;
bHasPhoto: Boolean;

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

// --------------------------------------------------------------------------------------------------------
// Note: The code for setting up the Chilkat REST object and making the initial connection can be done once.
// Once connected, the REST object may be re-used for many REST API calls.
// (It's a good idea to put the connection setup code in a separate function/subroutine.)
// --------------------------------------------------------------------------------------------------------

// It is assumed we previously obtained an OAuth2 access token.
// This example loads the JSON access token file 
// saved by this example: Get Google Contacts OAuth2 Access Token

jsonToken := CkJsonObject_Create();
success := CkJsonObject_LoadFile(jsonToken,'qa_data/tokens/googleContacts.json');
if (success <> True) then
  begin
    Memo1.Lines.Add('Failed to load googleContacts.json');
    Exit;
  end;

gAuth := CkAuthGoogle_Create();
CkAuthGoogle_putAccessToken(gAuth,CkJsonObject__stringOf(jsonToken,'access_token'));

rest := CkRest_Create();

// Connect using TLS.
bAutoReconnect := True;
success := CkRest_Connect(rest,'www.google.com',443,True,bAutoReconnect);

// Provide the authentication credentials (i.e. the access token)
CkRest_SetAuthGoogle(rest,gAuth);

// ----------------------------------------------
// OK, the REST connection setup is completed..
// ----------------------------------------------

startIndex := 1;
maxResults := 25;
// The totalResults will get updated with the correct value in the 1st loop iteration..
totalResults := 100;
// To retrieve the contacts in pages of 25 each, we need to send the following for each page.

// 	GET /m8/feeds/contacts/default/full?max-results=25&start-index=<startIndex>
// 	GData-Version: 3.0

sbMaxResults := CkStringBuilder_Create();
CkStringBuilder_AppendInt(sbMaxResults,maxResults);
sbStartIndex := CkStringBuilder_Create();

loopIteration := 0;
while startIndex <= totalResults do
  begin

    CkStringBuilder_Clear(sbStartIndex);
    CkStringBuilder_AppendInt(sbStartIndex,startIndex);

    CkRest_ClearAllHeaders(rest);
    CkRest_ClearAllQueryParams(rest);
    CkRest_AddHeader(rest,'GData-Version','3.0');
    CkRest_AddQueryParam(rest,'start-index',CkStringBuilder__getAsString(sbStartIndex));
    CkRest_AddQueryParam(rest,'max-results',CkStringBuilder__getAsString(sbMaxResults));

    sbResponseBody := CkStringBuilder_Create();
    success := CkRest_FullRequestNoBodySb(rest,'GET','/m8/feeds/contacts/default/full',sbResponseBody);
    if (success <> True) then
      begin
        Memo1.Lines.Add(CkRest__lastErrorText(rest));
        Exit;
      end;

    // A successful response will have a status code equal to 200.
    if (CkRest_getResponseStatusCode(rest) <> 200) then
      begin
        Memo1.Lines.Add('response status code = ' + IntToStr(CkRest_getResponseStatusCode(rest)));
        Memo1.Lines.Add('response status text = ' + CkRest__responseStatusText(rest));
        Memo1.Lines.Add('response header: ' + CkRest__responseHeader(rest));
        Memo1.Lines.Add('response body: ' + CkStringBuilder__getAsString(sbResponseBody));
        Exit;
      end;

    // If the 200 response was received, then the contacts XML is contained
    // in the response body.
    xml := CkXml_Create();
    CkXml_LoadSb(xml,sbResponseBody,False);

    // Now let's parse the XML...

    // Get the the total number of results, the start index, and the items per page.
    // We'll likely NOT get the full list, but will instead get the 1st page.
    totalResults := CkXml_GetChildIntValue(xml,'openSearch:totalResults');
    startIndex2 := CkXml_GetChildIntValue(xml,'openSearch:startIndex');
    itemsPerPage := CkXml_GetChildIntValue(xml,'openSearch:itemsPerPage');
    Memo1.Lines.Add('totalResults = ' + IntToStr(totalResults));
    Memo1.Lines.Add('startIndex = ' + IntToStr(startIndex2));
    Memo1.Lines.Add('itemsPerPage = ' + IntToStr(itemsPerPage));

    // Iterate over each contact.
    numEntries := CkXml_NumChildrenHavingTag(xml,'entry');
    i := 0;
    while i < numEntries do
      begin
        CkXml_putI(xml,i);
        Memo1.Lines.Add(IntToStr(loopIteration * maxResults + i + 1) + ' ----');
        Memo1.Lines.Add('title: ' + CkXml__getChildContent(xml,'entry[i]|title'));

        idUrl := CkXml__getChildContent(xml,'entry[i]|id');
        Memo1.Lines.Add('id: ' + idUrl);

        fullName := CkXml__chilkatPath(xml,'entry[i]|gd:name|gd:fullName|*');
        if (CkXml_getLastMethodSuccess(xml) = True) then
          begin
            Memo1.Lines.Add('fullName: ' + fullName);
          end;

        emailAddress := CkXml__chilkatPath(xml,'entry[i]|gd:email|(address)');
        if (CkXml_getLastMethodSuccess(xml) = True) then
          begin
            Memo1.Lines.Add('email address: ' + emailAddress);
          end;

        // Find the photo link and check to see if this contact has a photo.
        xLink := CkXml_GetChildWithAttr(xml,'link','rel','http://schemas.google.com/contacts/2008/rel#photo');
        if (CkXml_getLastMethodSuccess(xml) = True) then
          begin
            // Get the photo etag.
            bHasPhoto := CkXml_HasAttribute(xLink,'gd:etag');
            if (bHasPhoto = True) then
              begin
                Memo1.Lines.Add('This contact has a photo.');
              end;
            CkXml_Dispose(xLink);
          end;

        i := i + 1;
      end;

    startIndex := startIndex + maxResults;
    loopIteration := loopIteration + 1;
  end;

CkJsonObject_Dispose(jsonToken);
CkAuthGoogle_Dispose(gAuth);
CkRest_Dispose(rest);
CkStringBuilder_Dispose(sbMaxResults);
CkStringBuilder_Dispose(sbStartIndex);
    CkStringBuilder_Dispose(sbResponseBody);
    CkXml_Dispose(xml);

end;