(Delphi ActiveX) Page Through All Contacts

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

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

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
jsonToken: TChilkatJsonObject;
success: Integer;
gAuth: TChilkatAuthGoogle;
rest: TChilkatRest;
bAutoReconnect: Integer;
startIndex: Integer;
maxResults: Integer;
totalResults: Integer;
sbMaxResults: TChilkatStringBuilder;
sbStartIndex: TChilkatStringBuilder;
loopIteration: Integer;
sbResponseBody: TChilkatStringBuilder;
xml: TChilkatXml;
startIndex2: Integer;
itemsPerPage: Integer;
numEntries: Integer;
i: Integer;
idUrl: WideString;
fullName: WideString;
emailAddress: WideString;
xLink: IChilkatXml;
bHasPhoto: Integer;

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 := TChilkatJsonObject.Create(Self);
success := jsonToken.LoadFile('qa_data/tokens/googleContacts.json');
if (success <> 1) then
  begin
    Memo1.Lines.Add('Failed to load googleContacts.json');
    Exit;
  end;

gAuth := TChilkatAuthGoogle.Create(Self);
gAuth.AccessToken := jsonToken.StringOf('access_token');

rest := TChilkatRest.Create(Self);

// Connect using TLS.
bAutoReconnect := 1;
success := rest.Connect('www.google.com',443,1,bAutoReconnect);

// Provide the authentication credentials (i.e. the access token)
rest.SetAuthGoogle(gAuth.ControlInterface);

// ----------------------------------------------
// 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 := TChilkatStringBuilder.Create(Self);
sbMaxResults.AppendInt(maxResults);
sbStartIndex := TChilkatStringBuilder.Create(Self);

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

    sbStartIndex.Clear();
    sbStartIndex.AppendInt(startIndex);

    rest.ClearAllHeaders();
    rest.ClearAllQueryParams();
    rest.AddHeader('GData-Version','3.0');
    rest.AddQueryParam('start-index',sbStartIndex.GetAsString());
    rest.AddQueryParam('max-results',sbMaxResults.GetAsString());

    sbResponseBody := TChilkatStringBuilder.Create(Self);
    success := rest.FullRequestNoBodySb('GET','/m8/feeds/contacts/default/full',sbResponseBody.ControlInterface);
    if (success <> 1) then
      begin
        Memo1.Lines.Add(rest.LastErrorText);
        Exit;
      end;

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

    // If the 200 response was received, then the contacts XML is contained
    // in the response body.
    xml := TChilkatXml.Create(Self);
    xml.LoadSb(sbResponseBody.ControlInterface,0);

    // 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 := xml.GetChildIntValue('openSearch:totalResults');
    startIndex2 := xml.GetChildIntValue('openSearch:startIndex');
    itemsPerPage := xml.GetChildIntValue('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 := xml.NumChildrenHavingTag('entry');
    i := 0;
    while i < numEntries do
      begin
        xml.I := i;
        Memo1.Lines.Add(IntToStr(loopIteration * maxResults + i + 1) + ' ----');
        Memo1.Lines.Add('title: ' + xml.GetChildContent('entry[i]|title'));

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

        fullName := xml.ChilkatPath('entry[i]|gd:name|gd:fullName|*');
        if (xml.LastMethodSuccess = 1) then
          begin
            Memo1.Lines.Add('fullName: ' + fullName);
          end;

        emailAddress := xml.ChilkatPath('entry[i]|gd:email|(address)');
        if (xml.LastMethodSuccess = 1) then
          begin
            Memo1.Lines.Add('email address: ' + emailAddress);
          end;

        // Find the photo link and check to see if this contact has a photo.
        xLink := xml.GetChildWithAttr('link','rel','http://schemas.google.com/contacts/2008/rel#photo');
        if (xml.LastMethodSuccess = 1) then
          begin
            // Get the photo etag.
            bHasPhoto := xLink.HasAttribute('gd:etag');
            if (bHasPhoto = 1) then
              begin
                Memo1.Lines.Add('This contact has a photo.');
              end;

          end;

        i := i + 1;
      end;

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