Delphi DLL

Page Through All Contacts

See more Google APIs Examples

Demonstrates how to page through the entire list of Google Contacts. Delphi 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
success: Boolean;
jsonToken: HCkJsonObject;
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
success := False;

// 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;