Lazarus Pascal Requires Chilkat v11.7.0+
Lazarus Pascal
Box: Resolve a File Version by Name and Verify the Download
See more Box Examples
Run the reusable setup once per HttpCurl object, then select names and execute the operation. The setup is repeated here only to make this published example independently runnable. One target request requires file_id and file_version_id. The engine uses AddOutput2 for name lookups and AddOutput for version/SHA-1 metadata, then downloads that version to local_path and verifies its digest.
See the Box API guide for setup and the complete workflow.
Chilkat Lazarus Pascal Downloads
program ChilkatDemo;
// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.
{$IFDEF FPC}
{$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}
uses
{$IFDEF UNIX}
cthreads,
{$ENDIF}
SysUtils,
CkDllLoader,
Chilkat.HttpCurl,
Chilkat.StringBuilder,
Chilkat.Crypt2;
// ---------------------------------------------------------------------------
procedure RunDemo;
var
success: Boolean;
curl: THttpCurl;
setupCommand: TStringBuilder;
setupReplacements: Integer;
parentName: string;
folderName: string;
fileName: string;
authorizedCommand1: TStringBuilder;
headerReplacement1: Integer;
digest: TCrypt2;
actualSha1: string;
begin
success := False;
// Requires Chilkat 11.7.0 or later and a previously unlocked Chilkat bundle.
// See Global Unlock Sample.
// Guide: Box API Guide.
success := False;
// BEGIN ONE-TIME SETUP
// This block is repeated so each published example can run on its own.
// In an application, run the setup example once and pass the SAME curl object
// to operation code below. Do not recreate it for every operation.
// See Reusable Box HttpCurl Setup.
curl := THttpCurl.Create;
curl.SetVar('access_token','BOX_ACCESS_TOKEN');
curl.SetVar('parent_name','/');
// Box's fixed root ID is an implementation detail; callers supply names.
curl.SetVar('parent_id','0');
setupCommand := TStringBuilder.Create;
// Register findParent; registration sends no request.
setupCommand.SetString('curl -X GET "https://api.box.com/2.0/folders/0/items?limit=1000&fields=id,type,name" -H "Authorization: Bearer ACCESS_TOKEN"');
setupReplacements := setupCommand.Replace('ACCESS_TOKEN',curl.GetVar('access_token'));
success := curl.AddFunction('findParent',setupCommand.GetAsString());
if (success <> True) then
begin
WriteLn(curl.LastErrorText);
Exit;
end;
// Register findFolder; registration sends no request.
setupCommand.SetString('curl -X GET "https://api.box.com/2.0/folders/{{parent_id}}/items?limit=1000&fields=id,type,name" -H "Authorization: Bearer ACCESS_TOKEN"');
setupReplacements := setupCommand.Replace('ACCESS_TOKEN',curl.GetVar('access_token'));
success := curl.AddFunction('findFolder',setupCommand.GetAsString());
if (success <> True) then
begin
WriteLn(curl.LastErrorText);
Exit;
end;
// Register findFile; registration sends no request.
setupCommand.SetString('curl -X GET "https://api.box.com/2.0/folders/{{folder_id}}/items?limit=1000&fields=id,type,name" -H "Authorization: Bearer ACCESS_TOKEN"');
setupReplacements := setupCommand.Replace('ACCESS_TOKEN',curl.GetVar('access_token'));
success := curl.AddFunction('findFile',setupCommand.GetAsString());
if (success <> True) then
begin
WriteLn(curl.LastErrorText);
Exit;
end;
// Register findDestination; registration sends no request.
setupCommand.SetString('curl -X GET "https://api.box.com/2.0/folders/0/items?limit=1000&fields=id,type,name" -H "Authorization: Bearer ACCESS_TOKEN"');
setupReplacements := setupCommand.Replace('ACCESS_TOKEN',curl.GetVar('access_token'));
success := curl.AddFunction('findDestination',setupCommand.GetAsString());
if (success <> True) then
begin
WriteLn(curl.LastErrorText);
Exit;
end;
// Register getFileDetails; registration sends no request.
setupCommand.SetString('curl -X GET "https://api.box.com/2.0/files/{{file_id}}?fields=id,sha1,file_version" -H "Authorization: Bearer ACCESS_TOKEN"');
setupReplacements := setupCommand.Replace('ACCESS_TOKEN',curl.GetVar('access_token'));
success := curl.AddFunction('getFileDetails',setupCommand.GetAsString());
if (success <> True) then
begin
WriteLn(curl.LastErrorText);
Exit;
end;
// Register getEnterprise; registration sends no request.
setupCommand.SetString('curl -X GET "https://api.box.com/2.0/users/me?fields=enterprise" -H "Authorization: Bearer ACCESS_TOKEN"');
setupReplacements := setupCommand.Replace('ACCESS_TOKEN',curl.GetVar('access_token'));
success := curl.AddFunction('getEnterprise',setupCommand.GetAsString());
if (success <> True) then
begin
WriteLn(curl.LastErrorText);
Exit;
end;
// Register output rules once. Chilkat 11.7.0 evaluates {{name}} variables
// when extracting each output, using the current value at that time.
success := curl.AddOutput2('findParent','entries','name','{{parent_name}}',True,'id','parent_id');
if (success <> True) then
begin
WriteLn(curl.LastErrorText);
Exit;
end;
success := curl.AddOutput2('findFolder','entries','name','{{folder_name}}',True,'id','folder_id');
if (success <> True) then
begin
WriteLn(curl.LastErrorText);
Exit;
end;
success := curl.AddOutput2('findFile','entries','name','{{file_name}}',True,'id','file_id');
if (success <> True) then
begin
WriteLn(curl.LastErrorText);
Exit;
end;
success := curl.AddOutput2('findDestination','entries','name','{{destination_name}}',True,'id','destination_id');
if (success <> True) then
begin
WriteLn(curl.LastErrorText);
Exit;
end;
success := curl.AddOutput('getFileDetails','file_version.id','file_version_id');
if (success <> True) then
begin
WriteLn(curl.LastErrorText);
Exit;
end;
success := curl.AddOutput('getFileDetails','sha1','file_sha1');
if (success <> True) then
begin
WriteLn(curl.LastErrorText);
Exit;
end;
success := curl.AddOutput('getEnterprise','enterprise.id','enterprise_id');
if (success <> True) then
begin
WriteLn(curl.LastErrorText);
Exit;
end;
// END ONE-TIME SETUP
// The name lookups below assume each listing fits in one page (1000 items).
// Parent and destination names select root children; folder_name selects a child
// of parent_name. "/" selects the root parent. These are not arbitrary paths.
// BEGIN OPERATION -- keep the configured object when reusing it.
// Inputs are names. Retain cached IDs when the selected names have not changed.
parentName := '/';
folderName := 'images';
fileName := 'penguins.jpg';
if ((curl.GetVar('parent_name') <> parentName) or ((parentName = '/') and (curl.VarDefined('parent_id') = False))) then
begin
curl.SetVar('parent_name',parentName);
curl.ClearVar('parent_id');
curl.ClearVar('folder_id');
curl.ClearVar('file_id');
curl.ClearVar('file_version_id');
curl.ClearVar('file_sha1');
if (parentName = '/') then
begin
curl.SetVar('parent_id','0');
end;
end;
if (curl.GetVar('folder_name') <> folderName) then
begin
curl.SetVar('folder_name',folderName);
curl.ClearVar('folder_id');
curl.ClearVar('file_id');
curl.ClearVar('file_version_id');
curl.ClearVar('file_sha1');
end;
if (curl.GetVar('file_name') <> fileName) then
begin
curl.SetVar('file_name',fileName);
curl.ClearVar('file_id');
curl.ClearVar('file_version_id');
curl.ClearVar('file_sha1');
end;
curl.SetVar('local_path','qa_output/penguins-verified.jpg');
// file_version_id is also unknown, so getFileDetails becomes a prerequisite.
// Its AddOutput mappings cache both the selected version and its SHA-1.
curl.ClearTargetOutput('*');
authorizedCommand1 := TStringBuilder.Create;
authorizedCommand1.SetString('curl -X GET "https://api.box.com/2.0/files/{{file_id}}/content?version={{file_version_id}}" -H "Authorization: Bearer {{access_token}}" -L -o "{{local_path}}"');
headerReplacement1 := authorizedCommand1.Replace('{{access_token}}',curl.GetVar('access_token'));
success := curl.DoYourThing(authorizedCommand1.GetAsString());
if ((success <> True) or (curl.StatusCode <> 200)) then
begin
WriteLn('Box request failed. HTTP status: ' + curl.StatusCode);
WriteLn('Failure reason: ' + curl.FailReason);
WriteLn(curl.ResponseBodyStr);
Exit;
end;
digest := TCrypt2.Create;
digest.HashAlgorithm := 'sha1';
digest.EncodingMode := 'hex_lower';
actualSha1 := digest.HashFileENC(curl.GetVar('local_path'));
if (digest.LastMethodSuccess <> True) then
begin
WriteLn(digest.LastErrorText);
Exit;
end;
if (actualSha1 <> curl.GetVar('file_sha1')) then
begin
WriteLn('Downloaded content did not match the selected version''s SHA-1.');
Exit;
end;
WriteLn('Version-specific download verified.');
curl.Free;
setupCommand.Free;
authorizedCommand1.Free;
digest.Free;
end;
// ---------------------------------------------------------------------------
begin
try
RunDemo;
except
on E: Exception do
WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
end;
WriteLn;
{$IFDEF MSWINDOWS}
WriteLn('Press Enter to exit...');
ReadLn;
{$ENDIF}
end.