Using lkJSON - an example with Google Drive data

lkJSON is free (BSD license) JSon parser for Delphi. It works great with Delphi 7.

lkJSON Source: http://sourceforge.net/projects/lkjson/

When you are looking for a JSon parser, you look for someting that you can use in the next minute. There is no documentation for lkJSON, just a few examples included with the sources. I hope this quick and dirty example can save you some time.

A Google Drive API returns you something like this:

{ "kind": "drive#fileList", "etag": "\"ia2FS23424234234ANFYAdsc1Tyua2KKA-HnMs\"", "selfLink": "https://www.googleapis.com/drive/v2/files", "items": [ { "kind": "drive#file", "id": "0BwtHRVB3TFRHVllvRVE", "etag": "\"ia2H5NSXK_wk/MTM0MTc3MTMwMTU5Mg\"", "selfLink": "https://www.googleapis.com/drive/v2/files/0BwPgllvRVE", "alternateLink": "https://docs.google.com/folder/d/0BwPgllvRVE/edit", "permissionsLink": "https://www.googleapis.com/drive/v2/files/0BwPgllvRVE/permissions", "title": "Folder0", "mimeType": "application/vnd.google-apps.folder", "description": "Folzer Zero", "labels": { "starred": false, "hidden": false, "trashed": false, "restricted": false, "viewed": true }, "createdDate": "2012-07-08T18:13:51.185Z", "modifiedDate": "2012-07-08T18:15:01.592Z", "modifiedByMeDate": "2012-07-08T18:15:01.592Z", "lastViewedByMeDate": "2012-07-08T18:15:07.039Z", "parents": [ { "kind": "drive#parentReference", "id": "0AAPgHUk9PVA", "selfLink": "https://www.googleapis.com/drive/v2/files/0BwPgllvRVE1/parents/0AA6_KcYtHUk9PVA", "parentLink": "https://www.googleapis.com/drive/v2/files/0AA6_KcYtHUk9PVA", "isRoot": true } ], "userPermission": { "kind": "drive#permission", "etag": "\"ia2FSHMEjvcFQvtI4rH3hoJimnEgfM\"", "id": "current", "role": "owner", "type": "user" }, "quotaBytesUsed": "0", "ownerNames": [ "Artur" ], "lastModifyingUserName": "Artur", "editable": true, "writersCanShare": true }, { "kind": "drive#file", ... } { "kind": "drive#file", ... } ] }

And here is some Delphi code:

procedure TForm1.BlaBlaBla( JSonString : string ); var js, itjs: TlkJSONobject; ii : integer; Str : string; Trash : boolean; begin // Parse the String js := TlkJSON.ParseText( JSonString ) as TlkJsonObject; // Values on the first level are as easy as this selfLink := js.getString( 'selfLink' ); // let's digg into each document ... for ii:=0 to js.Field['items'].Count-1 do begin // each document is a TlkJSONobject ... ijs := (js.Field['items'].Child[ ii ] as TlkJSONobject); // So, it will be so simple to get something like this... Item.etag := ijs.getString( 'etag' ); Item.Id := ijs.getString( 'id' ); Item.title := ijs.getString( 'title' ); // Or a little bit different... Item.IsTrash := ijs['labels'].Field['trashed'].Value; end; js.Free; end

stay free.