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Bug 553

Summary: Recognize automatically the datetime data when you export to TeeChart Javascript
Product: VCL TeeChart Reporter: sandra pazos <sandra>
Component: ExportAssignee: Steema Issue Manager <issuemanager>
Status: RESOLVED FIXED    
Severity: enhancement CC: david, r.krause
Priority: High    
Version: 131119   
Target Milestone: ---   
Hardware: PC   
OS: Windows   
Chart Series: --- Delphi / C++ Builder RAD IDE Version:
Attachments: Test project (VCL)

Description sandra pazos 2014-01-27 06:18:11 EST 
I think the problems in bug 548 aren't related, for this reason I separated them.

2. Javascript data is written using my local (german) decimal separator, which is a comma. 

Sample for wrong data, produced by built in chart editor's export series data to JSON preview function: 
{ "chart": [
  {
   "series": {
   "name":"P4_NN_ROK",
   "color":"#0000FF",
   "point": [
     { "value":165,13445, "x":38831,750775463 },
     { "value":165,1343, "x":38831,7924537037 },
     { "value":165,1346, "x":38831,8341319444 },
     { "value":165,1329, "x":38831,8758101852 },

Btw: above example used a date axis. The windows date format you are writing here is pretty useless. Do you think it might be possible to export datetime data so they are automatically recognized by TeeChart Javascript?
Comment 1 david berneda 2014-02-05 06:10:35 EST 
Partially fixed. 

Added support for datetime series values when exporting a chart to JavaScript format using TeeJavaScript.pas "TJavaScriptExportFormat" class.

See attachment with test VCL project.

Note: The latest TeeChart source code (Feb-5th or greater) is required.

Pending: DateTime support when exporting to JSON format.
Comment 2 david berneda 2014-02-05 08:50:01 EST 
Fixed. Added a new property to TSeriesDataJSON class to determine which format to use for datetime values.

It seems there's no standard about datetime data in JSON format.
http://markembling.info/2011/07/json-date-time

So, by default datetime values will be simply exported as timestamps (Delphi date timestamps), and the new property allows exporting to JavaScript Date format (milliseconds since 1-1-1970):

uses TeeStore, TeeStringsEditor;

procedure TForm1.Button2Click(Sender: TObject);
var s : String;
begin
  with TSeriesDataJSON.Create(Chart1) do
  try
    DateTimeFormat:=jdJavaScript;

    s:=AsString;
    
    TeeEditStrings(Self,s);
  finally
    Free;
  end;
end;


However, datetime values in JSON format cannot be imported automatically because the browser JSON parser does not know that numbers are datetime values.

So, a conversion should be done in JavaScript from JSON data to valid dates, like:

series.data.x[0] = new Date(series.data.x[0]);

This will make the chart axes to recognize series data as datetime values.
Comment 3 david berneda 2014-02-05 08:51:34 EST 
Created attachment 83 [details]
Test project (VCL)