System/Beta/Grid API

Grid API Usability Test

Here are the results of the Grid API Usability test. programming/2006-June/002530

1. Grid API Usability Test
   1. Requirements
2. CSV Edit
   1. Tracking
   2. Notes
   3. Methods vs Commands
3. CSV Grid
   1. Notes

Goal

• Determine how fast and easy it is to create a simple Grid-based application

Process

• Creating a simple Grid-based application and tracking the progress

Requirements

• Application: CSV editor, that can load, edit and save CSV files

• File format: numeric dense CSV with configurable separator and optional string row header and column headers

• File->New (including start): open empty grid with some default size

  • new window also create a new document

• File->Open dialog: selects a file with CSV or * extension, specifies

  • custom separator (",", ";", "<TAB>")

  • if contains row headers,

  • if contains column headers,

• File->Save dialog: same as open dialog, headers taken from current view

• File->Exit (or close [X]) closes current window, asking to save if dirty

• Edit:

  • edit numeric values in central cells

  • delete/cut/copy/paste/clear/insert-blank column(s) or row(s) based on current selection

  • cut/copy/paste/clear (to Missing value) a range of cells

  • cleared cells contain a Missing value

• Options

  • choose row and column headers: from file, otherwise choice of 0- or 1- or A- based enumeration

  • specify Missing value: 0, _, blank

CSV Edit

CSV Edit is an application submitted by OlegKobchenko. See help inside the package for notes on installation and details of implementation.

• Download csvedit-0.01.zip at Oleg's J Page

Tracking

Initial version development time and issue tracking. The following categories are used

Tracking log

Summarizing,

'T K'=: (0&".&>@{. ; <@{:)|:;:;._2 (0 : 0)
10 app
10 grid
...
)
   (~.K) ,. <@(24 60&#:)"0 K +//. T
+----+----+
|app |2 35|
+----+----+
|grid|2 43|
+----+----+
|doc |0 15|
+----+----+

Notes

I added some comments to these notes, and otherwise will try to address the points for the 601 release. (Marked [CB]) -- ChrisBurke 2006-06-26 03:00:41

Thanks Chris, I added a few reponses. (Marked [OK]) -- OlegKobchenko 2006-06-26 10:02:39

• It's hard to find Grid on "User Contents" page. It could be re-groupped differently, e.g. why not next to Plot? Also why DLL and OCX is a package, and not next to WD? This page could also be 2 or 3 column, like Dictionary.

• In examples, there is pack before grid__show, what is it for?
  

  • [CB] pack creates a 2-col dictionary of names and values. This can be passed to the grid object to define options.

  • [OK] it would be good to mention it on grid_methods.htm next to show

• How to specify numeric vs. character cells? E.g. grid_types.htm does not talk about that.
  

  • [CB] the grid get this information from the data that is given. There is no specific numeric vs character type.

• In grid_options.htm it would help to describe "top headers" (although it's in the picture, it's not immediately clear how they are different from column headers) in the line
  HDRTOP  top headers

• should have info how to set options next to options grid_options.htm

• what is the difference between setting option with grid__show and using commands
  

  • [CB] there is no difference, use whichever is more convenient.

• grid demo does not show stand-alone snippets, so it's hard to relate it to stand-alone script, especially dinamic aspects, such as changing content programmatically. For example, there is the Flip button, but no idea how it works. Also the demo does not have things like event processing.

• It kind of was a revalation that you need to specify menu shortcuts in two places: menu itself and a keyboard handler in code.
  

  • [CB] they are two different things. I guess they could be linked in the code, but you really are giving menu and keyboard as two ways to invoke an action.

  • [OK] I used to know that. But it was displaced with more envolved UI designs, like Swing, which treat these as unity

• Status bar set does not work in Java FE

• Absense of dirty flag is OK, because it's application specific

• There is no undo support. This is typically done in control with hookup calls.

• Discrepancy in grid_events.htm: grid_handler vs grid_gridhandler
  

  • [CB] it should be grid_gridhandler. The first is obselete, since it may conflict with other _handler events.

• errors in grid_events.htm, in example: select. control

• no API support to select/insert/delete whole rows, columns; select all

• DEL key could have configurable missing value

• DEL key sets to 0 only the top-left cell of selection; the rest is blank even in numeric cells

• paste is not consistent, sometimes for a multicell clipboard pastes only one cell; needs an additional click to paste the matrix.

• Is is possible to bind grid (where it takes pronouns at grid__show) from a non-form locale? If it's not its creator.

• No support to edit headers

• How to start editing a cell with keyboard preserving content (like double-click)
  

  • [CB] double click should work

  • [OK] but keyboard is very handy when typing. Excel uses F2, same as other Windows cell editors: Explorer--file rename, etc. See more at Methods vs Commands

• Grid Esc key not working: doesn't end edit mode. In demo closes window.
  

  • [CB] this will be fixed before the release

Methods vs Commands

Grid Methods are high-level control functions, which modify the grid at large. For example, reading, writing data, setting selection, etc.

• Note: on the same page there is a list of even handlers. I am not sure they are directly related to methods, since the user code is not supporsed to call them.

Grid Commands are yet undocumented functions which are invoked upon specific user actions with keyboard and mouse. For example, clear cells (DEL key), copy, paste, extend selection etc. Typically in editors, like wordprocesors, such commands are mapped to the user actions in a configurable way. It would be good to document them so that they can be used custom applications. For example, a command to start edit mode could be hooked up to a keyboard command (typically F2 on Windows and Enter on Mac).

CSV Grid

An interesting and useful exercise!

Here is another quick and dirty implementation, in the public repository. Download and load csvgrid.ijs, then:

  run_pcsvgrid_'' 

and select a Demo to populate the grid.

I did not time individual steps, but it was roughly 4 hours app and 1 hour on the rest (grid + doc).

There are some features in CSV Edit not in CSV Grid, and vice versa.

Notes

Much of this functionality should be added to the core Grid code, for example:

• support missing value

• insert/add/delete row or column, plus corresponding change to header

• import/export to CSV, semicolon or TAB-delimited file, or Excel

• undo

Missing values need 3 definitions: value in file, value in actual data and value shown in grid. Where data is all numeric (as in the specs), the missing value in data itself has to be numeric (e.g. __).

It would be nice to have an method for defining cell type, for example, CSV files where the second row gives column type.

Other comments are appended to Oleg's notes above.