Export And Import

Importing and exporting data to and from tables is a matter of converting a serialized textual representation into discrete cell values and vice-versa. Those cells can be numbers, general text, pairs of numbers or sets of numbers. If importing to a cell with one value then importing and exporting is easy as it is a one-to-one relationship. However, if multiple cells are involved then the serialized textual representation must include inlined delimiters. If multiple rows and columns are specified then the serialization contiguous dimension must be specified. Historically, there are many heuristics involved during import and export operations. What follows is an explanation of this process from the perspective of the Import and Export Selectors.

Before proceeding it is important to clarify that vertical means with the row index running fastest, that is within one column. Saying row-contiguous does not make sense because that could mean the row-index varies fastest or the data is contiguous within one row. People that use row-contiguous nomenclature artificially agree upon one way of thinking about it and if everyone knows what the agreement is then it is OK. In this text things like row-contiguous is avoided and instead vertical-contiguous or single-column is used.

Historically speaking, exporting and importing is to and from ASCII files of data; especially for CSV and spreadsheet data. For this reason, the serialization is assumed to be UTF-8 encoded because that encompasses traditional character sets in data files. That means that when you work with UNICODE data then it must be in UTF-8 encoding.

The Export Selector is encountered while attempting to export data to a file as well as a pasteboard (or other service) string when the delimiter specifications are not implicit. The Export Selector is described below.

Preset Configuration

One of None, Spreadsheet, CSV or Robust. If None then then the other parameters must be manually set. If Spreadsheet then parameters are set consistent to a spreadsheet and if CSV then consistent with comma separated values data. If Robust then the parameters are set to vertically contiguous which is more robust because each column has elements (cells) of the same type and the underlying data structure is contiguous in the vertical direction.

Main Parameters

Non-Contiguous Delimiter Type : For a spreadsheet or CSV this is a single return character and for robust it is a two return characters.

Contiguous Delimiter Type : One of White Space, Blank, Tab, Comma or Single Return. For a spreadsheet this is a tab character, for CSV a comma and for robust it is a single return character.

Vertically Contiguous : If on then the data runs fastest along a column (vertically) otherwise along a row. Since a column often represents a curve or other sequence of data the most effective and efficient ordering is vertically contiguous even though that is the opposite of a spreadsheet.

Delete After Export : If on then the data in the table is irretrievably deleted. This option is mostly encountered when the data is exported using a cut operation.

Advanced Options

Do not alter these parameters.

Perform Operation

Information Text : This specifies what is being exported.

Cancel : Select this to cancel the operation. Selecting a region away from the Export Selector also cancels the operation.

Export From Table : Select this to perform the export and also dismiss the selector.

The Import Selector is encountered while attempting to import from a file as well as a pasteboard (or other service) string when the delimiter specifications are not implicit. The Import Selector is described below.

Preset Configuration

Same as Export.

Main Parameters

Non-Contiguous Delimiter Type : Same as Export.

Contiguous Delimiter Type : For a spreadsheet this is tab, for CSV a comma and for robust it is a single return character.

Number Of Columns : The number of columns to import to. This may be disabled if the table requires a specific value.

Number Of Rows : The number of rows to import to. Normally this is set to zero to let the import run its course.

Vertically Contiguous : Same as Export.

First Sequence Is Header : If the first sequence of the data to be imported is Header labels then that sequence is parsed and for a Spreadsheet those fields are placed in the table headers. For Spreadsheet and CSV data the first sequence is the first row of data. For Robust it is the number of lines up to the delimiter of two return characters.

Advanced Options

Do not alter these parameters.

Perform Operation

Information Text : This specifies how many characters is being imported. Characters for scalars are restricted to digits, -, + and 'e' which specifies exponential notation. For general strings the import is in terms of UTF-8 encoding.

Cancel : Select this to cancel the operation. Selecting a region away from the Import Selector also cancels the operation.

Import To Table : Select this to perform the import and also dismiss the selector.