importCsv
|
|
importCsv
|
The importCsv function with its Lambda argument provides powerful programmable export functionality. The
Lambda performs any necessary editing of the imported records, and may be programmed to process any header or
trailer records that an incoming file may have. The importCsv function natively parses comma-delimited fields,
but again, can be programmed to parse any record with no fields or any record with fields that are delimited by
any character. The only assumption made by the importCsv function, is that the file is a text file and that each
record is separated by a line terminator eol (end-of line) character that applicable to the operating system. The Lambda is responsible for supplying a container to accept the imported fields. The container must be
appropriate to handle the type of data it is to receive. By specifying the {recordsOnly:} argument, the
Lambda of importCsv function makes the assumption the data to be imported as a single record that is
terminated by the eol character. By specifying the {recordVectors:} option, the Lambda will make the
assumption that the data it is receiving from the importCsv function is a collection of fields, therefore
the container must be an aggregate container such as a Vector, Structure or Dictionary to accept multiple fields. Usage The importCsv function is typically used to import or convert data from non-Analytic Information
Server applications. The native importCsv makes no assumptions of the format of the foreign data (it may
have header records or not, it may have trailer records or not, the output fields may be comma-delimited, or comma-delimited,
or have no fields at all)where the data should go nor does it have any built-in editing algorithms for the imported data.
The Lambda handles the container and editing issues. In order for the importCsv function to work properly,
the Lambda argument must be supplied and must have the refImport(row) and the setImport(row) child Lambdas.
The only requirement of the importCsv function is that the imported file must be text. The optional
argument, recordVectors:, is useful when it is known by the Lambda that the records consists of comma-delimited
fields. When recordVectors: is specified, the record is automatically parsed and the individual fields
are stored as items in an aggregate container, such as a Vector, Structure, or Dictionary. The Lambda establishes
the container type and it is passed from the Lambda to the importCsv function via the refImport method.
When the importCsv function is finished filling the container it passes the filled-in container to the
Lambda, setImport method then receives the container and performs the desired formatting or editing. refExport ChildLambda
refExport(row)
Called by importCsv function to receive an empty container from the Lambda. The refImport method receives
a row argument and must return an empty container. The empty container will be used to store the next imported
record.
setImport(row container)
Called when importCsv is finished filling the record with data. The setImport function receives a row
index argument and a record argument. The record argument is the filled container record. The Lambda may
process the filled container in any manner.
(importCsv fileid anLambda) (importCsv fileid anLambda recordsOnly:) (importCsv fileid anLambda recordVectors:) The number of rows imported.
Expression:
Arguments
Name
Type
Description Argument: fileid Text
A file identifier previously obtained from a call to fileopen for an Lambda comma delimited file. Argument: anLambda Lambda
Mandatory Lambda. An Lambda which is to be imported in comma delimited format. If an object Repository may be passed,
the Object repository's Librarian will be used as the import Lambda. Argument: recordsOnly: Symbol
Optional argument.. If present, the importCsv function sends the Lambda a record that is delimited by the
system end-of-line (eol) character. Note: In the Intel-base platforms, the standard record terminator is
carriage-return, line-feed (CR)(LF). 68000-based platforms (such as the Mac OS) use a single eol character:
(CR). Argument: recordVectors: Symbol
Optional argument. If present, the importCsv function sends the Lambda a Vector or other aggregate container.
The individual elements of the vector are converted to text and each text fields is separated by the #\, (comma)
character.
Returns:
Here are a number of links to Lambda coding examples which contain this instruction in various use cases.
Here are the links to the data types of the function arguments.
| ObjectRepository | Text | Lambda | String |
| Vector | Structure | Dictionary | Boolean |
| Integer |
Here are also a number of links to functions having arguments with any of these data types.
|
|
Analytic Information Server (AIS)AIS Component Systems
|