Input port reading allows you to read file names or data from an optional input port. This feature is available in most of Readers.
To use input port mapping, connect an edge to an input port. Assign metadata to the edge. In the Reader, edit the File URL attribute.
The attribute value has the syntax
You can enter the value directly or with help of URL File Dialog.
processingType is optional and defines if the
data is processed as plain data or URL addresses.
It can be
If not set explicitly,
discrete is applied by default.
Each data record field from an input port represents one particular data source.
Each data record field from an input port represents a URL to be loaded in and parsed.
All data fields from an input port are concatenated and processed as
one input file. If the
null value of this field is met,
it is replaced by the
EOF. Following data record fields
are parsed as another input file in the same way, i.e. until the
null value is met. The Reader starts parsing data as
soon as first bytes come by the port and process it progressively
until EOF comes. For more information about writing with
stream processing type, see Output Port Writing.
In input port reading, only metadata field of some particular data types
can be used. The type of the
FieldName input field can
When graph runs, data is read from original data source (according to metadata of an edge connected to an optional input port of Readers) and received by a Reader through its optional input port. Each record is read independently of the other records. The specified field of each one is processed by the Reader according to the output metadata.
Remember that port reading can also be used by DBExecute
for receiving SQL commands. Query URL will be as follows:
Metadata on the input port of EmailReader can have only one field.