WWW Wrappers

The statement CREATE WRAPPER ITP creates WWW wrappers. These wrappers import semi-structured data sources (typically semi-structured web sources). These sources may be accessible in the web, through the local file system or through a FTP service. You need Denodo ITPilot to execute this type of wrappers. ITPilot provides the Wrapper Generation Tool to create these wrappers graphically.

Note

The user does not have to create VQL statements to import these wrappers manually. ITPilot includes options to automatically generate the necessary VQL for these tasks. The use of statements generated automatically by ITPilot is strongly recommended.

Syntax of the CREATE WRAPPER ITP statement
CREATE [ OR REPLACE ] WRAPPER ITP <name:identifier>
    [ FOLDER = <literal> ]
    [ VERIFICATION { TRUE | FALSE } ]
    [ DENODOBROWSEROPTIMIZATION { TRUE | FALSE } ]
    [ PASSTHROUGH { TRUE | FALSE } ]
    [ [ JSCRIPT ] <script code:literal> ]
    [ [ MODEL ] <model xml:literal> ]
    [ SCANNERS ( <scanner name:literal> [, <scanner name:literal> ]* ]
    [ SOURCECONFIGURATION ( [ <source configuration property>
    [, <source configuration property> ]* ] ) ]

<source configuration property> ::=
    DATAINORDERFIELDSLIST = { DEFAULT | ( <name:identifier> { ASC | DESC }
    [, <name:identifier> { ASC | DESC } ]* ) }

The command for modifying WWW wrappers is similar.

Syntax of the ALTER WRAPPER ITP statement
ALTER WRAPPER ITP <name:identifier>
    [ VERIFICATION { TRUE | FALSE } ]
    [ DENODOBROWSEROPTIMIZATION { TRUE | FALSE } ]
    [ PASSTHROUGH { TRUE | FALSE } ]
    [ [ JSCRIPT ] <script code:literal> ]
    [ [ MODEL ] <model xml:literal> ]
    [ SCANNERS ( <scanner name:literal> [, <scanner name:literal> ]* ]
    [ SOURCECONFIGURATION ( [ <source configuration property>
    [, <source configuration property> ]* ] ) ]
<source configuration property> ::= (see Syntax of the CREATE WRAPPER ITP statement)

The VERIFICATION clause allows enabling/disabling the ITPilot automatic maintenance system for the wrapper. See the ITPilot documentation for further details.

If DENODOBROWSEROPTIMIZATION is TRUE, ITPilot will use the optimization data of the Denodo Browser-based sequences.

If the ITPilot wrapper has two input parameters that were marked as “Pass-through session credentials” and PASSTHROUGH is TRUE, these two parameters will not belong to the schema of the base views created over this wrapper. At runtime, the Server will set the value of these input parameters to the user name and password of the user that queries the view.

If PASSTHROUGH is FALSE, these fields will be part of the base views.

Lastly, certain wrapper properties can be specified (SOURCECONFIGURATION). These properties are used to determine the operations that can be executed over the wrapper. The applicable properties are indicated in the corresponding statement declaration (Syntax of the CREATE WRAPPER ITP statement), and are explained in the section Wrapper Configuration Properties.

ITPilot wrappers may contain Custom components. The syntax of the command to create them is the following:

Syntax of the CREATE CUSTOMCOMPONENT statement
CREATE [ OR REPLACE ] CUSTOMCOMPONENT <name:literal>
    [ JSCRIPT ] <javascript:literal>
    [ MODEL ] <xml:literal>