Field Aggregation Filter¶
This filter adds one or several fields to the processed tuple. For each new field it allows a name and its value to be specified.
The name of the field is established using the configuration parameter Field name. The value of the field can be established in two ways:
- By specifying a constant value in the parameter Field value.
- By specifying a field of the tuple containing a URL as value in the Input field parameter and by specifying the name of a HTTP request parameter used in the URLs of such field in Parameter name. This is useful in Aracne-type jobs, when it is known that the URL for the documents obtained includes a parameter that you want to extract separately to use it for other purposes. For example, it may happen that a parameter included in the document URL identifies the section in the website from which the document was extracted.
Although this filter is applicable to the tuples returned for any type of job, it is especially oriented to ARN jobs, hence appearing by default as Input field the field “url”, which is the one that stores the URL of the document obtained by ARN.