Extractor Token: General tab
- Identifier: This is a string that will be used to identify the piece of data that gets extracted as a result of this token. You can use only alphanumeric characters and underscores here.
- Save in session variable: Checking this box causes the value extracted by the token to be saved in a session variable using the token's identifier.
- Null session variable if no match (enterprise edition only): When checked, if a session variable was matched previously but not this time, the value will be set to null. If unchecked the unmatched token would do nothing to the session variable so that the old session variable persists.
- Regular Expression: Here you can designate a regular expression that will be used to match the text covered by this token. In most cases you should designate a regular expression for tokens. This makes the extraction more efficient and helps to guard against future changes that might be made to the target web site.
- Enter: Type in your own regular expression.
- Select: Select a predefined regular expression by name.
The regular expressions that appear in the drop-down list can be edited by selecting Edit regular expressions from the menu.
scraper on 07/16/2010 at 5:16 pm