Example: Keyword Anchor

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Related example macro: Demo-Extract

Often you just want to extract information connected to a certain word on a web site. In this case, you can use a so-called keyword anchor, which is nothing else than the cunning use of wildcards.

In this example, we would like to extract the information about the appearance of an object. As you can see from the example, this information is always connected with the word "Appeared".

FSBO 4-2-2, $110 KCHAPEL CREEK 111-222-3333 Fort Worth West Sale First Appeared in the FW Newspaper

FSBO NICE AREA4-2.5-2 2243SF, $139KMSID 222-555-9879 Arlington Southwest Sale First Appeared in ABC Star

SALE/LEASE condo, 3-2-2 enclosed patio comm. pool SW FW in Villas on the Bluff a gated comm. FSBO $169.5k 555-1111-7997 Condo/Townhome/Apt/DuplexSale First Appeared in the Star-Telegram

Using the Extraction Wizard, it would suggest a very general extract command, e.g.:

EXTRACT POS=29 TYPE=TXT ATTR=<TD>*

While this might work, it is sensitive to small changes in the web page layout. If another table cell is inserted before this one, you will extract the wrong data. In this case, however, you can easily fine tune your extraction to make it more robust against web page changes using the keyword "Appeared" and wildcards:

EXTRACT POS=1 TYPE=TXT ATTR=<TD>*Appeared* 

Remeber to reset the POS attribute since, with the "Appeared" part, it is the first occurence.

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