Make sure you see the videos at http://code.google.com/p/freebase-gridworks/
Some tricks I want to remember for myself:
+ followed by the country code: e.g. +32
followed by the area code with the 0 between parentheses: e.g. (0)15
followed by the local code following this pattern X?XX XX XX: e.g. 23 45 67
Full example: +32 (0)15 23 45 67
The existing dataset contains slightly different phone numbers; shown as loaded into Gridworks.
Using regular expressions we can split the existing numbers in 2 groups using parentheses to indicate the groups:
The regular expression as shown in the RX Toolkit of Komodo IDE.
Now using these groups to replace the existing values with a value conforming the wished structure using the replacement expression
group 1 followed by '(0) followed by group 2.
Now that we have our regex working, let's move on to Gridworks now.
On the column containing the telephone numbers, choose Edit cells, Transform ...
Now we can use the Gridworks expression language (GEL) to do our transform.
GEL offers a whole list of functions; we will be using 'replace'. 'Replace' takes 3 arguments:
where value refers to the value in the cell
where // delimits the regex
and '' contains the replacement string using the captured groups being indicated with '$', e.g. $1, $2.
In our case the expression became:
forNonBlank(e, v, eNonBlank, eBlank)
In our case
forNonBlank(value, v, 'not relevant', 'museum')