PHP-ETL - Cook Books
Filtering data
We can also filter data preventing some of it from being propagated through all the chain, in our example it will prevent unsubscribed customers from being written in our final csv file. So we can add this opertion to our
The rule engine is used for the filtering, If the rule returns false, 0, empty string or null then the item will not
be propagated. We can also inverse this rule, but changing negate: true, in this case the rule needs to return
false for the item to be propagated.
This might seem limiting but the rule engine does support SymfonyExpressions which opens a whole lot of flexibility.
filter-unsubscribed:
operation: filter
options:
rule: [{get : {field: 'IsSubscribed'}}]
negate: false
Complete yaml
chain:
read-file:
operation: csv-read
options: [] # The default delimeter,&
filter-unsubscribed:
operation: filter
options:
rule: [{get : {field: 'IsSubscribed'}}]
negate: false
write-new-file:
operation: csv-write
options:
file: "output.csv"