...
| Code Block | ||
|---|---|---|
| ||
rule create_child_pico {
select when gen_rs ruleset_needed
pre {
rid = event:attr("rid")
}
fired {
raise wrangler event "new_child_request" attributes {
"name": random:uuid(), "rids": [meta:rid], "rid_to_gen": rid
}
}
}
rule evaluate_expression {
select when wrangler new_child_created
pre {
rid = event:attr("rs_attrs"){"rid_to_gen"})
eci = event:attr("eci")
url = <<#{meta:host}/sky/cloud/#{eci}/gen_rs/rs.txt?rid=#{rid}>>
picoId = event:attr("id")
}
engine:registerRuleset(url=url) setting(rid)
fired {
raise wrangler event "child_deletion" attributes event:attrs
}
} |
...
The attribute expr provided by the user is passed along as an extra attribute when we raise wrangler event: "new_child_request". This extra attribute is passed through the sequence of events we are initiating in wrangler, in a map named rs_attrs. We pick it up in the next rule:
| Code Block | ||
|---|---|---|
| ||
rule evaluate_expression {
select when wrangler new_child_created
pre {
expr = event:attr("rs_attrsexpr"){"expr"}
e = expr.math:base64encode().replace(re#[+]#g,"-")
eci = event:attr("eci")
url = <<#{meta:host}/sky/cloud/#{eci}/gen_rs/rs.txt?expr=#{e}>>
picoId = event:attr("id")
}
every {
// actions unchanged
}
fired {
raise wrangler event "child_deletion" attributes event:attrs
}
} |
Line 4 retrieves the user-supplied expression from the rs_attrs attribute that has the attributes that have been passed along.
Since line 7 is embedding the expression in a URL, we Base 64 encode it in line 5. The function rs will then expect the user-supplied expression as its argument.
...