// Abstract ------------------------------------------------------------------------------------------------------------------------------
This sample fetch data from api.fixer.io (as JSON) and import it as knowledge.
// Examples ------------------------------------------------------------------------------------------------------------------------------
$ ./fizz.x64 ./etc/samples/fixer-pull.fizz -c api.key=\"XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX\"
fizz 0.3.N-X (20180505.1956) [x64|8|w|l]
load : loading ./etc/samples/fixer-pull.fizz ...
load : loaded ./etc/samples/fixer-pull.fizz in 0.007s
load : loading completed in 0.007s
conversion(1525588507, EUR, AED, 4.394742)
conversion(1525588507, EUR, AFN, 84.252313)
...
conversion(1525588507, EUR, ZMW, 12.014256)
conversion(1525588507, EUR, ZWL, 385.728644)
// Code ----------------------------------------------------------------------------------------------------------------------------------
// an HTTP service puller elemental, fetching data every 60 seconds
web.conv.puller {
class = FZZCWebAPIPuller,
tick = 60.0,
pull.on.attach = true,
url.host = "http://data.fixer.io",
url.path = "/api/latest",
url.query = { access_key = $api.key }
} {
}
web.conv.input {
// handle erroneous status coming back from the server
() :- @web.conv.puller(:t,:s?[neq(200)],_,:f),
console.puts("pulling error: ",:s," ",:f);
// handle success status
() :- @web.conv.puller(:t,200,_,:f), // trigger
frm.fetch(:f,base,:base), // fetch the base
frm.fetch(:f,rates,:r), #web.conv.proc(:t,:base,:r); // fetch the rate and pass it to a secondary elemental for processing
}
web.conv.proc { // process each rate and assert a conversion statement for each
(:t,:base,:f) :- frm.fetch(:f,:l?[is.symbol],:v?[is.number]), #assert(conversion(:t,:base,:l,:v));
}
// wrap the primitive 'assert' so that what is being asserted during execution can be more easily seen (in the console)
assert {
(:f) :- console.puts(:f), assert(:f);
}
// ---------------------------------------------------------------------------------------------------------------------------------------
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