Add commodities (#75)

Project.toml

@@ -2,7 +2,7 @@ name = "AlphaVantage"
 uuid = "6348297c-a006-11e8-3a05-9bbf8830fd7b"
 license = "MIT"
 authors = ["Ellis Valentiner <ellisvalentiner@gmail.com>", "Dean Markwick <dean.markwick@talk21.com>"]
-version = "0.4.1"
+version = "0.5.0"
 
 [deps]
 ArgCheck = "dce04be8-c92d-5529-be00-80e4d2c0e197"

README.md

@@ -43,7 +43,7 @@ If you encounter a clear bug, please file a minimal reproducible example on GitH
 ## Features
 
 * Intraday prices for stocks, currencies and cryptocurrencies.
-* Daily, weekly and monthly prices for stocks, currencies and cryptocurrencies.
+* Daily, weekly and monthly prices for stocks, currencies, cryptocurrencies, and commodities.
 * Technical indicators for stock prices.
 * Crypto currency health index from Flipside Crypto.
 * Fundamental data for stocks.

src/AlphaVantage.jl

@@ -20,6 +20,7 @@ include("sector_performance.jl")
 include("fundamental_values.jl")
 include("fundamentals.jl")
 include("economic_indicators.jl")
+include("commodities.jl")
 
 # avclient
 export key, AlphaVantageClient, AlphaVantageResponse
@@ -69,4 +70,7 @@ export
     federal_fund_rate,
     cpi
 
+# commodities
+# `WTI` etc are exported in macro
+
 end # module

src/commodities.jl

@@ -0,0 +1,21 @@
+for func in (:wti, :brent, :natural_gas, :copper, :aluminum, :wheat, :corn, :cotton, :coffee, :all_commodities)
+    x = "$(func)"
+    fname = Symbol(x)
+    @eval begin
+        function ($fname)(interval::Union{String, Nothing}=nothing, client = GLOBAL[], datatype::Union{String, Nothing}=nothing, parser = "default")
+            @argcheck in(interval, ["daily", "weekly", "monthly", nothing])
+            @argcheck in(datatype, ["json", "csv", nothing])
+            params = Dict(
+                "function"=>uppercase($x),
+                "interval"=>isnothing(interval) ? "monthly" : interval,
+                "datatype"=>isnothing(datatype) ? "csv" : datatype,
+                "apikey"=>key(client)
+            )
+            uri = _build_uri(client.scheme, client.host, "query", params)
+            data = retry(_get_request, delays=Base.ExponentialBackOff(n=3, first_delay=5, max_delay=1000))(uri)
+            p = _parser(parser, datatype)
+            return p(data)
+        end
+        export $fname
+    end
+end