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mop/cnn_market.go

188 lines
5.6 KiB

// Copyright (c) 2013-2019 by Michael Dvorkin and contributors. All Rights Reserved.
// Use of this source code is governed by a MIT-style license that can
// be found in the LICENSE file.
package mop
import (
`bytes`
`fmt`
`io/ioutil`
`net/http`
`regexp`
`strings`
)
const marketURL = `https://money.cnn.com/data/markets/`
// Market stores current market information displayed in the top three lines of
// the screen. The market data is fetched and parsed from the HTML page above.
type Market struct {
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IsClosed bool // True when U.S. markets are closed.
Dow map[string]string // Hash of Dow Jones indicators.
Nasdaq map[string]string // Hash of NASDAQ indicators.
Sp500 map[string]string // Hash of S&P 500 indicators.
Tokyo map[string]string
HongKong map[string]string
London map[string]string
Frankfurt map[string]string
Yield map[string]string
Oil map[string]string
Yen map[string]string
Euro map[string]string
Gold map[string]string
regex *regexp.Regexp // Regex to parse market data from HTML.
errors string // Error(s), if any.
}
// Returns new initialized Market struct.
func NewMarket() *Market {
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market := &Market{}
market.IsClosed = false
market.Dow = make(map[string]string)
market.Nasdaq = make(map[string]string)
market.Sp500 = make(map[string]string)
market.Tokyo = make(map[string]string)
market.HongKong = make(map[string]string)
market.London = make(map[string]string)
market.Frankfurt = make(map[string]string)
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market.Yield = make(map[string]string)
market.Oil = make(map[string]string)
market.Yen = make(map[string]string)
market.Euro = make(map[string]string)
market.Gold = make(map[string]string)
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market.errors = ``
const any = `\s*(?:.+?)`
const change = `>([\+\-]?[\d\.,]+)<\/span>`
const price = `>([\d\.,]+)<\/span>`
const percent = `>([\+\-]?[\d\.,]+%?)<`
rules := []string{
`>Dow<`, any, percent, any, price, any, change, any,
`>Nasdaq<`, any, percent, any, price, any, change, any,
`">S&P<`, any, percent, any, price, any, change, any,
`>10\-year yield<`, any, price, any, percent, any,
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`>Oil<`, any, price, any, percent, any,
`>Yen<`, any, price, any, percent, any,
`>Euro<`, any, price, any, percent, any,
`>Gold<`, any, price, any, percent, any,
`>Nikkei 225<`, any, percent, any, price, any, change, any,
`>Hang Seng<`, any, percent, any, price, any, change, any,
`>FTSE 100<`, any, percent, any, price, any, change, any,
`>DAX<`, any, percent, any, price, any, change, any,
}
market.regex = regexp.MustCompile(strings.Join(rules, ``))
return market
}
// Fetch downloads HTML page from the 'marketURL', parses it, and stores resulting data
// in internal hashes. If download or data parsing fails Fetch populates 'market.errors'.
func (market *Market) Fetch() (self *Market) {
self = market // <-- This ensures we return correct market after recover() from panic().
defer func() {
if err := recover(); err != nil {
market.errors = fmt.Sprintf("Error fetching market data...\n%s", err)
} else {
market.errors = ""
}
}()
response, err := http.Get(marketURL)
if err != nil {
panic(err)
}
defer response.Body.Close()
body, err := ioutil.ReadAll(response.Body)
if err != nil {
panic(err)
}
body = market.isMarketOpen(body)
return market.extract(market.trim(body))
}
// Ok returns two values: 1) boolean indicating whether the error has occured,
// and 2) the error text itself.
func (market *Market) Ok() (bool, string) {
return market.errors == ``, market.errors
}
//-----------------------------------------------------------------------------
func (market *Market) isMarketOpen(body []byte) []byte {
// TBD -- CNN page doesn't seem to have market open/close indicator.
return body
}
//-----------------------------------------------------------------------------
func (market *Market) trim(body []byte) []byte {
start := bytes.Index(body, []byte(`Markets Overview`))
finish := bytes.LastIndex(body, []byte(`Gainers`))
snippet := bytes.Replace(body[start:finish], []byte{'\n'}, []byte{}, -1)
snippet = bytes.Replace(snippet, []byte(`&amp;`), []byte{'&'}, -1)
return snippet
}
//-----------------------------------------------------------------------------
func (market *Market) extract(snippet []byte) *Market {
matches := market.regex.FindStringSubmatch(string(snippet))
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if len(matches) < 31 {
panic(`Unable to parse ` + marketURL)
}
market.Dow[`change`] = matches[1]
market.Dow[`latest`] = matches[2]
market.Dow[`percent`] = matches[3]
market.Nasdaq[`change`] = matches[4]
market.Nasdaq[`latest`] = matches[5]
market.Nasdaq[`percent`] = matches[6]
market.Sp500[`change`] = matches[7]
market.Sp500[`latest`] = matches[8]
market.Sp500[`percent`] = matches[9]
market.Yield[`name`] = `10-year Yield`
market.Yield[`latest`] = matches[10]
market.Yield[`change`] = matches[11]
market.Oil[`latest`] = matches[12]
market.Oil[`change`] = matches[13]
market.Yen[`latest`] = matches[14]
market.Yen[`change`] = matches[15]
market.Euro[`latest`] = matches[16]
market.Euro[`change`] = matches[17]
market.Gold[`latest`] = matches[18]
market.Gold[`change`] = matches[19]
market.Tokyo[`change`] = matches[20]
market.Tokyo[`latest`] = matches[21]
market.Tokyo[`percent`] = matches[22]
market.HongKong[`change`] = matches[23]
market.HongKong[`latest`] = matches[24]
market.HongKong[`percent`] = matches[25]
market.London[`change`] = matches[26]
market.London[`latest`] = matches[27]
market.London[`percent`] = matches[28]
market.Frankfurt[`change`] = matches[29]
market.Frankfurt[`latest`] = matches[30]
market.Frankfurt[`percent`] = matches[31]
return market
}