More tweaking of graceful panic/recover

layout.go

@@ -53,26 +53,24 @@ func (self *Layout) Market(market *Market) string {
 		return err
 	}
 
+	buffer := new(bytes.Buffer)
 	markup := `{{.Dow.name}}: {{.Dow.change}} ({{.Dow.percent}}) at {{.Dow.latest}}, {{.Sp500.name}}: {{.Sp500.change}} ({{.Sp500.percent}}) at {{.Sp500.latest}}, {{.Nasdaq.name}}: {{.Nasdaq.change}} ({{.Nasdaq.percent}}) at {{.Nasdaq.latest}}
 {{.Advances.name}}: {{.Advances.nyse}} ({{.Advances.nysep}}) on NYSE and {{.Advances.nasdaq}} ({{.Advances.nasdaqp}}) on Nasdaq. {{.Declines.name}}: {{.Declines.nyse}} ({{.Declines.nysep}}) on NYSE and {{.Declines.nasdaq}} ({{.Declines.nasdaqp}}) on Nasdaq {{if .IsClosed}}<right>U.S. markets closed</right>{{end}}
 New highs: {{.Highs.nyse}} on NYSE and {{.Highs.nasdaq}} on Nasdaq. New lows: {{.Lows.nyse}} on NYSE and {{.Lows.nasdaq}} on Nasdaq.`
 
-	template, err := template.New(`market`).Parse(markup)
-	if err != nil {
-		panic(err)
-	}
-
-	buffer := new(bytes.Buffer)
 	highlight(market.Dow, market.Sp500, market.Nasdaq)
-	if err := template.Execute(buffer, market); err != nil {
+	template,_ := template.New(`market`).Parse(markup)
-		panic(err)
+	template.Execute(buffer, market)
-	}
 
 	return buffer.String()
 }
 
 //-----------------------------------------------------------------------------
 func (self *Layout) Quotes(quotes *Quotes) string {
+	if ok, err := quotes.Ok(); !ok {
+		return err
+	}
+
 	vars := struct {
 		Now    string
 		Header string
@@ -83,6 +81,7 @@ func (self *Layout) Quotes(quotes *Quotes) string {
 		self.prettify(quotes),
 	}
 
+	buffer := new(bytes.Buffer)
 	markup := `<right><white>{{.Now}}</></right>
 
 
@@ -90,17 +89,9 @@ func (self *Layout) Quotes(quotes *Quotes) string {
 {{.Header}}
 {{range.Stocks}}{{if .Advancing}}<green>{{end}}{{.Ticker}}{{.LastTrade}}{{.Change}}{{.ChangePct}}{{.Open}}{{.Low}}{{.High}}{{.Low52}}{{.High52}}{{.Volume}}{{.AvgVolume}}{{.PeRatio}}{{.Dividend}}{{.Yield}}{{.MarketCap}}</>
 {{end}}`
-	//markup += fmt.Sprintf("[%v]", quotes.profile.Grouped)
-	template, err := template.New(`quotes`).Parse(markup)
-	if err != nil {
-		panic(err)
-	}
 
-	buffer := new(bytes.Buffer)
+	template,_ := template.New(`quotes`).Parse(markup)
-	err = template.Execute(buffer, vars)
+	template.Execute(buffer, vars)
-	if err != nil {
-		panic(err)
-	}
 
 	return buffer.String()
 }

yahoo_market.go

@@ -1,6 +1,7 @@
 // Copyright (c) 2013 by Michael Dvorkin. 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
 
@@ -13,7 +14,7 @@ import (
 	`strings`
 )
 
-const url = `http://finance.yahoo.com/marketupdate/overview`
+const market_url = `http://finance.yahoo.com/marketupdate/overview`
 
 type Market struct {
 	IsClosed   bool
@@ -67,14 +68,14 @@ func (self *Market) Initialize() *Market {
 
 //-----------------------------------------------------------------------------
 func (self *Market) Fetch() (this *Market) {
-	this = self	// <-- This ensures we return correct self in case of panic attack.
+	this = self // <-- This ensures we return correct self after recover() from panic() attack.
 	defer func() {
 		if err := recover(); err != nil {
 			self.errors = fmt.Sprintf("Error fetching market data...\n%s", err)
 		}
 	}()
 
-	response, err := http.Get(url)
+	response, err := http.Get(market_url)
 	if err != nil {
 		panic(err)
 	}
@@ -124,7 +125,7 @@ func (self *Market) trim(body []byte) []byte {
 func (self *Market) extract(snippet []byte) *Market {
 	matches := self.regex.FindAllStringSubmatch(string(snippet), -1)
 	if len(matches) < 1 || len(matches[0]) < 37 {
-		panic(`Unable to parse ` + url)
+		panic(`Unable to parse ` + market_url)
 	}
 
 	self.Dow[`name`] = matches[0][1]

yahoo_quotes.go

@@ -1,6 +1,7 @@
 // Copyright (c) 2013 by Michael Dvorkin. 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
 
@@ -35,7 +36,7 @@ import (
 // j3: market cap rt
 // j1: market cap
 
-const yahoo_quotes_url = `http://download.finance.yahoo.com/d/quotes.csv?s=%s&f=,l1c6k2oghjkva2r2rdyj3j1`
+const quotes_url = `http://download.finance.yahoo.com/d/quotes.csv?s=%s&f=,l1c6k2oghjkva2r2rdyj3j1`
 
 type Stock struct {
 	Ticker      string
@@ -62,48 +63,53 @@ type Quotes struct {
 	market	    *Market
 	profile	    *Profile
 	stocks	    []Stock
+	errors      string
 }
 
 //-----------------------------------------------------------------------------
 func (self *Quotes) Initialize(market *Market, profile *Profile) *Quotes {
 	self.market = market
 	self.profile = profile
+	self.errors = ``
 
 	return self
 }
 
 // Fetch the latest stock quotes and parse raw fetched data into array of
 // []Stock structs.
-func (self *Quotes) Fetch() *Quotes {
+//-----------------------------------------------------------------------------
-	if self.Ready() {
+func (self *Quotes) Fetch() (this *Quotes) {
-		// Format the URL and send the request.
+	this = self // <-- This ensures we return correct self after recover() from panic() attack.
-		url := fmt.Sprintf(yahoo_quotes_url, self.profile.ListOfTickers())
+	if self.is_ready() {
+		defer func() {
+			if err := recover(); err != nil {
+				self.errors = fmt.Sprintf("\n\n\n\nError fetching stock quotes...\n%s", err)
+			}
+		}()
+
+		url := fmt.Sprintf(quotes_url, self.profile.ListOfTickers())
 		response, err := http.Get(url)
 		if err != nil {
 			panic(err)
 		}
 
-		// Fetch response and get its body.
 		defer response.Body.Close()
 		body, err := ioutil.ReadAll(response.Body)
 		if err != nil {
 			panic(err)
 		}
 
-		self.parse(self.sanitize(body))
+		self.parse(sanitize(body))
 	}
 
 	return self
 }
 
-// Return true if we haven't fetched the quotes yet *or* the stock market is
+//-----------------------------------------------------------------------------
-// still open and we might want to grab the latest quotes. In both cases we
+func (self *Quotes) Ok() (bool, string) {
-// make sure the list of requested tickers is not empty.
+	return self.errors == ``, self.errors
-func (self *Quotes) Ready() bool {
-	return (self.stocks == nil || !self.market.IsClosed) && len(self.profile.Tickers) > 0
 }
 
-
 //-----------------------------------------------------------------------------
 func (self *Quotes) Format() string {
 	return new(Layout).Initialize().Quotes(self)
@@ -125,6 +131,17 @@ func (self *Quotes) RemoveTickers(tickers []string) (removed int, err error) {
 	return
 }
 
+// "Private" methods.
+
+// Return true if we haven't fetched the quotes yet *or* the stock market is
+// still open and we might want to grab the latest quotes. In both cases we
+// make sure the list of requested tickers is not empty.
+//-----------------------------------------------------------------------------
+func (self *Quotes) is_ready() bool {
+	return (self.stocks == nil || !self.market.IsClosed) && len(self.profile.Tickers) > 0
+}
+
+
 //-----------------------------------------------------------------------------
 func (self *Quotes) parse(body []byte) *Quotes {
 	lines := bytes.Split(body, []byte{'\n'})
@@ -155,7 +172,9 @@ func (self *Quotes) parse(body []byte) *Quotes {
 	return self
 }
 
+// Utility methods.
+
 //-----------------------------------------------------------------------------
-func (self *Quotes) sanitize(body []byte) []byte {
+func sanitize(body []byte) []byte {
 	return bytes.Replace(bytes.TrimSpace(body), []byte{'"'}, []byte{}, -1)
 }