go-chart/_examples/css_classes/main.go
Justin Kromlinger f97f94425f Add ability to set CSS classes instead of inline styles (#103)
* Add ability to set CSS classes instead of inline styles

This allows to set a `ClassName` field in `Style` structs. Setting this
field to anything but "" will cause all other styles to be ignored. The
element will then have a `class=` tag instead with the corresponding name.

Possible reasons to use this:
* Including multiple SVGs on the same webside, using the same styles
* Desire to use strict CSP headers

* Add warning that setting `ClassName` will drop all other inline styles
2018-10-11 17:21:46 -07:00

55 lines
1.5 KiB
Go

package main
import (
"fmt"
"github.com/wcharczuk/go-chart"
"log"
"net/http"
)
func inlineSVGWithClasses(res http.ResponseWriter, req *http.Request) {
res.Write([]byte(
"<!DOCTYPE html><html><head>" +
"<link rel=\"stylesheet\" type=\"text/css\" href=\"/main.css\">" +
"</head>" +
"<body>"))
pie := chart.PieChart{
// Note that setting ClassName will cause all other inline styles to be dropped!
Background: chart.Style{ClassName: "background"},
Canvas: chart.Style{
ClassName: "canvas",
},
Width: 512,
Height: 512,
Values: []chart.Value{
{Value: 5, Label: "Blue", Style: chart.Style{ClassName: "blue"}},
{Value: 5, Label: "Green", Style: chart.Style{ClassName: "green"}},
{Value: 4, Label: "Gray", Style: chart.Style{ClassName: "gray"}},
},
}
err := pie.Render(chart.SVG, res)
if err != nil {
fmt.Printf("Error rendering pie chart: %v\n", err)
}
res.Write([]byte("</body>"))
}
func css(res http.ResponseWriter, req *http.Request) {
res.Header().Set("Content-Type", "text/css")
res.Write([]byte("svg .background { fill: white; }" +
"svg .canvas { fill: white; }" +
"svg path.blue { fill: blue; stroke: lightblue; }" +
"svg path.green { fill: green; stroke: lightgreen; }" +
"svg path.gray { fill: gray; stroke: lightgray; }" +
"svg text.blue { fill: white; }" +
"svg text.green { fill: white; }" +
"svg text.gray { fill: white; }"))
}
func main() {
http.HandleFunc("/", inlineSVGWithClasses)
http.HandleFunc("/main.css", css)
log.Fatal(http.ListenAndServe(":8080", nil))
}