Dmitry Verkhoturov
07c7926453
Update all Go modules in backend/ and backend/_example/memory_store/ to their latest versions (chroma 2.27, go-redis 9.21, bbolt 1.5, slack 0.27, golang.org/x/* and others); re-tidy and re-vendor, keep the example module in sync. Hold github.com/go-chi/chi/v5 at v5.2.5: v5.3.0 deprecates middleware.RealIP (IP-spoofing advisories). Switching off RealIP changes how the client IP is derived for rate limiting and votes, which is a security decision better made on its own rather than inside a dependency bump. go test -race, go vet, golangci-lint and govulncheck all clean on both modules.
cascadia
The Cascadia package implements CSS selectors for use with the parse trees produced by the html package.
To test CSS selectors without writing Go code, check out cascadia the command line tool, a thin wrapper around this package.
Example
The following is an example of how you can use Cascadia.
package main
import (
"fmt"
"log"
"strings"
"github.com/andybalholm/cascadia"
"golang.org/x/net/html"
)
var pricingHtml string = `
<div class="card mb-4 box-shadow">
<div class="card-header">
<h4 class="my-0 font-weight-normal">Free</h4>
</div>
<div class="card-body">
<h1 class="card-title pricing-card-title">$0/mo</h1>
<ul class="list-unstyled mt-3 mb-4">
<li>10 users included</li>
<li>2 GB of storage</li>
<li><a href="https://example.com">See more</a></li>
</ul>
</div>
</div>
<div class="card mb-4 box-shadow">
<div class="card-header">
<h4 class="my-0 font-weight-normal">Pro</h4>
</div>
<div class="card-body">
<h1 class="card-title pricing-card-title">$15/mo</h1>
<ul class="list-unstyled mt-3 mb-4">
<li>20 users included</li>
<li>10 GB of storage</li>
<li><a href="https://example.com">See more</a></li>
</ul>
</div>
</div>
<div class="card mb-4 box-shadow">
<div class="card-header">
<h4 class="my-0 font-weight-normal">Enterprise</h4>
</div>
<div class="card-body">
<h1 class="card-title pricing-card-title">$29/mo</h1>
<ul class="list-unstyled mt-3 mb-4">
<li>30 users included</li>
<li>15 GB of storage</li>
<li><a>See more</a></li>
</ul>
</div>
</div>
`
func Query(n *html.Node, query string) *html.Node {
sel, err := cascadia.Parse(query)
if err != nil {
return &html.Node{}
}
return cascadia.Query(n, sel)
}
func QueryAll(n *html.Node, query string) []*html.Node {
sel, err := cascadia.Parse(query)
if err != nil {
return []*html.Node{}
}
return cascadia.QueryAll(n, sel)
}
func AttrOr(n *html.Node, attrName, or string) string {
for _, a := range n.Attr {
if a.Key == attrName {
return a.Val
}
}
return or
}
func main() {
doc, err := html.Parse(strings.NewReader(pricingHtml))
if err != nil {
log.Fatal(err)
}
fmt.Printf("List of pricing plans:\n\n")
for i, p := range QueryAll(doc, "div.card.mb-4.box-shadow") {
planName := Query(p, "h4").FirstChild.Data
price := Query(p, ".pricing-card-title").FirstChild.Data
usersIncluded := Query(p, "li:first-child").FirstChild.Data
storage := Query(p, "li:nth-child(2)").FirstChild.Data
detailsUrl := AttrOr(Query(p, "li:last-child a"), "href", "(No link available)")
fmt.Printf(
"Plan #%d\nName: %s\nPrice: %s\nUsers: %s\nStorage: %s\nDetails: %s\n\n",
i+1,
planName,
price,
usersIncluded,
storage,
detailsUrl,
)
}
}
The output is:
List of pricing plans:
Plan #1
Name: Free
Price: $0/mo
Users: 10 users included
Storage: 2 GB of storage
Details: https://example.com
Plan #2
Name: Pro
Price: $15/mo
Users: 20 users included
Storage: 10 GB of storage
Details: https://example.com
Plan #3
Name: Enterprise
Price: $29/mo
Users: 30 users included
Storage: 15 GB of storage
Details: (No link available)