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author | ale <ale@incal.net> | 2017-12-18 22:35:16 +0000 |
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committer | ale <ale@incal.net> | 2017-12-18 22:35:16 +0000 |
commit | 445bf898d2015d1e28e5f01ef07b26be9dd42bf1 (patch) | |
tree | 05bae03d8625be5dee79ac408cf96b6ffae97840 /vendor/github.com/PuerkitoBio/goquery/utilities.go | |
parent | 394de2d98a9cfde6244620f0b188625b60f68f96 (diff) | |
download | crawl-445bf898d2015d1e28e5f01ef07b26be9dd42bf1.tar.gz crawl-445bf898d2015d1e28e5f01ef07b26be9dd42bf1.zip |
Add vendor deps
Diffstat (limited to 'vendor/github.com/PuerkitoBio/goquery/utilities.go')
-rw-r--r-- | vendor/github.com/PuerkitoBio/goquery/utilities.go | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/vendor/github.com/PuerkitoBio/goquery/utilities.go b/vendor/github.com/PuerkitoBio/goquery/utilities.go new file mode 100644 index 0000000..b4c061a --- /dev/null +++ b/vendor/github.com/PuerkitoBio/goquery/utilities.go @@ -0,0 +1,161 @@ +package goquery + +import ( + "bytes" + + "golang.org/x/net/html" +) + +// used to determine if a set (map[*html.Node]bool) should be used +// instead of iterating over a slice. The set uses more memory and +// is slower than slice iteration for small N. +const minNodesForSet = 1000 + +var nodeNames = []string{ + html.ErrorNode: "#error", + html.TextNode: "#text", + html.DocumentNode: "#document", + html.CommentNode: "#comment", +} + +// NodeName returns the node name of the first element in the selection. +// It tries to behave in a similar way as the DOM's nodeName property +// (https://developer.mozilla.org/en-US/docs/Web/API/Node/nodeName). +// +// Go's net/html package defines the following node types, listed with +// the corresponding returned value from this function: +// +// ErrorNode : #error +// TextNode : #text +// DocumentNode : #document +// ElementNode : the element's tag name +// CommentNode : #comment +// DoctypeNode : the name of the document type +// +func NodeName(s *Selection) string { + if s.Length() == 0 { + return "" + } + switch n := s.Get(0); n.Type { + case html.ElementNode, html.DoctypeNode: + return n.Data + default: + if n.Type >= 0 && int(n.Type) < len(nodeNames) { + return nodeNames[n.Type] + } + return "" + } +} + +// OuterHtml returns the outer HTML rendering of the first item in +// the selection - that is, the HTML including the first element's +// tag and attributes. +// +// Unlike InnerHtml, this is a function and not a method on the Selection, +// because this is not a jQuery method (in javascript-land, this is +// a property provided by the DOM). +func OuterHtml(s *Selection) (string, error) { + var buf bytes.Buffer + + if s.Length() == 0 { + return "", nil + } + n := s.Get(0) + if err := html.Render(&buf, n); err != nil { + return "", err + } + return buf.String(), nil +} + +// Loop through all container nodes to search for the target node. +func sliceContains(container []*html.Node, contained *html.Node) bool { + for _, n := range container { + if nodeContains(n, contained) { + return true + } + } + + return false +} + +// Checks if the contained node is within the container node. +func nodeContains(container *html.Node, contained *html.Node) bool { + // Check if the parent of the contained node is the container node, traversing + // upward until the top is reached, or the container is found. + for contained = contained.Parent; contained != nil; contained = contained.Parent { + if container == contained { + return true + } + } + return false +} + +// Checks if the target node is in the slice of nodes. +func isInSlice(slice []*html.Node, node *html.Node) bool { + return indexInSlice(slice, node) > -1 +} + +// Returns the index of the target node in the slice, or -1. +func indexInSlice(slice []*html.Node, node *html.Node) int { + if node != nil { + for i, n := range slice { + if n == node { + return i + } + } + } + return -1 +} + +// Appends the new nodes to the target slice, making sure no duplicate is added. +// There is no check to the original state of the target slice, so it may still +// contain duplicates. The target slice is returned because append() may create +// a new underlying array. If targetSet is nil, a local set is created with the +// target if len(target) + len(nodes) is greater than minNodesForSet. +func appendWithoutDuplicates(target []*html.Node, nodes []*html.Node, targetSet map[*html.Node]bool) []*html.Node { + // if there are not that many nodes, don't use the map, faster to just use nested loops + // (unless a non-nil targetSet is passed, in which case the caller knows better). + if targetSet == nil && len(target)+len(nodes) < minNodesForSet { + for _, n := range nodes { + if !isInSlice(target, n) { + target = append(target, n) + } + } + return target + } + + // if a targetSet is passed, then assume it is reliable, otherwise create one + // and initialize it with the current target contents. + if targetSet == nil { + targetSet = make(map[*html.Node]bool, len(target)) + for _, n := range target { + targetSet[n] = true + } + } + for _, n := range nodes { + if !targetSet[n] { + target = append(target, n) + targetSet[n] = true + } + } + + return target +} + +// Loop through a selection, returning only those nodes that pass the predicate +// function. +func grep(sel *Selection, predicate func(i int, s *Selection) bool) (result []*html.Node) { + for i, n := range sel.Nodes { + if predicate(i, newSingleSelection(n, sel.document)) { + result = append(result, n) + } + } + return result +} + +// Creates a new Selection object based on the specified nodes, and keeps the +// source Selection object on the stack (linked list). +func pushStack(fromSel *Selection, nodes []*html.Node) *Selection { + result := &Selection{nodes, fromSel.document, fromSel} + return result +} |