forked from mystiq/dex
67 lines
1.6 KiB
Go
67 lines
1.6 KiB
Go
package etreeutils
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import "github.com/beevik/etree"
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// SortedAttrs provides sorting capabilities, compatible with XML C14N, on top
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// of an []etree.Attr
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type SortedAttrs []etree.Attr
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func (a SortedAttrs) Len() int {
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return len(a)
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}
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func (a SortedAttrs) Swap(i, j int) {
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a[i], a[j] = a[j], a[i]
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}
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func (a SortedAttrs) Less(i, j int) bool {
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// This is the best reference I've found on sort order:
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// http://dst.lbl.gov/~ksb/Scratch/XMLC14N.html
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// If attr j is a default namespace declaration, attr i may
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// not be strictly "less" than it.
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if a[j].Space == defaultPrefix && a[j].Key == xmlnsPrefix {
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return false
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}
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// Otherwise, if attr i is a default namespace declaration, it
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// must be less than anything else.
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if a[i].Space == defaultPrefix && a[i].Key == xmlnsPrefix {
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return true
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}
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// Next, namespace prefix declarations, sorted by prefix, come before
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// anythign else.
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if a[i].Space == xmlnsPrefix {
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if a[j].Space == xmlnsPrefix {
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return a[i].Key < a[j].Key
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}
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return true
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}
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if a[j].Space == xmlnsPrefix {
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return false
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}
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// Then come unprefixed attributes, sorted by key.
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if a[i].Space == defaultPrefix {
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if a[j].Space == defaultPrefix {
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return a[i].Key < a[j].Key
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}
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return true
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}
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if a[j].Space == defaultPrefix {
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return false
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}
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// Wow. We're still going. Finally, attributes in the same namespace should be
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// sorted by key. Attributes in different namespaces should be sorted by the
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// actual namespace (_not_ the prefix). For now just use the prefix.
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if a[i].Space == a[j].Space {
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return a[i].Key < a[j].Key
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}
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return a[i].Space < a[j].Space
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}
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