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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package template
import (
"fmt"
)
// context describes the state an HTML parser must be in when it reaches the
// portion of HTML produced by evaluating a particular template node.
//
// The zero value of type context is the start context for a template that
// produces an HTML fragment as defined at
// http://www.w3.org/TR/html5/the-end.html#parsing-html-fragments
// where the context element is null.
type context struct {
state state
delim delim
urlPart urlPart
jsCtx jsCtx
attr attr
element element
err *Error
}
func (c context) String() string {
return fmt.Sprintf("{%v %v %v %v %v %v %v}", c.state, c.delim, c.urlPart, c.jsCtx, c.attr, c.element, c.err)
}
// eq returns whether two contexts are equal.
func (c context) eq(d context) bool {
return c.state == d.state &&
c.delim == d.delim &&
c.urlPart == d.urlPart &&
c.jsCtx == d.jsCtx &&
c.attr == d.attr &&
c.element == d.element &&
c.err == d.err
}
// mangle produces an identifier that includes a suffix that distinguishes it
// from template names mangled with different contexts.
func (c context) mangle(templateName string) string {
// The mangled name for the default context is the input templateName.
if c.state == stateText {
return templateName
}
s := templateName + "$htmltemplate_" + c.state.String()
if c.delim != 0 {
s += "_" + c.delim.String()
}
if c.urlPart != 0 {
s += "_" + c.urlPart.String()
}
if c.jsCtx != 0 {
s += "_" + c.jsCtx.String()
}
if c.attr != 0 {
s += "_" + c.attr.String()
}
if c.element != 0 {
s += "_" + c.element.String()
}
return s
}
// state describes a high-level HTML parser state.
//
// It bounds the top of the element stack, and by extension the HTML insertion
// mode, but also contains state that does not correspond to anything in the
// HTML5 parsing algorithm because a single token production in the HTML
// grammar may contain embedded actions in a template. For instance, the quoted
// HTML attribute produced by
// <div title="Hello {{.World}}">
// is a single token in HTML's grammar but in a template spans several nodes.
type state uint8
const (
// stateText is parsed character data. An HTML parser is in
// this state when its parse position is outside an HTML tag,
// directive, comment, and special element body.
stateText state = iota
// stateTag occurs before an HTML attribute or the end of a tag.
stateTag
// stateAttrName occurs inside an attribute name.
// It occurs between the ^'s in ` ^name^ = value`.
stateAttrName
// stateAfterName occurs after an attr name has ended but before any
// equals sign. It occurs between the ^'s in ` name^ ^= value`.
stateAfterName
// stateBeforeValue occurs after the equals sign but before the value.
// It occurs between the ^'s in ` name =^ ^value`.
stateBeforeValue
// stateHTMLCmt occurs inside an <!-- HTML comment -->.
stateHTMLCmt
// stateRCDATA occurs inside an RCDATA element (<textarea> or <title>)
// as described at http://dev.w3.org/html5/spec/syntax.html#elements-0
stateRCDATA
// stateAttr occurs inside an HTML attribute whose content is text.
stateAttr
// stateURL occurs inside an HTML attribute whose content is a URL.
stateURL
// stateJS occurs inside an event handler or script element.
stateJS
// stateJSDqStr occurs inside a JavaScript double quoted string.
stateJSDqStr
// stateJSSqStr occurs inside a JavaScript single quoted string.
stateJSSqStr
// stateJSRegexp occurs inside a JavaScript regexp literal.
stateJSRegexp
// stateJSBlockCmt occurs inside a JavaScript /* block comment */.
stateJSBlockCmt
// stateJSLineCmt occurs inside a JavaScript // line comment.
stateJSLineCmt
// stateCSS occurs inside a <style> element or style attribute.
stateCSS
// stateCSSDqStr occurs inside a CSS double quoted string.
stateCSSDqStr
// stateCSSSqStr occurs inside a CSS single quoted string.
stateCSSSqStr
// stateCSSDqURL occurs inside a CSS double quoted url("...").
stateCSSDqURL
// stateCSSSqURL occurs inside a CSS single quoted url('...').
stateCSSSqURL
// stateCSSURL occurs inside a CSS unquoted url(...).
stateCSSURL
// stateCSSBlockCmt occurs inside a CSS /* block comment */.
stateCSSBlockCmt
// stateCSSLineCmt occurs inside a CSS // line comment.
stateCSSLineCmt
// stateError is an infectious error state outside any valid
// HTML/CSS/JS construct.
stateError
)
var stateNames = [...]string{
stateText: "stateText",
stateTag: "stateTag",
stateAttrName: "stateAttrName",
stateAfterName: "stateAfterName",
stateBeforeValue: "stateBeforeValue",
stateHTMLCmt: "stateHTMLCmt",
stateRCDATA: "stateRCDATA",
stateAttr: "stateAttr",
stateURL: "stateURL",
stateJS: "stateJS",
stateJSDqStr: "stateJSDqStr",
stateJSSqStr: "stateJSSqStr",
stateJSRegexp: "stateJSRegexp",
stateJSBlockCmt: "stateJSBlockCmt",
stateJSLineCmt: "stateJSLineCmt",
stateCSS: "stateCSS",
stateCSSDqStr: "stateCSSDqStr",
stateCSSSqStr: "stateCSSSqStr",
stateCSSDqURL: "stateCSSDqURL",
stateCSSSqURL: "stateCSSSqURL",
stateCSSURL: "stateCSSURL",
stateCSSBlockCmt: "stateCSSBlockCmt",
stateCSSLineCmt: "stateCSSLineCmt",
stateError: "stateError",
}
func (s state) String() string {
if int(s) < len(stateNames) {
return stateNames[s]
}
return fmt.Sprintf("illegal state %d", int(s))
}
// isComment is true for any state that contains content meant for template
// authors & maintainers, not for end-users or machines.
func isComment(s state) bool {
switch s {
case stateHTMLCmt, stateJSBlockCmt, stateJSLineCmt, stateCSSBlockCmt, stateCSSLineCmt:
return true
}
return false
}
// isInTag return whether s occurs solely inside an HTML tag.
func isInTag(s state) bool {
switch s {
case stateTag, stateAttrName, stateAfterName, stateBeforeValue, stateAttr:
return true
}
return false
}
// delim is the delimiter that will end the current HTML attribute.
type delim uint8
const (
// delimNone occurs outside any attribute.
delimNone delim = iota
// delimDoubleQuote occurs when a double quote (") closes the attribute.
delimDoubleQuote
// delimSingleQuote occurs when a single quote (') closes the attribute.
delimSingleQuote
// delimSpaceOrTagEnd occurs when a space or right angle bracket (>)
// closes the attribute.
delimSpaceOrTagEnd
)
var delimNames = [...]string{
delimNone: "delimNone",
delimDoubleQuote: "delimDoubleQuote",
delimSingleQuote: "delimSingleQuote",
delimSpaceOrTagEnd: "delimSpaceOrTagEnd",
}
func (d delim) String() string {
if int(d) < len(delimNames) {
return delimNames[d]
}
return fmt.Sprintf("illegal delim %d", int(d))
}
// urlPart identifies a part in an RFC 3986 hierarchical URL to allow different
// encoding strategies.
type urlPart uint8
const (
// urlPartNone occurs when not in a URL, or possibly at the start:
// ^ in "^http://auth/path?k=v#frag".
urlPartNone urlPart = iota
// urlPartPreQuery occurs in the scheme, authority, or path; between the
// ^s in "h^ttp://auth/path^?k=v#frag".
urlPartPreQuery
// urlPartQueryOrFrag occurs in the query portion between the ^s in
// "http://auth/path?^k=v#frag^".
urlPartQueryOrFrag
// urlPartUnknown occurs due to joining of contexts both before and
// after the query separator.
urlPartUnknown
)
var urlPartNames = [...]string{
urlPartNone: "urlPartNone",
urlPartPreQuery: "urlPartPreQuery",
urlPartQueryOrFrag: "urlPartQueryOrFrag",
urlPartUnknown: "urlPartUnknown",
}
func (u urlPart) String() string {
if int(u) < len(urlPartNames) {
return urlPartNames[u]
}
return fmt.Sprintf("illegal urlPart %d", int(u))
}
// jsCtx determines whether a '/' starts a regular expression literal or a
// division operator.
type jsCtx uint8
const (
// jsCtxRegexp occurs where a '/' would start a regexp literal.
jsCtxRegexp jsCtx = iota
// jsCtxDivOp occurs where a '/' would start a division operator.
jsCtxDivOp
// jsCtxUnknown occurs where a '/' is ambiguous due to context joining.
jsCtxUnknown
)
func (c jsCtx) String() string {
switch c {
case jsCtxRegexp:
return "jsCtxRegexp"
case jsCtxDivOp:
return "jsCtxDivOp"
case jsCtxUnknown:
return "jsCtxUnknown"
}
return fmt.Sprintf("illegal jsCtx %d", int(c))
}
// element identifies the HTML element when inside a start tag or special body.
// Certain HTML element (for example <script> and <style>) have bodies that are
// treated differently from stateText so the element type is necessary to
// transition into the correct context at the end of a tag and to identify the
// end delimiter for the body.
type element uint8
const (
// elementNone occurs outside a special tag or special element body.
elementNone element = iota
// elementScript corresponds to the raw text <script> element.
elementScript
// elementStyle corresponds to the raw text <style> element.
elementStyle
// elementTextarea corresponds to the RCDATA <textarea> element.
elementTextarea
// elementTitle corresponds to the RCDATA <title> element.
elementTitle
)
var elementNames = [...]string{
elementNone: "elementNone",
elementScript: "elementScript",
elementStyle: "elementStyle",
elementTextarea: "elementTextarea",
elementTitle: "elementTitle",
}
func (e element) String() string {
if int(e) < len(elementNames) {
return elementNames[e]
}
return fmt.Sprintf("illegal element %d", int(e))
}
// attr identifies the most recent HTML attribute when inside a start tag.
type attr uint8
const (
// attrNone corresponds to a normal attribute or no attribute.
attrNone attr = iota
// attrScript corresponds to an event handler attribute.
attrScript
// attrStyle corresponds to the style attribute whose value is CSS.
attrStyle
// attrURL corresponds to an attribute whose value is a URL.
attrURL
)
var attrNames = [...]string{
attrNone: "attrNone",
attrScript: "attrScript",
attrStyle: "attrStyle",
attrURL: "attrURL",
}
func (a attr) String() string {
if int(a) < len(attrNames) {
return attrNames[a]
}
return fmt.Sprintf("illegal attr %d", int(a))
}