This simplifies transition functions to make it easier to reliably
elide comments in a later CL.
Before:
- transition functions are responsible for detecting special end tags.
After:
- the code to detect special end tags is done in one place.
We were relying on end tags being skipped which meant we were
not noticing comments inside script/style elements that contain no
substitutions.
This change means we will notice all such comments where necessary,
but stripTags will notice none since it does not need to. This speeds
up stripTags.
R=nigeltao
CC=golang-dev
https://golang.org/cl/5074041
Formulaic changes to transition functions in preparation for CL 5074041.
This should be completely semantics preserving.
R=nigeltao
CC=golang-dev
https://golang.org/cl/5091041
Instead of erroring on actions inside comments, use existing escaping
pipeline to quash the output of actions inside comments.
If a template maintainer uses a comment to disable template code:
{{if .}}Hello, {{.}}!{{end}}
->
<!--{{if true}}Hello, {{.}}!{{end}}-->
will result in
<!--Hello, !-->
regardless of the value of {{.}}.
In a later CL, comment elision will result in the entire commented-out
section being dropped from the template output.
Any side-effects in pipelines, such as panics, will still be realized.
R=nigeltao
CC=golang-dev
https://golang.org/cl/5078041
This addresses several use cases:
(1) <h{{.HeaderLevel}}> used to build hierarchical documents.
(2) <input on{{.EventType}}=...> used in widgets.
(3) <div {{" dir=ltr"}}> used to embed bidi-hints.
It also makes sure that we treat the two templates below the same:
<img src={{if .Avatar}}"{{.Avatar}}"{{else}}"anonymous.png"{{end}}>
<img src="{{if .Avatar}}{{.Avatar}}{{else}}anonymous.png{{end}}">
This splits up tTag into a number of sub-states and adds testcases.
R=nigeltao
CC=golang-dev
https://golang.org/cl/5043042
Not all content is plain text. Sometimes content comes from a trusted
source, such as another template invocation, an HTML tag whitelister,
etc.
Template authors can deal with over-escaping in two ways.
1) They can encapsulate known-safe content via
type HTML, type CSS, type URL, and friends in content.go.
2) If they know that the for a particular action never needs escaping
then they can add |noescape to the pipeline.
{{.KnownSafeContent | noescape}}
which will prevent any escaping directives from being added.
This CL defines string type aliases: HTML, CSS, JS, URI, ...
It then modifies stringify to unpack the content type.
Finally it modifies the escaping functions to use the content type and
decline to escape content that does not require it.
There are minor changes to escapeAction and helpers to treat as
equivalent explicit escaping directives such as "html" and "urlquery"
and the escaping directives defined in the contextual autoescape module
and to recognize the special "noescape" directive.
The html escaping functions are rearranged. Instead of having one
escaping function used in each {{.}} in
{{.}} : <textarea title="{{.}}">{{.}}</textarea>
a slightly different escaping function is used for each.
When {{.}} binds to a pre-sanitized string of HTML
`one < <i>two</i> & two < "3"`
we produces something like
one < <i>two</i> & two < "3" :
<textarea title="one < two & two < "3"">
one < <i>two</i> & two < "3"
</textarea>
Although escaping is not required in <textarea> normally, if the
substring </textarea> is injected, then it breaks, so we normalize
special characters in RCDATA and do the same to preserve attribute
boundaries. We also strip tags since developers never intend
typed HTML injected in an attribute to contain tags escaped, but
do occasionally confuse pre-escaped HTML with HTML from a
tag-whitelister.
R=golang-dev, nigeltao
CC=golang-dev
https://golang.org/cl/4962067
This does not wire up <style> elements as that is pending support
for raw text content in CL https://golang.org/cl/4964045/
This CL allows actions to appear in contexts like
selectors: {{.Tag}}{{.Class}}{{.Id}}
property names: border-{{.BidiLeadingEdge}}
property values: color: {{.Color}}
strings: font-family: "{{font-name}}"
URL strings: background: "/foo?image={{.ImgQuery}}"
URL literals: background: url("{{.Image}}")
but disallows actions inside CSS comments and disallows
embedding of JS in CSS entirely.
It is based on the CSS3 lexical grammar with affordances for
common browser extensions including line comments.
R=nigeltao
CC=golang-dev
https://golang.org/cl/4968058
Mike Samuel