Golang Set.Template方法代码示例

// EscapeSet rewrites the template set to guarantee that the output of any of
// the named templates is properly escaped.
// Names should include the names of all templates that might be Executed but
// need not include helper templates.
// If no error is returned, then the named templates have been modified. 
// Otherwise the named templates have been rendered unusable.
func EscapeSet(s *template.Set, names ...string) (*template.Set, os.Error) {
	if len(names) == 0 {
		// TODO: Maybe add a method to Set to enumerate template names
		// and use those instead.
		return nil, &Error{ErrNoNames, "", 0, "must specify names of top level templates"}
	}
	e := newEscaper(s)
	for _, name := range names {
		c, _ := e.escapeTree(context{}, name, 0)
		var err os.Error
		if c.err != nil {
			err, c.err.Name = c.err, name
		} else if c.state != stateText {
			err = &Error{ErrEndContext, name, 0, fmt.Sprintf("ends in a non-text context: %v", c)}
		}
		if err != nil {
			// Prevent execution of unsafe templates.
			for _, name := range names {
				if t := s.Template(name); t != nil {
					t.Tree = nil
				}
			}
			return nil, err
		}
	}
	e.commit()
	return s, nil
}

//.........这里部分代码省略.........
				// "<b" is not a full tag.
				"helper": `{{"<a>"}}<b`,
			},
			`<a onclick='a = &#34;\u003ca\u003e&#34;<b;'>`,
		},
		// A recursive template that ends in its start context.
		{
			map[string]string{
				"main": `{{range .Children}}{{template "main" .}}{{else}}{{.X}} {{end}}`,
			},
			`foo &lt;bar&gt; baz `,
		},
		// A recursive helper template that ends in its start context.
		{
			map[string]string{
				"main":   `{{template "helper" .}}`,
				"helper": `{{if .Children}}<ul>{{range .Children}}<li>{{template "main" .}}</li>{{end}}</ul>{{else}}{{.X}}{{end}}`,
			},
			`<ul><li>foo</li><li>&lt;bar&gt;</li><li><ul><li>baz</li></ul></li></ul>`,
		},
		// Co-recursive templates that end in its start context.
		{
			map[string]string{
				"main":   `<blockquote>{{range .Children}}{{template "helper" .}}{{end}}</blockquote>`,
				"helper": `{{if .Children}}{{template "main" .}}{{else}}{{.X}}<br>{{end}}`,
			},
			`<blockquote>foo<br>&lt;bar&gt;<br><blockquote>baz<br></blockquote></blockquote>`,
		},
		// A template that is called in two different contexts.
		{
			map[string]string{
				"main":   `<button onclick="title='{{template "helper"}}'; ...">{{template "helper"}}</button>`,
				"helper": `{{11}} of {{"<100>"}}`,
			},
			`<button onclick="title='11 of \x3c100\x3e'; ...">11 of &lt;100&gt;</button>`,
		},
		// A non-recursive template that ends in a different context.
		// helper starts in jsCtxRegexp and ends in jsCtxDivOp.
		{
			map[string]string{
				"main":   `<script>var x={{template "helper"}}/{{"42"}};</script>`,
				"helper": "{{126}}",
			},
			`<script>var x= 126 /"42";</script>`,
		},
		// A recursive template that ends in a similar context.
		{
			map[string]string{
				"main":      `<script>var x=[{{template "countdown" 4}}];</script>`,
				"countdown": `{{.}}{{if .}},{{template "countdown" . | pred}}{{end}}`,
			},
			`<script>var x=[ 4 , 3 , 2 , 1 , 0 ];</script>`,
		},
		// A recursive template that ends in a different context.
		/*
			{
				map[string]string{
					"main":   `<a href="/foo{{template "helper" .}}">`,
					"helper": `{{if .Children}}{{range .Children}}{{template "helper" .}}{{end}}{{else}}?x={{.X}}{{end}}`,
				},
				`<a href="/foo?x=foo?x=%3cbar%3e?x=baz">`,
			},
		*/
	}

	// pred is a template function that returns the predecessor of a
	// natural number for testing recursive templates.
	fns := template.FuncMap{"pred": func(a ...interface{}) (interface{}, error) {
		if len(a) == 1 {
			if i, _ := a[0].(int); i > 0 {
				return i - 1, nil
			}
		}
		return nil, fmt.Errorf("undefined pred(%v)", a)
	}}

	for _, test := range tests {
		var s template.Set
		for name, src := range test.inputs {
			t := template.New(name)
			t.Funcs(fns)
			s.Add(template.Must(t.Parse(src)))
		}
		s.Funcs(fns)
		if _, err := EscapeSet(&s, "main"); err != nil {
			t.Errorf("%s for input:\n%v", err, test.inputs)
			continue
		}
		var b bytes.Buffer

		if err := s.Execute(&b, "main", data); err != nil {
			t.Errorf("%q executing %v", err.Error(), s.Template("main"))
			continue
		}
		if got := b.String(); test.want != got {
			t.Errorf("want\n\t%q\ngot\n\t%q", test.want, got)
		}
	}

}