打包template

type Inventory struct {
	Material string
	Count    uint
}
sweaters := Inventory{"wool", 17}
tmpl, err := template.New("test").Parse("{{.Count}} items are made of {{.Material}}")
if err != nil { panic(err) }
err = tmpl.Execute(os.Stdout, sweaters)
if err != nil { panic(err) }

"{{23 -}} < {{- 45}}"

"23<45"

{{/* a comment */}}
	A comment; discarded. May contain newlines.
	Comments do not nest and must start and end at the
	delimiters, as shown here.

{{pipeline}}
	The default textual representation (the same as would be
	printed by fmt.Print) of the value of the pipeline is copied
	to the output.

{{if pipeline}} T1 {{end}}
	If the value of the pipeline is empty, no output is generated;
	otherwise, T1 is executed. The empty values are false, 0, any
	nil pointer or interface value, and any array, slice, map, or
	string of length zero.
	Dot is unaffected.

{{if pipeline}} T1 {{else}} T0 {{end}}
	If the value of the pipeline is empty, T0 is executed;
	otherwise, T1 is executed. Dot is unaffected.

{{if pipeline}} T1 {{else if pipeline}} T0 {{end}}
	To simplify the appearance of if-else chains, the else action
	of an if may include another if directly; the effect is exactly
	the same as writing
		{{if pipeline}} T1 {{else}}{{if pipeline}} T0 {{end}}{{end}}

{{range pipeline}} T1 {{end}}
	The value of the pipeline must be an array, slice, map, or channel.
	If the value of the pipeline has length zero, nothing is output;
	otherwise, dot is set to the successive elements of the array,
	slice, or map and T1 is executed. If the value is a map and the
	keys are of basic type with a defined order ("comparable"), the
	elements will be visited in sorted key order.

{{range pipeline}} T1 {{else}} T0 {{end}}
	The value of the pipeline must be an array, slice, map, or channel.
	If the value of the pipeline has length zero, dot is unaffected and
	T0 is executed; otherwise, dot is set to the successive elements
	of the array, slice, or map and T1 is executed.

{{template "name"}}
	The template with the specified name is executed with nil data.

{{template "name" pipeline}}
	The template with the specified name is executed with dot set
	to the value of the pipeline.

{{block "name" pipeline}} T1 {{end}}
	A block is shorthand for defining a template
		{{define "name"}} T1 {{end}}
	and then executing it in place
		{{template "name" .}}
	The typical use is to define a set of root templates that are
	then customized by redefining the block templates within.

{{with pipeline}} T1 {{end}}
	If the value of the pipeline is empty, no output is generated;
	otherwise, dot is set to the value of the pipeline and T1 is
	executed.

{{with pipeline}} T1 {{else}} T0 {{end}}
	If the value of the pipeline is empty, dot is unaffected and T0
	is executed; otherwise, dot is set to the value of the pipeline
	and T1 is executed.

- A boolean, string, character, integer, floating-point, imaginary
  or complex constant in Go syntax. These behave like Go's untyped
  constants.
- The keyword nil, representing an untyped Go nil.
- The character '.' (period):
	.
  The result is the value of dot.
- A variable name, which is a (possibly empty) alphanumeric string
  preceded by a dollar sign, such as
	$piOver2
  or
	$
  The result is the value of the variable.
  Variables are described below.
- The name of a field of the data, which must be a struct, preceded
  by a period, such as
	.Field
  The result is the value of the field. Field invocations may be
  chained:
    .Field1.Field2
  Fields can also be evaluated on variables, including chaining:
    $x.Field1.Field2
- The name of a key of the data, which must be a map, preceded
  by a period, such as
	.Key
  The result is the map element value indexed by the key.
  Key invocations may be chained and combined with fields to any
  depth:
    .Field1.Key1.Field2.Key2
  Although the key must be an alphanumeric identifier, unlike with
  field names they do not need to start with an upper case letter.
  Keys can also be evaluated on variables, including chaining:
    $x.key1.key2
- The name of a niladic method of the data, preceded by a period,
  such as
	.Method
  The result is the value of invoking the method with dot as the
  receiver, dot.Method(). Such a method must have one return value (of
  any type) or two return values, the second of which is an error.
  If it has two and the returned error is non-nil, execution terminates
  and an error is returned to the caller as the value of Execute.
  Method invocations may be chained and combined with fields and keys
  to any depth:
    .Field1.Key1.Method1.Field2.Key2.Method2
  Methods can also be evaluated on variables, including chaining:
    $x.Method1.Field
- The name of a niladic function, such as
	fun
  The result is the value of invoking the function, fun(). The return
  types and values behave as in methods. Functions and function
  names are described below.
- A parenthesized instance of one the above, for grouping. The result
  may be accessed by a field or map key invocation.
	print (.F1 arg1) (.F2 arg2)
	(.StructValuedMethod "arg").Field

Argument
	The result is the value of evaluating the argument.
.Method [Argument...]
	The method can be alone or the last element of a chain but,
	unlike methods in the middle of a chain, it can take arguments.
	The result is the value of calling the method with the
	arguments:
		dot.Method(Argument1, etc.)
functionName [Argument...]
	The result is the value of calling the function associated
	with the name:
		function(Argument1, etc.)
	Functions and function names are described below.

$variable := pipeline

range $index, $element := pipeline

{{"\"output\""}}
	A string constant.
{{`"output"`}}
	A raw string constant.
{{printf "%q" "output"}}
	A function call.
{{"output" | printf "%q"}}
	A function call whose final argument comes from the previous
	command.
{{printf "%q" (print "out" "put")}}
	A parenthesized argument.
{{"put" | printf "%s%s" "out" | printf "%q"}}
	A more elaborate call.
{{"output" | printf "%s" | printf "%q"}}
	A longer chain.
{{with "output"}}{{printf "%q" .}}{{end}}
	A with action using dot.
{{with $x := "output" | printf "%q"}}{{$x}}{{end}}
	A with action that creates and uses a variable.
{{with $x := "output"}}{{printf "%q" $x}}{{end}}
	A with action that uses the variable in another action.
{{with $x := "output"}}{{$x | printf "%q"}}{{end}}
	The same, but pipelined.

and
	Returns the boolean AND of its arguments by returning the
	first empty argument or the last argument, that is,
	"and x y" behaves as "if x then y else x". All the
	arguments are evaluated.
call
	Returns the result of calling the first argument, which
	must be a function, with the remaining arguments as parameters.
	Thus "call .X.Y 1 2" is, in Go notation, dot.X.Y(1, 2) where
	Y is a func-valued field, map entry, or the like.
	The first argument must be the result of an evaluation
	that yields a value of function type (as distinct from
	a predefined function such as print). The function must
	return either one or two result values, the second of which
	is of type error. If the arguments don't match the function
	or the returned error value is non-nil, execution stops.
html
	Returns the escaped HTML equivalent of the textual
	representation of its arguments. This function is unavailable
	in html/template, with a few exceptions.
index
	Returns the result of indexing its first argument by the
	following arguments. Thus "index x 1 2 3" is, in Go syntax,
	x[1][2][3]. Each indexed item must be a map, slice, or array.
js
	Returns the escaped JavaScript equivalent of the textual
	representation of its arguments.
len
	Returns the integer length of its argument.
not
	Returns the boolean negation of its single argument.
or
	Returns the boolean OR of its arguments by returning the
	first non-empty argument or the last argument, that is,
	"or x y" behaves as "if x then x else y". All the
	arguments are evaluated.
print
	An alias for fmt.Sprint
printf
	An alias for fmt.Sprintf
println
	An alias for fmt.Sprintln
urlquery
	Returns the escaped value of the textual representation of
	its arguments in a form suitable for embedding in a URL query.
	This function is unavailable in html/template, with a few
	exceptions.

eq
	Returns the boolean truth of arg1 == arg2
ne
	Returns the boolean truth of arg1 != arg2
lt
	Returns the boolean truth of arg1 < arg2
le
	Returns the boolean truth of arg1 <= arg2
gt
	Returns the boolean truth of arg1 > arg2
ge
	Returns the boolean truth of arg1 >= arg2

arg1==arg2 || arg1==arg3 || arg1==arg4 ...

`{{define "T1"}}ONE{{end}}
{{define "T2"}}TWO{{end}}
{{define "T3"}}{{template "T1"}} {{template "T2"}}{{end}}
{{template "T3"}}`

ONE TWO

err := tmpl.Execute(os.Stdout, "no data needed")
if err != nil {
	log.Fatalf("execution failed: %s", err)
}

err := tmpl.ExecuteTemplate(os.Stdout, "T2", "no data needed")
if err != nil {
	log.Fatalf("execution failed: %s", err)
}

func HTMLEscape(w io.Writer, b []byte)

func HTMLEscapeString(s string) string

func HTMLEscaper(args ...interface{}) string

func IsTrue(val interface{}) (truth, ok bool)

func JSEscape(w io.Writer, b []byte)

func JSEscapeString(s string) string

func JSEscaper(args ...interface{}) string

func URLQueryEscaper(args ...interface{}) string

type ExecError struct {
        Name string // Name of template.
        Err  error  // Pre-formatted error.
}

func (e ExecError) Error() string

type FuncMap map[string]interface{}

type Template struct {
        *parse.Tree
        // contains filtered or unexported fields
}

package main

import (
	"log"
	"os"
	"text/template"
)

func main() {
	// Define a template.
	const letter = `
Dear {{.Name}},
{{if .Attended}}
It was a pleasure to see you at the wedding.
{{- else}}
It is a shame you couldn't make it to the wedding.
{{- end}}
{{with .Gift -}}
Thank you for the lovely {{.}}.
{{end}}
Best wishes,
Josie
`

	// Prepare some data to insert into the template.
	type Recipient struct {
		Name, Gift string
		Attended   bool
	}
	var recipients = []Recipient{
		{"Aunt Mildred", "bone china tea set", true},
		{"Uncle John", "moleskin pants", false},
		{"Cousin Rodney", "", false},
	}

	// Create a new template and parse the letter into it.
	t := template.Must(template.New("letter").Parse(letter))

	// Execute the template for each recipient.
	for _, r := range recipients {
		err := t.Execute(os.Stdout, r)
		if err != nil {
			log.Println("executing template:", err)
		}
	}

}

package main

import (
	"log"
	"os"
	"strings"
	"text/template"
)

func main() {
	const (
		master  = `Names:{{block "list" .}}{{"\n"}}{{range .}}{{println "-" .}}{{end}}{{end}}`
		overlay = `{{define "list"}} {{join . ", "}}{{end}} `
	)
	var (
		funcs     = template.FuncMap{"join": strings.Join}
		guardians = []string{"Gamora", "Groot", "Nebula", "Rocket", "Star-Lord"}
	)
	masterTmpl, err := template.New("master").Funcs(funcs).Parse(master)
	if err != nil {
		log.Fatal(err)
	}
	overlayTmpl, err := template.Must(masterTmpl.Clone()).Parse(overlay)
	if err != nil {
		log.Fatal(err)
	}
	if err := masterTmpl.Execute(os.Stdout, guardians err != nil {
		log.Fatal(err)
	}
	if err := overlayTmpl.Execute(os.Stdout, guardians err != nil {
		log.Fatal(err)
	}
}

package main

import (
	"log"
	"os"
	"strings"
	"text/template"
)

func main() {
	// First we create a FuncMap with which to register the function.
	funcMap := template.FuncMap{
		// The name "title" is what the function will be called in the template text.
		"title": strings.Title,
	}

	// A simple template definition to test our function.
	// We print the input text several ways:
	// - the original
	// - title-cased
	// - title-cased and then printed with %q
	// - printed with %q and then title-cased.
	const templateText = `
Input: {{printf "%q" .}}
Output 0: {{title .}}
Output 1: {{title . | printf "%q"}}
Output 2: {{printf "%q" . | title}}
`

	// Create a template, add the function map, and parse the text.
	tmpl, err := template.New("titleTest").Funcs(funcMap).Parse(templateText)
	if err != nil {
		log.Fatalf("parsing: %s", err)
	}

	// Run the template to verify the output.
	err = tmpl.Execute(os.Stdout, "the go programming language")
	if err != nil {
		log.Fatalf("execution: %s", err)
	}

}

// Here we create a temporary directory and populate it with our sample
// template definition files; usually the template files would already
// exist in some location known to the program.
dir := createTestDir([]templateFile{
        // T0.tmpl is a plain template file that just invokes T1.
        {"T0.tmpl", `T0 invokes T1: {{template "T1"}})`},
        // T1.tmpl defines a template, T1 that invokes T2.
        {"T1.tmpl", `{{define "T1"}}T1 invokes T2: {{template "T2"}}){{end}}`},
        // T2.tmpl defines a template T2.
        {"T2.tmpl", `{{define "T2"}}This is T2{{end}}`},
})
// Clean up after the test; another quirk of running as an example.
defer os.RemoveAll(dir)

// pattern is the glob pattern used to find all the template files.
pattern := filepath.Join(dir, "*.tmpl")

// Here starts the example proper.
// T0.tmpl is the first name matched, so it becomes the starting template,
// the value returned by ParseGlob.
tmpl := template.Must(template.ParseGlob(pattern))

err := tmpl.Execute(os.Stdout, nil)
if err != nil {
        log.Fatalf("template execution: %s", err)
}

T0 invokes T1: (T1 invokes T2: (This is T2))

// Here we create a temporary directory and populate it with our sample
// template definition files; usually the template files would already
// exist in some location known to the program.
dir := createTestDir([]templateFile{
        // T1.tmpl defines a template, T1 that invokes T2.
        {"T1.tmpl", `{{define "T1"}}T1 invokes T2: {{template "T2"}}){{end}}`},
        // T2.tmpl defines a template T2.
        {"T2.tmpl", `{{define "T2"}}This is T2{{end}}`},
})
// Clean up after the test; another quirk of running as an example.
defer os.RemoveAll(dir)

// pattern is the glob pattern used to find all the template files.
pattern := filepath.Join(dir, "*.tmpl")

// Here starts the example proper.
// Load the helpers.
templates := template.Must(template.ParseGlob(pattern))
// Add one driver template to the bunch; we do this with an explicit template definition.
_, err := templates.Parse("{{define `driver1`}}Driver 1 calls T1: {{template `T1`}})\n{{end}}")
if err != nil {
        log.Fatal("parsing driver1: ", err)
}
// Add another driver template.
_, err = templates.Parse("{{define `driver2`}}Driver 2 calls T2: {{template `T2`}})\n{{end}}")
if err != nil {
        log.Fatal("parsing driver2: ", err)
}
// We load all the templates before execution. This package does not require
// that behavior but html/template's escaping does, so it's a good habit.
err = templates.ExecuteTemplate(os.Stdout, "driver1", nil)
if err != nil {
        log.Fatalf("driver1 execution: %s", err)
}
err = templates.ExecuteTemplate(os.Stdout, "driver2", nil)
if err != nil {
        log.Fatalf("driver2 execution: %s", err)
}

Driver 1 calls T1: (T1 invokes T2: (This is T2))
Driver 2 calls T2: (This is T2)

// Here we create a temporary directory and populate it with our sample
// template definition files; usually the template files would already
// exist in some location known to the program.
dir := createTestDir([]templateFile{
        // T0.tmpl is a plain template file that just invokes T1.
        {"T0.tmpl", "T0 {{.}} version) invokes T1: {{template `T1`}})\n"},
        // T1.tmpl defines a template, T1 that invokes T2. Note T2 is not defined
        {"T1.tmpl", `{{define "T1"}}T1 invokes T2: {{template "T2"}}){{end}}`},
})
// Clean up after the test; another quirk of running as an example.
defer os.RemoveAll(dir)

// pattern is the glob pattern used to find all the template files.
pattern := filepath.Join(dir, "*.tmpl")

// Here starts the example proper.
// Load the drivers.
drivers := template.Must(template.ParseGlob(pattern))

// We must define an implementation of the T2 template. First we clone
// the drivers, then add a definition of T2 to the template name space.

// 1. Clone the helper set to create a new name space from which to run them.
first, err := drivers.Clone()
if err != nil {
        log.Fatal("cloning helpers: ", err)
}
// 2. Define T2, version A, and parse it.
_, err = first.Parse("{{define `T2`}}T2, version A{{end}}")
if err != nil {
        log.Fatal("parsing T2: ", err)
}

// Now repeat the whole thing, using a different version of T2.
// 1. Clone the drivers.
second, err := drivers.Clone()
if err != nil {
        log.Fatal("cloning drivers: ", err)
}
// 2. Define T2, version B, and parse it.
_, err = second.Parse("{{define `T2`}}T2, version B{{end}}")
if err != nil {
        log.Fatal("parsing T2: ", err)
}

// Execute the templates in the reverse order to verify the
// first is unaffected by the second.
err = second.ExecuteTemplate(os.Stdout, "T0.tmpl", "second")
if err != nil {
        log.Fatalf("second execution: %s", err)
}
err = first.ExecuteTemplate(os.Stdout, "T0.tmpl", "first")
if err != nil {
        log.Fatalf("first: execution: %s", err)
}

T0 (second version) invokes T1: (T1 invokes T2: (T2, version B))
T0 (first version) invokes T1: (T1 invokes T2: (T2, version A))

func Must(t *Template, err error) *Template

var t = template.Must(template.New("name").Parse("text"))

func New(name string) *Template

func ParseFiles(filenames ...string) (*Template, error)

func ParseGlob(pattern string) (*Template, error)

func (t *Template) AddParseTree(name string, tree *parse.Tree) (*Template, error)

func (t *Template) Clone() (*Template, error)

func (t *Template) DefinedTemplates() string

func (t *Template) Delims(left, right string) *Template

func (t *Template) Execute(wr io.Writer, data interface{}) error

func (t *Template) ExecuteTemplate(wr io.Writer, name string, data interface{}) error

func (t *Template) Funcs(funcMap FuncMap) *Template

func (t *Template) Lookup(name string) *Template

func (t *Template) Name() string

func (t *Template) New(name string) *Template

func (t *Template) Option(opt ...string) *Template

"missingkey=default" or "missingkey=invalid"
	The default behavior: Do nothing and continue execution.
	If printed, the result of the index operation is the string
	"<no value>".
"missingkey=zero"
	The operation returns the zero value for the map type's element.
"missingkey=error"
	Execution stops immediately with an error.

func (t *Template) Parse(text string) (*Template, error)

func (t *Template) ParseFiles(filenames ...string) (*Template, error)

func (t *Template) ParseGlob(pattern string) (*Template, error)

func (t *Template) Templates() []*Template