diff --git a/examples/text-templates/text-templates.go b/examples/text-templates/text-templates.go
index cd0d9a0..ec391fd 100644
--- a/examples/text-templates/text-templates.go
+++ b/examples/text-templates/text-templates.go
@@ -1,38 +1,36 @@
-// Go offers built-in support for creating
-// dynamic content or showing customized output to the user called Template.
+// Go offers built-in support for creating dynamic content or showing customized
+// output to the user with the `text/template` package. A sibling package
+// named `html/template` provides the same API but has additional security
+// features and should be used for generating HTML.
package main
-// Go has two template packages. one is "text/template" for
-// regular text manipulation, and another one is "html/template"
-// which has the same API as "text/template" but has additional security features.
-// It should be used when generating HTML.
import (
- "log"
"os"
"text/template"
)
func main() {
- // New creates a template with a specific name and returns a pointer to it.
+ // We can create a new template and parse its body from
+ // a string.
+ // Templates are a mix of static text and "actions" enclosed in
+ // `{{...}}` that are used to dynamically insert content.
t1 := template.New("t1")
-
- // Parse parses its parameter as template body.
- // We use {{.}} to access the value passed to the template when it's getting executed.
t1, err := t1.Parse("Value is {{.}}\n")
if err != nil {
- log.Fatal(err)
+ panic(err)
}
- // If we want to ignore the errors we can use Must function.
- // It will panic if an error occurs when parsing the template.
- t1 = template.Must(t1.Parse("Value is {{.}}\n"))
+ // Alternatively, we can use the `template.Must` function to
+ // panic in case `Parse` returns an error. This is especially
+ // useful for templates initialized in the global scope.
+ t1 = template.Must(t1.Parse("Value: {{.}}\n"))
- // Execute applies parsed template to the data we pass to it and writes the output to the io.Writer.
- t1.Execute(os.Stdout, t1.Name())
+ // By "executing" the template we generate its text with
+ // specific values for its actions. The `{{.}}` action is
+ // replaced by the value passed as a parameter to `Execute`.
t1.Execute(os.Stdout, "some text")
- t1.Execute(os.Stdout, true)
t1.Execute(os.Stdout, 5)
t1.Execute(os.Stdout, []string{
"Go",
@@ -40,61 +38,41 @@ func main() {
"C++",
"C#",
})
- t1.Execute(os.Stdout, struct{ name string }{
- name: "Jane Doe",
- })
- // If the data is a struct we can use the {{.FieldName}} action to access its fields.
- // The fields should be exported to be accessible when template is executing.
- t2, _ := template.
- New("t2").
- Parse("Fullname: {{.Fullname}}\n")
+ // Helper function we'll use below.
+ Create := func(name, t string) *template.Template {
+ return template.Must(template.New(name).Parse(t))
+ }
+
+ // If the data is a struct we can use the `{{.FieldName}}` action to access
+ // its fields. The fields should be exported to be accessible when a
+ // template is executing.
+ t2 := Create("t2", "Name: {{.Name}}\n")
t2.Execute(os.Stdout, struct {
- Fullname string
- }{
- Fullname: "Jane Doe",
- })
+ Name string
+ }{"Jane Doe"})
- // The same applies to maps; with maps there is no restriction on the case of key names.
+ // The same applies to maps; with maps there is no restriction on the
+ // case of key names.
t2.Execute(os.Stdout, map[string]string{
- "Fullname": "Mickey Mouse",
+ "Name": "Mickey Mouse",
})
- // You can use if control structure to show data conditionally.
- // The data between if block will be shown if the field is truthy.
- // Means it is not false boolean, empty string, nil or zero length slice, nil map/pointer.
- t3, _ := template.
- New("t3").
- Parse(`{{if .Field1}}
- If block => {{.Field1}}
- {{ else if .Field2}}
- Else if block => {{.Field2}}
- {{ else }}
- Else block
- {{ end }}`)
+ // if/else provide conditional execution for templates. A value is considered
+ // false if it's the default value of a type, such as 0, an empty string,
+ // nil pointer, etc.
+ // This sample demonstrates another
+ // feature of templates: using `-` in actions to trim whitespace.
+ t3 := Create("t3",
+ "{{if . -}} yes {{else -}} no {{end}}\n")
+ t3.Execute(os.Stdout, "not empty")
+ t3.Execute(os.Stdout, "")
- s := struct {
- Field1 string
- Field2 []string
- }{}
-
- s.Field1 = ""
- s.Field2 = []string{}
- t3.Execute(os.Stdout, s)
-
- s.Field1 = "Some text"
- s.Field2 = nil
- t3.Execute(os.Stdout, s)
-
- // Using a range action you can loop through a slice.
- // Each time the range block is getting executed dot will be set
- // to current item of slice.
- t4, _ := template.
- New("t4").
- Parse(`Range: {{ range . }}
- {{.}}
- {{ end }}`)
+ // range blocks let us loop through slices, arrays, maps or channels. Inside
+ // the range block `{{.}}` is set to the current item of the iteration.
+ t4 := Create("t4",
+ "Range: {{range .}}{{.}} {{end}}\n")
t4.Execute(os.Stdout,
[]string{
"Go",
@@ -102,14 +80,4 @@ func main() {
"C++",
"C#",
})
-
- // You can assign and reassign a value to a variable in templates.
- t5, _ := template.
- New("t5").
- Parse(`Variables:
- {{ $language := "go" }}
- {{ $language }}
- {{ $language = "C" }}
- {{ $language }}`)
- t5.Execute(os.Stdout, nil)
}
diff --git a/examples/text-templates/text-templates.hash b/examples/text-templates/text-templates.hash
index d0418a6..859241b 100644
--- a/examples/text-templates/text-templates.hash
+++ b/examples/text-templates/text-templates.hash
@@ -1,2 +1,2 @@
-69a28314f7ebd877b184b35a8166e2fcaab56754
--mRr-NuSB6f
+c29676a83f4832a77b7a9e300d3fb5fe315de7b8
+pDwkw1iMACF
diff --git a/examples/text-templates/text-templates.sh b/examples/text-templates/text-templates.sh
index 3cf70b9..4c951f1 100644
--- a/examples/text-templates/text-templates.sh
+++ b/examples/text-templates/text-templates.sh
@@ -1,24 +1,9 @@
$ go run templates.go
-Value is t1
-Value is some text
-Value is true
-Value is 5
-Value is [Go Rust C++ C#]
-Value is {Jane Doe}
-Fullname: Jane Doe
-Fullname: Mickey Mouse
-
- Else block
-
- Else if block => Some text
-Range:
- Go
-
- Rust
-
- C++
-
- C#
-Variables:
-go
-C
+Value: some text
+Value: 5
+Value: [Go Rust C++ C#]
+Name: Jane Doe
+Name: Mickey Mouse
+yes
+no
+Range: Go Rust C++ C#
diff --git a/public/text-templates b/public/text-templates
index 1f03b49..2b97618 100644
--- a/public/text-templates
+++ b/public/text-templates
@@ -27,8 +27,10 @@
|
- Go offers built-in support for creating
-dynamic content or showing customized output to the user called Template.
+ Go offers built-in support for creating dynamic content or showing customized
+output to the user with the text/template package. A sibling package
+named html/template provides the same API but has additional security
+features and should be used for generating HTML.
|
@@ -42,7 +44,7 @@ dynamic content or showing customized output to the user called Template.
|
-  
+
package main
|
@@ -50,17 +52,11 @@ dynamic content or showing customized output to the user called Template.
|
- Go has two template packages. one is “text/template” for
-regular text manipulation, and another one is “html/template”
-which has the same API as “text/template” but has additional security features.
-It should be used when generating HTML.
-
+
|
-
-import (
- "log"
+ import (
"os"
"text/template"
)
@@ -81,29 +77,19 @@ It should be used when generating HTML.
|
- New creates a template with a specific name and returns a pointer to it.
+ We can create a new template and parse its body from
+a string.
+Templates are a mix of static text and “actions” enclosed in
+{{...}} that are used to dynamically insert content.
|
t1 := template.New("t1")
-
- |
-
-
-
- |
- Parse parses its parameter as template body.
-We use {{.}} to access the value passed to the template when it’s getting executed.
-
- |
-
-
-
t1, err := t1.Parse("Value is {{.}}\n")
if err != nil {
- log.Fatal(err)
+ panic(err)
}
|
@@ -111,29 +97,30 @@ We use {{.}} to access the value passed to the template when it’s getting
|
- If we want to ignore the errors we can use Must function.
-It will panic if an error occurs when parsing the template.
+ Alternatively, we can use the template.Must function to
+panic in case Parse returns an error. This is especially
+useful for templates initialized in the global scope.
|
- t1 = template.Must(t1.Parse("Value is {{.}}\n"))
+ t1 = template.Must(t1.Parse("Value: {{.}}\n"))
|
|
- Execute applies parsed template to the data we pass to it and writes the output to the io.Writer.
+ By “executing” the template we generate its text with
+specific values for its actions. The {{.}} action is
+replaced by the value passed as a parameter to Execute.
|
- t1.Execute(os.Stdout, t1.Name())
t1.Execute(os.Stdout, "some text")
- t1.Execute(os.Stdout, true)
t1.Execute(os.Stdout, 5)
t1.Execute(os.Stdout, []string{
"Go",
@@ -141,25 +128,36 @@ It will panic if an error occurs when parsing the template.
"C++",
"C#",
})
- t1.Execute(os.Stdout, struct{ name string }{
- name: "Jane Doe",
- })
|
|
- If the data is a struct we can use the {{.FieldName}} action to access its fields.
-The fields should be exported to be accessible when template is executing.
+ Helper function we’ll use below.
|
- t2, _ := template.
- New("t2").
- Parse("Fullname: {{.Fullname}}\n")
+ Create := func(name, t string) *template.Template {
+ return template.Must(template.New(name).Parse(t))
+ }
+
+ |
+
+
+
+ |
+ If the data is a struct we can use the {{.FieldName}} action to access
+its fields. The fields should be exported to be accessible when a
+template is executing.
+
+ |
+
+
+
+ t2 := Create("t2", "Name: {{.Name}}\n")
|
@@ -171,24 +169,23 @@ The fields should be exported to be accessible when template is executing.
t2.Execute(os.Stdout, struct {
- Fullname string
- }{
- Fullname: "Jane Doe",
- })
+ Name string
+ }{"Jane Doe"})
|
|
|
- The same applies to maps; with maps there is no restriction on the case of key names.
+ The same applies to maps; with maps there is no restriction on the
+case of key names.
|
t2.Execute(os.Stdout, map[string]string{
- "Fullname": "Mickey Mouse",
+ "Name": "Mickey Mouse",
})
|
@@ -196,82 +193,35 @@ The fields should be exported to be accessible when template is executing.
|
- You can use if control structure to show data conditionally.
-The data between if block will be shown if the field is truthy.
-Means it is not false boolean, empty string, nil or zero length slice, nil map/pointer.
+ if/else provide conditional execution for templates. A value is considered
+false if it’s the default value of a type, such as 0, an empty string,
+nil pointer, etc.
+This sample demonstrates another
+feature of templates: using - in actions to trim whitespace.
|
- t3, _ := template.
- New("t3").
- Parse(`{{if .Field1}}
- If block => {{.Field1}}
- {{ else if .Field2}}
- Else if block => {{.Field2}}
- {{ else }}
- Else block
- {{ end }}`)
+ t3 := Create("t3",
+ "{{if . -}} yes {{else -}} no {{end}}\n")
+ t3.Execute(os.Stdout, "not empty")
+ t3.Execute(os.Stdout, "")
|
|
-
- |
-
-
- s := struct {
- Field1 string
- Field2 []string
- }{}
-
- |
-
-
-
- |
-
- |
-
-
- s.Field1 = ""
- s.Field2 = []string{}
- t3.Execute(os.Stdout, s)
-
- |
-
-
-
- |
-
- |
-
-
- s.Field1 = "Some text"
- s.Field2 = nil
- t3.Execute(os.Stdout, s)
-
- |
-
-
-
- |
- Using a range action you can loop through a slice.
-Each time the range block is getting executed dot will be set
-to current item of slice.
+ range blocks let us loop through slices, arrays, maps or channels. Inside
+the range block {{.}} is set to the current item of the iteration.
|
-
+ |
- t4, _ := template.
- New("t4").
- Parse(`Range: {{ range . }}
- {{.}}
- {{ end }}`)
+ t4 := Create("t4",
+ "Range: {{range .}}{{.}} {{end}}\n")
t4.Execute(os.Stdout,
[]string{
"Go",
@@ -279,25 +229,6 @@ to current item of slice.
"C++",
"C#",
})
-
- |
-
-
-
- |
- You can assign and reassign a value to a variable in templates.
-
- |
-
-
-
- t5, _ := template.
- New("t5").
- Parse(`Variables: {{ $language := "go" }}
- {{ $language }}
- {{ $language = "C" }}
- {{ $language }}`)
- t5.Execute(os.Stdout, nil)
}
|
@@ -307,76 +238,21 @@ to current item of slice.
-
- |
-
- |
-
-
- $ go run templates.go
-Value is my-template
-Value is some text
-Value is true
-Value is 5
-Value is [Go Rust C++ C#]
-Value is {Jane Doe}
-Fullname: Jane Doe
-Fullname: Mickey Mouse
- |
-
-
-
- |
-
- |
-
-
- Else block
- |
-
-
-
- |
-
- |
-
-
- Else if block => Some text
-Range:
- Go
- |
-
-
-
- |
-
- |
-
-
- Rust
- |
-
-
-
- |
-
- |
-
-
- C++
- |
-
-
|
|
- C#
-Variables:
-go
-C
+ $ go run templates.go
+Value: some text
+Value: 5
+Value: [Go Rust C++ C#]
+Name: Jane Doe
+Name: Mickey Mouse
+yes
+no
+Range: Go Rust C++ C#
|
@@ -395,7 +271,7 @@ to current item of slice.