salix/namespace.go

140 lines
3.5 KiB
Go

package salix
import (
"fmt"
"io"
"sync"
)
// Namespace represents a collection of templates that can include each other
type Namespace struct {
mu sync.Mutex
tmpls map[string]Template
vars map[string]any
tags map[string]Tag
// WhitespaceMutations enables postprocessing to remove whitespace where it isn't needed
// to make the resulting document look better. Postprocessing is only done once when the
// template is parsed, so it will not affect performance. (default: true)
WhitespaceMutations bool
// WriteOnSuccess indicates whether the output should only be written if generation fully succeeds.
// This option buffers the output of the template, so it will use more memory. (default: false)
WriteOnSuccess bool
escapeHTML *bool
}
// New returns a new template namespace
func New() *Namespace {
return &Namespace{
tmpls: map[string]Template{},
vars: map[string]any{},
tags: map[string]Tag{},
WhitespaceMutations: true,
WriteOnSuccess: false,
}
}
// WithVarMap sets the namespace's variable map to m
func (n *Namespace) WithVarMap(m map[string]any) *Namespace {
n.mu.Lock()
defer n.mu.Unlock()
if m == nil {
n.vars = map[string]any{}
} else {
n.vars = m
}
return n
}
// WithTagMap sets the namespace's tag map to m
func (n *Namespace) WithTagMap(m map[string]Tag) *Namespace {
n.mu.Lock()
defer n.mu.Unlock()
if m == nil {
n.tags = map[string]Tag{}
} else {
n.tags = m
}
return n
}
// WithEscapeHTML turns HTML escaping on or off for the namespace
func (n *Namespace) WithEscapeHTML(b bool) *Namespace {
n.mu.Lock()
defer n.mu.Unlock()
n.escapeHTML = &b
return n
}
// WithWriteOnSuccess enables or disables only writing if generation fully succeeds.
func (n *Namespace) WithWriteOnSuccess(b bool) *Namespace {
n.mu.Lock()
defer n.mu.Unlock()
n.WriteOnSuccess = true
return n
}
// WithWhitespaceMutations turns whitespace mutations on or off for the namespace
func (n *Namespace) WithWhitespaceMutations(b bool) *Namespace {
n.mu.Lock()
defer n.mu.Unlock()
n.WhitespaceMutations = true
return n
}
// GetTemplate tries to get a template from the namespace's template map.
// If it finds the template, it returns the template and true. If it
// doesn't find it, it returns nil and false.
func (n *Namespace) GetTemplate(name string) (Template, bool) {
n.mu.Lock()
defer n.mu.Unlock()
t, ok := n.tmpls[name]
return t, ok
}
// MustGetTemplate is the same as GetTemplate but it panics if the template
// doesn't exist in the namespace.
func (n *Namespace) MustGetTemplate(name string) Template {
tmpl, ok := n.GetTemplate(name)
if !ok {
panic(fmt.Errorf("no such template: %q", name))
}
return tmpl
}
// ExecuteTemplate gets and executes a template with the given name.
func (n *Namespace) ExecuteTemplate(w io.Writer, name string, vars map[string]any) error {
tmpl, ok := n.GetTemplate(name)
if !ok {
return fmt.Errorf("no such template: %q", name)
}
return tmpl.WithVarMap(vars).Execute(w)
}
// getVar tries to get a variable from the namespace's variable map
func (n *Namespace) getVar(name string) (any, bool) {
n.mu.Lock()
defer n.mu.Unlock()
v, ok := n.vars[name]
return v, ok
}
// getTag tries to get a tag from the namespace's tag map
func (n *Namespace) getTag(name string) (Tag, bool) {
n.mu.Lock()
defer n.mu.Unlock()
t, ok := n.tags[name]
return t, ok
}
// getEscapeHTML returns the namespace's escapeHTML value
func (n *Namespace) getEscapeHTML() *bool {
n.mu.Lock()
defer n.mu.Unlock()
return n.escapeHTML
}