salix/tags.go

51 lines
1.1 KiB
Go

package salix
import (
"io"
"go.elara.ws/salix/ast"
)
// Tag represents a tag in a Salix template
type Tag interface {
Run(tc *TagContext, block, args []ast.Node) error
}
var globalTags = map[string]Tag{
"if": ifTag{},
"for": forTag{},
"include": includeTag{},
}
// TagContext is passed to Tag implementations to allow them to control the interpreter
type TagContext struct {
w io.Writer
t *Template
local map[string]any
}
// Execute runs the interpreter on the given AST nodes, with the given local variables.
func (tc *TagContext) Execute(nodes []ast.Node, local map[string]any) error {
return tc.t.execute(tc.w, nodes, mergeMap(tc.local, local))
}
// GetValue evaluates the given AST node using the given local variables.
func (tc *TagContext) GetValue(node ast.Node, local map[string]any) (any, error) {
return tc.t.getValue(node, mergeMap(tc.local, local))
}
func mergeMap(a, b map[string]any) map[string]any {
out := map[string]any{}
if a != nil {
for k, v := range a {
out[k] = v
}
}
if b != nil {
for k, v := range b {
out[k] = v
}
}
return out
}