mirror of
https://github.com/danog/liquid.git
synced 2024-12-11 17:19:40 +01:00
127 lines
2.9 KiB
Go
127 lines
2.9 KiB
Go
// Package render renders a compiled template parse tree.
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package render
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import (
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"fmt"
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"io"
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"reflect"
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"github.com/osteele/liquid/evaluator"
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)
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// Render renders the render tree.
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func Render(node Node, w io.Writer, vars map[string]interface{}, c Config) Error {
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tw := trimWriter{w: w}
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if err := node.render(&tw, newNodeContext(vars, c)); err != nil {
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return err
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}
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if err := tw.Flush(); err != nil {
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panic(err)
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}
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return nil
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}
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// RenderASTSequence renders a sequence of nodes.
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func (c nodeContext) RenderSequence(w io.Writer, seq []Node) Error {
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tw := trimWriter{w: w}
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for _, n := range seq {
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if err := n.render(&tw, c); err != nil {
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return err
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}
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}
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if err := tw.Flush(); err != nil {
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panic(err)
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}
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return nil
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}
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func (n *BlockNode) render(w *trimWriter, ctx nodeContext) Error {
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cd, ok := ctx.config.findBlockDef(n.Name)
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if !ok || cd.parser == nil {
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// this should have been detected during compilation; it's an implementation error if it happens here
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panic(fmt.Errorf("undefined tag %q", n.Name))
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}
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renderer := n.renderer
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if renderer == nil {
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panic(fmt.Errorf("unset renderer for %v", n))
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}
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err := renderer(w, rendererContext{ctx, nil, n})
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return wrapRenderError(err, n)
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}
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func (n *RawNode) render(w *trimWriter, ctx nodeContext) Error {
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for _, s := range n.slices {
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_, err := io.WriteString(w, s)
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if err != nil {
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return wrapRenderError(err, n)
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}
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}
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return nil
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}
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func (n *ObjectNode) render(w *trimWriter, ctx nodeContext) Error {
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w.TrimLeft(n.TrimLeft)
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value, err := ctx.Evaluate(n.expr)
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if err != nil {
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return wrapRenderError(err, n)
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}
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if err := wrapRenderError(writeObject(value, w), n); err != nil {
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return err
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}
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w.TrimRight(n.TrimRight)
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return nil
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}
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func (n *SeqNode) render(w *trimWriter, ctx nodeContext) Error {
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for _, c := range n.Children {
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if err := c.render(w, ctx); err != nil {
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return err
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}
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}
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return nil
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}
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func (n *TagNode) render(w *trimWriter, ctx nodeContext) Error {
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w.TrimLeft(n.TrimLeft)
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err := wrapRenderError(n.renderer(w, rendererContext{ctx, n, nil}), n)
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w.TrimRight(n.TrimRight)
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return err
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}
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func (n *TextNode) render(w *trimWriter, ctx nodeContext) Error {
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_, err := io.WriteString(w, n.Source)
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return wrapRenderError(err, n)
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}
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// writeObject writes a value used in an object node
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func writeObject(value interface{}, w io.Writer) error {
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value = evaluator.ToLiquid(value)
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if value == nil {
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return nil
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}
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switch value := value.(type) {
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case []byte:
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_, err := w.Write(value)
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return err
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case fmt.Stringer:
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_, err := io.WriteString(w, value.String())
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return err
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}
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rt := reflect.ValueOf(value)
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switch rt.Kind() {
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case reflect.Array, reflect.Slice:
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for i := 0; i < rt.Len(); i++ {
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item := rt.Index(i)
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if item.IsValid() {
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if err := writeObject(item.Interface(), w); err != nil {
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return err
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}
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}
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}
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return nil
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default:
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_, err := io.WriteString(w, fmt.Sprint(value))
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return err
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}
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}
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