51 lines
1.1 KiB
Go
51 lines
1.1 KiB
Go
// Copyright 2012 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package present
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import (
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"fmt"
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"strings"
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)
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func init() {
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Register("image", parseImage)
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}
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type Image struct {
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URL string
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Width int
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Height int
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}
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func (i Image) TemplateName() string { return "image" }
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func parseImage(ctx *Context, fileName string, lineno int, text string) (Elem, error) {
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args := strings.Fields(text)
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img := Image{URL: args[1]}
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a, err := parseArgs(fileName, lineno, args[2:])
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if err != nil {
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return nil, err
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}
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switch len(a) {
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case 0:
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// no size parameters
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case 2:
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// If a parameter is empty (underscore) or invalid
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// leave the field set to zero. The "image" action
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// template will then omit that img tag attribute and
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// the browser will calculate the value to preserve
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// the aspect ratio.
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if v, ok := a[0].(int); ok {
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img.Height = v
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}
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if v, ok := a[1].(int); ok {
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img.Width = v
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}
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default:
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return nil, fmt.Errorf("incorrect image invocation: %q", text)
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}
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return img, nil
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}
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