github.com/kovansky/hugo@v0.92.3-0.20220224232819-63076e4ff19f/tpl/encoding/encoding.go (about)

     1  // Copyright 2020 The Hugo Authors. All rights reserved.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  // http://www.apache.org/licenses/LICENSE-2.0
     7  //
     8  // Unless required by applicable law or agreed to in writing, software
     9  // distributed under the License is distributed on an "AS IS" BASIS,
    10  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    11  // See the License for the specific language governing permissions and
    12  // limitations under the License.
    13  
    14  // Package encoding provides template functions for encoding content.
    15  package encoding
    16  
    17  import (
    18  	"encoding/base64"
    19  	"encoding/json"
    20  	"errors"
    21  	"html/template"
    22  
    23  	"github.com/gohugoio/hugo/common/maps"
    24  	"github.com/spf13/cast"
    25  )
    26  
    27  // New returns a new instance of the encoding-namespaced template functions.
    28  func New() *Namespace {
    29  	return &Namespace{}
    30  }
    31  
    32  // Namespace provides template functions for the "encoding" namespace.
    33  type Namespace struct{}
    34  
    35  // Base64Decode returns the base64 decoding of the given content.
    36  func (ns *Namespace) Base64Decode(content interface{}) (string, error) {
    37  	conv, err := cast.ToStringE(content)
    38  	if err != nil {
    39  		return "", err
    40  	}
    41  
    42  	dec, err := base64.StdEncoding.DecodeString(conv)
    43  	return string(dec), err
    44  }
    45  
    46  // Base64Encode returns the base64 encoding of the given content.
    47  func (ns *Namespace) Base64Encode(content interface{}) (string, error) {
    48  	conv, err := cast.ToStringE(content)
    49  	if err != nil {
    50  		return "", err
    51  	}
    52  
    53  	return base64.StdEncoding.EncodeToString([]byte(conv)), nil
    54  }
    55  
    56  // Jsonify encodes a given object to JSON.  To pretty print the JSON, pass a map
    57  // or dictionary of options as the first argument.  Supported options are
    58  // "prefix" and "indent".  Each JSON element in the output will begin on a new
    59  // line beginning with prefix followed by one or more copies of indent according
    60  // to the indentation nesting.
    61  func (ns *Namespace) Jsonify(args ...interface{}) (template.HTML, error) {
    62  	var (
    63  		b   []byte
    64  		err error
    65  	)
    66  
    67  	switch len(args) {
    68  	case 0:
    69  		return "", nil
    70  	case 1:
    71  		b, err = json.Marshal(args[0])
    72  	case 2:
    73  		var opts map[string]string
    74  
    75  		opts, err = maps.ToStringMapStringE(args[0])
    76  		if err != nil {
    77  			break
    78  		}
    79  
    80  		b, err = json.MarshalIndent(args[1], opts["prefix"], opts["indent"])
    81  	default:
    82  		err = errors.New("too many arguments to jsonify")
    83  	}
    84  
    85  	if err != nil {
    86  		return "", err
    87  	}
    88  
    89  	return template.HTML(b), nil
    90  }