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

     1  // Copyright 2020 The Hugo Authors. All rights reserved.
     2  //
     3  // Portions Copyright The Go Authors.
     4  
     5  // Licensed under the Apache License, Version 2.0 (the "License");
     6  // you may not use this file except in compliance with the License.
     7  // You may obtain a copy of the License at
     8  // http://www.apache.org/licenses/LICENSE-2.0
     9  //
    10  // Unless required by applicable law or agreed to in writing, software
    11  // distributed under the License is distributed on an "AS IS" BASIS,
    12  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  // See the License for the specific language governing permissions and
    14  // limitations under the License.
    15  
    16  package resourcehelpers
    17  
    18  import (
    19  	"errors"
    20  	"fmt"
    21  
    22  	_errors "github.com/pkg/errors"
    23  
    24  	"github.com/gohugoio/hugo/common/maps"
    25  	"github.com/gohugoio/hugo/resources"
    26  )
    27  
    28  // We allow string or a map as the first argument in some cases.
    29  func ResolveIfFirstArgIsString(args []interface{}) (resources.ResourceTransformer, string, bool) {
    30  	if len(args) != 2 {
    31  		return nil, "", false
    32  	}
    33  
    34  	v1, ok1 := args[0].(string)
    35  	if !ok1 {
    36  		return nil, "", false
    37  	}
    38  	v2, ok2 := args[1].(resources.ResourceTransformer)
    39  
    40  	return v2, v1, ok2
    41  }
    42  
    43  // This roundabout way of doing it is needed to get both pipeline behaviour and options as arguments.
    44  func ResolveArgs(args []interface{}) (resources.ResourceTransformer, map[string]interface{}, error) {
    45  	if len(args) == 0 {
    46  		return nil, nil, errors.New("no Resource provided in transformation")
    47  	}
    48  
    49  	if len(args) == 1 {
    50  		r, ok := args[0].(resources.ResourceTransformer)
    51  		if !ok {
    52  			return nil, nil, fmt.Errorf("type %T not supported in Resource transformations", args[0])
    53  		}
    54  		return r, nil, nil
    55  	}
    56  
    57  	r, ok := args[1].(resources.ResourceTransformer)
    58  	if !ok {
    59  		if _, ok := args[1].(map[string]interface{}); !ok {
    60  			return nil, nil, fmt.Errorf("no Resource provided in transformation")
    61  		}
    62  		return nil, nil, fmt.Errorf("type %T not supported in Resource transformations", args[0])
    63  	}
    64  
    65  	m, err := maps.ToStringMapE(args[0])
    66  	if err != nil {
    67  		return nil, nil, _errors.Wrap(err, "invalid options type")
    68  	}
    69  
    70  	return r, m, nil
    71  }