github.com/pdfcpu/pdfcpu@v0.11.1/pkg/api/collect.go (about)

     1  /*
     2  	Copyright 2020 The pdfcpu Authors.
     3  
     4  	Licensed under the Apache License, Version 2.0 (the "License");
     5  	you may not use this file except in compliance with the License.
     6  	You may obtain a copy of the License at
     7  
     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  
    17  package api
    18  
    19  import (
    20  	"io"
    21  	"os"
    22  
    23  	"github.com/pdfcpu/pdfcpu/pkg/pdfcpu"
    24  	"github.com/pdfcpu/pdfcpu/pkg/pdfcpu/model"
    25  	"github.com/pkg/errors"
    26  )
    27  
    28  // Collect creates a custom PDF page sequence for selected pages of rs and writes the result to w.
    29  func Collect(rs io.ReadSeeker, w io.Writer, selectedPages []string, conf *model.Configuration) error {
    30  	if rs == nil {
    31  		return errors.New("pdfcpu: Collect: missing rs")
    32  	}
    33  
    34  	if conf == nil {
    35  		conf = model.NewDefaultConfiguration()
    36  	}
    37  	conf.Cmd = model.COLLECT
    38  
    39  	ctx, err := ReadValidateAndOptimize(rs, conf)
    40  	if err != nil {
    41  		return err
    42  	}
    43  
    44  	pages, err := PagesForPageCollection(ctx.PageCount, selectedPages)
    45  	if err != nil {
    46  		return err
    47  	}
    48  
    49  	ctxDest, err := pdfcpu.ExtractPages(ctx, pages, false)
    50  	if err != nil {
    51  		return err
    52  	}
    53  
    54  	return Write(ctxDest, w, conf)
    55  }
    56  
    57  // CollectFile creates a custom PDF page sequence for inFile and writes the result to outFile.
    58  func CollectFile(inFile, outFile string, selectedPages []string, conf *model.Configuration) (err error) {
    59  	tmpFile := inFile + ".tmp"
    60  	if outFile != "" && inFile != outFile {
    61  		tmpFile = outFile
    62  		logWritingTo(outFile)
    63  	} else {
    64  		logWritingTo(inFile)
    65  	}
    66  
    67  	var f1, f2 *os.File
    68  
    69  	if f1, err = os.Open(inFile); err != nil {
    70  		return err
    71  	}
    72  
    73  	if f2, err = os.Create(tmpFile); err != nil {
    74  		f1.Close()
    75  		return err
    76  	}
    77  
    78  	defer func() {
    79  		if err != nil {
    80  			f2.Close()
    81  			f1.Close()
    82  			os.Remove(tmpFile)
    83  			return
    84  		}
    85  		if err = f2.Close(); err != nil {
    86  			return
    87  		}
    88  		if err = f1.Close(); err != nil {
    89  			return
    90  		}
    91  		if outFile == "" || inFile == outFile {
    92  			err = os.Rename(tmpFile, inFile)
    93  		}
    94  	}()
    95  
    96  	return Collect(f1, f2, selectedPages, conf)
    97  }