EPPlus/Packaging/ZipPackageRelationshipCollection.cs

/*******************************************************************************
 * You may amend and distribute as you like, but don't remove this header!
 *
 * EPPlus provides server-side generation of Excel 2007/2010 spreadsheets.
 * See http://www.codeplex.com/EPPlus for details.
 *
 * Copyright (C) 2011  Jan Källman
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.

 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  
 * See the GNU Lesser General Public License for more details.
 *
 * The GNU Lesser General Public License can be viewed at http://www.opensource.org/licenses/lgpl-license.php
 * If you unfamiliar with this license or have questions about it, here is an http://www.gnu.org/licenses/gpl-faq.html
 *
 * All code and executables are provided "as is" with no warranty either express or implied. 
 * The author accepts no liability for any damage or loss of business that this product may cause.
 *
 * Code change notes:
 * 
 * Author							Change						Date
 *******************************************************************************
 * Jan Källman		Added		25-Oct-2012
 *******************************************************************************/
using System;
using System.Collections.Generic;
using System.IO;
using System.IO.Compression;
using System.Security;

namespace OfficeOpenXml.Packaging
{
    public class ZipPackageRelationshipCollection : IEnumerable<ZipPackageRelationship>
    {
        internal protected Dictionary<string, ZipPackageRelationship> _rels = new Dictionary<string, ZipPackageRelationship>(StringComparer.InvariantCultureIgnoreCase);
        internal void Add(ZipPackageRelationship item)
        {
            _rels.Add(item.Id, item);
        }
        public IEnumerator<ZipPackageRelationship> GetEnumerator()
        {
            return _rels.Values.GetEnumerator();
        }

        System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
        {
            return _rels.Values.GetEnumerator();
        }

        internal void Remove(string id)
        {
            _rels.Remove(id);
        }
        internal bool ContainsKey(string id)
        {
            return _rels.ContainsKey(id);
        }
        internal ZipPackageRelationship this[string id]
        {
            get
            {
                return _rels[id];
            }
        }
        internal ZipPackageRelationshipCollection GetRelationshipsByType(string relationshipType)
        {
            var ret = new ZipPackageRelationshipCollection();
            foreach (var rel in _rels.Values)
            {
                if (rel.RelationshipType == relationshipType)
                {
                    ret.Add(rel);
                }
            }
            return ret;
        }

        internal void WriteZip(ZipArchive zipArchive, string filename)
        {
            var entry = zipArchive.CreateEntry(filename);
            using var writer = new StreamWriter(entry.Open());
                
            writer.Write("<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?><Relationships xmlns=\"http://schemas.openxmlformats.org/package/2006/relationships\">");
            foreach (var rel in _rels.Values)
            {
                writer.Write("<Relationship Id=\"{0}\" Type=\"{1}\" Target=\"{2}\"{3}/>", SecurityElement.Escape(rel.Id), rel.RelationshipType, SecurityElement.Escape(rel.TargetUri.OriginalString), rel.TargetMode == TargetMode.External ? " TargetMode=\"External\"" : "");
            }
            writer.Write("</Relationships>");
        }

        public int Count
        {
            get
            {
                return _rels.Count;
            }
        }
    }
}