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//-----------------------------------------------------------------------------
// <copyright file="ContentTypeField.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
//-----------------------------------------------------------------------------
namespace System.Net.Mime
{
using System;
using System.Collections;
using System.Collections.Specialized;
using System.IO;
using System.Text;
using System.Globalization;
using System.Net.Mail;
/// <summary>
/// Typed Content-Type header
///
/// We parse the type during construction and set.
/// null and string.empty will throw for construction,set and mediatype/subtype
/// constructors set isPersisted to false. isPersisted needs to be tracked seperately
/// than isChanged because isChanged only determines if the cached value should be used.
/// isPersisted tracks if the object has been persisted. However, obviously if isChanged is true
/// the object isn't persisted.
/// If any subcomponents are changed, isChanged is set to true and isPersisted is false
/// ToString caches the value until a isChanged is true, then it recomputes the full value.
/// </summary>
public class ContentType
{
string mediaType;
string subType;
bool isChanged;
string type;
bool isPersisted;
TrackingStringDictionary parameters;
/// <summary>
/// Default content type - can be used if the Content-Type header
/// is not defined in the message headers.
/// </summary>
internal readonly static string Default = "application/octet-stream";
public ContentType() : this(Default)
{
}
/// <summary>
/// ctor.
/// </summary>
/// <param name="fieldValue">Unparsed value of the Content-Type header.</param>
public ContentType(string contentType)
{
if (contentType == null) {
throw new ArgumentNullException("contentType");
}
if (contentType == String.Empty) {
throw new ArgumentException(SR.GetString(SR.net_emptystringcall,"contentType"), "contentType");
}
isChanged = true;
type = contentType;
ParseValue();
}
public string Boundary
{
get
{
return Parameters["boundary"];
}
set
{
if (value == null || value == string.Empty) {
Parameters.Remove("boundary");
}
else{
Parameters["boundary"] = value;
}
}
}
public string CharSet
{
get
{
return Parameters["charset"];
}
set
{
if (value == null || value == string.Empty) {
Parameters.Remove("charset");
}
else{
Parameters["charset"] = value;
}
}
}
/// <summary>
/// Gets the media type.
/// </summary>
public string MediaType
{
get
{
return mediaType + "/" + subType;
}
set
{
if (value == null) {
throw new ArgumentNullException("value");
}
if (value == string.Empty) {
throw new ArgumentException(SR.GetString(SR.net_emptystringset), "value");
}
int offset = 0;
mediaType = MailBnfHelper.ReadToken(value, ref offset, null);
if (mediaType.Length == 0 || offset >= value.Length || value[offset++] != '/')
throw new FormatException(SR.GetString(SR.MediaTypeInvalid));
subType = MailBnfHelper.ReadToken(value, ref offset, null);
if(subType.Length == 0 || offset < value.Length){
throw new FormatException(SR.GetString(SR.MediaTypeInvalid));
}
isChanged = true;
isPersisted = false;
}
}
public string Name {
get {
string value = Parameters["name"];
Encoding nameEncoding = MimeBasePart.DecodeEncoding(value);
if(nameEncoding != null)
value = MimeBasePart.DecodeHeaderValue(value);
return value;
}
set {
if (value == null || value == string.Empty) {
Parameters.Remove("name");
}
else{
Parameters["name"] = value;
}
}
}
public StringDictionary Parameters
{
get
{
if (parameters == null)
{
if (type == null) {
parameters = new TrackingStringDictionary();
}
}
return parameters;
}
}
internal void Set(string contentType, HeaderCollection headers) {
type = contentType;
ParseValue();
headers.InternalSet(MailHeaderInfo.GetString(MailHeaderID.ContentType), ToString());
isPersisted = true;
}
internal void PersistIfNeeded(HeaderCollection headers, bool forcePersist) {
if (IsChanged || !isPersisted || forcePersist) {
headers.InternalSet(MailHeaderInfo.GetString(MailHeaderID.ContentType), ToString());
isPersisted = true;
}
}
internal bool IsChanged {
get {
return (isChanged || parameters != null && parameters.IsChanged);
}
}
public override string ToString() {
if (type == null || IsChanged)
{
type = Encode(false); // Legacy wire-safe format
isChanged = false;
parameters.IsChanged = false;
isPersisted = false;
}
return type;
}
internal string Encode(bool allowUnicode)
{
StringBuilder builder = new StringBuilder();
builder.Append(mediaType); // Must not have unicode, already validated
builder.Append('/');
builder.Append(subType); // Must not have unicode, already validated
// Validate and encode unicode where required
foreach (string key in Parameters.Keys)
{
builder.Append("; ");
EncodeToBuffer(key, builder, allowUnicode);
builder.Append('=');
EncodeToBuffer(parameters[key], builder, allowUnicode);
}
return builder.ToString();
}
private static void EncodeToBuffer(string value, StringBuilder builder, bool allowUnicode)
{
Encoding encoding = MimeBasePart.DecodeEncoding(value);
if (encoding != null) // Manually encoded elsewhere, pass through
{
builder.Append("\"" + value + "\"");
}
else if ((allowUnicode && !MailBnfHelper.HasCROrLF(value)) // Unicode without CL or LF's
|| MimeBasePart.IsAscii(value, false)) // Ascii
{
MailBnfHelper.GetTokenOrQuotedString(value, builder, allowUnicode);
}
else
{
// MIME Encoding required
encoding =Encoding.GetEncoding(MimeBasePart.defaultCharSet);
builder.Append("\"" + MimeBasePart.EncodeHeaderValue(value, encoding,
MimeBasePart.ShouldUseBase64Encoding(encoding)) + "\"");
}
}
public override bool Equals(object rparam) {
if (rparam == null) {
return false;
}
return (String.Compare(ToString(), rparam.ToString(), StringComparison.OrdinalIgnoreCase ) == 0);
}
public override int GetHashCode(){
return ToString().ToLowerInvariant().GetHashCode();
}
// Helper methods.
void ParseValue()
{
int offset = 0;
Exception exception = null;
parameters = new TrackingStringDictionary();
try{
mediaType = MailBnfHelper.ReadToken(type, ref offset, null);
if (mediaType == null || mediaType.Length == 0 || offset >= type.Length || type[offset++] != '/'){
exception = new FormatException(SR.GetString(SR.ContentTypeInvalid));
}
if (exception == null) {
subType = MailBnfHelper.ReadToken(type, ref offset, null);
if (subType == null || subType.Length == 0){
exception = new FormatException(SR.GetString(SR.ContentTypeInvalid));
}
}
if (exception == null) {
while (MailBnfHelper.SkipCFWS(type, ref offset))
{
if (type[offset++] != ';'){
exception = new FormatException(SR.GetString(SR.ContentTypeInvalid));
break;
}
if (!MailBnfHelper.SkipCFWS(type, ref offset))
break;
string paramAttribute = MailBnfHelper.ReadParameterAttribute(type, ref offset, null);
if(paramAttribute == null || paramAttribute.Length == 0){
exception = new FormatException(SR.GetString(SR.ContentTypeInvalid));
break;
}
string paramValue;
if ( offset >= type.Length || type[offset++] != '='){
exception = new FormatException(SR.GetString(SR.ContentTypeInvalid));
break;
}
if (!MailBnfHelper.SkipCFWS(type, ref offset)){
exception = new FormatException(SR.GetString(SR.ContentTypeInvalid));
break;
}
if (type[offset] == '"')
paramValue = MailBnfHelper.ReadQuotedString(type, ref offset, null);
else
paramValue = MailBnfHelper.ReadToken(type, ref offset, null);
if(paramValue == null){
exception = new FormatException(SR.GetString(SR.ContentTypeInvalid));
break;
}
parameters.Add(paramAttribute, paramValue);
}
}
parameters.IsChanged = false;
}
catch(FormatException){
throw new FormatException(SR.GetString(SR.ContentTypeInvalid));
}
if(exception != null){
throw new FormatException(SR.GetString(SR.ContentTypeInvalid));
}
}
}
}
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