intl/strres/nsStringBundleTextOverride.cpp

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6
   7 #include "nsStringBundleTextOverride.h"
   8 #include "nsString.h"
   9
  10 #include "nsNetUtil.h"
  11 #include "nsAppDirectoryServiceDefs.h"
  12
  13 // first we need a simple class which wraps a nsIPropertyElement and
  14 // cuts out the leading URL from the key
  15 class URLPropertyElement : public nsIPropertyElement
  16 {
  17 public:
  18     URLPropertyElement(nsIPropertyElement *aRealElement, uint32_t aURLLength) :
  19         mRealElement(aRealElement),
  20         mURLLength(aURLLength)
  21     { }
  22
  23     NS_DECL_ISUPPORTS
  24     NS_DECL_NSIPROPERTYELEMENT
  25
  26 private:
  27     nsCOMPtr<nsIPropertyElement> mRealElement;
  28     uint32_t mURLLength;
  29
  30     virtual ~URLPropertyElement() {}
  31 };
  32
  33 NS_IMPL_ISUPPORTS(URLPropertyElement, nsIPropertyElement)
  34
  35 // we'll tweak the key on the way through, and remove the url prefix
  36 NS_IMETHODIMP
  37 URLPropertyElement::GetKey(nsACString& aKey)
  38 {
  39     nsresult rv =  mRealElement->GetKey(aKey);
  40     if (NS_FAILED(rv)) return rv;
  41
  42     // chop off the url
  43     aKey.Cut(0, mURLLength);
  44
  45     return NS_OK;
  46 }
  47
  48 // values are unaffected
  49 NS_IMETHODIMP
  50 URLPropertyElement::GetValue(nsAString& aValue)
  51 {
  52     return mRealElement->GetValue(aValue);
  53 }
  54
  55 // setters are kind of strange, hopefully we'll never be called
  56 NS_IMETHODIMP
  57 URLPropertyElement::SetKey(const nsACString& aKey)
  58 {
  59     // this is just wrong - ideally you'd take the key, append it to
  60     // the url, and set that as the key. However, that would require
  61     // us to hold onto a copy of the string, and that's a waste,
  62     // considering nobody should ever be calling this.
  63     NS_ERROR("This makes no sense!");
  64     return NS_ERROR_NOT_IMPLEMENTED;
  65 }
  66
  67 NS_IMETHODIMP
  68 URLPropertyElement::SetValue(const nsAString& aValue)
  69 {
  70     return mRealElement->SetValue(aValue);
  71 }
  72
  73
  74 // this is a special enumerator which returns only the elements which
  75 // are prefixed with a particular url
  76 class nsPropertyEnumeratorByURL : public nsISimpleEnumerator
  77 {
  78 public:
  79     nsPropertyEnumeratorByURL(const nsACString& aURL,
  80                               nsISimpleEnumerator* aOuter) :
  81         mOuter(aOuter),
  82         mURL(aURL)
  83     {
  84         // prepare the url once so we can use its value later
  85         // persistent properties uses ":" as a delimiter, so escape
  86         // that character
  87         mURL.ReplaceSubstring(":", "%3A");
  88         // there is always a # between the url and the real key
  89         mURL.Append('#');
  90     }
  91
  92     NS_DECL_ISUPPORTS
  93     NS_DECL_NSISIMPLEENUMERATOR
  94
  95 private:
  96
  97     // actual enumerator of all strings from nsIProperties
  98     nsCOMPtr<nsISimpleEnumerator> mOuter;
  99
 100     // the current element that is valid for this url
 101     nsCOMPtr<nsIPropertyElement> mCurrent;
 102
 103     // the url in question, pre-escaped and with the # already in it
 104     nsCString mURL;
 105
 106     virtual ~nsPropertyEnumeratorByURL() {}
 107 };
 108
 109 //
 110 // nsStringBundleTextOverride implementation
 111 //
 112 NS_IMPL_ISUPPORTS(nsStringBundleTextOverride,
 113                   nsIStringBundleOverride)
 114
 115 nsresult
 116 nsStringBundleTextOverride::Init()
 117 {
 118     nsresult rv;
 119
 120     // check for existence of custom-strings.txt
 121
 122     nsCOMPtr<nsIFile> customStringsFile;
 123     rv = NS_GetSpecialDirectory(NS_APP_CHROME_DIR,
 124                                 getter_AddRefs(customStringsFile));
 125
 126     if (NS_FAILED(rv)) return rv;
 127
 128     // bail if not found - this will cause the service creation to
 129     // bail as well, and cause this object to go away
 130
 131     customStringsFile->AppendNative(NS_LITERAL_CSTRING("custom-strings.txt"));
 132
 133     bool exists;
 134     rv = customStringsFile->Exists(&exists);
 135     if (NS_FAILED(rv) || !exists)
 136         return NS_ERROR_FAILURE;
 137
 138     NS_WARNING("Using custom-strings.txt to override string bundles.");
 139     // read in the custom bundle. Keys are in the form
 140     // chrome://package/locale/foo.properties:keyname
 141
 142     nsAutoCString customStringsURLSpec;
 143     rv = NS_GetURLSpecFromFile(customStringsFile, customStringsURLSpec);
 144     if (NS_FAILED(rv)) return rv;
 145
 146     nsCOMPtr<nsIURI> uri;
 147     rv = NS_NewURI(getter_AddRefs(uri), customStringsURLSpec);
 148     if (NS_FAILED(rv)) return rv;
 149
 150     nsCOMPtr<nsIInputStream> in;
 151     rv = NS_OpenURI(getter_AddRefs(in), uri);
 152     if (NS_FAILED(rv)) return rv;
 153
 154     static NS_DEFINE_CID(kPersistentPropertiesCID, NS_IPERSISTENTPROPERTIES_CID);
 155     mValues = do_CreateInstance(kPersistentPropertiesCID, &rv);
 156     if (NS_FAILED(rv)) return rv;
 157
 158     rv = mValues->Load(in);
 159
 160     // turn this on to see the contents of custom-strings.txt
 161 #ifdef DEBUG_alecf
 162     nsCOMPtr<nsISimpleEnumerator> enumerator;
 163     mValues->Enumerate(getter_AddRefs(enumerator));
 164     NS_ASSERTION(enumerator, "no enumerator!\n");
 165
 166     printf("custom-strings.txt contains:\n");
 167     printf("----------------------------\n");
 168
 169     bool hasMore;
 170     enumerator->HasMoreElements(&hasMore);
 171     do {
 172         nsCOMPtr<nsISupports> sup;
 173         enumerator->GetNext(getter_AddRefs(sup));
 174
 175         nsCOMPtr<nsIPropertyElement> prop = do_QueryInterface(sup);
 176
 177         nsAutoCString key;
 178         nsAutoString value;
 179         prop->GetKey(key);
 180         prop->GetValue(value);
 181
 182         printf("%s = '%s'\n", key.get(), NS_ConvertUTF16toUTF8(value).get());
 183
 184         enumerator->HasMoreElements(&hasMore);
 185     } while (hasMore);
 186 #endif
 187
 188     return rv;
 189 }
 190
 191 NS_IMETHODIMP
 192 nsStringBundleTextOverride::GetStringFromName(const nsACString& aURL,
 193                                               const nsACString& key,
 194                                               nsAString& aResult)
 195 {
 196     // concatenate url#key to get the key to read
 197     nsAutoCString combinedURL(aURL + NS_LITERAL_CSTRING("#") + key);
 198
 199     // persistent properties uses ":" as a delimiter, so escape that character
 200     combinedURL.ReplaceSubstring(":", "%3A");
 201
 202     return mValues->GetStringProperty(combinedURL, aResult);
 203 }
 204
 205 NS_IMETHODIMP
 206 nsStringBundleTextOverride::EnumerateKeysInBundle(const nsACString& aURL,
 207                                                   nsISimpleEnumerator** aResult)
 208 {
 209     // enumerate all strings, and let the enumerator know
 210     nsCOMPtr<nsISimpleEnumerator> enumerator;
 211     mValues->Enumerate(getter_AddRefs(enumerator));
 212
 213     // make the enumerator wrapper and pass it off
 214     nsPropertyEnumeratorByURL* propEnum =
 215         new nsPropertyEnumeratorByURL(aURL, enumerator);
 216
 217     if (!propEnum) return NS_ERROR_OUT_OF_MEMORY;
 218
 219     NS_ADDREF(*aResult = propEnum);
 220
 221     return NS_OK;
 222 }
 223
 224
 225 //
 226 // nsPropertyEnumeratorByURL implementation
 227 //
 228
 229
 230 NS_IMPL_ISUPPORTS(nsPropertyEnumeratorByURL, nsISimpleEnumerator)
 231
 232 NS_IMETHODIMP
 233 nsPropertyEnumeratorByURL::GetNext(nsISupports **aResult)
 234 {
 235     if (!mCurrent) return NS_ERROR_UNEXPECTED;
 236
 237     // wrap mCurrent instead of returning it
 238     *aResult = new URLPropertyElement(mCurrent, mURL.Length());
 239     NS_ADDREF(*aResult);
 240
 241     // release it so we don't return it twice
 242     mCurrent = nullptr;
 243
 244     return NS_OK;
 245 }
 246
 247 NS_IMETHODIMP
 248 nsPropertyEnumeratorByURL::HasMoreElements(bool * aResult)
 249 {
 250     bool hasMore;
 251     mOuter->HasMoreElements(&hasMore);
 252     while (hasMore) {
 253
 254         nsCOMPtr<nsISupports> supports;
 255         mOuter->GetNext(getter_AddRefs(supports));
 256
 257         mCurrent = do_QueryInterface(supports);
 258
 259         if (mCurrent) {
 260             nsAutoCString curKey;
 261             mCurrent->GetKey(curKey);
 262
 263             if (StringBeginsWith(curKey, mURL))
 264                 break;
 265         }
 266
 267         mOuter->HasMoreElements(&hasMore);
 268     }
 269
 270     if (!hasMore)
 271         mCurrent = nullptr;
 272
 273     *aResult = mCurrent ? true : false;
 274
 275     return NS_OK;
 276 }