[gxml] Document.vala: use error messages from libxml2

[Richard Hans Schwarting <rschwart src gnome org>]

commit c3b7d343c410f7e185264cb0c0bcf599d684f12e
Author: Richard Schwarting <aquarichy gmail com>
Date:   Mon Oct 14 05:06:42 2013 -0400

    Document.vala: use error messages from libxml2

 gxml/Document.vala |   87 +++++++++++++++++++++++++++++++++++----------------
 1 files changed, 60 insertions(+), 27 deletions(-)
---
diff --git a/gxml/Document.vala b/gxml/Document.vala
index ea0827e..62ddcbd 100644
--- a/gxml/Document.vala
+++ b/gxml/Document.vala
@@ -301,7 +301,6 @@ namespace GXml {
                        // TODO: consider passing root as a base node?
                        base.for_document ();
 
-
                        this.owner_document = this; // must come after base ()
                        this.xmldoc = doc;
                        if (doc->int_subset == null && doc->ext_subset == null) {
@@ -323,11 +322,15 @@ namespace GXml {
                 * @throws GXml.Error A { link GXml.Error} if an error occurs while loading
                 */
                public Document.from_path (string file_path) throws GXml.Error {
-                       Xml.ParserCtxt ctxt = new Xml.ParserCtxt ();
-                       Xml.Doc *doc = ctxt.read_file (file_path, null /* encoding */, 0 /* options */);
+                       Xml.ParserCtxt ctxt;
+                       Xml.Doc *doc;
+                       Xml.Error *e;
+
+                       ctxt = new Xml.ParserCtxt ();
+                       doc = ctxt.read_file (file_path, null /* encoding */, 0 /* options */);
 
                        if (doc == null) {
-                               Xml.Error *e = ctxt.get_last_error ();
+                               e = ctxt.get_last_error ();
                                GXml.warning (DomException.INVALID_DOC, "Could not load document from path: 
%s".printf (e->message));
                                throw new GXml.Error.PARSER (GXml.libxml2_error_to_string (e));
                        }
@@ -421,9 +424,10 @@ namespace GXml {
                 *
                 * @return A new { link GXml.Document} for `fin`; this must be freed with { link 
GLib.Object.unref}
                 *
-                * @throws GLib.Error A { link GXml.Error} if an error cocurs while reading the file
+                * @throws GLib.Error A { link GLib.Error} if an error cocurs while reading the { link 
GLib.File}
+                * @throws GXml.Error A { link GXml.Error} if an error occurs while reading the file as a 
stream
                 */
-               public Document.from_gfile (File fin, Cancellable? can = null) throws GLib.Error {
+               public Document.from_gfile (File fin, Cancellable? can = null) throws GXml.Error, GLib.Error {
                        // TODO: actually handle cancellable
                        InputStream instream;
 
@@ -432,7 +436,7 @@ namespace GXml {
                                this.from_stream (instream, can);
                                instream.close ();
                        } catch (GLib.Error e) {
-                               GXml.warning (DomException.INVALID_DOC, "Could not load document from GFile: 
%s".printf (e.message));
+                               GXml.warning (DomException.INVALID_DOC, "Could not load document from GFile: 
" + e.message);
                                throw e;
                        }
                }
@@ -456,24 +460,32 @@ namespace GXml {
                        /* TODO: provide Cancellable as user data so we can actually
                           cancel these */
                        Xml.TextReader reader;
+                       Xml.Error *e;
+                       string errmsg = null;
 
                        reader = new Xml.TextReader.for_io ((Xml.InputReadCallback)_ioread,
                                                            (Xml.InputCloseCallback)_ioinclose,
                                                            &box, "", null, 0);
                        if (-1 == reader.read ()) {
-                               GXml.warning (DomException.INVALID_DOC, "Could not load document from 
stream");
-                               throw new GXml.Error.PARSER ("Error reading from stream");
-                               // TODO: see if we can pull an error from libxml2 somewhere
-                       }
-                       if (null == reader.expand ()) {
-                               GXml.warning (DomException.INVALID_DOC, "Could not load document from 
stream");
-                               throw new GXml.Error.PARSER ("Error expanding from stream");
-                               // TODO: see if we can pull an error from libxml2 somewhere
+                               errmsg = "Error reading from stream";
+                       } else if (null == reader.expand ()) {
+                               errmsg = "Error expanding from stream";
+                       } else {
+                               // yay
+                               doc = reader.current_doc ();
+                               reader.close ();
+                               this.from_libxml2 (doc);
+
+                               return;
                        }
-                       doc = reader.current_doc ();
-                       reader.close ();
 
-                       this.from_libxml2 (doc);
+                       // uh oh
+                       e = Xml.Error.get_last_error ();
+                       if (e != null) {
+                               errmsg += ".  " + libxml2_error_to_string (e);
+                       }
+                       GXml.warning (DomException.INVALID_DOC, errmsg);
+                       throw new GXml.Error.PARSER (errmsg);
                }
 
                /**
@@ -484,10 +496,13 @@ namespace GXml {
                 * @return A new { link GXml.Document} from `memory`; this must be freed with { link 
GLib.Object.unref}
                 */
                public Document.from_string (string xml) {
+                       Xml.Doc *doc;
+
                        /* TODO: consider breaking API to support
                         * xmlParserOptions, encoding, and base URL
                         * from xmlReadMemory */
-                       Xml.Doc *doc = Xml.Parser.parse_memory (xml, (int)xml.length);
+
+                       doc = Xml.Parser.parse_memory (xml, (int)xml.length);
                        this.from_libxml2 (doc);
                }
 
@@ -497,7 +512,9 @@ namespace GXml {
                 * @return A new, empty { link GXml.Document}; this must be freed with { link 
GLib.Object.unref}
                 */
                public Document () {
-                       Xml.Doc *doc = new Xml.Doc ();
+                       Xml.Doc *doc;
+
+                       doc = new Xml.Doc ();
                        this.from_libxml2 (doc, false);
                }
 
@@ -511,7 +528,7 @@ namespace GXml {
                 * should sync.
                 */
                internal void sync_dirty_elements () {
-                       Xml.Node * tmp_node;
+                       Xml.Node *tmp_node;
 
                        // TODO: test that adding attributes works with stringification and saving
                        if (this.dirty_elements.length () > 0) {
@@ -536,19 +553,29 @@ namespace GXml {
                 */
                // TODO: is this a simple Unix file path, or does libxml2 do networks, too?
                public void save_to_path (string file_path) throws GXml.Error {
-                       int ret;
+                       string errmsg;
+                       Xml.Error *e;
 
                        sync_dirty_elements ();
 
                        // TODO: change this to a GIO file so we can save to in a cool way
 
-                       ret = this.xmldoc->save_file (file_path);
+                       if (-1 == this.xmldoc->save_file (file_path)) {
+                               errmsg = "Failed to write file to path '%s'".printf (file_path);
+                       } else {
+                               // yay!
+                               return;
+                       }
 
-                       if (ret == -1) {
-                               // TODO: use xmlGetLastError to get the real error message
-                               GXml.warning (DomException.X_OTHER, "Could not write document");
-                               throw new GXml.Error.WRITER ("Failed to write file to path '%s'".printf 
(file_path));
+                       // uh oh
+                       e = Xml.Error.get_last_error ();
+                       if (e != null) {
+                               errmsg += ".  " + libxml2_error_to_string (e);
                        }
+
+                       // TODO: use xmlGetLastError to get the real error message
+                       GXml.warning (DomException.X_OTHER, errmsg);
+                       throw new GXml.Error.WRITER (errmsg);
                }
 
                /* TODO: consider adding a save_to_file, but then we
@@ -567,6 +594,7 @@ namespace GXml {
                public void save_to_stream (OutputStream outstream, Cancellable? can = null) throws 
GXml.Error {
                        OutputStreamBox box = { outstream, can };
                        string errmsg = null;
+                       Xml.Error *e;
 
                        sync_dirty_elements ();
 
@@ -590,6 +618,11 @@ namespace GXml {
                        }
 
                        /* uh oh */
+                       e = Xml.Error.get_last_error ();
+                       if (e != null) {
+                               errmsg += ".  " + libxml2_error_to_string (e);
+                       }
+
                        GXml.warning (DomException.X_OTHER, errmsg);
                        throw new GXml.Error.WRITER (errmsg);
                }