wxXML load/save improvements: added ability to not ignore whitespace and specify indentation level (patch #1541888)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@41157 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/latex/wx/xmldocument.tex

@@ -18,7 +18,7 @@ A simple example of using XML classes is:
 
 \begin{verbatim}
 wxXmlDocument doc;
-if (!doc.Load(wxT("myfile.xml"))
+if (!doc.Load(wxT("myfile.xml")))
     return false;
 
 // start processing the XML file
@@ -51,6 +51,23 @@ while (child) {
 }
 \end{verbatim}
 
+{\bf Note:} if you want to preserve the original formatting of the loaded file including whitespaces
+and indentation, you need to turn off whitespace-only textnode removal and automatic indentation:
+
+\begin{verbatim}
+wxXmlDocument doc;
+doc.Load(wxT("myfile.xml"), wxT("UTF-8"), wxXMLDOC_KEEP_WHITESPACE_NODES);
+doc.Save(wxT("myfile2.xml"), wxXML_NO_INDENTATION);       // myfile2.xml will be indentic to myfile.xml
+\end{verbatim}
+
+Using default parameters, you will get a reformatted document which in general is different from
+the original loaded content:
+
+\begin{verbatim}
+wxXmlDocument doc;
+doc.Load(wxT("myfile.xml"));
+doc.Save(wxT("myfile2.xml"));       // myfile2.xml != myfile.xml
+\end{verbatim}
 
 
 \wxheading{Derived from}
@@ -74,11 +91,11 @@ while (child) {
 \func{}{wxXmlDocument}{\void}
 
 
-\func{}{wxXmlDocument}{\param{const wxString\& }{filename}, \param{const wxString\& }{encoding = wxT("UTF-8")}}
+\func{}{wxXmlDocument}{\param{const wxString\& }{filename}, \param{const wxString\& }{encoding = wxT("UTF-8")}, \param{int }{flags = wxXMLDOC_NONE}}
 
 Loads the given {\it filename} using the given encoding. See \helpref{Load()}{wxxmldocumentload}.
 
-\func{}{wxXmlDocument}{\param{wxInputStream\& }{stream}, \param{const wxString\& }{encoding = wxT("UTF-8")}}
+\func{}{wxXmlDocument}{\param{wxInputStream\& }{stream}, \param{const wxString\& }{encoding = wxT("UTF-8")}, \param{int }{flags = wxXMLDOC_NONE}}
 
 Loads the XML document from given stream using the given encoding. See \helpref{Load()}{wxxmldocumentload}.
 
@@ -149,23 +166,36 @@ Returns \true if the document has been loaded successfully.
 
 \membersection{wxXmlDocument::Load}\label{wxxmldocumentload}
 
-\func{bool}{Load}{\param{const wxString\& }{filename}, \param{const wxString\& }{encoding = wxT("UTF-8")}}
+\func{bool}{Load}{\param{const wxString\& }{filename}, \param{const wxString\& }{encoding = wxT("UTF-8")}, \param{int }{flags = wxXMLDOC_NONE}}
 
-Parses {\it filename} as an xml document and loads data. Returns \true on success, \false otherwise.
+Parses {\it filename} as an xml document and loads its data.
 
-\func{bool}{Load}{\param{wxInputStream\& }{stream}, \param{const wxString\& }{encoding = wxT("UTF-8")}}
+If {\tt flags} does not contain {\tt wxXMLDOC_KEEP_WHITESPACE_NODES}, then, while loading, all nodes of
+type {\tt wxXML_TEXT_NODE} (see \helpref{wxXmlNode}{wxxmlnode}) are automatically skipped if they
+contain whitespaces only.
+The removal of these nodes makes the load process slightly faster and requires less memory however
+makes impossible to recreate exactly the loaded text with a \helpref{Save}{wxxmldocumentsave} call later.
+Read the initial description of this class for more info.
+
+Returns \true on success, \false otherwise.
+
+\func{bool}{Load}{\param{wxInputStream\& }{stream}, \param{const wxString\& }{encoding = wxT("UTF-8")}, \param{int }{flags = wxXMLDOC_NONE}}
 
 Like above but takes the data from given input stream.
 
 \membersection{wxXmlDocument::Save}\label{wxxmldocumentsave}
 
-\constfunc{bool}{Save}{\param{const wxString\& }{filename}}
+\constfunc{bool}{Save}{\param{const wxString\& }{filename}, \param{int }{indentstep = 1}}
 
 Saves XML tree creating a file named with given string.
 
-\constfunc{bool}{Save}{\param{wxOutputStream\& }{stream}}
+If {\tt indentstep} is greater than or equal to zero, then, while saving, an automatic indentation
+is added with steps composed by {\tt indentstep} spaces.
+If {\tt indentstep} is {\tt wxXML_NO_INDENTATION}, then, automatic indentation is turned off.
 
-Saves XML tree in the given output stream.
+\constfunc{bool}{Save}{\param{wxOutputStream\& }{stream}, \param{int }{indentstep = 1}}
+
+Saves XML tree in the given output stream. See other overload for a description of {\tt indentstep}.
 
 \membersection{wxXmlDocument::SetEncoding}\label{wxxmldocumentsetencoding}
 

docs/latex/wx/xmlnode.tex

@@ -124,7 +124,7 @@ Removes the first properties which has the given {\it name} from the list of pro
 
 \membersection{wxXmlNode::GetChildren}\label{wxxmlnodegetchildren}
 
-\constfunc{wxXmlNode*}{GetChildren}{\param{void}{}}
+\constfunc{wxXmlNode*}{GetChildren}{\void}
 
 Returns the first child of this node.
 To get a pointer to the second child of this node (if it does exist), use the
@@ -139,6 +139,17 @@ Be aware that for nodes of type \texttt{wxXML\_ELEMENT\_NODE} (the most used nod
 content is an empty string. See \helpref{GetNodeContent()}{wxxmlnodegetnodecontent} for more details.
 
 
+\membersection{wxXmlNode::GetDepth}\label{wxxmlnodegetdepth}
+
+\constfunc{int}{GetDepth}{\param{wxXmlNode* }{grandparent = NULL}}
+
+Returns the number of nodes which separe this node from {\tt grandparent}.
+
+This function searches only the parents of this node until it finds {\tt grandparent}
+or the \NULL node (which is the parent of non-linked nodes or the parent of a
+\helpref{wxXmlDocument}{wxxmldocument}'s root node).
+
+
 \membersection{wxXmlNode::GetNodeContent}\label{wxxmlnodegetnodecontent}
 
 \constfunc{wxString}{GetNodeContent}{\void}
@@ -220,6 +231,14 @@ If {\it before\_node} is \NULL, then {\it child} is prepended to the list of chi
 becomes the first child of this node.
 Returns \true if {\it before\_node} has been found and the {\it child} node has been inserted.
 
+\membersection{wxXmlNode::IsWhitespaceOnly}\label{wxxmlnodecontainsiswhitespaceonly}
+
+\constfunc{bool}{IsWhitespaceOnly}{\void}
+
+Returns \true if the content of this node is a string containing only whitespaces (spaces,
+tabs, new lines, etc). Note that this function is locale-independent since the parsing of XML
+documents must always produce the exact same tree regardless of the locale it runs under.
+
 \membersection{wxXmlNode::RemoveChild}\label{wxxmlnoderemovechild}
 
 \func{bool}{RemoveChild}{\param{wxXmlNode* }{child}}

include/wx/xml/xml.h

@@ -125,6 +125,9 @@ public:
     wxString GetName() const { return m_name; }
     wxString GetContent() const { return m_content; }
 
+    bool IsWhitespaceOnly() const;
+    int GetDepth(wxXmlNode *grandparent = NULL) const;
+
     // Gets node content from wxXML_ENTITY_NODE
     // The problem is, <tag>content<tag> is represented as
     // wxXML_ENTITY_NODE name="tag", content=""
@@ -165,8 +168,15 @@ private:
 
 
 
+// special indentation value for wxXmlDocument::Save
+#define wxXML_NO_INDENTATION           (-1)
 
-
+// flags for wxXmlDocument::Load
+enum wxXmlDocumentLoadFlag
+{
+    wxXMLDOC_NONE = 0,
+    wxXMLDOC_KEEP_WHITESPACE_NODES = 1
+};
 
 
 // This class holds XML data/document as parsed by XML parser.
@@ -187,13 +197,13 @@ public:
     // Parses .xml file and loads data. Returns TRUE on success, FALSE
     // otherwise.
     virtual bool Load(const wxString& filename,
-              const wxString& encoding = wxT("UTF-8"));
+                      const wxString& encoding = wxT("UTF-8"), int flags = wxXMLDOC_NONE);
     virtual bool Load(wxInputStream& stream,
-              const wxString& encoding = wxT("UTF-8"));
+                      const wxString& encoding = wxT("UTF-8"), int flags = wxXMLDOC_NONE);
     
     // Saves document as .xml file.
-    virtual bool Save(const wxString& filename) const;
+    virtual bool Save(const wxString& filename, int indentstep = 1) const;
-    virtual bool Save(wxOutputStream& stream) const;
+    virtual bool Save(wxOutputStream& stream, int indentstep = 1) const;
 
     bool IsOk() const { return m_root != NULL; }
 

src/xml/xml.cpp

@@ -39,6 +39,9 @@ WX_CHECK_BUILD_OPTIONS("wxXML")
 IMPLEMENT_CLASS(wxXmlDocument, wxObject)
 
 
+// a private utility used by wxXML
+static bool wxIsWhiteOnly(const wxChar *buf);
+
 
 //-----------------------------------------------------------------------------
 //  wxXmlNode
@@ -309,6 +312,28 @@ wxString wxXmlNode::GetNodeContent() const
     return wxEmptyString;
 }
 
+int wxXmlNode::GetDepth(wxXmlNode *grandparent) const
+{
+    const wxXmlNode *n = this;
+    int ret = -1;
+
+    do
+    {
+        ret++;
+        n = n->GetParent();
+        if (n == grandparent)
+            return ret;
+
+    } while (n);
+
+    return wxNOT_FOUND;
+}
+
+bool wxXmlNode::IsWhitespaceOnly() const
+{
+    return wxIsWhiteOnly(m_content);
+}
+
 
 
 //-----------------------------------------------------------------------------
@@ -364,20 +389,20 @@ void wxXmlDocument::DoCopy(const wxXmlDocument& doc)
     m_root = new wxXmlNode(*doc.m_root);
 }
 
-bool wxXmlDocument::Load(const wxString& filename, const wxString& encoding)
+bool wxXmlDocument::Load(const wxString& filename, const wxString& encoding, int flags)
 {
     wxFileInputStream stream(filename);
     if (!stream.Ok())
         return false;
-    return Load(stream, encoding);
+    return Load(stream, encoding, flags);
 }
 
-bool wxXmlDocument::Save(const wxString& filename) const
+bool wxXmlDocument::Save(const wxString& filename, int indentstep) const
 {
     wxFileOutputStream stream(filename);
     if (!stream.Ok())
         return false;
-    return Save(stream);
+    return Save(stream, indentstep);
 }
 
 
@@ -386,11 +411,6 @@ bool wxXmlDocument::Save(const wxString& filename) const
 //  wxXmlDocument loading routines
 //-----------------------------------------------------------------------------
 
-/*
-    FIXME:
-       - process all elements, including CDATA
- */
-
 // converts Expat-produced string in UTF-8 into wxString using the specified
 // conv or keep in UTF-8 if conv is NULL
 static wxString CharToString(wxMBConv *conv,
@@ -417,6 +437,16 @@ static wxString CharToString(wxMBConv *conv,
 #endif // wxUSE_UNICODE/!wxUSE_UNICODE
 }
 
+// returns true if the given string contains only whitespaces
+bool wxIsWhiteOnly(const wxChar *buf)
+{
+    for (const wxChar *c = buf; *c != wxT('\0'); c++)
+        if (*c != wxT(' ') && *c != wxT('\t') && *c != wxT('\n') && *c != wxT('\r'))
+            return false;
+    return true;
+}
+
+
 struct wxXmlParsingContext
 {
     wxMBConv  *conv;
@@ -426,6 +456,7 @@ struct wxXmlParsingContext
     wxString   encoding;
     wxString   version;
 	bool	bLastCdata;
+    bool       removeWhiteOnlyNodes;
 };
 
 extern "C" {
@@ -462,42 +493,32 @@ extern "C" {
 static void TextHnd(void *userData, const char *s, int len)
 {
     wxXmlParsingContext *ctx = (wxXmlParsingContext*)userData;
-    char *buf = new char[len + 1];
+    wxString str = CharToString(ctx->conv, s, len);
-
-    buf[len] = '\0';
-    memcpy(buf, s, (size_t)len);
 
     if (ctx->lastAsText)
     {
 		if ( ctx->bLastCdata )
 		{
 			ctx->lastAsText->SetContent(ctx->lastAsText->GetContent() +
-                                    CharToString(NULL, buf));
+                                        CharToString(NULL, s, len));
 		}
 		else
 		{
-			ctx->lastAsText->SetContent(ctx->lastAsText->GetContent() +
+            ctx->lastAsText->SetContent(ctx->lastAsText->GetContent() + str);
-                                    CharToString(ctx->conv, buf));
 		}
     }
     else
     {
-        bool whiteOnly = true;
+        bool whiteOnly = false;
-        for (char *c = buf; *c != '\0'; c++)
+        if (ctx->removeWhiteOnlyNodes)
-            if (*c != ' ' && *c != '\t' && *c != '\n' && *c != '\r')
+            whiteOnly = wxIsWhiteOnly(str);
-            {
+
-                whiteOnly = false;
-                break;
-            }
         if (!whiteOnly)
         {
-            ctx->lastAsText = new wxXmlNode(wxXML_TEXT_NODE, wxT("text"),
+            ctx->lastAsText = new wxXmlNode(wxXML_TEXT_NODE, wxT("text"), str);
-                                            CharToString(ctx->conv, buf));
             ctx->node->AddChild(ctx->lastAsText);
         }
     }
-
-    delete[] buf;
 }
 }
 
@@ -593,7 +614,7 @@ static int UnknownEncodingHnd(void * WXUNUSED(encodingHandlerData),
 }
 }
 
-bool wxXmlDocument::Load(wxInputStream& stream, const wxString& encoding)
+bool wxXmlDocument::Load(wxInputStream& stream, const wxString& encoding, int flags)
 {
 #if wxUSE_UNICODE
     (void)encoding;
@@ -614,6 +635,7 @@ bool wxXmlDocument::Load(wxInputStream& stream, const wxString& encoding)
     if ( encoding != wxT("UTF-8") && encoding != wxT("utf-8") )
         ctx.conv = new wxCSConv(encoding);
 #endif
+    ctx.removeWhiteOnlyNodes = (flags & wxXMLDOC_KEEP_WHITESPACE_NODES) == 0;
 	ctx.bLastCdata = false;
 
     XML_SetUserData(parser, (void*)&ctx);
@@ -755,7 +777,7 @@ inline static void OutputIndentation(wxOutputStream& stream, int indent)
 }
 
 static void OutputNode(wxOutputStream& stream, wxXmlNode *node, int indent,
-                       wxMBConv *convMem, wxMBConv *convFile)
+                       wxMBConv *convMem, wxMBConv *convFile, int indentstep)
 {
     wxXmlNode *n, *prev;
     wxXmlProperty *prop;
@@ -793,13 +815,13 @@ static void OutputNode(wxOutputStream& stream, wxXmlNode *node, int indent,
                 n = node->GetChildren();
                 while (n)
                 {
-                    if (n && n->GetType() != wxXML_TEXT_NODE)
+                    if (indentstep >= 0 && n && n->GetType() != wxXML_TEXT_NODE)
-                        OutputIndentation(stream, indent + 1);
+                        OutputIndentation(stream, indent + indentstep);
-                    OutputNode(stream, n, indent + 1, convMem, convFile);
+                    OutputNode(stream, n, indent + indentstep, convMem, convFile, indentstep);
                     prev = n;
                     n = n->GetNext();
                 }
-                if (prev && prev->GetType() != wxXML_TEXT_NODE)
+                if (indentstep >= 0 && prev && prev->GetType() != wxXML_TEXT_NODE)
                     OutputIndentation(stream, indent);
                 OutputString(stream, wxT("</"));
                 OutputString(stream, node->GetName());
@@ -820,7 +842,7 @@ static void OutputNode(wxOutputStream& stream, wxXmlNode *node, int indent,
     }
 }
 
-bool wxXmlDocument::Save(wxOutputStream& stream) const
+bool wxXmlDocument::Save(wxOutputStream& stream, int indentstep) const
 {
     if ( !IsOk() )
         return false;
@@ -844,7 +866,7 @@ bool wxXmlDocument::Save(wxOutputStream& stream) const
              GetVersion().c_str(), GetFileEncoding().c_str());
     OutputString(stream, s);
 
-    OutputNode(stream, GetRoot(), 0, convMem, convFile);
+    OutputNode(stream, GetRoot(), 0, convMem, convFile, indentstep);
     OutputString(stream, wxT("\n"));
 
     if ( convFile )