[gxml] XParser: can create InputStream

[Daniel Espinosa Ortiz <despinosa src gnome org>]

commit 98955256b87756ea20b690f660d407e962b922c4
Author: Daniel Espinosa <esodan gmail com>
Date:   Fri May 5 11:29:09 2017 -0500

    XParser: can create InputStream
    
    XParser can create an InputStream to be used with OutputStream
    to get parsing.
    
    Added methods for GomDocument and GomElement to use it.

 gxml/GomDocument.vala    |    8 ++++++++
 gxml/GomElement.vala     |    7 +++++++
 gxml/XParser.vala        |   25 +++++++++++++++++++++++++
 test/GomElementTest.vala |   44 ++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 84 insertions(+), 0 deletions(-)
---
diff --git a/gxml/GomDocument.vala b/gxml/GomDocument.vala
index 196655f..963a108 100644
--- a/gxml/GomDocument.vala
+++ b/gxml/GomDocument.vala
@@ -120,6 +120,14 @@ public class GXml.GomDocument : GomNode,
     parser.write_stream (stream, null);
   }
   /**
+   * Creates an {@link GLib.InputStream} to write a string representation
+   * in XML of {@link GomDocument}
+   */
+  public InputStream create_stream () throws GLib.Error {
+    var parser = new XParser (this);
+    return parser.create_stream (null);
+  }
+  /**
    * Reads a file contents and parse it to document.
    */
   public void read_from_file (GLib.File file) throws GLib.Error {
diff --git a/gxml/GomElement.vala b/gxml/GomElement.vala
index af60b17..fb24d1e 100644
--- a/gxml/GomElement.vala
+++ b/gxml/GomElement.vala
@@ -86,6 +86,13 @@ public class GXml.GomElement : GomNode,
   public void write_stream (GLib.OutputStream stream) throws GLib.Error {
     (this.owner_document as GomDocument).write_stream (stream);
   }
+  /**
+   * Creates an {@link GLib.InputStream} to write a string representation
+   * in XML of {@link GomElement} using node's {@link GomDocument}
+   */
+  public InputStream create_stream () throws GLib.Error {
+    return (this.owner_document as GomDocument).create_stream ();
+  }
   // DomNode overrides
   public new string? lookup_prefix (string? nspace) {
     if (_namespace_uri == nspace)
diff --git a/gxml/XParser.vala b/gxml/XParser.vala
index 2a0fc4f..5c3a2af 100644
--- a/gxml/XParser.vala
+++ b/gxml/XParser.vala
@@ -83,6 +83,31 @@ public class GXml.XParser : Object, GXml.Parser {
     tw = null;
   }
 
+  /**
+   * Creates an {@link GLib.InputStream} to write a string representation
+   * in XML
+   */
+  public InputStream
+  create_stream (GLib.Cancellable? cancellable = null) throws GLib.Error {
+    var buf = new Xml.Buffer ();
+    tw = new TextWriter.memory (buf);
+    if (_node is DomDocument) tw.start_document ();
+    tw.set_indent (indent);
+    // Root
+    if (_node is DomDocument) {
+      if ((_node as DomDocument).document_element == null)
+        tw.end_document ();
+    }
+    start_node (_node);
+    tw.end_element ();
+    tw.end_document ();
+    tw.flush ();
+    var s = new GLib.StringBuilder ();
+    s.append (buf.content ());
+    tw = null;
+    return new GLib.MemoryInputStream.from_data ((uint8[]) s.str.dup (), null);
+  }
+
   public string write_string () throws GLib.Error  {
     return dump ();
   }
diff --git a/test/GomElementTest.vala b/test/GomElementTest.vala
index e017882..687f6b2 100644
--- a/test/GomElementTest.vala
+++ b/test/GomElementTest.vala
@@ -221,5 +221,49 @@ class GomElementTest : GXmlTest  {
                    assert_not_reached ();
                  }
                });
+               Test.add_func ("/gxml/gom-element/write/string", () => {
+                       try {
+                               var n = new GomElement ();
+                               n.initialize ("Node");
+                               n.set_attribute ("name","value");
+                               string str = n.write_string ();
+                               assert ("<Node" in str);
+                               assert ("<Node name=\"value\"/>" in str);
+                       } catch (GLib.Error e) {
+                   GLib.message ("Error: "+e.message);
+                   assert_not_reached ();
+                 }
+               });
+               Test.add_func ("/gxml/gom-element/write/stream", () => {
+                       try {
+                               var n = new GomElement ();
+                               n.initialize ("Node");
+                               n.set_attribute ("name","value");
+                               var ostream = new MemoryOutputStream.resizable ();
+                               n.write_stream (ostream);
+                               string str = (string) ostream.data;
+                               assert ("<Node" in str);
+                               assert ("<Node name=\"value\"/>" in str);
+                       } catch (GLib.Error e) {
+                   GLib.message ("Error: "+e.message);
+                   assert_not_reached ();
+                 }
+               });
+               Test.add_func ("/gxml/gom-element/write/input_stream", () => {
+                       try {
+                               var n = new GomElement ();
+                               n.initialize ("Node");
+                               n.set_attribute ("name","value");
+                               var ostream = new MemoryOutputStream.resizable ();
+                               var istream = n.create_stream ();
+                               ostream.splice (istream, GLib.OutputStreamSpliceFlags.NONE);
+                               string str = (string) ostream.data;
+                               assert ("<Node" in str);
+                               assert ("<Node name=\"value\"/>" in str);
+                       } catch (GLib.Error e) {
+                   GLib.message ("Error: "+e.message);
+                   assert_not_reached ();
+                 }
+               });
        }
 }