dot2gxl.c   [plain text]

/*
    This software may only be used by you under license from AT&T Corp.
    ("AT&T").  A copy of AT&T's Source Code Agreement is available at
    AT&T's Internet website having the URL:
    <http://www.research.att.com/sw/tools/graphviz/license/source.html>
    If you received this software without first entering into a license
    with AT&T, you have an infringing copy of this software and cannot use
    it without violating AT&T's intellectual property rights.
*/
#pragma prototyped

#include <convert.h>
#include <aghdr.h>

#define SMALLBUF    128

#define NEW(t)      (t*)malloc(sizeof(t))
#define N_NEW(n,t)  (t*)malloc((n)*sizeof(t))
#define EMPTY(s)	((s == 0) || (*s == '\0'))
#define SLEN(s)     (sizeof(s)-1)

#define NODE		1
#define EDGE		2
#define GRAPH		3

#define GXL_ATTR    "_gxl_"
#define GXL_ROLE	"_gxl_role"
#define GXL_HYPER	"_gxl_hypergraph"
#define GXL_ID      "_gxl_id"
#define GXL_FROM    "_gxl_fromorder"
#define GXL_TO      "_gxl_toorder"
#define GXL_TYPE    "_gxl_type"
#define GXL_COMP    "_gxl_composite_"
#define GXL_LOC     "_gxl_locator_"

#define GXL_ATTR_LEN (SLEN(GXL_ATTR))
#define GXL_COMP_LEN (SLEN(GXL_COMP))
#define GXL_LOC_LEN  (SLEN(GXL_LOC))

typedef struct {
    Agrec_t    h;
    int        written;
} Agnodeinfo_t;

static int Level;   /* level of tabs */
static Agsym_t *Tailport,*Headport;

typedef struct {
  Dtlink_t   link;
  char*      name;
  char*      unique_name;
} namev_t;

static namev_t*
make_nitem (Dt_t* d, namev_t* objp, Dtdisc_t* disc)
{
	namev_t*  np = NEW(namev_t);
	np->name = objp->name;
	np->unique_name = 0;
	return np;
}

static void
free_nitem (Dt_t* d, namev_t* np, Dtdisc_t* disc)
{
    free (np);
}

static Dtdisc_t nameDisc = {
    offsetof(namev_t,name),
    -1,
    offsetof(namev_t,link),
    (Dtmake_f)make_nitem,
    (Dtfree_f)free_nitem,
    NIL(Dtcompar_f),
    NIL(Dthash_f),
    NIL(Dtmemory_f),
    NIL(Dtevent_f)
};

typedef struct {
  Dtlink_t   link;
  char*      name;
} idv_t;

static void
free_iditem (Dt_t* d, idv_t* idp, Dtdisc_t* disc)
{
	free (idp->name);
	free (idp);
}

static Dtdisc_t idDisc = {
    offsetof(idv_t,name),
    -1,
    offsetof(idv_t,link),
    NIL(Dtmake_f),
    (Dtfree_f)free_iditem,
    NIL(Dtcompar_f),
    NIL(Dthash_f),
    NIL(Dtmemory_f),
    NIL(Dtevent_f)
};

typedef struct {
  Dt_t*  nodeMap;
  Dt_t*  graphMap;
  Dt_t*  synNodeMap;
  Dt_t*  idList;
  Agraph_t*  root;
  char   attrsNotWritten;
  char   directed;
} gxlstate_t;

static void writeBody(gxlstate_t*, Agraph_t *g, FILE *gxlFile);
static void iterateBody(gxlstate_t* stp, Agraph_t *g);

static void 
tabover(FILE* gxlFile)
{
	int temp;
	temp = Level;
	while (temp--) putc('\t',gxlFile);
}

/* legalGXLName:
 * By XML spec, 
 *   ID := (alpha|'_'|':')(NameChar)*
 *   NameChar := alpha|digit|'.'|':'|'-'|'_'
 */
static int
legalGXLName (char* id)
{
	char  c = *id++;
	if (!isalpha(c) && (c != '_') && (c != ':')) return 0;
	while ((c = *id++)) {
		if (!isalnum(c) && (c != '_') && (c != ':') &&
			(c != '-') && (c != '.')) return 0;
	}
	return 1;
}

static void
escapeForXML(FILE* gxlFile, char* value)
{
	char  c;

	while ((c = *value++)) {
		switch (c) {
		case '>' :
			fputs("&gt;", gxlFile);
			break;
		case '<' :
			fputs("&lt;", gxlFile);
			break;
		case '&' :
			fputs("&amp;", gxlFile);
			break;
		default :
			putc(c, gxlFile);
			break;
		} 
	} 
}

static int
isGxlGrammar(char *name) 
{
	return (strncmp(name, GXL_ATTR, (sizeof(GXL_ATTR)-1) ) == 0);
}

static int
isLocatorType(char *name) 
{
	return (strncmp(name, GXL_LOC, GXL_LOC_LEN) == 0);
}

static void*
idexists(Dt_t* ids, char *id)
{
	return dtmatch (ids, id);
}

/* addid:
 * assume id is not in ids.
 */
static char*
addid(Dt_t* ids, char *id)
{
	idv_t*  idp = NEW(idv_t);

	idp->name = strdup(id);
	dtinsert (ids, idp);
	return idp->name;
}

static char*
createGraphId(Dt_t* ids)
{
	static int graphIdCounter = 0;
	char buf[SMALLBUF];

	do {
		sprintf(buf, "G_%d", graphIdCounter++);
	} while (idexists(ids, buf));
	return addid (ids, buf);
}

static char*
createNodeId(Dt_t* ids)
{
	static int nodeIdCounter = 0;
	char     buf[SMALLBUF];

	do {
		sprintf(buf, "N_%d", nodeIdCounter++);
	} while (idexists(ids, buf));
	return addid (ids, buf);
}

static char*
mapLookup(Dt_t* nm, char* name)
{
	namev_t* objp = dtmatch (nm, name);
	if (objp) return objp->unique_name;
	else return 0;
}

static char*
nodeID(gxlstate_t* stp, Agnode_t *n)
{
	char		*name, *uniqueName;

	name = agnameof(n);
	uniqueName = mapLookup(stp->nodeMap, name);
	assert (uniqueName);
	return uniqueName;
}

#define EXTRA 32     /* space for ':' followed by a number */
#define EDGEOP "--"  /* cannot use '>'; illegal in ID in GXL */

static char*
createEdgeId(gxlstate_t* stp,  Agedge_t *e)
{
	int      edgeIdCounter = 1;
	char     buf[BUFSIZ];
	char*    hname = nodeID(stp,AGHEAD(e));
	char*    tname = nodeID(stp,AGTAIL(e));
	int      baselen = strlen(hname)+strlen(tname)+sizeof(EDGEOP);
	int      len = baselen+EXTRA;
	char*    bp;
	char*    endp;     /* where to append ':' and number */
	char*    rv;

	if (len <= BUFSIZ) bp = buf;
	else bp = N_NEW(len,char);
	endp = bp + (baselen-1);
	
	sprintf(bp, "%s%s%s", tname, EDGEOP, hname);
	while (idexists(stp->idList, bp)) {
		sprintf(endp, ":%d", edgeIdCounter++);
	}

	rv = addid (stp->idList, bp);
	if (bp != buf) free (bp);
	return rv;
}

static void
addToMap(Dt_t* map, char* name, char* uniqueName)
{
	namev_t  obj;
	namev_t* objp;

    obj.name = name;
	objp = dtinsert (map, &obj);
	assert (objp->unique_name == 0);
	objp->unique_name = uniqueName;
}

static void
graphAttrs(FILE* gxlFile, Agraph_t* g) 
{
	char *val;

	val = agget(g, GXL_ROLE);
	if (!EMPTY(val)) {
		fprintf(gxlFile, " role=\"%s\"", val);
	}
	val = agget(g, GXL_HYPER);
	if (!EMPTY(val)) {
		fprintf(gxlFile, " hypergraph=\"%s\"", val);
	}
}

static void
edgeAttrs(FILE* gxlFile, Agedge_t* e) 
{
	char *val;

	val = agget(e, GXL_ID);
	if(!EMPTY(val)) {
		fprintf(gxlFile, " id=\"%s\"", val);
	}
	val = agget(e, GXL_FROM);
	if(!EMPTY(val)) {
		fprintf(gxlFile, " fromorder=\"%s\"", val);
	}
	val = agget(e, GXL_TO);
	if(!EMPTY(val)) {
		fprintf(gxlFile, " toorder=\"%s\"", val);
	}
}


static void
printHref(FILE* gxlFile, void* n) 
{
	char *val;

	val = agget(n, GXL_TYPE);
	if(!EMPTY(val)) {
		tabover(gxlFile);
		fprintf(gxlFile, "\t<type xlink:href=\"%s\">\n", val);
		tabover(gxlFile);
		fprintf(gxlFile, "\t</type>\n");
	}
}


static void
writeDict(Agraph_t *g, FILE *gxlFile, char *name, Dict_t *dict, int isGraph)
{
	Dict_t	*view;
	Agsym_t	*sym,*psym;

	view = dtview(dict,NIL(Dict_t*));
	for (sym = (Agsym_t*)dtfirst(dict); sym; sym = (Agsym_t*)dtnext(dict,sym)) {
		if(!isGxlGrammar(sym->name)) {
			if (EMPTY(sym->defval)) {	/* try to skip empty str (default) */
				if (view == NIL(Dict_t*)) continue;	/* no parent */
				psym = (Agsym_t*)dtsearch(view,sym);
				/* assert(psym); */
				if (EMPTY(psym->defval)) continue;	/* also empty in parent */
			}

			if(isLocatorType(sym->defval)) {
				char *locatorVal;
				locatorVal = sym->defval;
				locatorVal += 13;

				tabover(gxlFile);
				fprintf(gxlFile, "\t<attr name=\"%s\">\n", sym->name);
				tabover(gxlFile);
				fprintf(gxlFile, "\t\t<locator xlink:href=\"%s\"/>\n", locatorVal);
				tabover(gxlFile);
				fprintf(gxlFile, "\t</attr>\n");
			} else {
				tabover(gxlFile);
				if (isGraph)
					fprintf(gxlFile, "\t<attr name=\"%s\" kind=\"%s\">\n", sym->name, name);
				else
					fprintf(gxlFile, "\t<attr name=\"%s:%s\" kind=\"%s\">\n", name, sym->name, name);
				tabover(gxlFile);
				fprintf(gxlFile, "\t\t<string>");
				escapeForXML(gxlFile, sym->defval);
				fprintf(gxlFile, "</string>\n");
				tabover(gxlFile);
				fprintf(gxlFile, "\t</attr>\n");
			}
		} else {
			/* gxl attr; check for special cases like composites */
			if(strncmp(sym->name, GXL_COMP, GXL_COMP_LEN) == 0) {
				if (EMPTY(sym->defval)) {	
					if (view == NIL(Dict_t*)) continue;	
					psym = (Agsym_t*)dtsearch(view,sym);
					if (EMPTY(psym->defval)) continue;
				}

				tabover(gxlFile);
				fprintf(gxlFile, "\t<attr name=\"%s\" kind=\"%s\">\n", ((sym->name) + GXL_COMP_LEN), name);
				tabover(gxlFile);
				fprintf(gxlFile, "\t\t%s\n", sym->defval);
				tabover(gxlFile);
				fprintf(gxlFile, "\t</attr>\n");
			}
		}
	}
	dtview(dict,view);			/* restore previous view */
}

static void
writeDicts(Agraph_t *g, FILE *gxlFile)
{
	Agdatadict_t	*def;
	if ((def = (Agdatadict_t*)agdatadict(g))) {
		writeDict(g, gxlFile, "graph", def->dict.g, 1);
		writeDict(g, gxlFile, "node", def->dict.n, 0);
		writeDict(g, gxlFile, "edge", def->dict.e, 0);
	}
}

static void
writeHdr(gxlstate_t* stp, Agraph_t *g, FILE *gxlFile, int top)
{
	char*    name;
	char*    kind;
	char*    uniqueName;
	char     buf[BUFSIZ];
	char*    bp;
	char*    dynbuf = 0;
	int      len;
	
	Level++;
	stp->attrsNotWritten = AGATTRWF(g);

	name = agnameof(g);
	if (g->desc.directed) kind = "directed";
	else kind = "undirected";
	if (!top && agparent(g)) { 
		/* this must be anonymous graph */

		len = strlen(name)+sizeof("N_");
		if (len <= BUFSIZ)
			bp = buf;
		else {
			bp = dynbuf = N_NEW(len, char);
		}
		sprintf(bp, "N_%s", name);
		if(idexists(stp->idList,bp) || !legalGXLName(bp)) {
			bp = createNodeId(stp->idList);
		} else {
			bp = addid(stp->idList, bp);
		}
		addToMap(stp->synNodeMap, name, bp);

		tabover(gxlFile);
		fprintf(gxlFile, "<node id=\"%s\">\n", bp);
		if (dynbuf) free (dynbuf);
		Level++;
	}
	else {
		Tailport = agattr(g,AGEDGE,"tailport",NIL(char*));
		Headport = agattr(g,AGEDGE,"headport",NIL(char*));
	}


	uniqueName = mapLookup(stp->graphMap, name);
	tabover(gxlFile);
	fprintf(gxlFile, "<graph id=\"%s\" edgeids=\"true\" edgemode=\"%s\"", uniqueName, kind);
	graphAttrs(gxlFile, g);
	fprintf(gxlFile, ">\n");

	if (uniqueName && (strcmp(name, uniqueName) != 0)) {
		tabover(gxlFile);
		fprintf(gxlFile, "\t<attr name=\"name\">\n");
		tabover(gxlFile);
		fprintf(gxlFile, "\t\t<string>%s</string>\n", name);
		tabover(gxlFile);
		fprintf(gxlFile, "\t</attr>\n");
	}
	
	if(agisstrict(g)) {
		tabover(gxlFile);
		fprintf(gxlFile, "\t<attr name=\"strict\">\n");
		tabover(gxlFile);
		fprintf(gxlFile, "\t\t<string>true</string>\n");
		tabover(gxlFile);
		fprintf(gxlFile, "\t</attr>\n");
	}

	writeDicts(g, gxlFile);
	printHref(gxlFile, g);
	AGATTRWF(g) = !(AGATTRWF(g));
}

static void
writeTrl(Agraph_t *g, FILE *gxlFile, int top)
{
	tabover(gxlFile);
	fprintf(gxlFile, "</graph>\n");
	Level--;
	if (!(top) && agparent(g)) { 
		tabover(gxlFile);
		fprintf(gxlFile, "</node>\n");
		Level--;
	}
}


static void
writeSubgs(gxlstate_t* stp, Agraph_t *g, FILE *gxlFile)
{
	Agraph_t	*subg;

	for (subg = agfstsubg(g); subg; subg = agnxtsubg(subg)) {
		writeHdr(stp, subg, gxlFile, FALSE);
		writeBody(stp, subg, gxlFile);
		writeTrl(subg, gxlFile, FALSE);
	}
}

static int
writeEdgeName(Agedge_t *e, FILE *gxlFile, int terminate)
{
	int		rv;
	char		*p;

	p = agnameof(e);
	if (!(EMPTY(p))) {
		tabover(gxlFile);
		fprintf(gxlFile, "\t<attr name=\"key\">\n");
		tabover(gxlFile);
		fprintf(gxlFile, "\t\t<string>%s</string>\n", p);
		tabover(gxlFile);
		fprintf(gxlFile, "\t</attr>\n");
		rv = TRUE;
	}
	else rv = FALSE;
	return rv;
}


static void
writeNondefaultAttr(void *obj, FILE *gxlFile, Dict_t *defdict)
{
	Agattr_t	*data;
	Agsym_t		*sym;
	int		cnt = 0;

	if ((AGTYPE(obj) == AGINEDGE) || (AGTYPE(obj) == AGOUTEDGE)) {
		if (writeEdgeName(obj, gxlFile, FALSE)) cnt++;
	}
	data = (Agattr_t*)agattrrec(obj);
	if (data) 
	{
		for(sym = (Agsym_t*)dtfirst(defdict); sym; sym = (Agsym_t*)dtnext(defdict,sym)) 
		{
			if(!isGxlGrammar(sym->name)) {
				if ((AGTYPE(obj) == AGINEDGE) || (AGTYPE(obj) == AGOUTEDGE)) {
					if (Tailport && (sym->id == Tailport->id)) continue;
					if (Headport && (sym->id == Headport->id)) continue;
				}
				if (data->str[sym->id] != sym->defval) {

					if(strcmp(data->str[sym->id], "") == 0)
						continue;

					if(isLocatorType(data->str[sym->id])) {
						char *locatorVal;
						locatorVal = data->str[sym->id];
						locatorVal += 13;

						tabover(gxlFile);
						fprintf(gxlFile, "\t<attr name=\"%s\">\n", sym->name);
						tabover(gxlFile);
						fprintf(gxlFile, "\t\t<locator xlink:href=\"%s\"/>\n", locatorVal);
						tabover(gxlFile);
						fprintf(gxlFile, "\t</attr>\n");
					} else {
						tabover(gxlFile);
						fprintf(gxlFile, "\t<attr name=\"%s\">\n", sym->name);
						tabover(gxlFile);
						fprintf(gxlFile, "\t\t<string>");
						escapeForXML(gxlFile, data->str[sym->id]);
						fprintf(gxlFile, "</string>\n");
						tabover(gxlFile);
						fprintf(gxlFile, "\t</attr>\n");
					}
				}
			} else {
				/* gxl attr; check for special cases like composites */
				if(strncmp(sym->name, GXL_COMP, GXL_COMP_LEN) == 0) {
					if (data->str[sym->id] != sym->defval) {

						tabover(gxlFile);
						fprintf(gxlFile, "\t<attr name=\"%s\">\n", ((sym->name) + GXL_COMP_LEN));
						tabover(gxlFile);
						fprintf(gxlFile, "\t\t%s\n", data->str[sym->id]);
						tabover(gxlFile);
						fprintf(gxlFile, "\t</attr>\n");
					}
				}
			}
		}
	}
	AGATTRWF((Agobj_t*)obj) = !(AGATTRWF((Agobj_t*)obj));
}

/* nodeID:
 * Return id associated with the given node.
 */ 
static int
attrs_written(gxlstate_t* stp, void *obj)
{
	return !(AGATTRWF((Agobj_t*)obj) == stp->attrsNotWritten);
}

static void
writeNode(gxlstate_t* stp, Agnode_t *n, FILE *gxlFile, Dict_t *d)
{
	char *name, *uniqueName;

	name = agnameof(n);
	uniqueName = nodeID(stp,n);
	Level++;
	tabover(gxlFile);
	fprintf(gxlFile, "<node id=\"%s\">\n", uniqueName);

	printHref(gxlFile, n);

	if(strcmp(name, uniqueName)) {
		tabover(gxlFile);
		fprintf(gxlFile, "\t<attr name=\"name\">\n");
		tabover(gxlFile);
		fprintf(gxlFile, "\t\t<string>%s</string>\n", name);
		tabover(gxlFile);
		fprintf(gxlFile, "\t</attr>\n");
	}

	if (!attrs_written(stp,n))
		writeNondefaultAttr(n, gxlFile, d);
	tabover(gxlFile);
	fprintf(gxlFile, "</node>\n");
	Level--;
}

static void
writePort(Agedge_t *e, FILE *gxlFile, char *name)
{
	char		*val;

	val = agget(e,name);
	if (val[0]) {
		tabover(gxlFile);
		fprintf(gxlFile, "\t<attr name=\"%s\">\n", name);
		tabover(gxlFile);
		fprintf(gxlFile, "\t\t<string>");
		escapeForXML(gxlFile, val);
		fprintf(gxlFile, "</string>\n");
		tabover(gxlFile);
		fprintf(gxlFile, "\t</attr>\n");
	}
}

static int
writeEdgeTest(Agraph_t *g, Agedge_t *e)
{
	Agraph_t	*subg;

	/* can use agedge() because we subverted the dict compar_f */
	for (subg = agfstsubg(g); subg; subg = agnxtsubg(subg)) {
		if (agsubedge(subg,e,FALSE)) return FALSE;
	}
	return TRUE;
}

static void
writeEdge(gxlstate_t* stp, Agedge_t *e, FILE *gxlFile, Dict_t *d)
{
	Agnode_t	*t,*h;
	char*       bp;
	char*		edge_id;

	t = AGTAIL(e);
	h = AGHEAD(e);

	Level++;
	tabover(gxlFile);
	fprintf(gxlFile,"<edge from=\"%s\" to=\"%s\"", nodeID(stp,t), nodeID(stp,h));
	edgeAttrs(gxlFile, e);

	if (stp->directed) { 
		fprintf(gxlFile, " isdirected=\"true\"");
	} else {
		fprintf(gxlFile, " isdirected=\"false\"");
	}

	edge_id = agget(e, GXL_ID);
	if(!EMPTY(edge_id)) {
		fprintf(gxlFile, ">\n");
	} 
    else {
		bp = createEdgeId(stp, e);
		fprintf(gxlFile, " id=\"%s\">\n", bp);
	}

	printHref(gxlFile, e);
		
	writePort(e, gxlFile, "tailport");
	writePort(e, gxlFile, "headport");
	if (!(attrs_written(stp,e)))
		writeNondefaultAttr(e, gxlFile, d);
	else
		writeEdgeName(e, gxlFile, TRUE);
	tabover(gxlFile);
	fprintf(gxlFile, "</edge>\n");
	Level--;
}


#define writeval(n) (((Agnodeinfo_t*)((n)->base.data))->written)

static void
writeBody(gxlstate_t* stp, Agraph_t *g, FILE *gxlFile)
{
	Agnode_t	*n;
	Agnode_t	*realn;
	Agedge_t	*e;
	Agdatadict_t *dd;

	writeSubgs(stp, g, gxlFile);
	dd = (Agdatadict_t*)agdatadict(g);
	for (n = agfstnode(g); n; n = agnxtnode(n)) {
		realn = agidnode (stp->root,AGID(n),0);
		if (!writeval(realn)) {
			writeval(realn) = 1;
			writeNode(stp, n, gxlFile, dd->dict.n);
		}

		for (e = agfstout(n); e; e = agnxtout(e)) {
			if (writeEdgeTest(g,e))
				writeEdge(stp, e, gxlFile, dd->dict.e);
		}
	}
}

static void
iterateHdr(gxlstate_t* stp, Agraph_t *g)
{
	char*	gxlId;
	char*   name;
	
	name = agnameof(g);
	gxlId = agget(g, GXL_ID);
	if(EMPTY(gxlId))
		gxlId = name;

	if(idexists(stp->idList, gxlId) || !legalGXLName(gxlId))
		gxlId = createGraphId(stp->idList);
	else
		gxlId = addid(stp->idList, gxlId);
	addToMap (stp->graphMap, name, gxlId);
}

static void
iterate_subgs(gxlstate_t* stp, Agraph_t *g)
{
	Agraph_t	*subg;

	for (subg = agfstsubg(g); subg; subg = agnxtsubg(subg)) {
		iterateHdr(stp, subg);
		iterateBody(stp, subg);
	}
}


static void
iterateBody(gxlstate_t* stp, Agraph_t *g)
{
	Agnode_t	*n;
	Agedge_t	*e;

	iterate_subgs(stp, g);
	for (n = agfstnode(g); n; n = agnxtnode(n)) {
		char* gxlId;
		char* nodename = agnameof(n);

		if(!mapLookup(stp->nodeMap, nodename)) {
			gxlId = agget(n, GXL_ID);	
			if(EMPTY(gxlId))
				gxlId = nodename;
			if(idexists(stp->idList, gxlId) || !legalGXLName(gxlId))
				gxlId = createNodeId(stp->idList);
			else
				gxlId = addid(stp->idList, gxlId);
			addToMap (stp->nodeMap, nodename, gxlId);
		}

		for (e = agfstout(n); e; e = agnxtout(e)) {
			if (writeEdgeTest(g,e)) {
				char* edge_id = agget(e, GXL_ID);
				if (!EMPTY(edge_id))
					addid(stp->idList, edge_id);
			}
		}
	}
}

static gxlstate_t*
initState (Agraph_t* g)
{
  gxlstate_t* stp = NEW(gxlstate_t);
  stp->nodeMap = dtopen (&nameDisc, Dtoset);
  stp->graphMap = dtopen (&nameDisc, Dtoset);
  stp->synNodeMap = dtopen (&nameDisc, Dtoset);
  stp->idList = dtopen (&idDisc, Dtoset);
  stp->attrsNotWritten = 0;
  stp->root = g;
  stp->directed = agisdirected(g);
  return stp;
}

static void
freeState (gxlstate_t* stp)
{
  dtclose (stp->nodeMap);
  dtclose (stp->graphMap);
  dtclose (stp->synNodeMap);
  dtclose (stp->idList);
  free (stp);
}

void 
dot_to_gxl(Agraph_t* g, FILE* gxlFile)
{	
	gxlstate_t* stp = initState (g);
	aginit(g,AGNODE,"node",sizeof(Agnodeinfo_t),TRUE);
	
	iterateHdr(stp, g);
	iterateBody(stp, g);

	Level = 0;

	fprintf(gxlFile, "<?xml version=\"1.0\" encoding=\"iso-8859-1\"?>\n");
	fprintf(gxlFile, "<gxl>\n");

	writeHdr(stp, g, gxlFile, TRUE);
	writeBody(stp, g, gxlFile);
	writeTrl(g, gxlFile, TRUE);

	fprintf(gxlFile, "</gxl>\n");

	freeState (stp);
}