add mechanism to run external JavaScript

Add the :script <filename> command to load and execute a piece of
JavaScript in the current tab context.  This should enable all kinds of
awesome extension for xxxterm.  This is also dangerous and not yet
properly cordoned off so use with care.  This feature is experimental.

New things will be added to it as it becomes apparent what else needs to
be done to add things such as password managers etc.

2 files changed, 80 insertions, 0 deletions

diff --git a/xxxterm.1 b/xxxterm.1
index 4225559..c431afb 100644
--- a/xxxterm.1
+++ b/xxxterm.1
@@ -535,6 +535,8 @@ and reload all current tabs.
 Runs the script path_to_script with the current uri as the argument.
 If path_to_script is not provided, the value of default_script is used
 instead.
+.It Cm script [filename]
+Run an external JavaScript script file in the current tab context.
 .It Cm session , Cm session show
 Display the current session name.
 By default the session name is main_session.
diff --git a/xxxterm.c b/xxxterm.c
index 5eb8825..1e2945a 100644
--- a/xxxterm.c
+++ b/xxxterm.c
@@ -541,6 +541,8 @@ struct karg {
 
 #define XT_BUFCMD_SZ		(8)
 
+#define XT_EJS_SHOW		(1<<0)
+
 /* mime types */
 struct mime_type {
 	char			*mt_type;
@@ -5649,6 +5651,79 @@ done:
 	return (XT_CB_PASSTHROUGH);
 }
 
+int
+script_cmd(struct tab *t, struct karg *args)
+{
+	JSGlobalContextRef	ctx;
+	WebKitWebFrame		*frame;
+	JSStringRef		str;
+	JSValueRef		val, exception;
+	char			*es;
+	struct stat		sb;
+	FILE			*f = NULL;
+	char			*buf = NULL;
+
+	if (t == NULL)
+		goto done;
+
+	if ((f = fopen(args->s, "r")) == NULL) {
+		show_oops(t, "Can't open script file: %s", args->s);
+		goto done;
+	}
+
+	if (fstat(fileno(f), &sb) == -1) {
+		show_oops(t, "Can't stat script file: %s", args->s);
+		goto done;
+	}
+
+	buf = g_malloc0(sb.st_size + 1);
+	if (fread(buf, 1, sb.st_size, f) != sb.st_size) {
+		show_oops(t, "Can't read script file: %s", args->s);
+		goto done;
+	}
+
+	/* this code needs to be redone */
+	frame = webkit_web_view_get_main_frame(t->wv);
+	ctx = webkit_web_frame_get_global_context(frame);
+
+	str = JSStringCreateWithUTF8CString(buf);
+	val = JSEvaluateScript(ctx, str, JSContextGetGlobalObject(ctx),
+	    NULL, 0, &exception);
+	JSStringRelease(str);
+
+	DNPRINTF(XT_D_JS, "run_script: val %p\n", val);
+	if (val == NULL) {
+		es = js_ref_to_string(ctx, exception);
+		if (es) {
+			show_oops(t, "script exception: %s", es);
+			g_free(es);
+		}
+		goto done;
+	} else {
+		es = js_ref_to_string(ctx, val);
+#if 0
+		/* return values */
+		if (!strncmp(es, XT_JS_DONE, XT_JS_DONE_LEN))
+			; /* do nothing */
+		if (!strncmp(es, XT_JS_INSERT, XT_JS_INSERT_LEN))
+			; /* do nothing */
+#endif
+		if (es) {
+			show_oops(t, "script complete return value: '%s'", es);
+			g_free(es);
+		} else
+			show_oops(t, "script complete: without a return value");
+	}
+
+done:
+	if (f)
+		fclose(f);
+	if (buf)
+		g_free(buf);
+
+	return (XT_CB_PASSTHROUGH);
+}
+
 /*
  * Make a hardcopy of the page
  */
@@ -6208,6 +6283,9 @@ struct cmd {
 	{ "open",		1,	session_cmd,		XT_OPEN,		XT_SESSARG },
 	{ "save",		1,	session_cmd,		XT_SAVE,		XT_USERARG },
 	{ "show",		1,	session_cmd,		XT_SHOW,		0 },
+
+	/* external javascript */
+	{ "script",		0,	script_cmd,		XT_EJS_SHOW,		XT_USERARG },
 };
 
 struct {