3 files changed, 54 insertions, 0 deletions
diff --git a/src/xml/xml.c b/src/xml/xml.c
index 33782c4..24d544c 100644
--- a/src/xml/xml.c
+++ b/src/xml/xml.c
@@ -1,3 +1,4 @@
+#include <stdlib.h>
 #include "xml.h"
 
 /* parse a string into a document */
@@ -31,3 +32,21 @@ char * kai_tag_get_attr(struct kai_tag_t *t, const char *attr)
 	}
 	return NULL;
 }
+
+
+long kai_tag_attr_to_long(
+	struct kai_tag_t *t, const char *attr, 
+	long base, int *flag)
+{
+	char *val = kai_tag_get_attr(t, attr);
+	if (val == NULL) {
+		/* attribute not present, fall back to base */
+		if (flag != NULL)
+			*flag = 1;
+		return base;
+	}
+
+	if (flag != NULL)
+		*flag = 0;
+	return strtol(val, NULL, 10);
+}
diff --git a/src/xml/xml.h b/src/xml/xml.h
index e2abf8f..ac956aa 100644
--- a/src/xml/xml.h
+++ b/src/xml/xml.h
@@ -13,4 +13,13 @@ struct kai_tag_t * kai_parse_string(const char *str);
  */
 char * kai_tag_get_attr(struct kai_tag_t *t, const char *attr);
 
+
+/* find an attribute and convert to long. if not found, return "base" instead.
+ * if flag is not NULL, then it is set to 0 when taking the value from an
+ * attribute and 1 when taking the value from "base"
+ */
+long kai_tag_attr_to_long(
+	struct kai_tag_t *t, const char *attr, 
+	long base, int *flag);
+
 #endif
diff --git a/src/xml/xml.test.c b/src/xml/xml.test.c
index acee4b4..11c85c9 100644
--- a/src/xml/xml.test.c
+++ b/src/xml/xml.test.c
@@ -30,5 +30,31 @@ LILY_TEST("get xml attributes")
 #include LILY_PUSH_TEST()
 
 
+LILY_TEST("convert xml attribute to long")
+{
+	struct kai_tag_t *t = kai_parse_string(
+		"<tag attr1=\"10\" qq=\"12\"></tag>"
+	);
+
+	int n = kai_tag_attr_to_long(t, "attr1", 0, NULL);
+	CHECK_EQ(n, 10, "%d");
+
+	int m = kai_tag_attr_to_long(t, "attr2", 14, NULL);
+	CHECK_EQ(m, 14, "%d");
+
+	int flag = -1;
+	int qq = kai_tag_attr_to_long(t, "qq", 0, &flag);
+	CHECK_EQ(qq, 12, "%d");
+	CHECK_EQ(flag, 0, "%d");
+
+	int k = kai_tag_attr_to_long(t, "dne", 22, &flag);
+	CHECK_EQ(k, 22, "%d");
+	CHECK_EQ(flag, 1, "%d");
+
+	kai_tag_destroy(t);
+}
+#include LILY_PUSH_TEST()
+
+
 #define LILY_FILE_END
 #include LILY_REGISTER_TESTS()