Add mg_json_get_long

docs/README.md

@@ -2820,6 +2820,29 @@ mg_json_get_bool(mg_str("[123]", "$[0]", &b));   // Error. b remains to be false
 mg_json_get_bool(mg_str("[true]", "$[0]", &b));  // b is true
 ```
 
+### mg\_json\_get\_long()
+
+```c
+long mg_json_get_bool(struct mg_str json, const char *path, long default_val);
+```
+
+Fetch integer numeric (long) value from the json string `json` at JSON path
+`path`. Return it if found, or `default_val` if not found.
+
+Parameters:
+- `json` - a string containing valid JSON
+- `path` - a JSON path. Must start with `$`
+- `default_val` - a default value for the failure case
+
+Return value: found value, or `default_val` value
+
+Usage example:
+
+```c
+long a = mg_json_get_bool(mg_str("[123]", "$a", -1));   // a = -1
+long b = mg_json_get_bool(mg_str("[123]", "$[0]", -1)); // b = 123
+```
+
 ### mg\_json\_get\_str()
 
 ```c

mongoose.c

@@ -2695,6 +2695,13 @@ char *mg_json_get_hex(struct mg_str json, const char *path, int *len) {
   return result;
 }
 
+long mg_json_get_long(struct mg_str json, const char *path, long dflt) {
+  double dv;
+  long result = dflt;
+  if (mg_json_get_num(json, path, &dv)) result = (long) dv;
+  return result;
+}
+
 #ifdef MG_ENABLE_LINES
 #line 1 "src/log.c"
 #endif

mongoose.h

@@ -1320,6 +1320,7 @@ int mg_json_get(const char *buf, int len, const char *path, int *toklen);
 
 bool mg_json_get_num(struct mg_str json, const char *path, double *v);
 bool mg_json_get_bool(struct mg_str json, const char *path, bool *v);
+long mg_json_get_long(struct mg_str json, const char *path, long dflt);
 char *mg_json_get_str(struct mg_str json, const char *path);
 char *mg_json_get_hex(struct mg_str json, const char *path, int *len);
 char *mg_json_get_b64(struct mg_str json, const char *path, int *len);

src/json.c

@@ -245,3 +245,10 @@ char *mg_json_get_hex(struct mg_str json, const char *path, int *len) {
   }
   return result;
 }
+
+long mg_json_get_long(struct mg_str json, const char *path, long dflt) {
+  double dv;
+  long result = dflt;
+  if (mg_json_get_num(json, path, &dv)) result = (long) dv;
+  return result;
+}

src/json.h

@@ -13,6 +13,7 @@ int mg_json_get(const char *buf, int len, const char *path, int *toklen);
 
 bool mg_json_get_num(struct mg_str json, const char *path, double *v);
 bool mg_json_get_bool(struct mg_str json, const char *path, bool *v);
+long mg_json_get_long(struct mg_str json, const char *path, long dflt);
 char *mg_json_get_str(struct mg_str json, const char *path);
 char *mg_json_get_hex(struct mg_str json, const char *path, int *len);
 char *mg_json_get_b64(struct mg_str json, const char *path, int *len);

test/unit_test.c

@@ -2373,6 +2373,9 @@ static void test_json(void) {
     ASSERT(strcmp(str, "hi\nthere") == 0);
     free(str);
 
+    ASSERT(mg_json_get_long(mg_str(json), "$.foo", -42) == -42);
+    ASSERT(mg_json_get_long(mg_str(json), "$.b[0]", -42) == 12345);
+
     ASSERT(mg_json_get_num(mg_str(json), "$.a", &d) == false);
     ASSERT(mg_json_get_num(mg_str(json), "$.c", &d) == false);
     ASSERT(mg_json_get_num(mg_str(json), "$.b[0]", &d) == true);