w.deng | e87b500 | 2025-08-20 10:43:03 +0800 | [diff] [blame] | 1 | |
| 2 | #ifndef _json_c_json_visit_h_ |
| 3 | #define _json_c_json_visit_h_ |
| 4 | |
| 5 | /** |
| 6 | * @file |
| 7 | * @brief Methods for walking a tree of objects. |
| 8 | */ |
| 9 | #include "json_object.h" |
| 10 | |
| 11 | #ifdef __cplusplus |
| 12 | extern "C" { |
| 13 | #endif |
| 14 | |
| 15 | typedef int(json_c_visit_userfunc)(json_object *jso, int flags, json_object *parent_jso, |
| 16 | const char *jso_key, size_t *jso_index, void *userarg); |
| 17 | |
| 18 | /** |
| 19 | * Visit each object in the JSON hierarchy starting at jso. |
| 20 | * For each object, userfunc is called, passing the object and userarg. |
| 21 | * If the object has a parent (i.e. anything other than jso itself) |
| 22 | * its parent will be passed as parent_jso, and either jso_key or jso_index |
| 23 | * will be set, depending on whether the parent is an object or an array. |
| 24 | * |
| 25 | * Nodes will be visited depth first, but containers (arrays and objects) |
| 26 | * will be visited twice, the second time with JSON_C_VISIT_SECOND set in |
| 27 | * flags. |
| 28 | * |
| 29 | * userfunc must return one of the defined return values, to indicate |
| 30 | * whether and how to continue visiting nodes, or one of various ways to stop. |
| 31 | * |
| 32 | * Returns 0 if nodes were visited successfully, even if some were |
| 33 | * intentionally skipped due to what userfunc returned. |
| 34 | * Returns <0 if an error occurred during iteration, including if |
| 35 | * userfunc returned JSON_C_VISIT_RETURN_ERROR. |
| 36 | */ |
| 37 | JSON_EXPORT int json_c_visit(json_object *jso, int future_flags, json_c_visit_userfunc *userfunc, |
| 38 | void *userarg); |
| 39 | |
| 40 | /** |
| 41 | * Passed to json_c_visit_userfunc as one of the flags values to indicate |
| 42 | * that this is the second time a container (array or object) is being |
| 43 | * called, after all of it's members have been iterated over. |
| 44 | */ |
| 45 | #define JSON_C_VISIT_SECOND 0x02 |
| 46 | |
| 47 | /** |
| 48 | * This json_c_visit_userfunc return value indicates that iteration |
| 49 | * should proceed normally. |
| 50 | */ |
| 51 | #define JSON_C_VISIT_RETURN_CONTINUE 0 |
| 52 | |
| 53 | /** |
| 54 | * This json_c_visit_userfunc return value indicates that iteration |
| 55 | * over the members of the current object should be skipped. |
| 56 | * If the current object isn't a container (array or object), this |
| 57 | * is no different than JSON_C_VISIT_RETURN_CONTINUE. |
| 58 | */ |
| 59 | #define JSON_C_VISIT_RETURN_SKIP 7547 |
| 60 | |
| 61 | /** |
| 62 | * This json_c_visit_userfunc return value indicates that iteration |
| 63 | * of the fields/elements of the <b>containing</b> object should stop |
| 64 | * and continue "popped up" a level of the object hierarchy. |
| 65 | * For example, returning this when handling arg will result in |
| 66 | * arg3 and any other fields being skipped. The next call to userfunc |
| 67 | * will be the JSON_C_VISIT_SECOND call on "foo", followed by a userfunc |
| 68 | * call on "bar". |
| 69 | * <pre> |
| 70 | * { |
| 71 | * "foo": { |
| 72 | * "arg1": 1, |
| 73 | * "arg2": 2, |
| 74 | * "arg3": 3, |
| 75 | * ... |
| 76 | * }, |
| 77 | * "bar": { |
| 78 | * ... |
| 79 | * } |
| 80 | * } |
| 81 | * </pre> |
| 82 | */ |
| 83 | #define JSON_C_VISIT_RETURN_POP 767 |
| 84 | |
| 85 | /** |
| 86 | * This json_c_visit_userfunc return value indicates that iteration |
| 87 | * should stop immediately, and cause json_c_visit to return success. |
| 88 | */ |
| 89 | #define JSON_C_VISIT_RETURN_STOP 7867 |
| 90 | |
| 91 | /** |
| 92 | * This json_c_visit_userfunc return value indicates that iteration |
| 93 | * should stop immediately, and cause json_c_visit to return an error. |
| 94 | */ |
| 95 | #define JSON_C_VISIT_RETURN_ERROR -1 |
| 96 | |
| 97 | #ifdef __cplusplus |
| 98 | } |
| 99 | #endif |
| 100 | |
| 101 | #endif /* _json_c_json_visit_h_ */ |