v.info: add JSON support

lib/gis/testsuite/test_parser_json.py

@@ -97,13 +97,15 @@ def test_v_info(self):
         inputs = [
             {"param": "map", "value": "hospitals@PERMANENT"},
             {"param": "layer", "value": "1"},
+            {"param": "format", "value": "plain"},
         ]
 
         stdout, stderr = subprocess.Popen(args, stdout=subprocess.PIPE).communicate()
         print(stdout)
         json_code = json.loads(decode(stdout))
+        print(json_code)
         self.assertEqual(json_code["module"], "v.info")
-        self.assertEqual(len(json_code["inputs"]), 2)
+        self.assertEqual(len(json_code["inputs"]), 3)
         self.assertEqual(json_code["inputs"], inputs)
 
 

vector/v.info/Makefile

@@ -3,7 +3,7 @@ MODULE_TOPDIR = ../..
 
 PGM = v.info
 
-LIBES = $(VECTORLIB) $(DIG2LIB) $(DBMILIB) $(GISLIB)
+LIBES = $(VECTORLIB) $(DIG2LIB) $(DBMILIB) $(GISLIB) $(PARSONLIB)
 DEPENDENCIES = $(VECTORDEP) $(DIG2DEP) $(DBMIDEP) $(GISDEP)
 EXTRA_INC = $(VECT_INC)
 EXTRA_CFLAGS = $(VECT_CFLAGS)

vector/v.info/local_proto.h

@@ -1,20 +1,25 @@
 #include <grass/vector.h>
+#include <grass/parson.h>
 
 #define SHELL_NO     0x00
 #define SHELL_BASIC  0x02
 #define SHELL_REGION 0x04
 #define SHELL_TOPO   0x08
 
+enum OutputFormat { PLAIN, SHELL, JSON };
+
 /* level1.c */
 int level_one_info(struct Map_info *);
 
 /* parse.c */
-void parse_args(int, char **, char **, char **, int *, int *, int *);
+void parse_args(int, char **, char **, char **, int *, int *, int *,
+                enum OutputFormat *);
 
 /* print.c */
 void format_double(double, char *);
-void print_region(struct Map_info *);
-void print_topo(struct Map_info *);
+void print_region(struct Map_info *, enum OutputFormat, JSON_Object *);
+void print_topo(struct Map_info *, enum OutputFormat, JSON_Object *);
 void print_columns(struct Map_info *, const char *, const char *);
 void print_info(struct Map_info *);
-void print_shell(struct Map_info *, const char *);
+void print_shell(struct Map_info *, const char *, enum OutputFormat,
+                 JSON_Object *);

vector/v.info/main.c

@@ -29,6 +29,11 @@ int main(int argc, char *argv[])
     char *input_opt, *field_opt;
     int hist_flag, col_flag, shell_flag;
 
+    enum OutputFormat format;
+
+    JSON_Value *root_value;
+    JSON_Object *root_object;
+
     struct Map_info Map;
 
     G_gisinit(argv[0]);
@@ -47,7 +52,12 @@ int main(int argc, char *argv[])
     G_debug(1, "LFS is %s", sizeof(off_t) == 8 ? "available" : "not available");
 
     parse_args(argc, argv, &input_opt, &field_opt, &hist_flag, &col_flag,
-               &shell_flag);
+               &shell_flag, &format);
+
+    if (format == JSON) {
+        root_value = json_value_init_object();
+        root_object = json_value_get_object(root_value);
+    }
 
     /* try to open head-only on level 2 */
     if (Vect_open_old_head2(&Map, input_opt, "", field_opt) < 2) {
@@ -82,19 +92,29 @@ int main(int argc, char *argv[])
         return (EXIT_SUCCESS);
     }
 
-    if (shell_flag & SHELL_BASIC) {
-        print_shell(&Map, field_opt);
+    if ((shell_flag & SHELL_BASIC) || format == JSON) {
+        print_shell(&Map, field_opt, format, root_object);
     }
-    if (shell_flag & SHELL_REGION) {
-        print_region(&Map);
+    if ((shell_flag & SHELL_REGION) || format == JSON) {
+        print_region(&Map, format, root_object);
     }
-    if (shell_flag & SHELL_TOPO) {
-        print_topo(&Map);
+    if ((shell_flag & SHELL_TOPO) || format == JSON) {
+        print_topo(&Map, format, root_object);
     }
-    if (shell_flag == 0) {
+    if (shell_flag == 0 && format == PLAIN) {
         print_info(&Map);
     }
 
+    if (format == JSON) {
+        char *serialized_string = json_serialize_to_string_pretty(root_value);
+        if (serialized_string == NULL) {
+            G_fatal_error(_("Failed to initialize pretty JSON string."));
+        }
+        puts(serialized_string);
+        json_free_serialized_string(serialized_string);
+        json_value_free(root_value);
+    }
+
     Vect_close(&Map);
 
     return (EXIT_SUCCESS);

vector/v.info/parse.c

@@ -6,9 +6,9 @@
 #include "local_proto.h"
 
 void parse_args(int argc, char **argv, char **input, char **field, int *history,
-                int *columns, int *shell)
+                int *columns, int *shell, enum OutputFormat *format_ptr)
 {
-    struct Option *input_opt, *field_opt;
+    struct Option *input_opt, *field_opt, *format_opt;
     struct Flag *hist_flag, *col_flag, *shell_flag, *region_flag, *topo_flag;
 
     input_opt = G_define_standard_option(G_OPT_V_MAP);
@@ -42,6 +42,13 @@ void parse_args(int argc, char **argv, char **input, char **field, int *history,
     topo_flag->description = _("Print topology info in shell script style");
     topo_flag->guisection = _("Print");
 
+    format_opt = G_define_standard_option(G_OPT_F_FORMAT);
+    format_opt->options = "plain,shell,json";
+    format_opt->descriptions = _("plain;Human readable text output;"
+                                 "shell;shell script style text output;"
+                                 "json;JSON (JavaScript Object Notation);");
+    format_opt->guisection = _("Print");
+
     if (G_parser(argc, argv))
         exit(EXIT_FAILURE);
 
@@ -56,4 +63,17 @@ void parse_args(int argc, char **argv, char **input, char **field, int *history,
         *shell |= SHELL_REGION;
     if (topo_flag->answer)
         *shell |= SHELL_TOPO;
+
+    if (strcmp(format_opt->answer, "plain") == 0) {
+        *format_ptr = PLAIN;
+    }
+    else if (strcmp(format_opt->answer, "json") == 0)
+        *format_ptr = JSON;
+    else {
+        *format_ptr = SHELL;
+    }
+
+    if (*shell != 0 && *format_ptr == PLAIN) {
+        *format_ptr = SHELL;
+    }
 }