v.info: add JSON support (OSGeo#3755)

Use parson to have JSON as an output format support. The module has various flags to control the fields being output in case of plain shell format controlled by flags. All (-get) of these are enabled when using format=shell. format=plain now allows use of flags. This may need special handling in the future to resolve the edge cases in a better way.
neteler · Jun 18, 2024 · f3204e7 · f3204e7
1 parent 04fd63c
commit f3204e7
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Showing 8 changed files with 491 additions and 101 deletions.
diff --git a/lib/gis/testsuite/test_parser_json.py b/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)
 
 

diff --git a/vector/v.info/Makefile b/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)

diff --git a/vector/v.info/local_proto.h b/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 *);
diff --git a/vector/v.info/main.c b/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);

diff --git a/vector/v.info/parse.c b/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 +63,27 @@ 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) {
+        // if shell flags are specified and format=PLAIN (default),
+        // print in shell script format
+        if (*shell != 0) {
+            *format_ptr = SHELL;
+        }
+        else {
+            *format_ptr = PLAIN;
+        }
+    }
+    else if (strcmp(format_opt->answer, "json") == 0)
+        *format_ptr = JSON;
+    else {
+        *format_ptr = SHELL;
+        // if shell flags are specified with format=shell, obey them
+        // if only format=shell is specified, print all info
+        if (*shell == 0) {
+            *shell |= SHELL_BASIC;
+            *shell |= SHELL_REGION;
+            *shell |= SHELL_TOPO;
+        }
+    }
 }