UT_JSONPath_T< T, FUNC > Class Template Reference

Implement simple JSONPath parser. More...

#include <UT_JSONPath.h>

Static Public Member Functions
static bool	find (UT_Set< const T * > &matches, const T &src, const char *expr)

Detailed Description

template<typename T, class FUNC>
class UT_JSONPath_T< T, FUNC >

Implement simple JSONPath parser.

This supports a very simple JSONPath syntax:

• $: root object
• @, this: current object
• path: named operator
• . or []: child operator (path or index)
• [,]: union operator (union of paths or indices)
• ..: recursive descent
• *: wildcard

Limitations:

• Array slicing is not supported
• No expression support - you can't do $.book[?(@.cost<7)].title) Extensions:
• path objects can be regex expressions

As there's no formal syntax for JSONPath, this class was inspired from https://goessner.net/articles/JsonPath/

For example, with the JSON:

{
    "animals" : [
        {
            "type" : "cow",
            "legs" : 4,
            "wings" : false
        },
        {
            "type" : "cat",
            "legs" : 4,
            "wings" : false
        },
        {
            "type" : "budgie",
            "legs" : 2,
            "wings" : true
        }
    ],
    "vehicles" : [ ]
}

Paths would resolve:

$.animals[1]            -> { "type" : "cat", "legs" : 4, "wings : false }
$.animals[0,1]."type"   -> [ "cow", "cat" ]
$[animals].."type"      -> [ "cow", "cat", "budgie" ]
$[vehicles]             -> [ ]

The template expects a functor class to provide information about the object, which needs to have:

• static inline bool isArray(const T *obj);
• static inline bool isMap(const T *obj);
• static inline const T *arrayItem(const T *obj, exint idx);
• static inline const T *mapItem(const T *obj, const char *name);
• static inline iterator arrayBegin(const T &obj);
• static inline iterator arrayEnd(const T &obj);
• static inline iterator mapBegin(const T &obj);
• static inline iterator mapEnd(const T &obj);

Definition at line 90 of file UT_JSONPath.h.

Member Function Documentation

template<typename T , class FUNC >

static bool UT_JSONPath_T< T, FUNC >::find ( UT_Set< const T * > &  matches, const T &  src, const char *  expr  )

inlinestatic

Definition at line 93 of file UT_JSONPath.h.

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The documentation for this class was generated from the following file:

• UT/UT_JSONPath.h