'' is not a valid operation at 16 in $..book[?@.isbn]

[fkarakas]

Hello, Great work on this lib. Currently evaluating it. From the jsonpath specification i grabbed a query from the examples that i found interesting, and i got an error

x, err := jp.ParseString("$..book[?@.isbn]")

failed as follow

'' is not a valid operation at 16 in $..book[?@.isbn]

Did i miss something because you mentionned that you fully support jsonpath specs.

Regards

PS: specs example queries

+========================+=======================================+
| JSONPath               | Intended result                       |
+========================+=======================================+
| $.store.book[*].author | the authors of all books in the store |
+------------------------+---------------------------------------+
| $..author              | all authors                           |
+------------------------+---------------------------------------+
| $.store.*              | all things in store, which are some   |
|                        | books and a red bicycle               |
+------------------------+---------------------------------------+
| $.store..price         | the prices of everything in the store |
+------------------------+---------------------------------------+
| $..book[2]             | the third book                        |
+------------------------+---------------------------------------+
| $..book[2].author      | the third book's author               |
+------------------------+---------------------------------------+
| $..book[2].publisher   | empty result: the third book does not |
|                        | have a "publisher" member             |
+------------------------+---------------------------------------+
| $..book[-1]            | the last book in order                |
+------------------------+---------------------------------------+
| $..book[0,1]           | the first two books                   |
| $..book[:2]            |                                       |
+------------------------+---------------------------------------+
| $..book[?@.isbn]       | all books with an ISBN number         |
+------------------------+---------------------------------------+
| $..book[?@.price<10]   | all books cheaper than 10             |
+------------------------+---------------------------------------+
| $..*                   | all member values and array elements  |
|                        | contained in the input value          |
+------------------------+---------------------------------------+

[ohler55]

Looks like a bug. I'll try to fix it this weekend.

You didn't miss anything. The intent is indeed to fully support the JSONPath draft specification. That doesn't mean there aren't bugs.

[ohler55]

Please try the "jp-exists-bug" branch.

[fkarakas]

I have tried and it is working, great work 👍

My first plan was to use your lib with a special kind of json called jsonld (https://json-ld.org/) used by google. It is a regular json but with some field starting with @ character. Here is an example:

  {
    "@context": "http://schema.org",
    "@type": "DataFeed",
    "dateModified": "2023-10-25T12:05:01Z",
    "dataFeedElement": [
      {
        "@context": [
          "http://schema.org",
          {
            "@language": "fr"
          }
        ],
        "@type": "TVEpisode",
        "@id": "https://tv.com",
        "url": "https://tv.com/video1",
        "name": "video 1",
        "image": {
          "@context": "http://schema.org",
          "@type": "ImageObject",
          "contentUrl": "https://tv.com/video1",
          "additionalProperty": [
            {
              "@type": "PropertyValue",
              "name": "contentAttributes",
              "value": [
                "iconic",
                "poster",
                "smallFormat",
                "largeFormat"
              ]
            }
          ]
        },
        "episodeNumber": 10000,
        "partOfSeason": {
          "@type": "TVSeason",
          "@id": "https://tv.com/season1",
          "url": "https://tv.com/season1",
          "seasonNumber": 1
        },
        "partOfSeries": {
          "@type": "TVSeries",
          "@id": "https://tv.com/series1",
          "url": "https://tv.com/series1",
          "name": "Quotidien"
        },
        "potentialAction": [
          {
            "@type": "WatchAction",
            "target": {
              "@type": "EntryPoint",
              "urlTemplate": "https://tv.com/series1",
              "inLanguage": "fr",
              "actionPlatform": [
                "http://schema.org/AndroidPlatform",
                "http://schema.org/DesktopWebPlatform",
                "http://schema.org/IOSPlatform",
                "http://schema.org/MobileWebPlatform"
              ]
            },
            "actionAccessibilityRequirement": {
              "@type": "ActionAccessSpecification",
              "category": "free",
              "availabilityStarts": "2017-01-16T18:40:00Z",
              "availabilityEnds": "2029-12-31T20:00:00Z",
              "eligibleRegion": [
                {
                  "@type": "Country",
                  "name": "US"
                }
              ]
            }
          },
          {
            "@type": "WatchAction",
            "target": {
              "@type": "EntryPoint",
              "urlTemplate": "https://tv.com/video1",
              "inLanguage": "fr",
              "actionPlatform": [
                "http://schema.org/AndroidTVPlatform"
              ]
            },
            "actionAccessibilityRequirement": {
              "@type": "ActionAccessSpecification",
              "category": "free",
              "availabilityStarts": "2017-01-16T18:40:00Z",
              "availabilityEnds": "2029-12-31T20:00:00Z",
              "eligibleRegion": [
                {
                  "@type": "Country",
                  "name": "FR"
                }
              ]
            }
          }
        ]
      }
    ]
  }

So i think it is a regular json file but with "special" field name.

when i try to query something like :

x, err := jp.ParseString("$..dataFeedElement[?(@.@type=='TVEpisode')]")

i got the error: an expression fragment can not start with a '@' at 25 in $..dataFeedElement[?(@.@type=='TVEpisode')]

I can understand that your lib cannot handle this and to be honest i don't know if the jsonpath specification anticipated this kind of use cases. Because jsonld is for me a valid json....

So tell me what you thing about it.

[ohler55]

A little background first. The notation of @.type is shorthand for a path comprised of '@' and 'type'. The alternate or maybe the primary notation is bracket notation so instead of @.@type which uses a special character in the second token the bracket notation can be used and the path would look like @['@type'].

I added a test in script_test.go:64 as an example.

[fkarakas]

i have tried

x, err := jp.ParseString("(@['@type'] == 'TVEpisode')")

and got

parse error at 1 in (@['@type'] == 'TVEpisode')

i want to get all element of the array where the field @type is equal to 'TVEpisode' (there is other type of content in the array). Sorry if i do something wrong, a little newbie in jsonpath :)

[ohler55]

Hmm, should work. I'll get it fixed. Maybe tomorrow.

[ohler55]

After looking at the string being parsed, it is not a JSONPath string. If the intent was to format a filter or script then @[?@['@type'] == 'TVEpisode'] would be more appropriate.

Added a test to parse_test.go:35.

[fkarakas]

Thank you, the following filter works as you said:

x, err := jp.ParseString("$.dataFeedElement[?(@['@type'] == 'TVEpisode')]")

We can close this issue. Thanks

[ohler55]

Great. I'll release tonight and close after that.