Add string literal into JSONPath output

Question

Can I add a string literal to a JSONPath selector?

{ "items": [
    { "x": 1 },
    { "x": 2 },
    { "x": 3 },
    { "x": 4 }]
}

$.items[:].x gives...

[
  1,
  2,
  3,
  4
]

For example, can I make it return...

[
  { 1 },
  { 2 },
  { 3 },
  { 4 }
]

I want to generate some code that adds items to a dictionary.

`{1}` isn't valid JSON. JSON Path can only return it's results as valid JSON. What are you really wanting? Please expand on your question. — gregsdennis, Oct 21 '20 at 01:00
What library are you using? This question really needs some more information. — gregsdennis, Oct 21 '20 at 08:29
Most probably not possible unless you modify the source of your JSON path implementation; sure you using jsonpath-0.5.1.cs? — wp78de, Oct 21 '20 at 17:51
I'm using whatever version is supported by that website. I've done this now, anyhow. I used string replace to convert my results to C# tuple pairs. — Ian Warburton, Oct 21 '20 at 19:47

score 0 · Accepted Answer · answered Oct 22 '20 at 20:06

As discussed in the comments, this cannot be done using JSONPath (alone) since a path query returns only valid JSON and the target format is not valid. In general, JSONPath is not the right tool here, a JSON transformation using a library like Jolt would be more appropriate; but again, similar to XSLT transformations, we can only create valid output. So, as you already have found out, you would need to use string functions to mingle the code as needed. For instance, a regex substitution could do:

const regex = /(\d+),?/gm;
const str = `[
  1,
  2,
  3,
  4
]`;
const subst = `{ $1 },`;

// The substituted value will be contained in the result variable
const result = str.replace(regex, subst);

console.log('Substitution result: ', result);

Add string literal into JSONPath output

1 Answers1