How do I test if element exists in JSON object?

[compumate99]

I have JSON object and need to test if element exists.
This element will have empty string if exists.

{ 
    "XAVResponse": {
        "Response": {
            "ResponseStatus": {
                "Code": "1",
                "Description": "Success"
            },
            "TransactionReference": {
                "CustomerContext": "Verify that an XAV request with an Address Line 1 element returns a successful response."
            }
        },
        "AmbiguousAddressIndicator": "",
        .
        .
        .
    }
}

Element "AmbiguousAddressIndicator" will appear with empty string if needed.

Thank you in advance.

[dcarver]

You can use miva_json_decode and miva_member_exists to do this. Something like the following should work.

<MvIF EXPR = "{ NOT miva_json_decode( l.json, l.data ) }">
    <error handling here>
</MvIF>

<MvIF EXPR = "{ miva_member_exists( l.data:XAVResponse, 'AmbiguousAddressIndicator' ) }">
    <the element exists>
</MvIF> 

[compumate99]

That did the trick.

Thanks.

[compumate99]

How do I find what type the element is?
miva_array_elements does not give me array dimension when it is an object instead of an array.
miva_array_elements on Candidate element returns 2 for the first case.

{
    "Candidate": {
        "AddressKeyFormat": {
            "AddressLine": "2215 GESSNER RD",
            "PoliticalDivision2": "HOUSTON",
            "PoliticalDivision1": "TX",
            "PostcodePrimaryLow": "77080",
            "PostcodeExtendedLow": "5003",
            "Region": "HOUSTON TX 77080-5003",
            "CountryCode": "US"
        }
    }
}

or

{
    "Candidate": [{
        "AddressKeyFormat": {
            "AddressLine": "2215 GESSNER RD",
            "PoliticalDivision2": "HOUSTON",
            "PoliticalDivision1": "TX",
            "PostcodePrimaryLow": "77080",
            "PostcodeExtendedLow": "5003",
            "Region": "HOUSTON TX 77080-5003",
            "CountryCode": "US"
        }
    },
    {
        "AddressKeyFormat": {
            "AddressLine": "2215 GESSNER RD",
            "PoliticalDivision2": "HOUSTON",
            "PoliticalDivision1": "TX",
            "PostcodePrimaryLow": "77080",
            "PostcodeExtendedLow": "5003",
            "Region": "HOUSTON TX 77080-5003",
            "CountryCode": "US"
        }
    }]
}

Thanks.

[Scot - ScotsScripts.com]

Take the array and use MvRevealstructure

https://www.mivascript.com/item/miva...STRUCTURE.html

[compumate99]

Thanks Scot,

It is JSON object and I am parsing the result.
I am trying to find return result is single object or array of objects.

[Scot - ScotsScripts.com]

Oh, got it. Do what Carver said first:

miva_json_decode( l.json, l.data )

Then use miva_array_search(...) on l.data

https://www.mivascript.com/item/miva...ay_search.html

miva_Array_search is kind of tricky at first, but the examples are pretty good on the docs page.

[compumate99]

I do not know the element "Candidate" is array or not yet.
I know what to do when it is array or object.

Is there any function which finds the type of object?

[Scot - ScotsScripts.com]

One way is to use miva_array_serialize(...) on the array item. You can "see" what the names of the variables are this way.

After you decode the json and have l.data, do something like:

<MvFOREACH ITERATOR = "l.dataitem" INDEX = "l.dataitempos" ARRAY = "l.data">
   <MvASSIGN NAME = "l.ok" VALUE = "{ miva_array_serialize(l.dataitem) }" />
   <MvEVAL EXPR = "{ glosub(l.dataitem,',','<br>')}">
<br>
</MvFOREACH>

You can parse l.item_serialized to find the var names you are looking for.

[Kent Multer]

Referring back to post #4 (the numbers are along the right side of the page), it seems weird to me that miva_array_elements returned 2 for Candidate in the first example. I will guess that something isn't quite right in the way your code is handling the data.
If you run an object through miva_array_serialize, and then use glosub() to change the commas to <br/> tags, you can display it on your screen in an easy-to-read format that will allow you to see exactly what's in there.
If you post some of the code that's processing the JSON, some of us may be able to give more help.

[compumate99]

Here is the code.

<MIVA STANDARDOUTPUTLEVEL="html,text">
<MvCAPTURE VARIABLE = "l.response">
{
    "XAVResponse":
    {
        "Response":
        {
            "ResponseStatus":
            {
                "Code": "1",
                "Description": "Success"
            }
        },
        "ValidAddressIndicator": "",
        "AddressClassification":
        {
            "Code": "1",
            "Description": "Commercial"
        },
        "Candidate":
        {
            "AddressClassification":
            {
                "Code": "1",
                "Description": "Commercial"
            },
            "AddressKeyFormat":
            {
                "AddressLine": "2215 GESSNER RD",
                "PoliticalDivision2": "HOUSTON",
                "PoliticalDivision1": "TX",
                "PostcodePrimaryLow": "77080",
                "PostcodeExtendedLow": "5003",
                "Region": "HOUSTON TX 77080-5003",
                "CountryCode": "US"
            }
        }
    }
}
<//MvCAPTURE>
<MvASSIGN NAME = "l.ok" VALUE = "{ miva_json_decode(l.response, l.json_response) }">
<MvEVAL EXPR = "{ 'Number of candidates : ' $ miva_array_elements( l.json_response:xavresponse:candidate ) }"><br /><br />
<MvEVAL EXPR = "{ l.json_response:xavresponse:candidate }"><br /><br />

This block of codes will generate

Number of candidates : 2

1,Commercial,2215 GESSNER RD,US,TX,HOUSTON,5003,77080,HOUSTON TX 77080-5003

Thanks

[Kent Multer]

That does seem strange, that the first MvEVAL returns 2. It's even stranger that the second MvEVAL returns nothing; is that what actually happened, or did you just not include that part in your post?
If this was my project, I'd put in some code to check the return value from miva_json_decode, to see if it's encountering an error. I'd also try the above mentioned trick to serialize l.json_response, to see exactly what it contains.
Possibly this is a bug in miva_array_elements. If so, a work-around would be, when you want to know the structure of a variable, call miva_struct_members first, to see if it's an object. Don't call miva_array_elements unless miva_struct_members returns zero.
Hope that helps --

[compumate99]

I am sorry Kent, I missed output from second MvEVAL.

It returns

1,Commercial,2215 GESSNER RD,US,TX,HOUSTON,5003,77080,HOUSTON TX 77080-5003

I will try your suggestion later.

Thank you

[compumate99]

Following code was executed

<MvASSIGN NAME = "l.stru_count" VALUE = "{ miva_struct_members(l.json_response:xavresponse:ca ndidate, l.stru_array) }">
<MvEVAL EXPR = "{ 'Member Count : ' $ l.stru_count $ ' | Serialized: ' $ miva_array_serialize(l.stru_array) }"><br /><br />

And received the result.

Member Count : 2 | Serialized: [1]=AddressClassification,[2]=AddressKeyFormat

So this return value 2 matches with 2 returned from MIVA_ARRAY_ELEMENTS.

However, if I run this code for JSON object with element type ARRAY

"Candidate":[
{
    "AddressKeyFormat":
    {
        "PoliticalDivision2": "ROSWELL",
        "PoliticalDivision1": "GA",
        "PostcodePrimaryLow": "30076",
        "Region": "ROSWELL GA 30076",
        "CountryCode": "US"
    }
},
{
    "AddressKeyFormat":
    {
        "PoliticalDivision2": "ROSWELL",
        "PoliticalDivision1": "GA",
        "PostcodePrimaryLow": "30075",
        "Region": "ROSWELL GA 30075",
        "CountryCode": "US"
    }
},
{
    "AddressKeyFormat":
    {
        "PoliticalDivision2": "ROSWELL",
        "PoliticalDivision1": "GA",
        "PostcodePrimaryLow": "30077",
        "Region": "ROSWELL GA 30077",
        "CountryCode": "US"
    }
}]

I receive

Member Count : 0 | Serialized:

It looks MIVA_STRUCT_MEMBERS does not operate correctly on JSON ARRAY.

[Kent Multer]

Very strange ... I would check the return value from miva_json_decode. FYI, if it returns zero, you can call miva_json_decode_last_error() to get an error message telling what the problem was.
I would also do the serialize trick on the entire JSON reply (l.json_response), to see exactly what it contains.