Using a function to generate child row data

Neighlyd

My child rows have access to objects that I want to iterate through and concatenate into a field using a javascript function. However, when I call the function in the format function for my child rows, they only display "undefined."

My format row is:

function format(d) {
    return "<table class='table'>" +
               "<tr>"+
               "<td>Litigants:</td>" +
               "<td>" + list_litigants(data.litigant_list) + "</td>"
               "</tr>" +
               "</table>"
     }

And the function for list_litigants is:

function list_litigants(data){
       data.forEach(function (obj){
              concat='Name: ' + obj.name + ', Role: ' + obj.role + '; ';
              console.log(concat);
              return concat;
       })
};

The console.log is showing that the function is triggering just fine. However, the string isn't getting passed through to Datatables. Is there an extra step I need to take for it to render properly?

crwdzr

try this

function format(data) {
    return "<table class='table'>" +
               "<tr>"+
               "<td>Litigants:</td>" +
               "<td>" + list_litigants(data.litigant_list) + "</td>"
               "</tr>" +
               "</table>"
     }

format() had an argument of d therefor anything in that data object being passed would never be defined

Neighlyd

Thank you for your quick response.

I apologize, that was a typo on my part when I transcribed my code into the browser window.

The format() function was using the same variable as the call to list_litigants.

so:

function format(data){
    return "<table class='table'>"+
        "<tr>"+
        "<td>Litigants:</td>"+
        "<td>" + list_litigants(data.litigant_list) + "</td>" +
        "</tr>" +
        "</table>"
}

The console is spitting out the error: Uncaught TypeError: Cannot read property 'forEach' of undefined at list_litigants

crwdzr

with the code you've shown, assuming that data is structured properly, there should be no errors, this:

function format(data) {
    return "<table class='table'>" +
        "<tr>"+
        "<td>Litigants:</td>" +
        "<td>" + list_litigants(data.litigant_list) + "</td>"
        "</tr>" +
        "</table>"
}
function list_litigants(data){
    data.forEach(function (obj){
        concat='Name: ' + obj.name + ', Role: ' + obj.role + '; ';
        console.log(concat);
        return concat;
    })
};

let data = {
    litigant_list: [
        {name: 'foo', role: 'bar'},
        {name: 'baz', role: 'qux'},
    ],
}
format(data);

outputs:
Name: foo, Role: bar;
Name: baz, Role: qux;

I would have to say either the error is in the structuring of the data variable or somewhere else in the process

Neighlyd

Hello,

Thank you for replying.

The console.log(concat) is indeed showing the appropriate results (the concat results). So I think the data is structured appropriately:

        "litigant_list": [
            {
                "name": "Foo",
                "role": "bar"
            },
            {
                "name": "baz",
                "role": "qux"
            }
        ],

However, the table cell is still showing undefined.

When I use your formulation (not pulling data from ajax, but using a let function), I get the same undefined cell with the appropriate concat output to console.log as well.

allan

At the top of your format function could you do console.log( JSON.stringify( data ) ) and show us the result from the console?

Thanks,
Allan

Neighlyd

I have pasted the results of the console.log( JSON.stringify (data)) below. As you can see, the litigant list is nested within case. I have called list_litigants(data.case.litigants) and the cell still reads as undefined, even though the console.log(concat) in the list_litigants function works fine.

The litigant_list_concat is the programmatically created version that I have my django model creating right now as a stop gap until I get the Datatables version working.

Also, even though this is court data, it is 700 years old so I don't need to obfuscate the litigants' names or details.

{
"id":3466,
"amercement":null,
"damage":null,
"damage_notes":"",
"ad_proximum":null,
"role": {
      "id":37,
      "role":"Mentioned"
      },
"impercamentum_notes":null,
"chevage_id":null,
"heriot_assessment_id":null,
"fine_id":null,
"chevage":null,
"heriot_animal":null,
"impercamentum_animal_id":null,
"impercamentum_animal":null,
"habet_terram":null,
"person_id":1350,
"heriot_assessment":null,
"attached":null,
"distrained":null,
"heriot_animal_id":null,
"bail":null,
"heriot_quantity":null,
"case": {
        "id":1775,
        "of_interest":false,
        "ad_legem":false,
        "litigant_list_concat":"<div class=d-flex justify-content-end><div class='mr-auto p-0'><u>Name:</u> Walterus Bailly</div> <div class='p-0'><u>Role:</u> Defendant</div></div><hr><div class=d-flex justify-content-end><div class='mr-auto p-0'><u>Name:</u> Abbot of Tewkesbury</div> <div class='p-0'><u>Role:</u> Mentioned</div></div><hr>",
        "case_type": {
                   "id":66,
                   "case_type":"Does Not Reside"
                   },
        "court_type":"Hallmoot",
        "verdict_id":3,
        "summary":"Amercement in lieu of forefeiture. Claims that Walter lives on land of the Abbot of Tewkesbury.",
        "active_sale":false,
        "villeinage_mention":false,
        "session_id":55,
        "litigant_list": [
                        {
                        "name":"Walterus Bailly",
                        "role":"Defendant"
                        },
                        {
                        "name":"Abbot of Tewkesbury",
                        "role":"Mentioned"
                        }
                        ],
        "verdict": {
                 "id":3,
                 "verdict":"Amercements"
                 },
        "case_type_id":66,
        "incidental_land":false,
        "litigant_count":2,
        "session": {
                 "id":55,
                 "date":"1370-11-05",
                 "notes":"Tuesday after All Saints - Nov 1",
                 "record_id":14,
                 "law_term":"Michaelmas",
                 "year":1370,
                 "village_id":48,
                 "folio":"30v & 31"
                 }
        },
"impercamentum_amercement_id":null,
"chevage_notes":null,
"impercamentum_amercement":null,
"role_id":37,
"amercement_id":null,
"crossed":null,
"damage_id":null,
"recessit":null,
"impercamentum_quantity":null,
"case_id":1775,
"fine":null
}

allan

It looks like you would want to use:

list_litigants(data.case.litigant_list)

Allan

Neighlyd

I figured out the problem... it was a simple and very stupid mistake on my part. I wasn't returning the concat data properly.

My function was:

function list_litigants(data){
    data.forEach(function (obj){
        concat='Name: ' + obj.name + ', Role: ' + obj.role + '; ';
        return concat;
    })
};

When it should have been:

function list_litigants(data){
    var concat = '';
    data.forEach(function (obj){
        concat= concat + 'Name: ' + obj.name + ', Role: ' + obj.role + '; ';
        return concat;
    })
  return concat;
};

Without that extra return concat, the concat variable had no way to return itself from the function.

A completely rookie mistake and I feel like an idiot now...

Thank you everyone for your help!

allan

We all do it, all the time, no matter how long we've been programming!

Good to hear you've got it working now.

Allan