Help understanding Aggregate

[rosenjason]

Hi, I was looking for a node.js data transform module, and json2json is great!

I am having a little trouble getting the output data in the exact format that I need.

I am using aggregate to take an array and concatenate with a delimeter. Currently I am only able to get it to work if I nest the aggregate 'key' inside another JSON object.

The desired output is for the aggregate 'key' to be on the root JSON object that is returned.

I think I just have a syntax issue, but after re-arranging many different times, I have not been able to figure it out.

Any help you can offer would be much appreciated.

Here is my template:

        path : 'results',
        as : {
            "Action" : function() { return "Add"; },
            "Category" : function() { return ""; },
            "Title" : 'title',
            "Description" : 'description',
            "ConditionID" : 3000,
            '' : {  // Want to remove this empty 'key' and have 'PicURL' be the only 'key' that holds the aggregated value
                path : 'Images',
                key: function() { return "PicURL"; },
                value : 'url_fullxfull',
                aggregate : function(key, value, existing) {
                    if (existing) {
                        return existing + "|" + value;
                    } else {
                        return value;
                    }
                }
            }

Here is the source JSON:

    [
        {
            "count": 602,
            "results": [
                {   
                    "title": "Works!",
                    "description": "Works!",
                    "Images": [
                        {
                            "url_fullxfull": "img1"
                        },
                        {
                            "url_fullxfull": "img2"
                        },
                        {
                            "url_fullxfull": "img3"
                        },
                        {
                            "url_fullxfull": "img4"
                        }
                    ],
                }
            ]
        }
    ]

Here is the output:

    [
        {
            "Action": "Add",
            "Category": "",
            "Title": "Works!",
            "Description": "Works!",
            "ConditionID": 3000,
            "": { // Want to remove this empty 'key' and have 'PicURL' be the only 'key' that holds the aggregated value
                "PicURL": "img1|img2|img3|img4|img5"
            },
            "Quantity": 1,
            "Format": "FixedPrice",
            "Duration": "GTC"
        }
    ]   

The desired output is:

    [
        {
            "Action": "Add",
            "Category": "",
            "Title": "Works!",
            "Description": "Works!",
            "ConditionID": 3000,
            "PicURL": "img1|img2|img3|img4|img5",
            "Quantity": 1,
            "Format": "FixedPrice",
            "Duration": "GTC"
        }
    ]

[lpww]

I too would like to see better documentation surrounding the aggregate functionality. It is not clear how it works

[peteashworth]

ditto

[joelvh]

Hi all, I have not used this library in a long time. You'll have to look at the source code to determine how things work, and whether any updates need to be done. Please add documentation and submit a PR if you dig in. Thanks!

[joelvh]

@lpww @rosenjason @AshworthHub have you guys continued using this library? Could you contribute more information about how aggregate works? Would be greatly appreciated!

[rosenjason]

Hi @joelvh, I don't use this API anymore... once I had trouble figuring out the "aggregate" function, I found another API that did JSON data mappings and forked it: jsont

I found the jsont API cleaner and easier to use. I also added asynchronous event streaming capabilities to improve performance and allow for processing millions of records. Streaming also allows for sending processed records to alternate storage (like a DB, file, call another web endpoint, etc)

I added functionality for partial templates allowing for templates to be embedded and re-used. Like for addresses, line items on an order, shipping options, etc.