Package Exports

json-path-processor

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (json-path-processor) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

json-path-processor

JsonPathProcessor (JPP) - A common data processor target to process data without running try catch hell.

Install

npm install json-path-processor

Features

Chainning
Iterate objects by simplified JSONPath
Catch all throwed error automatically

Usage

var jpp = require('json-path-processor');

// I wanna update all product title
data = jpp(data).each('product', function (J) {
    return J.set('title', something()).value();
}).value();

// Ya, handle all product title and promotion description
// almost all jpp methods are chainable
data = jpp(data).each('extra.promotion', function (J) {
    return J.set('description', somevalue).value();
}).each('product', function (J) {
    return J.set('title', somevalue).value();
}).value();

API document

jpp(data) : create the JPP chainning object by data.
.value(path) : get the value(s) by JSON path. This is the only method can not be chainned. when path is undefined, get whole data.
`.get(path): get new JPP object by JSON path. All chainned methods on this is different from root object.
.set(path, value) : set new value by JSON path.
.each(path, function (value, key) {...}) : JPP wraped version of _.each(), the callback arguments are: value, index|key. The return value of callback will be assigned back to JPP object.
.forIn(path, function (value, key) {...}) : JPP wraped version of _.forIn(), the callback arguments are: value, index|key. The return value of callback will be assigned back to JPP object.

Supported JSON Path

We only support absolute JSON Path and only receive one item.

$ : refer to self
$.foo.bar : refer to foo then bar key
$.foo.3.bar : refer to foo then 4th array item then bar key

The long version of the story

All our life is to handle data....with a loop. Let's start from a basic loop:

for (I in data) {
    data[I] = something(data[I]);
}

To make jslint happy or ensure the loop correct, we should add property check:

for (I in data) {
    if (data.hasOwnProperty(I)) {
        data[I] = something(data[I]);
    }
}

In real life, data is not always ready. We must handle none data case:

if (data && is_object(data)) {
    for (I in data) {
        if (data.hasOwnProperty(I)) {
            data[I] = something(data[I]);
        }
    }
}

Furthermore, please catch something() because they may throw some error.

if (data && is_object(data)) {
    for (I in data) {
        if (data.hasOwnProperty(I)) {
            try {
                data[I] = something(data[I]);
            } catch (E) {
                handle_error(E);
            }
        }
    }
}

The more assign in the loop, the more try/catch you need.

if (data && is_object(data)) {
    for (I in data) {
        if (data.hasOwnProperty(I)) {
            try {
                data[I].title = something(data[I].title);
            } catch (E) {
                handle_error(E);
            }
            try {
                data[I].desciption = something(data[I].description);
            } catch (E) {
                handle_error(E);
            }
            try {
                data[I].url = something(data[I].url);
            } catch (E) {
                handle_error(E);
            }
        }
    }
}

The loop becomes a nightmare now, right? Let's use lodash to reduce indents in the loop:

_(data).each(function(V) {
    try {
        V.title = something(V.title);
    } catch (E) {
        handle_error(E);
    }
    try {
        V.desciption = something(V.description);
    } catch (E) {
        handle_error(E);
    }
    try {
        V.url = something(V.url);
    } catch (E) {
        handle_error(E);
    }
});

But, lodash still can not reduce the try/catch hell for you. Now, JsonPathProcessor help on this!