如何在Nightmare.js中处理JSON响应

Question

Interested to know if there is a better or another way to handle URLs that contain only JSON data using Nightmare.js than using document.querySelector('*').textContent within .evaluate?

Here is an example; the external URL here contains the following which is the contents of a linked select field

{
  "baseDeliveryModelId":1,
  "county": [
     {"id": "1000706000", "label": "Çukurova", "value": "Çukurova"},
     {"id": "1000707000", "label": "Sarıçam", "value": "Sarıçam" },
     {"id": "1000922000", "label": "Seyhan", "value": "Seyhan"}, 
     {"id": "1000921000", "label": "Yüreğir","value": "Yüreğir"}
  ], 
  "listType":"DISTRICT_LIST"
}

A sample.js code to retrieve just the county data from the URL (which works fine)

const Nightmare = require('nightmare'),
    vo = require('vo'),
    nightmare = Nightmare({show: true});


function counties(city) {
    let countyUrl = `https://www.sanalmarket.com.tr/kweb/getCityDeliveryLocation.do?shopId=1&locationId=${city}&locationType=city&deliveryTypeId=0`;
    return nightmare
        .goto(countyUrl)
        .evaluate(function() {
            return (JSON.parse(document.querySelector('*').textContent)).county;
        })
        .catch(function (err) {
            console.log('Error: ', err);
        });
}


vo(function* () {    
    return yield counties('01');    
})((err, result) => {    
    if (err) return console.log(err);
    console.log(result);    
});

Note: The question is about using Nightmare.js , or using other libraries with Nightmare.js in node.js for handling JSON responses, I am fully aware and capable of using other libraries such as axios.js on their own to solve the above.

Answer 1

You don't need nightmarejs. if you can use a library that auto parse the json response for you, for example request-promise

const rp = require('request-promise');

rp({
url: 'https://www.sanalmarket.com.tr/kweb/getCityDeliveryLocation.do?shopId=1&locationId=${city}&locationType=city&deliveryTypeId=0',
json: true
}).then(function (data) {
    console.log(data.country);
})
.catch(function (err) {
    // Crawling failed...
});

Answer 2

This is how I did it, it's faster to implement, easier to remember. We can use it like this until someone creates functions like .text() and .json() .

// Initiate nightmare instance
var nightmare = Nightmare({
                show: true,
                alwaysOnTop: false
            })
            // go to a page with json response
            .goto('https://api.ipify.org/?format=json')
            .evaluate(() => {
                // since all of the text is just json, get the text and parse as json, return it.
                return JSON.parse(document.body.innerText)
            })
            .then((data) => {
             // then use it however we want
                console.log(data)
            });