webmiddle-service-jsonselect-to-virtual v0.3.0

webmiddle-service-jsonselect-to-virtual

Similar to the CheerioToVirtual service, but for JSON resources via the JSONSelect library.

Install

npm install --save webmiddle-service-jsonselect-to-virtual 

Usage

import { PropTypes, rootContext } from 'webmiddle';
import Pipe from 'webmiddle-service-pipe';
import HttpRequest from 'webmiddle-service-http-request';
import JSONSelectToVirtual, { helpers } from 'webmiddle-service-jsonselect-to-virtual';
const { elGet, elMap, elPipe } = helpers;

const MyService = ({ apiKey, query, pageNumber }) => (
  <Pipe>
    <HttpRequest
      name="rawJson"
      contentType="application/json"
      url={
        `https://api.nytimes.com/svc/search/v2/articlesearch.json` +
         `?q=${encodeURIComponent(query)}` +
        `&response-format=json&api-key=${encodeURIComponent(apiKey)}` +
        `&page=${encodeURIComponent(pageNumber)}`
      }
    />

    {({ rawJson }) =>
      <JSONSelectToVirtual
        name="searchArticles"
        from={rawJson}
      >
        <articles el=".docs > *">
            {elMap(el =>
              <article el={el}>
                <url el=".web_url">{elGet()}</url>
                <title el=".headline > .main">{elGet()}</title>
                <description el=".snippet">{elGet()}</description>
                <image
                  el=".multimedia > *"
                  condition={currEl =>
                    currEl.subtype === 'thumbnail'}
                >
                  {elPipe([
                    elGet('.url'),
                    relativeUrl => relativeUrl ?
                      `http://www.nytimes.com/${relativeUrl}`
                      : null,
                  ])}
                </image>
              </article>
            )}
        </articles>
      </JSONSelectToVirtual>
    }
  </Pipe>
);

rootContext.evaluate(
  <MyService
    apiKey="MY API KEY HERE"
    query="javascript"
    pageNumber={0}
  />
).then(resource => {
  console.log(resource.contentType); // "application/x-webmiddle-virtual"
  console.log(resource.content); // { type, attributes, children }
});

How it works

The following values can be specified as child in the virtual schema, as they will be processed in the same way of CheerioToVirtual:

• Any element that can be evaluated by means of the evaluate function.

• virtual

• array

• object

• undefined

• (default): any other value is kept as is.

Helper functions:

• elGet(selector, values): if selector is set, then it starts by querying the collection of elements with such selector. The values property is used in case the selector contains placeholders (see the JSONSelect documentation). Returns the first element of the (obtained) collection.

• elJoin(separator): plain Array join.

• elMap(callback): plain Array map, however the function is called with a collection (i.e. an array) containing the single current element.

• elPipe(tasks): plain Array reduce on the given tasks, where the initial value is the collection of elements.

Properties