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    phantom-page-eval

    1.2.0 • Public • Published

    phantom-page-eval

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    Evaluate a script function on a page with PhantomJS

    This module let you evaluate a script function on a page using PhantomJS and get the return value of the evaluation in node.

    Usage

    <!-- sample.html -->
    <!DOCTYPE html>
    <html lang="en">
    <head>
      <meta charset="UTF-8">
      <title>Test page</title>
    </head>
    <body>
      <div class="content">1</div>
      <div class="content">2</div>
      <div class="content">3</div>
      <div class="content">4</div>
    </body>
    </html>
    const phantomPath = require('phantomjs').path
    const phantomPageEval = require('phantom-page-eval')
    const phantomEval = phantomPageEval({ phantomPath })
     
    (async () => {
      try {
        const result = await phantomEval({
          html: '/path/to/sample.html',
          scriptFn: `
            function () {
              var title = document.title
              var content = Array.prototype.slice.call(document.getElementsByClassName('content'))
     
              content = content.map(function (node) {
                return node.textContent
              })
     
              return {
                title: title,
                content: content
              }
            }
          `
        })
     
        console.log(result.title) // -> Test page
        console.log(result.content) // -> [1, 2, 3, 4]
      } catch (e) {
        console.error('Error while trying to evaluate script:', e)
      }
    })()

    Constructor options

    const phantomPageEval = require('phantom-page-eval')
    const phantomEval = phantomPageEval({ /*[constructor options here]*/ })
    • phantomPath string [required] - the path to the phantomjs executable that your app is going to use
    • tmpDir string - the directory path that the module is going to use to save temporary files needed during the evaluation. defaults to require('os').tmpdir()
    • clean boolean - specifies if the module should delete any temp file automatically after an evaluation, if false temp files will not be cleaned by the module and app developer will be responsible to clean them. defaults to true
    • launchArgs array - array with any of the command line options supported by phantomjs. defaults to ['--ignore-ssl-errors=yes', '--web-security=false', '--ssl-protocol=any']

    Evaluate options

    const phantomPath = require('phantomjs').path
    const phantomPageEval = require('phantom-page-eval')
    const phantomEval = phantomPageEval({ phantomPath })
     
    (async () => {
      const result = await phantomEval({ /*[evaluate options here]*/ })
    })()
    • html string [required] - the path to the html file to load in a phantom page
    • scriptFn string [required] - the script to evaluate in the phantom page. the script must be a function that returns a value. ex: scriptFn: 'function () { return 1 + 2}'
    • viewport object - object with any of the viewportSize options supported by phantomjs
    • args array - a list of custom arguments to pass to the scriptFn function. ex: args: [1, 2] and with scriptFn: function (a, b) { return a + b}' will produce 3 as result
    • timeout number - time in ms to wait for the script evaluation to complete, when the timeout is reached the evaluation is cancelled. defaults to 30000

    Requirements

    • Have available a phantomjs executable. you can download phantomjs and get access to the path to the executable by doing: npm install phantomjs --save or npm install phantomjs-prebuilt --save and then in your project call require('phantomjs').path and pass it to phantom-page-eval constructor function.

    Caveats

    • What you return in your script function (scriptFn option) must be a serializable value recognized by phantomjs in order to receive it properly (normal javascript primitives like object, arrays, string, booleans, etc are good), if a non serializable value is returned you will get undefined as the result.

    Debugging

    • To get more information (internal debugging logs of the module) about what's happening during the evaluation on the page start your app in this way: DEBUG=phantom-page-eval* node [your-entry-file-here].js (on Windows use set DEBUG=phantom-page-eval* && node [your-entry-file-here].js). This will print out to the console some additional information about what's going on.

    License

    See license

    Install

    npm i phantom-page-eval

    DownloadsWeekly Downloads

    822

    Version

    1.2.0

    License

    MIT

    Unpacked Size

    27.8 kB

    Total Files

    14

    Last publish

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