51Degrees Pipeline PHP  4.1

51Degrees Pipeline for PHP

CustomFlowElement.php

This example demonstrates the creation of a custom flow element. In this case the FlowElement takes the results of a client side form collecting date of birth, setting this as evidence on a FlowData object to calculate a person's starsign. The FlowElement also serves additional JavaScript which gets a user's geolocation and saves the latitude as a cookie. This latitude is also then passed in to the FlowData to calculate if a person is in the northern or southern hemispheres.

<?php
/* *********************************************************************
* This Original Work is copyright of 51 Degrees Mobile Experts Limited.
* Copyright 2019 51 Degrees Mobile Experts Limited, 5 Charlotte Close,
* Caversham, Reading, Berkshire, United Kingdom RG4 7BY.
*
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* v.1.2 and is subject to its terms as set out below.
*
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*
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* clause in Article 5 of the EUPL shall not apply.
*
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* including the attribution notice(s) required under Article 5 of the EUPL
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include(__DIR__ . "/../vendor/autoload.php");
// Function to get star sign from month and day
function getStarSign($month, $day)
{
if (($month == 1 && $day <= 20) || ($month == 12 && $day >= 22)) {
return "capricorn";
} elseif (($month == 1 && $day >= 21) || ($month == 2 && $day <= 18)) {
return "aquarius";
} elseif (($month == 2 && $day >= 19) || ($month == 3 && $day <= 20)) {
return "pisces";
} elseif (($month == 3 && $day >= 21) || ($month == 4 && $day <= 20)) {
return "aries";
} elseif (($month == 4 && $day >= 21) || ($month == 5 && $day <= 20)) {
return "taurus";
} elseif (($month == 5 && $day >= 21) || ($month == 6 && $day <= 20)) {
return "gemini";
} elseif (($month == 6 && $day >= 22) || ($month == 7 && $day <= 22)) {
return "cancer";
} elseif (($month == 7 && $day >= 23) || ($month == 8 && $day <= 23)) {
return "leo";
} elseif (($month == 8 && $day >= 24) || ($month == 9 && $day <= 23)) {
return "virgo";
} elseif (($month == 9 && $day >= 24) || ($month == 10 && $day <= 23)) {
return "libra";
} elseif (($month == 10 && $day >= 24) || ($month == 11 && $day <= 22)) {
return "scorpio";
} elseif (($month == 11 && $day >= 23) || ($month == 12 && $day <= 21)) {
return "sagittarius";
}
};
class AstrologyFlowElement extends FlowElement
{
// datakey used to categorise data coming back from this
// FlowElement in a Pipeline
public $dataKey = "astrology";
// The processInternal function is the core working of a FlowElement.
// It takes FlowData, reads evidence and returns data.
public function processInternal($FlowData)
{
$result = [];
// Get the date of birth from the query string (submitted through
// a form on the client side)
$dateOfBirth = $FlowData->evidence->get("query.dateOfBirth");
if ($dateOfBirth) {
$dateOfBirth = explode("-", $dateOfBirth);
$month = $dateOfBirth[1];
$day = $dateOfBirth[2];
$result["starSign"] = getStarSign($month, $day);
}
// Serve some JavaScript to the user that will be used to save
// a cookie with the user's latitude in it
$result["getLatitude"] = "navigator.geolocation.getCurrentPosition(function(position) {
document.cookie = \"latitude=\" + position.coords.latitude;
loadHemisphere();
});";
// Get the latitude from the above cookie
$latitude = $FlowData->evidence->get("cookie.latitude");
// Calculate the hemisphere
if ($latitude) {
$result["hemisphere"] = $latitude > 0 ? "Northern" : "Southern";
}
$data = new ElementDataDictionary($this, $result);
$FlowData->setElementData($data);
}
public $properties = array(
"starSign" => array(
"type" => "string",
"description" => "the user's starsign"
),
"hemisphere" => array(
"type" => "string",
"description" => "the user's hemisphere"
),
"getLatitude" => array(
"type" => "javascript",
"description" => "JavaScript used to get a user's latitude"
)
);
public function getEvidenceKeyFilter()
{
// A filter (in this case a basic list) stating which evidence
// the FlowElement is interested in
return new BasicListEvidenceKeyFilter(["cookie.latitude", "query.dateOfBirth"]);
}
}
// Add some callback settings for the page to make a request with extra evidence from the client side, in this case the same url with an extra query string.
$javascriptBuilderSettings = array(
"host" => "localhost:3000",
"protocol" => "http",
"endpoint" => "/?json"
);
// Make the Pipeline and add the element we want to it
$Pipeline = (new PipelineBuilder(["javascriptBuilderSettings"=>$javascriptBuilderSettings]))->add(new AstrologyFlowElement())->build();
$FlowData = $Pipeline->createFlowData();
// Add any information from the request (headers, cookies and additional
// client side provided information)
$FlowData->evidence->setFromWebRequest();
// Process the FlowData
$FlowData->process();
// The client side JavaScript calls back to this page
if (isset($_GET["json"])) {
header("Content-Type: application/json; charset=UTF-8");
echo json_encode($FlowData->jsonbundler->json);
return;
}
// Generate the HTML for the form that gets a user's starsign
$output = "";
$output .= "<h1>Starsign</h1>";
$output .= "<form><label for='dateOfBirth'>Date of birth</label><input type='date' name='dateOfBirth' id='dateOfBirth'><input type='submit'></form>";
// Add the results if they're available
if ($FlowData->astrology->starSign) {
$output .= "<p>Your starsign is " . $FlowData->astrology->starSign . "</p>";
}
$output .= "<div id='hemispheretext'>";
if ($FlowData->astrology->hemisphere) {
$output .= "<p>Look at the " . $FlowData->astrology->hemisphere . " hemisphere stars tonight!</p>";
}
$output .= "</div>";
$output .= "<script>";
// This function will fire when the JSON data object is updated
// with information from the server.
// The sequence is:
// 1. Response contains JavaScript property 'getLatitude' that gets executed on the client
// 2. This triggers another call to the webserver that passes the location as evidence
// 3. The web server responds with new JSON data that contains the hemisphere based on the location.
// 4. The JavaScript integrates the new JSON data and fires the onChange callback below.
$output .= $FlowData->javascriptbuilder->javascript;
$output .= 'loadHemisphere = function() {
fod.complete(function (data) {
if(data.astrology.hemisphere) {
var para = document.createElement("p");
var text = document.createTextNode("Look at the " +
data.astrology.hemisphere + " hemisphere stars tonight");
para.appendChild(text);
var element = document.getElementById("hemispheretext");
var child = element.lastElementChild;
while (child) {
element.removeChild(child);
child = element.lastElementChild;
}
element.appendChild(para);
}
})};';
$output .= "</script>";
// Return the full output to the page
echo $output;