href="data:image/svg+xml;base64,@FAVICON@" />
<title>
- CharmBypass: it's transit equity y'all
+ CharmBypass: got that transit equity
</title>
<style>
+ body {
+ /* For consistency with the SVG */
+ font-family: sans-serif;
+ }
+
fieldset {
margin-top: 1em;
padding-top: 1em;
font-weight: bold;
}
+ /* Display form errors for the one browser that doesn't support
+ * them natively, mobile Firefox. We use "visibility" to toggle
+ * it on and off, but "display" to hide it completely in non-
+ * stupid web browsers. */
+ #marc-form-errors {
+ color: #a00;
+ visibility: hidden;
+ display: none;
+ }
+
svg {
/* Set the height to 100% of the screen, which we'll keep; and the
* initial position to (0,0), which we're going to change
<body>
<div id="menu">
<h1>CharmBypass</h1>
- <h2>it's transit equity y'all</h2>
+ <p><strong>got that <em>transit equity</em></strong></p>
- <p>
- <em>Hint:</em> If you think the driver or fare inspector will
- actually check it, the daily security code is the same on a
- $2.00 BaltimoreLink ticket as it is on a $9.00 MARC Train
- ticket. It's also the same on your friend's phone, or for
- anyone else in Maryland that day.
- </p>
+ <ol>
+ <li>
+ <a href="https://michael.orlitzky.com/articles/charmbypass_pt._1%3A_introducing_charmbypass.xhtml">
+ Introduction
+ </a>
+ </li>
+ </ol>
<form>
<fieldset>
pattern="[a-zA-Z0-9]*" />
</div>
- <p>Zone:</p>
+ <p>
+ Zone<sup>†</sup>:
+ </p>
<div>
<input type="radio" required
name="zone"
<label for="zone2">Zone 2</label>
</div>
<div>
- <input type="radio" required
+ <input type="radio" required checked
name="zone"
id="zone3"
value="Zone 3" />
</div>
<input type="submit" name="go" value="Generate Ticket" />
+
+ <p>
+ <sup>†</sup>
+ On the MTA's PDF schedule for your route
+ </p>
</fieldset>
</form>
<form>
<p>Origin:</p>
<div>
- <input type="radio" required
+ <input type="radio" required checked
name="origin"
id="origin1"
value="BAL" />
<label for="destination6">Seabrook (Penn Line)</label>
</div>
<div>
- <input type="radio" required
+ <input type="radio" required checked
name="destination"
id="destination7"
value="WAS" />
<label for="destination8">West Baltimore (Penn Line)</label>
</div>
+ <p id="marc-form-errors">OK</p>
+
<input type="hidden" name="serviceid" value="R" />
<input type="hidden" name="servicename" value="MARC Train" />
- <input type="submit" name="go" value="Generate Ticket" />
+ <input type="submit"
+ name="go"
+ id="marc-submit"
+ value="Generate Ticket" />
</fieldset>
</form>
</div>
* Compute the zone (string) for the given origin/destination pair.
*
* If we don't know it or if you chose in invalid pair (destination
- * not on the same line as your origin?) then the empty string is
- * returned.
+ * not on the same line as your origin?) then null is returned.
*/
function compute_marc_zone(src, dest) {
- /* Sorted on the first component, then the second */
+ /* Sorted on the first component, then the second.
+ *
+ * Key:
+ *
+ * $6.00 => 1
+ * $7.00 => 2
+ * $8.00 => 3
+ * $9.00 => 4
+ */
const zone_map = {
BAL_BWE: 2,
BAL_BWI: 1,
BAL_SEB: 3,
BAL_WAS: 4,
BAL_WBL: 1,
- BCA_CPK_: 3,
- BCA_WAS_: 4,
+ BCA_CPK: 3,
+ BCA_WAS: 4,
BWE_BWI: 1,
BWE_SEB: 1,
BWE_WAS: 2,
BWE_WBL: 2,
+ BWI_SEB: 2,
BWI_WAS: 3,
- BWI_WBL: 1
+ BWI_WBL: 1,
+ SEB_WAS: 1,
+ SEB_WBL: 3,
+ WAS_WBL: 4
};
/* Forward direction key for zone_map */
case 4:
return "Four Zone";
default:
- return "";
+ return null;
}
}
const dest = params.get("destination");
if (src && dest) {
- /* MARC Train */
+ /* MARC Train. We can assume that compute_marc_zone() doesn't
+ * return null because that's part of our form validation. */
const zone = compute_marc_zone(src, dest);
set_zone(zone);
}
menu.style.display = "none";
}
+ /**
+ * Determine if the user agent is mobile Firefox.
+ */
+ function ua_is_mobile_ff() {
+ const ua = navigator.userAgent.toLowerCase();
+ return (ua.includes("firefox") && ua.includes("mobile"));
+ }
+
+ /**
+ * Validate the MARC form's origin/destination.
+ *
+ * We don't want the user to be able to choose a pair of stops that
+ * aren't actually connected by the same MARC line. If we don't have
+ * zone information for the (origin,destination) pair, that indicates
+ * that it's probably not a valid choice; otherwise I would have
+ * filled in the information from the CharmPass app already.
+ *
+ * All browsers except mobile Firefox let us call setCustomValidity()
+ * to provide an error message that is displayed if the user tries
+ * to submit invalid choices. But amazingly, mobile Firefox does not:
+ *
+ * https://bugzilla.mozilla.org/show_bug.cgi?id=1510450
+ *
+ * Instead we have to work around it (in that one browser) by
+ * showing/hiding a paragraph that we fill with the errors.
+ */
+ function validate_origin_destination(event) {
+ const origins = document.getElementsByName("origin");
+ const destinations = document.getElementsByName("destination");
+ const mfe = document.getElementById("marc-form-errors");
+ const marcsubmit = document.getElementById("marc-submit");
+
+ if (ua_is_mobile_ff()) {
+ /* Even though this is only for one browser, empty paragraphs
+ * are handled inconsistently and should be avoided as a rule.
+ * So, we make it say "OK" before we hide it. */
+ mfe.textContent = "OK";
+ mfe.style.visibility = "hidden";
+ marcsubmit.disabled = false;
+ }
+
+ let src = null;
+ let dest = null;
+ origins.forEach((x) => { if (x.checked) src = x; })
+ destinations.forEach((x) => {
+ if (x.checked) dest = x;
+
+ /* clear all errors before possibly setting one */
+ x.setCustomValidity('');
+ })
+
+ if (src.value === dest.value) {
+ let err = "Origin and destination are the same";
+ dest.setCustomValidity(err);
+
+ if (ua_is_mobile_ff()) {
+ mfe.textContent = err;
+ mfe.style.visibility = "visible";
+ marcsubmit.disabled = true;
+ }
+ }
+ else if (compute_marc_zone(src.value, dest.value) === null) {
+ let err = "Origin and destination are on different lines";
+ dest.setCustomValidity(err);
+
+ if (ua_is_mobile_ff()) {
+ mfe.textContent = err;
+ mfe.style.visibility = "visible";
+ marcsubmit.disabled = true;
+ }
+ }
+ }
/*****************************************************/
/* Add event handlers for all of the functions above */
/* Swap colors when the screen is tapped */
document.body.addEventListener("click", swap_day_night);
}
+ else {
+ /* If we haven't submitted the form yet, set up change handlers
+ * for the origin/destination radio buttons that validate that
+ * the origin and destination are on the same line. */
+ document.getElementsByName("origin").forEach(
+ (x) => x.addEventListener("change", validate_origin_destination)
+ );
+ document.getElementsByName("destination").forEach(
+ (x) => x.addEventListener("change", validate_origin_destination)
+ );
+
+ /* Also do it when the page loads, because firefox likes to
+ * remember your selection even after the page reloads. */
+ window.addEventListener("load", validate_origin_destination);
+
+ /* Finally, we have to babysit mobile Firefox, who doesn't
+ * support HTML5 form validation going into 2024. Turn on
+ * the little form errors paragraph so we can toggle its
+ * visibility (and make it display the error) when the user
+ * makes an invalid selection. */
+ window.addEventListener("load", () => {
+ if (ua_is_mobile_ff()) {
+ const mfe = document.getElementById("marc-form-errors");
+ mfe.style.display = "block";
+ }
+ });
+ }
</script>
</body>
projects / charm-bypass.git / blobdiff