N3O tag capture

Captures campaign tags from the URL into the n3o_tags cookie, which the Umbraco checkout reads and passes on to Engage.

This is transitional. It serves the sites still on the legacy Umbraco checkout; a site moving to platforms drops the script, and the package retires when the last one has moved.

What it captures

Every query parameter prefixed ntm_ or utm_, with the key kept exactly as it appears:

| URL parameter | Tag key | Tag value | | --- | --- | --- | | ntm_ad_campaign=Gaza+Emergency | ntm_ad_campaign | Gaza Emergency | | utm_source=google | utm_source | google |

The prefix is part of the tag key and is never removed. utm_ is the industry-standard set; ntm_ is N3O's own namespace, carrying the ad hierarchy the backend declares — ntm_ad_campaign, ntm_ad_group and the rest — plus any custom key built in the link builder.

Getting this wrong fails quietly rather than loudly: nothing validates the prefix on the way in, so a stripped ad_campaign is stored happily and simply never joins the ntm_ad_campaign definition. The tag is there; the reporting is not.

There is no fixed list of names, so a new parameter needs no change here. Keys are lowercased and their punctuation normalised to underscores; values are kept as they are. Tags merge as a visitor moves around the site, the newest value winning per key, and the cookie lasts 90 days.

A key longer than 200 characters, or a value longer than 2000, is skipped — those are the limits the backend enforces, and a tag breaching them would be rejected on arrival.

How to use

No configuration is required.

<script>
    (function (w, d, s, u) {
        let f = d.body.getElementsByTagName(s)[0],
            j = d.createElement(s)
        j.async = true
        j.src = u
        j.type = 'text/javascript'
        f.parentNode.insertBefore(j, f)
    })(window, document, 'script', 'https://unpkg.com/@n3oltd/link-builder/umd/n3o-tags.js')
</script>

API

window.n3o_tags:

| Member | Does | | --- | --- | | get() | Returns the stored tags as a flat object | | add(key, value) | Sets one tag; removes it when value is empty. An unprefixed key gains ntm_ | | capture() | Re-reads the current URL | | init() | Kept because cooperating sites call it on load; there is nothing to configure |

Capture runs on load and on navigation, so calling anything by hand is optional.

Links built by the old in-page link builder

Those links carry their tag values in a single base64 ea parameter, keyed by number. Such links are still in circulation — in sent emails, in ad platforms, in scheduled campaigns — and cannot be recalled, so the script still reads them: ea is decoded and each dimension becomes a tag keyed ntm_d0, ntm_d1 and so on, up to twelve.

The dimension names were held in per-subscription backend configuration that a browser script cannot see, so only the number survives. The value — the part that identifies the campaign — is preserved intact. An explicit ntm_/utm_ parameter on the same URL takes precedence over a legacy dimension of the same name.

This can be removed once links carrying ea are out of use.

#linkbuilder

The link builder UI used to render inside the page on this hash. It has been replaced by the standalone app, so the hash now redirects to https://linkbuilder.n3o.cloud/eu1/.