Inspector error when tagging non-English Wikipedia article

[1ec5]

When a feature has wikipedia set to a non-English article, the inspector is unable to display the article’s excerpt and then fails to show any explicitly tagged image.

Example

This forum post by @nafergo gives the Algoso Castle as an example:

Diagnosis

The feature is tagged wikipedia=pt:Castelo_de_Algoso. This is a perfectly valid tag for the feature (although I would’ve used spaces instead of underscores). wikipedia=* should always begin with a language code prefix. Unfortunately, when sniffing out the Wikipedia link, the inspector sees wikipedia=*, as opposed to wikipedia:xy=*, and assumes it’s in English:

https://github.com/OpenHistoricalMap/ohm-inspector/blob/bf1f3c38dc967a86aa3cdfb5531dc56c4b91a300/openhistoricalmap-inspector.js#L550-L554

Then it asks the English Wikipedia’s API for the article titled “pt:Castelo_de_Algoso”:

https://github.com/OpenHistoricalMap/ohm-inspector/blob/bf1f3c38dc967a86aa3cdfb5531dc56c4b91a300/openhistoricalmap-inspector.js#L601

• Actual: https://en.wikipedia.org/w/api.php?action=query&prop=extracts&exsentences=2&exlimit=1&format=xml&explaintext=true&exintro=true&origin=*&titles=pt:Castelo_de_Algoso
• Expected: https://pt.wikipedia.org/w/api.php?action=query&prop=extracts&exsentences=2&exlimit=1&format=xml&explaintext=true&exintro=true&origin=*&titles=Castelo_de_Algoso

Since the English and Portuguese Wikipedias happen to be on the same server farm, it obliges by returning an interwiki redirect, but it doesn’t have access to the Portuguese Wikipedia database in order to return an extract. Nevertheless, the inspector assumes there is an extract in the response:

https://github.com/OpenHistoricalMap/ohm-inspector/blob/bf1f3c38dc967a86aa3cdfb5531dc56c4b91a300/openhistoricalmap-inspector.js#L607

This results in an uncaught JavaScript error:

Uncaught TypeError: can't access property "textContent", (new DOMParser()).parseFromString(...).getElementsByTagName(...)[0] is undefined
    onload openhistoricalmap-inspector.js:607
    value openhistoricalmap-inspector.js:605
    value openhistoricalmap-inspector.js:331
    value openhistoricalmap-inspector.js:77
    onload openhistoricalmap-inspector.js:102
    value openhistoricalmap-inspector.js:98
    value openhistoricalmap-inspector.js:87
    value openhistoricalmap-inspector.js:64
    n index-32cceb42370ca13698403957a382becf901b1bd43a49db62b2e9b610b78298b1.js:1
    o index-32cceb42370ca13698403957a382becf901b1bd43a49db62b2e9b610b78298b1.js:1
    i index-32cceb42370ca13698403957a382becf901b1bd43a49db62b2e9b610b78298b1.js:1
    i index-32cceb42370ca13698403957a382becf901b1bd43a49db62b2e9b610b78298b1.js:1
    setInterval handler*r index-32cceb42370ca13698403957a382becf901b1bd43a49db62b2e9b610b78298b1.js:1
    addOpenHistoricalMapTimeSlider index-32cceb42370ca13698403957a382becf901b1bd43a49db62b2e9b610b78298b1.js:1
    load index-32cceb42370ca13698403957a382becf901b1bd43a49db62b2e9b610b78298b1.js:1
    run index-32cceb42370ca13698403957a382becf901b1bd43a49db62b2e9b610b78298b1.js:11
    load index-32cceb42370ca13698403957a382becf901b1bd43a49db62b2e9b610b78298b1.js:11
    <anonymous> index-32cceb42370ca13698403957a382becf901b1bd43a49db62b2e9b610b78298b1.js:1
    c application-1db896435e361ddc9564449bac4adc0cf20096cf4759b3febd4e9c27af35866b.js:12
    p application-1db896435e361ddc9564449bac4adc0cf20096cf4759b3febd4e9c27af35866b.js:12
    setTimeout handler*Deferred/then/r/< application-1db896435e361ddc9564449bac4adc0cf20096cf4759b3febd4e9c27af35866b.js:12
    u application-1db896435e361ddc9564449bac4adc0cf20096cf4759b3febd4e9c27af35866b.js:12
    fireWith application-1db896435e361ddc9564449bac4adc0cf20096cf4759b3febd4e9c27af35866b.js:12
    fire application-1db896435e361ddc9564449bac4adc0cf20096cf4759b3febd4e9c27af35866b.js:12
    u application-1db896435e361ddc9564449bac4adc0cf20096cf4759b3febd4e9c27af35866b.js:12
    fireWith application-1db896435e361ddc9564449bac4adc0cf20096cf4759b3febd4e9c27af35866b.js:12
    ready application-1db896435e361ddc9564449bac4adc0cf20096cf4759b3febd4e9c27af35866b.js:12
    d application-1db896435e361ddc9564449bac4adc0cf20096cf4759b3febd4e9c27af35866b.js:11
    EventListener.handleEvent* application-1db896435e361ddc9564449bac4adc0cf20096cf4759b3febd4e9c27af35866b.js:12
    <anonymous> application-1db896435e361ddc9564449bac4adc0cf20096cf4759b3febd4e9c27af35866b.js:11
    <anonymous> application-1db896435e361ddc9564449bac4adc0cf20096cf4759b3febd4e9c27af35866b.js:11
openhistoricalmap-inspector.js:607:33

The error prevents any subsequent code from running. This feature happens to have an unnecessary, redundant wikipedia:pt=* tag, but the following code is never reached:

https://github.com/OpenHistoricalMap/ohm-inspector/blob/bf1f3c38dc967a86aa3cdfb5531dc56c4b91a300/openhistoricalmap-inspector.js#L555-L559

It also has an image=* tag, but that code is never reached either.