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NEH Institute materials

July 2022

Steps toward minimal functional search

Hugh: Clone, build, install

Clone https://github.com/Pittsburgh-NEH-Institute/06-controller (hopefully you already did this in the first session; if you did, do git pull).
cd into the repo and type ant to build
Make sure eXist-db is started (if it is running, don’t start a second instance!), open it, log in as userid “admin”, open the package manager, and install the new repo that you just built.
Switch to the launcher and launch “My amazing 06-controller application”. You’ll see an error message; this is correct, and we fix it in the next step.
Edit the browser address bar to read <http://localhost:8080/exist/apps/06-controller/titles>. If you see a list of titles, put up your green sticky note. If you don’t, put up your red sticky note.
We’re going to work in VS Code and sync to eXist. Open the 06-controller directory in VS Code (hint: if you’re on a Mac, do View -> Command Palette…, start typing “shell”, and then choose “Install ‘code’ command in PATH, then you can open folders from the terminal by typing code <directory_name>). You will need to start synchronization (lower right status bar, where it says “Off”).

If you built and installed this repo earlier, just install the new one over the old one.

David: `contains()` and `matches()`

Practice contains() and matches() in eXide:

declare namespace tei="http://www.tei-c.org/ns/1.0";
collection('/db/apps/06-controller/data/hoax_xml')/descendant::tei:TEI[contains(., 'constable')]

Issue: contains() is case-sensitive.
Solution: matches() can (optionally) be case-insensitive.
Bonus: matches() can match patterns, and not just literal strings.

declare namespace tei="http://www.tei-c.org/ns/1.0";
collection('/db/apps/06-controller/data/hoax_xml')/descendant::tei:TEI[matches(., 'constable', 'i')]

Hugh: Add `request:get-parameter()` to retrieve search term

declare variable $term as xs:string := request:get-parameter('term','');
declare variable $articles-coll := collection($path-to-data || '/hoax_xml');
declare variable $articles as element(tei:TEI)* := $articles-coll/tei:TEI[matches(., $term, 'i')];

Test by specifying parameter in browser address bar:

http://localhost:8080/exist/apps/06-controller/titles?term=constable

See how contains() and matches() differ.

David: Create form in view to accept user input

<form action="titles" method="get">
    <input id="term" name="term" placeholder="[Search term]"/>
    <input id="submit" type="submit" value="Submit"/>
 </form>

What happens when there’s no search term?
How do you reset the form?

Hugh: Improve the form

The input field and buttons are too close to one another

<head>
    <title>Article titles</title>
    <style>
        input 
    </style>
</head>

What should happen if no results are found?

{
if ($data//descendant::m:title) (: Are there any titles? :)
then (: If there are, show them :)
    <ul>{
        for $title in $data/descendant::m:title
        order by $title
        return <li>{$title ! string()}</li>
    }</ul>
else (: If not, say something user-friendly :)
    <p>No matching articles found.</p>}

How can we clear the input field?

<form action="titles" method="get">
    <input id="term" name="term" placeholder="[Search term]" value="{request:get-parameter('term','')}"/>
    <input id="submit" type="submit" value="Submit"/>
    <button id="clear-form" onclick="document.getElementById('term').value='';">Reset</button>
</form>

Hmm … why doesn’t <input type="reset"/> do what we think it does? Why do we need <button> with onclick instead?