Constructing repeated functions - php

Question

I've created the following function to print HTML tags in PHP.
function div($attr = [], $child = []) {
$div = "<div";
if (is_array($attr)) {
foreach ($attr as $key => $value) {
$div .= " " . $key . '="' . $value . '"';
}
}
$div .= ">";
if (is_array($child)) {
foreach ($child as $value) {
$div .= $value;
}
}
$div .= "</div>";
return $div;
}
echo div(["class" => "container"], [
div(["class" => "title"], ["Lorem Ipsum"]])
]);
Now, I use this function with multiple tags; div, table, tr, td, etc.
For each tag, I declare the function over and over again with little modification in the body. This seems redundant. I want to create a main function which will return the actual function. For example,
$div = construct("div");
$tr = construct("div");
Of course, PHP is different than JS. In JS, this would work:
function construct(tagName) {
var elm = tagName;
return function(value) {
console.log(elm + ": " + value);
}
}
var div = construct("div");
var tr = construct("tr");
div("test"); // div: test
tr("test"); // tr: test
How should I proceed?

Answer 1

Similar actually as in js:
Just use the first argument of the function to pass the element type as a string.
function construct($elem, $attr = [], $child = []) {
$out = "<".$elem;
if (is_array($attr)) {
foreach ($attr as $key => $value) {
$out .= " " . $key . '="' . $value . '"';
}
}
$out .= ">";
if (is_array($child)) {
foreach ($child as $value) {
$out .= $value;
}
}
$out .= "</".$elem.">";
return $out;
}
echo construct("div",["class" => "container"], [
div(["class" => "title"], ["Lorem Ipsum"]])
]);

Answer 2

You could pass the type of tag through a parameter of the function.
function ConstrucElement($tag, $attr, $body)
{
$output = '<' . $tag;
....
$output .= '</' . $tag . '>';
}

Answer 3

This is how I would solve the problem at hand:
function element($elementName, $attr = [], $child = []) {
$element = "<" . $elementName;
...
return $element;
}
function div($attr = [], $child = []) {
return element("div", $attr, $child);
}
This has the additional benefit of enabling element specific validations etc.: (pseudocode)
function a($attr = [], $child = []) {
if(attr contains no href) return ERROR;
return element("div", $attr, $child);
}

Answer 4

Doing some more digging, I figured out a way to make it work the JS way. The use of use in the examples in PHP: Closure - Manual did the job.
function construct($tag_name = "") {
return function($attr = [], $child = []) use ($tag_name) {
$element = "<$tag_name";
if (is_array($attr)) {
foreach ($attr as $key => $value) {
$element .= " " . $key . '="' . $value . '"';
}
}
$element .= ">";
if (is_string($child)) {
$element .= $child;
}
if (is_array($child)) {
foreach ($child as $value) {
$element .= $value;
}
}
$element .= "</$tag_name>";
return $element;
};
}
$h2 = construct("h2");
$span = construct("span");
$div = construct("div");
$table = construct("table");
$tr = construct("tr");
$td = construct("td");
Using a generic function to print the tags seems like a more practical approach, but not that desirable, because the code gets harder to read. Compare the following blocks.
while ($row = $albums->fetch_assoc()) {
echo $div(["class" => "album"], [
$h2([], [$row["album"] . " (" . $row["year"] . ")"]),
$div(["class" => "album-cover"], [
img(["src" => "covers/" . $row["cover"]]),
]),
$div(["class" => "songs"], [
$table([], [
loop_songs($row["album"]),
]),
]),
]);
}
while ($row = $albums->fetch_assoc()) {
echo construct("div", ["class" => "album"], [
construct("h2", [], [$row["album"] . " (" . $row["year"] . ")"]),
construct("div", ["class" => "album-cover"], [
construct("img", ["src" => "covers/" . $row["cover"]]),
]),
construct("div", ["class" => "songs"], [
construct("table", [], [
loop_songs($row["album"]),
]),
]),
]);
}
First one seems more readable to me.

Answer 5

Here's another approach using __callStatic:
So now you can build your HTML with these:
Build::div(...)
Build::span(...)
Build::table(...)
Like this:
<?php
class Build {
public static function __callStatic($name, $arguments) {
$attr = $arguments[0];
$child = $arguments[1];
$div = "<" . $name;
if (is_array($attr))
foreach ($attr as $key => $value)
$div .= " " . $key . '="' . $value . '"';
$div .= ">";
if (is_array($child))
foreach ($child as $value)
$div .= $value;
$div .= "</" . $name . ">";
return $div;
}
}
echo Build::div(["class" => "container"], [
Build::span(["class" => "title"], ["Lorem Ipsum"])
]);
Output:
<div class="container"><span class="title">Lorem Ipsum</span></div>