findElement — Find matching elements in an htmlTree object.

findElement(tree, selector) searches a RunMat htmlTree object and returns matching subtrees as a column cell array of scalar htmlTree objects.

Syntax

subtrees = findElement(tree, selector)

Inputs

Returns

Errors

How findElement works

• tree must be a scalar RunMat htmlTree object or a cell array of htmlTree objects.
• selector must be a string scalar or character vector.
• Numeric, logical, complex, and provider-resident inputs are not htmlTree or selector values and reject before any provider access.
• Supported selectors include element tags, *, .class, #id, [attr], [attr=value], [attr~=value], [attr|=value], [attr^=value], [attr$=value], [attr*=value], descendant combinators, child combinators (>), adjacent-sibling combinators (+), general-sibling combinators (~), comma-separated groups, :empty, :first-child, :first-of-type, and :not(...) for these supported pseudo-classes.
• Attribute names are matched case-insensitively through the parser's lowercase attribute map. Attribute values, ids, and classes use CSS-style exact, whitespace-list, dash-prefix, prefix, suffix, or substring string matching according to the selector operator.
• Sibling matching follows element siblings and ignores intervening whitespace text nodes.
• The result is a column cell array because RunMat does not yet have a first-class MATLAB object-array representation for htmlTree.
• Unsupported CSS pseudo-classes and selector forms raise an explicit error instead of silently returning partial results.
• Full CSS3 selector parity remains tracked by the broader Text Analytics compatibility issue.

GPU memory and residency

findElement traverses host-resident HTML metadata and has no provider kernel.

Examples

Find Links

tree = htmlTree("<div><a class='nav' href='/home'>Home</a><a class='nav'>Docs</a></div>");
links = findElement(tree, "a.nav");
text = extractHTMLText(links)

Expected output:

text = ["Home"; "Docs"]

Use Combinators

tree = htmlTree("<section><h1>Title</h1><p>Lead</p></section>");
lead = findElement(tree, "h1 + p")

Expected output:

`lead` is a one-element cell array containing the matching `P` subtree.

Use CSS Attribute Operators

tree = htmlTree("<div><a href='manual.pdf'>Manual</a><a href='guide.html'>Guide</a></div>");
pdfs = findElement(tree, "a[href$='.pdf']")

Expected output:

`pdfs` contains the link whose `href` ends with `.pdf`.

Use Positional Pseudo-Classes

tree = htmlTree("<section><p>Intro</p><a>First</a><a>Second</a></section>");
firstLink = findElement(tree, "a:first-of-type")

Expected output:

`firstLink` contains the first `A` element under the section.

Using findElement with coding agents

Open a RunMat example with live inputs, then ask the agent to explain how findElement changes the result.

FAQ

Related Strings functions

Open-source implementation

Unlike proprietary runtimes, every RunMat function is open-source. Read exactly how findElement is executed, line by line, in Rust.

• View the source for findElement in Rust on GitHub
• Learn how the RunMat runtime works
• Found a bug? Open an issue with a minimal reproduction.

About RunMat

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