PSParseHTML

PSParseHTML started as a suite of data processing Cmdlets to help PSWriteHTML, but it has gained functionality enough to be its own module. Basic usage instructions are described on this blog post.

PSParseHTML exposes a suite of PowerShell cmdlets that let you parse, format and optimise web resources right from the shell. The module currently ships with eleven cmdlets:

• Convert-HTMLToText – convert markup to plain text

• ConvertFrom-HtmlTable – turn table elements into objects

• ConvertFrom-HTMLAttributes – extract elements by tag, class, id or name (aliases: ConvertFrom-HTMLTag, ConvertFrom-HTMLClass)

• ConvertFrom-HTML – parse full documents or fragments

• Format-CSS – pretty‑print style sheets

• Format-HTML – tidy up HTML markup

• Format-JavaScript – beautify JavaScript (Format-JS alias)

• Optimize-CSS – minify style sheets

• Optimize-Email – inline CSS for email bodies

• Optimize-HTML – minify HTML

• Optimize-JavaScript – minify JavaScript

Cmdlet quick start

# Convert an entire file to plain text
Convert-HTMLToText -Path '.\report.html'

# Extract all <a> tags with a specific class
ConvertFrom-HTMLAttributes -Path '.\site.html' -Class 'promo'

# Parse a snippet of markup
$doc = ConvertFrom-HTML -Content '<div>Hello</div>'

# Format a CSS style sheet
Format-CSS -Path '.\style.css'

# Beautify an HTML fragment
Format-HTML -Content $html

# Format a JavaScript file
Format-JavaScript -Path '.\script.js'

# Minify a CSS file
Optimize-CSS -Path '.\style.css'

# Inline CSS in an email body
Optimize-Email -Body $html -UseEmailFormatter

# Minify an HTML file
Optimize-HTML -Path '.\page.html'

# Minify JavaScript and save to a new file
Optimize-JavaScript -Path '.\app.js' -OutputFile '.\app.min.js'

The expected input is a string literal or data read from a file. The output can be PowerShell objects (classes are HtmlNode or AngleSharp.Html.Dom.HtmlElement depending on the selected engine) or strings written to stdout.

It may not seem like much, but those eleven cmdlets are powerful enough to enable robust HTML processing in shell.

Examples

# Parse tables from a web page
$tables = ConvertFrom-HtmlTable -Url 'https://en.wikipedia.org/wiki/PowerShell'
$tables[0] | Format-Table -AutoSize

# Inline CSS in an e-mail body and pretty print the result
$html = Optimize-Email -Body $body -RemoveComments
Format-HTML -Content $html

# Minify JavaScript from a file
Optimize-JavaScript -Path './script.js' -OutputFile './script.min.js'

# Convert HTML file to plain text
Get-Content './report.html' -Raw | Convert-HTMLToText

# Extract all product entries
$markup = Get-Content './catalog.html' -Raw
ConvertFrom-HTMLAttributes -Content $markup -Class 'product'

Installation

Install from PSGallery

Install-Module -Name PSParseHTML -AllowClobber -Force

Force and AllowClobber aren't necessary but they do skip errors in case some appear.

Update from PSGallery

Update-Module -Name PSParseHTML

That's it. Whenever there's a new version you simply run the Update-Module command and enjoy. Remember that you may need to close, re-open your PowerShell session if you had used the module prior to updating it.

As usual, remember module updates may break your scripts: if your scripts work for you in production, retain those versions until you test new versions in a dev environment. I may make small changes which are big enough so that your automated updates will break your scripts. For example, I might make a small rename to a parameter — boom, your code stops working! Be responsible!

3rd party references

This module utilizes several external dependencies to do its work. The authors of those libraries have done fantastic work — I've just added some PowerShell to the mix. All are distributed under permissive licenses:

• AngleSharp - MIT License
• AngleSharp CSS - MIT License
• AngleSharp.Js - MIT License
• AngleSharp.Diffing - MIT License
• Jsbeautifier - MIT License
• NUglify - BSD-Clause 2 license
• Html Agility Pack - MIT License
• PreMailer.Net - Apache 2.0 License

Refer to each project's repository for complete license information.

C# API overview

If you are writing your own .NET applications you can reference the compiled libraries directly. All classes live in the PSParseHTML namespace and expose methods equivalent to the cmdlets:

• HtmlParser – ParseWithAngleSharp, ParseWithHtmlAgilityPack and table extraction helpers such as ParseTablesWithAngleSharpDetailed
• HtmlParserExtensions – GetElements for quick element queries
• HtmlFormatter – FormatHtml, FormatCss, FormatJavaScript
• HtmlOptimizer – OptimizeHtml, OptimizeCss, OptimizeJavaScript
• HtmlUtilities – ConvertToText to strip markup
• PreMailerClient – methods like MoveCssInline and MoveCssInlineFromFile

These methods can be consumed from C# or directly from PowerShell. For example:

string html = File.ReadAllText("example.html");
var tables = HtmlParser.ParseTablesWithHtmlAgilityPack(html);
string pretty = HtmlFormatter.FormatHtml(html);

# PowerShell using the same API
[PSParseHTML.HtmlFormatter]::FormatHtml($html)

Both approaches yield identical results, so you can choose the most convenient tool for your workflow.