HtmlFragments.psm1
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[System.IO.DirectoryInfo]$SCRIPT:moduleDir = Split-Path -Parent $MyInvocation.MyCommand.Path [string]$SCRIPT:svgbob = Join-Path $SCRIPT:moduleDir 'svgbob.exe' # Send utf8 without BOM throught the pipe to external programs $OutputEncoding = [Text.UTF8Encoding]::new($false) # Match hyperlinks to Markdown files $SCRIPT:mdhrefRE = New-Object Regex '(?<=^<a[^>]*href=")([^"]+)\.(md|markdown)(?=["#])' <# .SYNOPSIS Convert fenced svgbob code blocks to svg images. .DESCRIPTION Scans the input data (lines of Markdown text) for svgbob fenced code blocks and converts them to a Markdown style image link to a svg file containing the rendered diagram. Svgbob code blocks define human readable diagrams and are labeled as `bob`. For example: ``` Markdown ~~~ bob +------+ .-. +---+ o----| elem |--( ; )--| n |----o +------+ '-' +---+ ~~~ ``` The generated svg file is put right next to the HTML file currently being assembled and named after that HTML file with an unique index appended. .PARAMETER SiteDirectory Location of the static HTML site. The Svg file will be generated relative to this path. .PARAMETER Options Svg conversion options. An object or hashtable with follwing properties or keys: | Property | Description | | :------------: | :------------------------------------------- | | `background` | Diagram background color (default: white) | | `fill_color` | Fill color for solid shapes (default: black) | | `font_family` | Text font (default: monospace) | | `font_size` | Text font size (default 14) | | `scale` | Diagram scale (default: 1) | | `stroke_width` | Stroke width for all lines (default: 2) | When using conversion projects instantiated by `New-StaticHTMLSiteProject` these parameters are configured in `Build.json` parameter section `svgbob`. .INPUTS HTML fragment objects emitted by `Convert-MarkdownToHTMLFragment` with the `-Split` switch or equivalent objects. .OUTPUTS Lines of Markdown text where all fenced code blocks labelled `bob` are replaced by Markdown style image links to svg files. .EXAMPLE PS> Convert-MarkdownToHTMLFragment -InputObject $md -Split | Convert-SvgbobToSvg -SiteDirectory $site -RelativePath $relativePath Read Markdown content from the file `$md` and replace all fenced code blocks marled as `bob` with Markdown style image links to the svg version of the diagram. The conversion is performed using default svg rendering options. Where `$site` : Is the **absolute path** to the HTML site's root directory `$relativePath` : is the **relative path** of the HTML file currently being assembled below `$site`. `$md` : is a Markdown file `test.md` which contains a fenced svgbob diagram: ``` Markdown Some text ... ~~~ bob +------+ .-. +---+ o----| elem |--( ; )--| n |----o +------+ '-' +---+ ~~~ Some more text ... ``` this fragment is converted to: * A file `test1.svg` which is placed right next to the html file `test.html` which is going to be created by `Publish-StaticHtmlSite` in a subsequent stage of the conversion pipeline. The numerical postfix is the index of the Svgbob diagram in the fragment. The svg image renders as: ~~~ bob +------+ .-. +---+ o----| elem |--( ; )--| n |----o +------+ '-' +---+ ~~~ * An updated html fragment where the fenced Svgbob diagram is replaced with a reference to the svg image. ~~~ html Some text ... <img src='test1.svg' alt='Diagram 1.' /> Some more text ... ~~~ .NOTES The svg conversion is performed by the external utility `svgbob.exe` which is packaged with this module. `svgbob.exe` is a [Rust](https://www.rust-lang.org/) [crate](https://doc.rust-lang.org/rust-by-example/crates.html) which can be installed from [lib.rs](https://lib.rs/crates/svgbob_cli). .LINK https://wethat.github.io/MarkdownToHtml/2.5.0/Convert-SvgbobToSvg.html .LINK [Svgbob](https://ivanceras.github.io/content/Svgbob.html) #> function Convert-SvgbobToSvg { [OutputType([hashtable])] [CmdletBinding()] param( [parameter(Mandatory=$true,ValueFromPipeline=$true)] [ValidateScript({$_.HtmlFragment})] [Alias('HtmlFragment')] [hashtable]$InputObject, [parameter(Mandatory=$true,ValueFromPipeline=$false)] [string]$SiteDirectory, [parameter(Mandatory=$false,ValueFromPipeline=$false)] [object]$Options ) Begin { # svgbob default options [string]$background = 'white' [string]$fillColor = 'black' $fontSize = 14; [string]$fontFamily = 'Monospace' $scale = 1 $strokeWidth = 2 # override with specified options if ($options) { $value=$options.background if ($value) { $background = $value } $value=$options.fill_color if ($value) { $fillColor = $value } $value=$options.font_size if ($value) { $fontSize = $value } $value=$options.font_family if ($value) { $fontFamily = $value } $value=$options.scale if ($value) { $scale = $value } $value=$options.stroke_width if ($value) { $strokeWidth = $value } } } Process { $n = 0 $bob = $null [System.IO.Fileinfo]$fullpath = Join-Path $SiteDirectory $_.RelativePath $fragment = $InputObject.HtmlFragment for($i=0; $i -lt $fragment.Count; $i++) { $itm = $fragment[$i] if ($bob -is [Array]) { if ($itm -eq '</code>') { # svgbob drawing complete $n++ $svgname = $fullpath.BaseName + "$n.svg" # replace the fenced code block by a hyperlink $fragment[$i] = "<img src='$svgname' alt='Diagram ${n}.' />" # we need to create that site directory upfront so that the # svg image can be put there if (!$fullpath.Directory.Exists) { $fullpath.Directory.Create() } $svgfullpath = Join-Path $fullpath.DirectoryName $svgname # do the conversion $bob | & $SCRIPT:svgbob -o "$svgfullpath" ` --background $background ` --fill-color $fillColor ` --font-family $fontFamily ` --font-size $fontSize ` --scale $scale ` --stroke-width $strokeWidth $bob = $null # starting over } else { $bob += [System.Net.WebUtility]::HtmlDecode($itm.TrimEnd()) $fragment[$i] = [string]::Empty } } elseif ($itm -eq '<code class="language-bob">') { $fragment[$i] = [string]::Empty $bob=@() # Enable capturing of svgbob drawing } } $InputObject } } <# .SYNOPSIS Convert Markdown text to HTML fragments. .DESCRIPTION Converts Markdown text to HTML fragments using configured [Markdown extensions](about_MarkdownToHTML.md#supported-markdown-extensions). .PARAMETER InputObject The input object can have one of the following types: * An annotated `[System.IO.FileInfo]` object as emitted by `Find-MarkdownFiles`. * A plain markdown string [`string`]. * A markdown descriptor object which is a [`hashtable`] with following contents: | Key | Value Type | Description | | :------------- | :--------- | :------------------------------------------------------------ | | `Markdown` | [`string`] | The markdown text. | | `RelativePath` | [`string`] | Relative path of the Markdown file below the input directory. | .PARAMETER IncludeExtension Comma separated list of Markdown parsing extension names. See [Markdown extensions](about_MarkdownToHTML.md#supported-markdown-extensions) for an annotated list of supported extensions. .PARAMETER ExcludeExtension Comma separated list of Markdown parsing extensions to exclude. Mostly used when the the 'advanced' parsing option is included and certain individual options need to be removed. .PARAMETER Split Split the Html fragment into an Array where each tag is in a separate slot. This somewhat simplifies Html fragment post-processing. For example the fragment ~~~ html <pre><code class="language-PowerShell">PS> Install-Module -Name MarkdownToHTML</pre></code> ~~~ is split up into the array | Index | Value | | :---: | :------------------------------------------- | | 0 | `<pre>` | | 1 | `<code class="language-PowerShell">` | | 2 | `PS> Install-Module -Name MarkdownToHTML` | | 3 | `</pre>` | | 4 | `</code>` | .INPUTS Markdown text `[string]`, Markdown file `[System.IO.FileInfo]`, or a markdown descriptor `[hashtable]`. .OUTPUTS HTML fragment object with following properties: | Property | Description | | :------------: | :------------------------------------------------------------------ | | `Title` | Optional page title. The first heading in the Markdown content. | | `HtmlFragment` | The HTML fragment string or array generated from the Markdown text. | | `RelativePath` | Passed through from the input object, provided it exists. | .NOTES The conversion to HTML fragments also includes: * Changing links to Markdown files to the corresponding Html files. ~~~ Markdown [Hello World](Hello.md) ~~~ becomes: ~~~ html <a href="Hello.html"> ~~~ * HTML encoding code blocks: ~~~ Markdown ```xml <root> <thing/> </root> ``` ~~~ becomes ~~~ HTML <pre><code class="language-xml"><root> <thing/> </root> </code></pre> ~~~ which renders as ```xml <root> <thing/> </root> ``` .EXAMPLE Convert-MarkdownToHTMLFragment -Markdown '# Hello World' Returns the HTML fragment object: Name Value ---- ----- HtmlFragment <h1 id="hello-world">Hello World</h1>... Title Hello World .EXAMPLE Convert-MarkdownToHTMLFragment -Markdown '# Hello World' -Split Returns the HTML fragment object: Name Value ---- ----- HtmlFragment {<h1 id="hello-world">,Hello World,</h1>,...} Title Hello World .EXAMPLE Get-Item -LiteralPath "Convert-MarkdownToHTML.md" | Convert-MarkdownToHTMLFragment Reads the content of Markdown file `Example.md` and returns a Html fragment object. Name Value ---- ----- Title Convert-MarkdownToHTML HtmlFragment <h1 id="convert-Markdowntohtml">Convert-MarkdownToHTML</h1>... RelativePath Convert-MarkdownToHTML.md .LINK https://wethat.github.io/MarkdownToHtml/2.5.0/Convert-MarkdownToHTMLFragment.html .LINK `Convert-MarkdownToHTML` .LINK `Convert-SvgbobToSvg` .LINK `Find-MarkdownFiles` .LINK `Publish-StaticHtmlSite` .LINK `New-HTMLTemplate` .LINK [Markdown extensions](about_MarkdownToHTML.md#supported-markdown-extensions) #> function Convert-MarkdownToHTMLFragment { [OutputType([hashtable])] [CmdletBinding()] param( [parameter(Mandatory=$true,ValueFromPipeline=$true)] [ValidateScript({$_ -is [string] -or $_ -is [System.IO.FileInfo] -or $_ -is [hashtable]})] [Alias('Markdown')] $InputObject, [parameter(Mandatory=$false,ValueFromPipeline=$false)] [string[]]$IncludeExtension = @('advanced'), [parameter(Mandatory=$false,ValueFromPipeline=$false)] [string[]]$ExcludeExtension = @(), [switch]$Split ) BEGIN { ## Determine which parser extensions to use if ($null -eq $IncludeExtension -or $IncludeExtension.Count -eq 0) { $IncludeExtension = @('common') # use _common_ extensions by default } elseif ('advanced' -in $IncludeExtension) { if ($ExcludeExtension.Count -gt 0) { $IncludeExtension = $IncludeExtension | Where-Object { $_ -ne 'advanced'} ## add the extensions explicitely so that we can remove individual ones $IncludeExtension += $SCRIPT:advancedMarkdownExtensions } elseif ($IncludeExtension.Count -gt 1) { $IncludeExtension = $IncludeExtension | Where-Object { $_ -ne 'advanced'} ## make sure the advanced option comes last $IncludeExtension += 'advanced' } } ## make sure the 'attributes' extension is last if ('attributes' -in $IncludeExtension) { $IncludeExtension = $IncludeExtension | Where-Object { $_ -ne 'attributes' } $IncludeExtension += 'attributes' } # Remove the excluded extensions $IncludeExtension = $IncludeExtension | Where-Object { $_ -notin $ExcludeExtension} # configure the converter pipeline [Markdig.MarkdownPipelineBuilder]$pipelineBuilder = (New-Object Markdig.MarkdownPipelineBuilder) Write-Verbose "Using parser extensions $IncludeExtension" $pipelineBuilder = [Markdig.MarkDownExtensions]::Configure($pipelineBuilder,[string]::Join('+',$IncludeExtension)) $pipeline = $pipelineBuilder.Build() } PROCESS { [string]$md = if ($InputObject -is [System.IO.FileInfo]) { Get-Content -LiteralPath $InputObject.FullName -Encoding UTF8 | Out-String } elseif ($InputObject -is [hashtable]) { $InputObject.Markdown } else { $InputObject } # Create HTML fragment and split it at tag level. # |----------| <- Html tag $fragment = [Markdig.Markdown]::ToHtml($md, $pipeline) -split '(<[^<>]+>)' | Where-Object { $_ } # update local markdown links to make them point to HTML for($i=0; $i -lt $fragment.Count; $i++) { $itm = $fragment[$i] if ($itm.StartsWith('<a') -and $itm -notlike '*://*') { $fragment[$i] = $SCRIPT:mdhrefRE.Replace($itm,'$1.html') } } if (!$Split) { # make it one string $fragment = $fragment -join '' } # assemble the descriptor object $htmlDescriptor = @{'HtmlFragment' = $fragment } $match = [regex]::Match($md,'^[#\s]*([^\r\n\{]+)') if ($match.Success) { $htmlDescriptor.Title = $match.Groups[1].Value } elseif ($InputObject.BaseName) { $htmlDescriptor.Title = $InputObject.BaseName } if ($InputObject.RelativePath) { $htmlDescriptor.RelativePath = $InputObject.RelativePath } elseif ($InputObject.Name) { $htmlDescriptor.RelativePath = $InputObject.Name } # return the annotated HTML fragment $htmlDescriptor } } # SIG # Begin signature block # MIIFYAYJKoZIhvcNAQcCoIIFUTCCBU0CAQExCzAJBgUrDgMCGgUAMGkGCisGAQQB # gjcCAQSgWzBZMDQGCisGAQQBgjcCAR4wJgIDAQAABBAfzDtgWUsITrck0sYpfvNR # AgEAAgEAAgEAAgEAAgEAMCEwCQYFKw4DAhoFAAQUQoV8acyUtylv7ICHMeOvOePC # FFWgggMAMIIC/DCCAeSgAwIBAgIQaejvMGXYIKhALoN4OCBcKjANBgkqhkiG9w0B # AQUFADAVMRMwEQYDVQQDDApXZXRIYXQgTGFiMCAXDTIwMDUwMzA4MTMwNFoYDzIw # NTAwNTAzMDgyMzA0WjAVMRMwEQYDVQQDDApXZXRIYXQgTGFiMIIBIjANBgkqhkiG # 9w0BAQEFAAOCAQ8AMIIBCgKCAQEArNo5GzE4BkP8HagZLFT7h189+EPxP0pmiSC5 # yi34ZctnpyFUz+Cv547+MvzAr0uRuLkxn6ArBkVLeHVAB58jenSeLwDFls5gS0I+ # pRJWO9eyyT64EcUSCMlfMLW2q1hzjfFckFR6iFnGp3TkE0s1kQANUNjAR9axC6ju # 4dpilIupCHW+/0s9aGz7LYuRQGcy3uIL9TURKdBtOsMOBeclUsEoFSEp/0D30E8r # PNk/VLu57G5H9n3HuX/DSBR2CL8LzOOv981hiS+SCds/pHqjCX9Qj+j47Kv7xZ1i # ha2fg4AEHDGbL/WJGnTpUKath+EmgmFRlsP7PgnZr4anvGdcdQIDAQABo0YwRDAO # BgNVHQ8BAf8EBAMCB4AwEwYDVR0lBAwwCgYIKwYBBQUHAwMwHQYDVR0OBBYEFKtE # 8xMwn4kGbe8AzXY0ineK5ToHMA0GCSqGSIb3DQEBBQUAA4IBAQAgaUJkHD9192H7 # OUhf9W3gR0ZkApD5fnPqsIgS91JFQ2fCnonudJinwbODs01yA55uUw4GJUnAKQOx # 6auVAC5KVzE2dMDbOrBOseoKj12EbzbF509FkVoT5O77NDpFrGErR1zmQ8fd1DXw # FAFC1x1vpxW7/F6g+xewpqlFKzjkPeEvLgyoUmKMCOnT0JdXS0BfyAyyIfHwvILo # 2eJWVG2UMioKOJ6vsttTu8mQgVZlfcoF6r81ee3hTEK24aHNR+frHmyrL9UplZxD # AuoUGVzYdDyOejlLPm+d+ew1d6dTf9QfurRxoKgI6OMOVI3iIIXd6HTiIW4ACwI9 # iUjry3dVMYIByjCCAcYCAQEwKTAVMRMwEQYDVQQDDApXZXRIYXQgTGFiAhBp6O8w # ZdggqEAug3g4IFwqMAkGBSsOAwIaBQCgeDAYBgorBgEEAYI3AgEMMQowCKACgACh # AoAAMBkGCSqGSIb3DQEJAzEMBgorBgEEAYI3AgEEMBwGCisGAQQBgjcCAQsxDjAM # BgorBgEEAYI3AgEVMCMGCSqGSIb3DQEJBDEWBBRugECfxVlYMXElJuPLRnJ6QOKq # xDANBgkqhkiG9w0BAQEFAASCAQCc7vq+YJrvKQQffXE5ZLNIs+lum1HjN570/wUV # Y/SN+L3VoGvsJ3wK/Tb1ZwAvVN38FxbmMKAlxrBKB+moLCOE30N5AabqjB38HWRV # UKTXSVRR77YCqaaHisNLzBLX0bVP4xs4hCnPcuSBT/fpKmGTndZRLyUykCkgjmsu # 7pB8blMkhKYIjjqE4zdGLYrITYf88ULHIWFRSGwVmcF5xjlgv8qmA+IvFr22hRR2 # 5IcYbRjFD7l0k8qrfC3zhZrVL8eIYspDPHNf6QL43uXimfwEbMw60Me3H17+fuur # NXWjRLgtt4L/YdvIDQ3muKvJk8vF1tgPYbkYHMUe/g29ZD8e # SIG # End signature block |