Markdown in RichTextEditor Control

21 Dec 202224 minutes to read

In Rich Text Editor, you click the toolbar buttons to format the words and the changes are visible immediately.

Markdown is not like that. When you format the word in Markdown format, you need to add Markdown syntax to the word to indicate which words and phrases should look different from each other.

Rich Text Editor supports markdown editing when the editorMode set as Markdown and using both keyboard interaction and toolbar action, you can apply the formatting to text.

Supported Commands

The ASP Core Markdown editor supports the following commands to format the markdown content:

Commands	Syntax	Description
Bold	Sample content for ``bold text``.	For bold, add `**` or `__` to front and back of the text.	For order list, precede each line with a number.
Italic	Sample content for ``Italic text``.	For Italic, add `*` or `_` to front and back of the text.
Bold and Italics	Sample content for `*`bold and Italic text`*`.	For bold and Italics, add `***` to the front and back of the text.
Heading 1	`#` Heading 1 content	For heading 1, add `#` to start of the line.
Heading 2	`##` Heading 2 content	For heading 2, add `##` to start of the line.
Heading 3	`###` Heading 3 content	For heading 3, add `###` to start of the line.
Heading 4	`####` Heading 4 content	For heading 4, add `####` to start of the line.
Heading 5	`#####` Heading 5 content	For heading 5, add `#####` to start of the line.
Heading 6	`######` Heading 6 content	For heading 6, add `######` to start of the line.
Line Break	First line `<br>`Second line	For line break, press enter two times (or) add `<br>` in between the first and the second line.
Blockquotes	`>` Blockquotes text	For blockquotes, add `>` to start of the line.
Strike Through	Sample content for `~~`strike through text`~~`.	For strike through, add `~~` to front and back of the text.
Code (Single line)	`Single line code`	For single line code, add ` to front and back of the text.
Code block (Multi Line)	``` Multi line code text Multi line code text ```	For multiple line code, add ``` in the new line before and after the content.
Subscript	`<sub>`Subscript text`</sub>`	For subscript, add `<sub>` to the front and `</sub>` to the back of the text.
Superscript	`<sup>`Superscript text`</sup>`	For superscript, add `<sup>` to the front and `</sup>` to the back of the text.
Ordered List	`1.` First `1.` Second	For ordered list, preceding one or more lines of text with `1.`
Unordered List	`` First `` second	For unordered list, preceding one or more lines of text with `*`.
Links	Link text without title text `[` Link text `](`URL`)` Link text with title text `[` Link text `](`URL , “title text”`)`	Create an inline link by wrapping link text in brackets `[ ]`, and then wrapping the URL as first parameter and title as second parameter in the parentheses `()`. Note: The title text is optional, if needed it can be given manually.
Table	`\|` Heading 1 `\|` Heading 2 `\|` `\|---------\|---------\|` `\|` Col A1 `\|` Col A2 `\|` `\|` Col B1 `\|` Col B2 `\|`	Create a table using the pipes and underscores as given in the syntax to create 2 x 2 table.
Horizontal Line	`***` (three asterix in new line) (or) `___` (three underscores in new line)	For horizontal line, add `***` or `___` to the start of the new line.
Image	`[` alternate text `](`URL path`)`	Create an image by wrapping the image source in parentheses `()`.
Image with alternate text	`[` alternate text `](`URL path`)`	Create an image with alternate text by wrapping an alternative text in brackets `[]`, and then link of the image source in parentheses `()`. Note: When inserting the image using toolbar, the alternate text cannot be provided that needs to be given manually.
Escape tick marks supported	Sample text content with ``bold and ``not bold`` text can be in the same line.``	In the syntax, the whole content is made as bold where the content `not bold` can be made as normal text by adding the bold syntax to the start and end of the respective text. Likewise you can do the same for various inline commands.
Escape Character	`\(`any syntax`)`	Escape any markdown syntax by prefix `\` to the syntax. Example: `\`Bold text``
HTML Entities	Copyright: © - `©` Trade mark: ™ - `™` Registered: ® - `®` Ampersand: & - `&` Less than: < - `<` Greater than: > - `>`	For HTML entities, add & and ; to the front and back of the respective entities.

NOTE

The above listed commands alone are supported in Syncfusion Markdown editor. For other unsupported commands, you can achieve using the HTML tags in Markdown editor. The foot notes, definitions, math, and check list markdown syntax are also not supported.

Markdown to HTML

The Rich Text Editor allows you to preview markdown changes immediately using preview. The third-party library Marked is used in this sample to convert markdown into HTML content.

This sample demonstrates how to preview markdown changes in Rich Text Editor. Type or edit the display text and apply format to view the preview of markdown.

CSHTML
Controller.cs
<ejs-richtexteditor id="markdown" value="@ViewBag.value" editorMode="Markdown" created="created">
    <e-richtexteditor-toolbarsettings items="@ViewBag.items"></e-richtexteditor-toolbarsettings>
</ejs-richtexteditor>

<script src="https://cdn.jsdelivr.net/npm/marked/marked.min.js"></script>
<script type="text/javascript">
    var mdsource, defaultRTE, textArea;
    function created() {
        defaultRTE = this;
        textArea = defaultRTE.contentModule.getEditPanel();
        textArea.addEventListener('keyup', (event) => { markDownConversion(); });
        var rteObj = defaultRTE;
        mdsource = document.getElementById('preview-code');
        mdsource.addEventListener('click', (event) => {
            fullPreview({ mode: true, type: 'preview' });
            if ((event.currentTarget).classList.contains('e-active')) {
                defaultRTE.disableToolbarItem(['Bold', 'Italic', 'StrikeThrough', '|',
                    'Formats', 'OrderedList', 'UnorderedList', '|',
                    'CreateLink', 'Image', 'Undo', 'Redo']);
            } else {
                defaultRTE.enableToolbarItem(['Bold', 'Italic', 'StrikeThrough', '|',
                    'Formats', 'OrderedList', 'UnorderedList', '|',
                    'CreateLink', 'Image', 'Undo', 'Redo']);
            }
        });
    };
    function markDownConversion() {
        if (mdsource.classList.contains('e-active')) {
            var id = defaultRTE.getID() + 'html-preview';
            var htmlPreview = defaultRTE.element.querySelector('#' + id);
            var rteElement = defaultRTE.contentModule.getEditPanel();
            var rteValue = rteElement.value;
            htmlPreview.innerHTML = marked(defaultRTE.value);
        }
    };
    function fullPreview(event) {
        var id = defaultRTE.getID() + 'html-preview';
        htmlPreview = defaultRTE.element.querySelector('#' + id);
        if (mdsource.classList.contains('e-active')) {
            mdsource.classList.remove('e-active');
            mdsource.parentElement.title = 'Preview';
            textArea.style.display = 'block';
            textArea.style.width = '100%';
            htmlPreview.style.display = 'none';
        } else {
            mdsource.classList.add('e-active');
            if (!htmlPreview) {
                htmlPreview = ej.base.createElement('div', { className: 'e-content' });
                htmlPreview.id = id;
                textArea.parentNode.appendChild(htmlPreview);
            }
            if (event.type === 'preview') {
                textArea.style.display = 'none'; htmlPreview.classList.add('e-pre-source');
            } else {
                htmlPreview.classList.remove('e-pre-source');
                textArea.style.width = '50%';
            }
            htmlPreview.style.display = 'block';
            markDownConversion();
            mdsource.parentElement.title = 'Code View';
        }
    }
</script>
<style>
    .e-richtexteditor textarea.e-content {
        float: left;
        border-right: 1px solid rgba(0, 0, 0, 0.12);
    }

    .e-richtexteditor .e-rte-content .e-content {
        min-height: 150px;
    }

    .e-richtexteditor .e-rte-content {
        overflow: hidden;
    }

    .e-icon-btn.e-active .e-md-preview::before {
        content: '\e350';
    }

    .e-icon-btn .e-md-preview::before {
        content: '\e345';
    }

    .e-rte-content .e-content {
        float: right;
        overflow: auto;
        height: inherit;
        padding: 8px;
        height: 100%;
    }

    .e-rte-content .e-content.e-pre-source {
        width: 100%;
    }
</style>
public class HomeController : Controller
{

    public ActionResult Index()
    {
        object tools1 = new
        {
            tooltipText = "Preview",
            template = "<button id='preview-code' class='e-tbar-btn e-control e-btn e-icon-btn'>" +
"<span class='e-btn-icon e-md-preview e-icons'></span></button>"
        };
        ViewBag.items = new[] { "Bold", "Italic", "StrikeThrough", "|", "Formats", "OrderedList", "UnorderedList", "|", "CreateLink", "Image", "CreateTable", "|", tools1, "|", "Undo", "Redo" };

        ViewBag.value = @"In Rich Text Editor , you click the toolbar buttons to format the words and the changes are visible immediately. 
Markdown is not like that. When you format the word in Markdown format, you need to add Markdown syntax to the word to indicate which words 
and phrases should look different from each other.

RichTextEditor supports markdown editing when the editorMode set as **markdown** and using both *keyboard interaction* and *toolbar action*, you can apply the formatting to text.

We can add our own custom formation syntax for the Markdown formation, [sample link](https://ej2.syncfusion.com/javascript/demos/#/material/rich-text-editor/markdown-editor-custom-format.html).

The third-party library <b>Marked</b> is used in this sample to convert markdown into HTML content";
        return View();
    }
}

Table

Rich Text Editor allows to insert Markdown table in edit panel with 2 X 2 rows and columns along with the heading. To use table tool, add the CreateTable item in toolbar items.

Insert Table

To insert the table in Rich Text Editor, click the table toolbar option to insert the table into Rich Text Editor content and this is the default way in all the devices. Refer the below sample and code snippets to add the table in Markdown editor.

CSHTML
Controller.cs
<ejs-richtexteditor id="markdown" value="@ViewBag.value" editorMode="Markdown" created="created">
    <e-richtexteditor-toolbarsettings items="@ViewBag.items"></e-richtexteditor-toolbarsettings>
</ejs-richtexteditor>
<script src="https://cdn.jsdelivr.net/npm/marked/marked.min.js"></script>
<script type="text/javascript">
    var mdsource, defaultRTE, textArea;
    function created() {
        defaultRTE = this;
        textArea = defaultRTE.contentModule.getEditPanel();
        textArea.addEventListener('keyup', (event) => { markDownConversion(); });
        var rteObj = defaultRTE;
        mdsource = document.getElementById('preview-code');
        mdsource.addEventListener('click', (event) => {
            fullPreview({ mode: true, type: 'preview' });
            if ((event.currentTarget).classList.contains('e-active')) {
                defaultRTE.disableToolbarItem(['Bold', 'Italic', 'StrikeThrough', '|',
                    'Formats', 'OrderedList', 'UnorderedList', '|',
                    'CreateLink', 'Image', 'Undo', 'Redo', 'CreateTable']);
            } else {
                defaultRTE.enableToolbarItem(['Bold', 'Italic', 'StrikeThrough', '|',
                    'Formats', 'OrderedList', 'UnorderedList', '|',
                    'CreateLink', 'Image', 'Undo', 'Redo', 'CreateTable']);
            }
        });
    };
    function markDownConversion() {
        if (mdsource.classList.contains('e-active')) {
            var id = defaultRTE.getID() + 'html-preview';
            var htmlPreview = defaultRTE.element.querySelector('#' + id);
            var rteElement = defaultRTE.contentModule.getEditPanel();
            var rteValue = rteElement.value;
            htmlPreview.innerHTML = marked(defaultRTE.value);
        }
    };
    function fullPreview(event) {
        var id = defaultRTE.getID() + 'html-preview';
        htmlPreview = defaultRTE.element.querySelector('#' + id);
        if (mdsource.classList.contains('e-active')) {
            mdsource.classList.remove('e-active');
            mdsource.parentElement.title = 'Preview';
            textArea.style.display = 'block';
            textArea.style.width = '100%';
            htmlPreview.style.display = 'none';
        } else {
            mdsource.classList.add('e-active');
            if (!htmlPreview) {
                htmlPreview = ej.base.createElement('div', { className: 'e-content' });
                htmlPreview.id = id;
                textArea.parentNode.appendChild(htmlPreview);
            }
            if (event.type === 'preview') {
                textArea.style.display = 'none'; htmlPreview.classList.add('e-pre-source');
            } else {
                htmlPreview.classList.remove('e-pre-source');
                textArea.style.width = '50%';
            }
            htmlPreview.style.display = 'block';
            markDownConversion();
            mdsource.parentElement.title = 'Code View';
        }
    }
</script>
<style>
    .e-richtexteditor textarea.e-content {
        float: left;
        border-right: 1px solid rgba(0, 0, 0, 0.12);
    }

    .e-richtexteditor .e-rte-content .e-content {
        min-height: 150px;
    }

    .e-richtexteditor .e-rte-content {
        overflow: hidden;
    }

    .e-icon-btn.e-active .e-md-preview::before {
        content: '\e350';
    }

    .e-icon-btn .e-md-preview::before {
        content: '\e345';
    }

    .e-rte-content .e-content {
        float: right;
        overflow: auto;
        height: inherit;
        padding: 8px;
        height: 100%;
    }

    .e-rte-content .e-content.e-pre-source {
        width: 100%;
    }
</style>
public class HomeController : Controller
{

    public ActionResult Index()
    {
        object tools1 = new
        {
            tooltipText = "Preview",
            template = "<button id='preview-code' class='e-tbar-btn e-control e-btn e-icon-btn'>" +
"<span class='e-btn-icon e-md-preview e-icons'></span></button>"
        };
        ViewBag.items = new[] { "Bold", "Italic", "StrikeThrough", "|", "Formats", "OrderedList", "UnorderedList", "|", "CreateLink", "Image", "CreateTable", "|", tools1, "|", "Undo", "Redo" };

        ViewBag.value = @"In Rich Text Editor , you click the toolbar buttons to format the words and the changes are visible immediately. 
Markdown is not like that. When you format the word in Markdown format, you need to add Markdown syntax to the word to indicate which words 
and phrases should look different from each other.

RichTextEditor supports markdown editing when the editorMode set as **markdown** and using both *keyboard interaction* and *toolbar action*, you can apply the formatting to text.

We can add our own custom formation syntax for the Markdown formation.

The third-party library <b>Marked</b> is used in this sample to convert markdown into HTML content";
        return View();
    }
}

Changing Table Constants

The Markdown table constants can be changed for the table heading and the column names.

CSHTML
Controller.cs
<ejs-richtexteditor id="markdown" locale="en-US" value="@ViewBag.value" editorMode="Markdown" created="created">
    <e-richtexteditor-toolbarsettings items="@ViewBag.items"></e-richtexteditor-toolbarsettings>
</ejs-richtexteditor>

<script src="https://cdn.jsdelivr.net/npm/marked/marked.min.js"></script>

<script type="text/javascript">
    window.onload = function () {
        ej.base.L10n.load({
            'en-US': {
                'richtexteditor': {
                    'TableHeadingText': 'Header',
                    'TableColText': 'Cell'
                }
            }
        });
    }
    var mdsource, defaultRTE, textArea;
    function created() {
        defaultRTE = this;
        textArea = defaultRTE.contentModule.getEditPanel();
        textArea.addEventListener('keyup', (event) => { markDownConversion(); });
        var rteObj = defaultRTE;
        mdsource = document.getElementById('preview-code');
        mdsource.addEventListener('click', (event) => {
            fullPreview({ mode: true, type: 'preview' });
            if ((event.currentTarget).classList.contains('e-active')) {
                defaultRTE.disableToolbarItem(['Bold', 'Italic', 'StrikeThrough', '|',
                    'Formats', 'OrderedList', 'UnorderedList', '|',
                    'CreateLink', 'Image', 'Undo', 'Redo', 'CreateTable']);
            } else {
                defaultRTE.enableToolbarItem(['Bold', 'Italic', 'StrikeThrough', '|',
                    'Formats', 'OrderedList', 'UnorderedList', '|',
                    'CreateLink', 'Image', 'Undo', 'Redo', 'CreateTable']);
            }
        });
    };
    function markDownConversion() {
        if (mdsource.classList.contains('e-active')) {
            var id = defaultRTE.getID() + 'html-preview';
            var htmlPreview = defaultRTE.element.querySelector('#' + id);
            var rteElement = defaultRTE.contentModule.getEditPanel();
            var rteValue = rteElement.value;
            htmlPreview.innerHTML = marked(defaultRTE.value);
        }
    };
    function fullPreview(event) {
        var id = defaultRTE.getID() + 'html-preview';
        htmlPreview = defaultRTE.element.querySelector('#' + id);
        if (mdsource.classList.contains('e-active')) {
            mdsource.classList.remove('e-active');
            mdsource.parentElement.title = 'Preview';
            textArea.style.display = 'block';
            textArea.style.width = '100%';
            htmlPreview.style.display = 'none';
        } else {
            mdsource.classList.add('e-active');
            if (!htmlPreview) {
                htmlPreview = ej.base.createElement('div', { className: 'e-content' });
                htmlPreview.id = id;
                textArea.parentNode.appendChild(htmlPreview);
            }
            if (event.type === 'preview') {
                textArea.style.display = 'none'; htmlPreview.classList.add('e-pre-source');
            } else {
                htmlPreview.classList.remove('e-pre-source');
                textArea.style.width = '50%';
            }
            htmlPreview.style.display = 'block';
            markDownConversion();
            mdsource.parentElement.title = 'Code View';
        }
    }
</script>
<style>
    .e-richtexteditor textarea.e-content {
        float: left;
        border-right: 1px solid rgba(0, 0, 0, 0.12);
    }

    .e-richtexteditor .e-rte-content .e-content {
        min-height: 150px;
    }

    .e-richtexteditor .e-rte-content {
        overflow: hidden;
    }

    .e-icon-btn.e-active .e-md-preview::before {
        content: '\e350';
    }

    .e-icon-btn .e-md-preview::before {
        content: '\e345';
    }

    .e-rte-content .e-content {
        float: right;
        overflow: auto;
        height: inherit;
        padding: 8px;
        height: 100%;
    }

        .e-rte-content .e-content.e-pre-source {
            width: 100%;
        }
</style>
public class HomeController : Controller
{

    public ActionResult Index()
    {
        object tools1 = new
        {
            tooltipText = "Preview",
            template = "<button id='preview-code' class='e-tbar-btn e-control e-btn e-icon-btn'>" +
        "<span class='e-btn-icon e-md-preview e-icons'></span></button>"
        };
        ViewBag.items = new[] { "Bold", "Italic", "StrikeThrough", "|", "Formats", "OrderedList", "UnorderedList", "|", "CreateLink", "Image", "CreateTable", "|", tools1, "|", "Undo", "Redo" };

        ViewBag.value = @"In Rich Text Editor , you click the toolbar buttons to format the words and the changes are visible immediately. 
Markdown is not like that. When you format the word in Markdown format, you need to add Markdown syntax to the word to indicate which words 
and phrases should look different from each other.

Rich Text Editor supports markdown editing when the editorMode set as **markdown** and using both *keyboard interaction* and *toolbar action*, you can apply the formatting to text.

We can add our own custom formation syntax for the Markdown formation.

The third-party library <b>Marked</b> is used in this sample to convert markdown into HTML content";
        return View();
    }
}