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Working with rich text fields

This section explains how to work with rich text fields.

Reference

Setting values​

Use the SetRichTextField method of the IModel object to set the value of a rich text field. Values in multiple formats can be set in a rich text field. When you edit in the application, the value is set in HTML and text format.

public void SetRichTextField(ICommandContext c, ICommandParams p)
{
    IModel model = c.App.Workspace.CurrentModel;

    //Specifying "html" format as the format also automatically sets the value in "text" format.
    var htmlText = $"<body>....</body>";
    model.SetRichTextField("Field1", htmlText, "html");
}
info
  • If you specify HTML format as the format in the above SetRichTextField method, the text format value will be automatically set along with the HTML format value.
  • If you prioritize response performance, use the SetRichTextFieldValues method and specify both the HTML format value and the text format value as arguments.

Setting an image​

To set an image in a rich text field, convert the byte array of the image to a string, and set the value defined by that string to the rich text field using the SetRichTextField method of the IModel object.

using System.IO;
using System.Drawing;

public void SetImageToRichText(ICommandContext c, ICommandParams p)
{
    //Read the specified file into a byte array.
    var filePath = c.App.Window.UI.ShowOpenFileDialog("Open", "Image Files|*.png");
    if (filePath == null)
    {
        return;
    }
    var bytes = File.ReadAllBytes(filePath);

    //Convert the read byte array into a BASE64 binary string.
    var base64 = System.Convert.ToBase64String(bytes);

    //Convert the read byte array into an Image to get the image width and height.
    var stream = new MemoryStream(bytes);
    var image = Image.FromStream(stream);

    //Define the HTML format value using the converted BASE64 binary string and the width and height of the Image.
    var htmlText = $"<body><p><img width=\"{image.Size.Width}\" height=\"{image.Size.Height}\" src=\"data:image/png;base64,{base64}\"/></p></body>";

    //Set the value of the rich text field of the selected model.
    IModel model = c.App.Workspace.CurrentModel;
    model.SetRichTextField("Field1", htmlText, "html");
}
info
  • Refers to System.IO when reading the specified file into a byte array or converting the byte array into stream format.
  • Refers to System.Drawing when converting a stream format file into an image.

Get value​

To get the rich text field value of a model, use the GetRichTextField method of the IModel object.

public void GetRichTextField(ICommandContext c, ICommandParams p)
{
    IModel model = c.App.Workspace.CurrentModel;

    //Get simple text
    var text = model.GetRichTextField("Field1", "text");

    //Get HTML
    var html = model.GetRichTextField("Field1", "html");

    //...
}

Get image​

To get an image from a rich text field, extract the image part of the string from the rich text field value obtained by the GetRichTextField method of the IModel object, and convert the string to a byte array.

using AngleSharp.Html.Parser;

public void GetImageFromRichText(ICommandContext c, ICommandParams p)
{
//Get the rich text field value of the selected model.
IModel model = c.App.Workspace.CurrentModel; var htmlText = model.GetRichTextField("Field1", "html"); //Parse HTML and extract img tags. var htmlDocument = new HtmlParser().ParseDocument(htmlText); var imgElement = htmlDocument.GetElementsByTagName("img").FirstOrDefault(); if (imgElement == null) { return; } //Get the BASE64 binary string from the extracted img tag. //The src attribute of the extracted img tag is "data:image/png;base64,~", and the actual BASE64 binary string is the string after ",". var srcAttribute = imgElement.GetAttribute("src"); var base64 = srcAttribute.Substring(srcAttribute.IndexOf(",") + 1); //Convert the obtained BASE64 binary string to a byte array. var bytes = System.Convert.FromBase64String(base64); //... } ``` :::info * When parsing HTML, refer to `AngleSharp.Html.Parser`. ::: ## Get the format

To get the rich text format stored in the field, use the `GetRichTextFieldFormats` method of the `IModel` object.

```cs
public void GetRichTextFieldFormats(ICommandContext c, ICommandParams p)
{
    IModel model = c.App.Workspace.CurrentModel;

    IEnumerable<string> formats = model.GetRichTextFieldFormats("Field1");

    //...
}
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