Font Substitution - PowerPoint JavaScript API

Aspose.Slides allows you to set rules for fonts that determines what must be done in certain conditions (for example, when a font cannot be accessed) this way:

1. Load the relevant presentation.
2. Load the font that will be replaced.
3. Load the new font.
4. Add a rule for the replacement.
5. Add the rule to the presentation font replacement rule collection.
6. Generate the slide image to observe the effect.

This JavaScript code demonstrates the font substitution process:

// Loads a presentation
var pres = new aspose.slides.Presentation("Fonts.pptx");
try {
    // Loads the source font that will be replaced
    var sourceFont = new aspose.slides.FontData("SomeRareFont");
    // Loads the new font
    var destFont = new aspose.slides.FontData("Arial");
    // Adds a font rule for font replacement
    var fontSubstRule = new aspose.slides.FontSubstRule(sourceFont, destFont, aspose.slides.FontSubstCondition.WhenInaccessible);
    // Adds the rule to font substitute rules collection
    var fontSubstRuleCollection = new aspose.slides.FontSubstRuleCollection();
    fontSubstRuleCollection.add(fontSubstRule);
    // Adds a font rule collection to the rule list
    pres.getFontsManager().setFontSubstRuleList(fontSubstRuleCollection);
    // Arial font will be used in place of SomeRareFont when the latter is inaccessible
    var slideImage = pres.getSlides().get_Item(0).getImage(1.0, 1.0);
    // Saves the image to disk in the JPEG format
    try {
        slideImage.save("Thumbnail_out.jpg", aspose.slides.ImageFormat.Jpeg);
    } finally {
        if (slideImage != null) {
            slideImage.dispose();
        }
    }
} finally {
    if (pres != null) {
        pres.dispose();
    }
}

NOTE

You may want to see Font Replacement.