ViewerConfig

ViewerConfig (namespace Doconut) describes the browser viewer's appearance and behavior. It does not affect document rendering quality; use a format config for that. The C# class and the legacy JavaScript plugin have different defaults, so map values explicitly.

C# properties

var config = new ViewerConfig
{
    ShowThumbs = true,
    AutoLoad = false,
    PageZoom = 100,
    MaxZoom = 300,
    FitType = "width",
    BasePath = "/",                 // "/" = the DocImage.axd handler at the site root (Web.config)
    ResPath = "doconut-res/images", // the images folder under ResourcesPath, no leading '/'
    ShowHyperlinks = true
};
// Emit it with viewer.RenderViewer("viewerEl", token, config) - see the Viewer reference.

Emitting a ViewerConfig with RenderViewer

Viewer.RenderViewer(elementId, token, config) turns a ViewerConfig into the widget's initialisation script. It writes six of the properties above — BasePath, ResPath, ShowThumbs, AutoLoad, PageZoom, and FitType — and then calls View(token). The other properties are not written: for MaxZoom, ShowHyperlinks, the zoom settings, or any callback, initialise the widget yourself with the JavaScript options below. See Viewer for RenderViewer.

C# to JavaScript mapping

Do not pass a directly serialized ViewerConfig to docViewer(...). Most widget keys are camelCase, while three established path/fit keys are PascalCase.

JavaScript defaults

The widget has older defaults that differ from the C# class. The following values come from the current docViewer.js implementation.

Set all behaviorally important values instead of relying on either set of defaults:

<div id="divDocViewer"><div id="div_ctlDoc"></div></div>

<script>
const objViewer = $('#div_ctlDoc').docViewer({
    showThumbs: true,
    autoLoad: false,
    autoFocus: true,
    autoPageFocus: true,
    pageZoom: 100,
    zoomStep: 10,
    maxZoom: 300,
    FitType: 'width',
    cacheEnabled: false,
    largeDoc: false,
    showHyperlinks: true,
    fixedZoom: true,
    fixedZoomPercent: 100,
    fixedZoomPercentMobile: 75,
    BasePath: '/',
    ResPath: 'doconut-res/images',
    onViewerReady: function () {},
    onError: function (message) { console.error('DocViewer:', message); }
});
</script>

Callbacks

Keep callbacks fast; send telemetry asynchronously and do not block page rendering.

Public method groups

The JavaScript file contains internal helpers too. Treat only methods used by the reference UI and documented here or in the feature guides as stable integration points.

Retry options

The widget also accepts retryOn409 and its backoff settings (retryInitialDelayMs, retryBackoffFactor, retryMaxDelayMs, retryMaxAttempts, retryMaxTotalMs). They serve deployments whose pages are produced in the background. DocImage.axd renders every page during the request, so leave retryOn409 off.

Path checklist

• BasePath is '/' when the DocImage.axd handler is at the site root — the path attribute of the handler in Web.config decides where it answers. In a virtual directory, use the directory name without a leading / ('myapp', not '/myapp': the viewer adds the slash, and //myapp/... is a request to another host).
• DoconutOptions.ResourcesPath is where the resource module serves the embedded files (/doconut-res by default).
• ResPath targets its images subfolder, also without a leading / ('doconut-res/images'). Pointing it at 'doconut-res' makes every icon 404 while the document still renders.
• In MVC, routes.IgnoreRoute("doconut-res/{*pathInfo}") must follow ResourcesPath if you change it.
• ExtractHyperlinks must be enabled in the server format config before showHyperlinks can display anything.