{"record":{"id":"22c2e30e8c25dfe6","repo":"yuliskov/SmartTube","slug":"somehow-we-couldn-t-create-the-viewholder-for-mess","errorCode":null,"errorMessage":"Somehow we couldn't create the ViewHolder for message. Please, report this issue on GitHub with full stacktrace in description.","messagePattern":"Somehow we couldn't create the ViewHolder for message\\. Please, report this issue on GitHub with full stacktrace in description\\.","errorType":"exception","errorClass":"UnsupportedOperationException","httpStatus":null,"severity":"error","filePath":"chatkit/src/main/java/com/stfalcon/chatkit/messages/MessageHolders.java","lineNumber":648,"sourceCode":"        View v = LayoutInflater.from(parent.getContext()).inflate(layout, parent, false);\n        try {\n            Constructor<HOLDER> constructor = null;\n            HOLDER holder;\n            try {\n                constructor = holderClass.getDeclaredConstructor(View.class, Object.class);\n                constructor.setAccessible(true);\n                holder = constructor.newInstance(v, payload);\n            } catch (NoSuchMethodException e) {\n                constructor = holderClass.getDeclaredConstructor(View.class);\n                constructor.setAccessible(true);\n                holder = constructor.newInstance(v);\n            }\n            if (holder instanceof DefaultMessageViewHolder && style != null) {\n                ((DefaultMessageViewHolder) holder).applyStyle(style);\n            }\n            return holder;\n        } catch (Exception e) {\n            throw new UnsupportedOperationException(\"Somehow we couldn't create the ViewHolder for message. Please, report this issue on GitHub with full stacktrace in description.\", e);\n        }\n    }\n\n    @SuppressWarnings(\"unchecked\")\n    private short getContentViewType(IMessage message) {\n        if (message instanceof MessageContentType.Image\n                && ((MessageContentType.Image) message).getImageUrl() != null) {\n            return VIEW_TYPE_IMAGE_MESSAGE;\n        }\n\n        // other default types will be here\n\n        if (message instanceof MessageContentType) {\n            for (int i = 0; i < customContentTypes.size(); i++) {\n                ContentTypeConfig config = customContentTypes.get(i);\n                if (contentChecker == null) {\n                    throw new IllegalArgumentException(\"ContentChecker cannot be null when using custom content types!\");\n                }","sourceCodeStart":630,"sourceCodeEnd":666,"githubUrl":"https://github.com/yuliskov/SmartTube/blob/3de8d90593e0166f012ca18cc3c7ba45bfd68ac4/chatkit/src/main/java/com/stfalcon/chatkit/messages/MessageHolders.java#L630-L666","documentation":"getHolder instantiates your holder class reflectively: it first tries the public (View, Object) constructor for payload support, falls back to (View), then applies the style. Any failure — missing both constructors, non-public or abstract class, non-static inner class, or an exception thrown inside the constructor — is wrapped in UnsupportedOperationException whose cause holds the real error. Diagnose from the caused-by chain, not the wrapper text.","triggerScenarios":"Registering a custom holder without a public BaseMessageViewHolder(View) (and (View, Object) when payloads are registered) constructor; registering an abstract base holder class instead of the concrete subclass; a non-static inner holder class whose implicit outer reference breaks the constructor signature; findViewById/cast failing inside the constructor because the wrong layout resource was registered.","commonSituations":"Writing a first custom content-type holder in Kotlin where the class or constructor is not public; passing the wrong item layout to registerContentType so constructor view lookups fail; R8/ProGuard renaming in release builds of classes referenced only reflectively.","solutions":["Read the caused-by exception: NoSuchMethodException means a missing constructor, InstantiationException means abstract/non-instantiable, InvocationTargetException means the constructor itself threw","Declare public MyHolder(View view) { super(view); } and, when registering a payload, public MyHolder(View view, Object payload) { this(view); ... }","Make nested holder classes public static and register the concrete class, never an abstract one","Verify the layout resource passed at registration matches the views the constructor expects"],"exampleFix":"// before\nclass CustomHolder extends BaseMessageViewHolder<CustomMsg> {\n    CustomHolder(View v) { super(v); } // package-private, no payload constructor\n}\n\n// after\npublic class CustomHolder extends BaseMessageViewHolder<CustomMsg> {\n    public CustomHolder(View v) { super(v); }\n    public CustomHolder(View v, Object payload) { this(v); initPayload(payload); }\n}","handlingStrategy":"validation","validationCode":"// Fail fast at registration instead of during layout:\ntry {\n    holderClass.getDeclaredConstructor(View.class, Object.class);\n    holderClass.getDeclaredConstructor(View.class);\n} catch (NoSuchMethodException e) {\n    throw new IllegalStateException(holderClass.getSimpleName() + \" needs public (View) and (View, Object) constructors\", e);\n}","typeGuard":null,"tryCatchPattern":null,"preventionTips":["Always declare public (View) and, when using payloads, public (View, Object) constructors on custom holders","Make nested holder classes public static and register concrete classes only","Smoke-test one bind of each custom type in debug builds to surface reflection failures early"],"tags":["chatkit","viewholder","reflection","constructor","payload"],"backgroundTag":"missing-viewholder-constructor","analyzedSha":"3de8d90593e0166f012ca18cc3c7ba45bfd68ac4","analyzedAt":"2026-08-22T09:19:26.383Z","schemaVersion":2},"datasetVersion":"2026-08-22T14:17:55.899Z"}