NativeScript/NativeScript · error · Error

Failed to read the 'responseText' property from 'XMLHttpRequ

Error message

Failed to read the 'responseText' property from 'XMLHttpRequest': The value is only accessible if the object's 'responseType' is '' or 'text' (was '${this._responseType}').

What it means

Per the XHR spec, responseText is only readable when responseType is '' (empty) or 'text'. This XHR implementation enforces that: reading responseText after setting responseType to 'json', 'arraybuffer', or 'blob' throws this descriptive error.

Source

Thrown at packages/core/xhr/index.ts:65

	public get readyState(): number {
		return this._readyState;
	}

	public get responseType(): string {
		return this._responseType;
	}

	public set responseType(value: string) {
		if (value === XMLHttpRequestResponseType.empty || value in XMLHttpRequestResponseType) {
			this._responseType = value;
		} else {
			throw new Error(`Response type of '${value}' not supported.`);
		}
	}

	public get responseText(): string {
		if (this._responseType !== XMLHttpRequestResponseType.empty && this._responseType !== XMLHttpRequestResponseType.text) {
			throw new Error("Failed to read the 'responseText' property from 'XMLHttpRequest': " + "The value is only accessible if the object's 'responseType' is '' or 'text' " + `(was '${this._responseType}').`);
		}

		if (isFunction(this._responseTextReader)) {
			return this._responseTextReader();
		}

		return '';
	}

	public get response(): any {
		if (this._responseType === XMLHttpRequestResponseType.empty || this._responseType === XMLHttpRequestResponseType.text) {
			if (this._readyState !== this.LOADING && this._readyState !== this.DONE) {
				return '';
			} else {
				return this._response;
			}
		} else {
			if (this._readyState !== this.DONE) {

View on GitHub (pinned to 6800aefa65)

Solutions

1. Read `xhr.response` instead of `xhr.responseText` when responseType is not '' or 'text'.
2. Reset `xhr.responseType = ''` (or 'text') before reading responseText — requires a new request for some implementations, so prefer reading response.
3. Branch on responseType in your load handler: use responseText for text modes, response otherwise.

Example fix

// before
xhr.responseType = 'json';
xhr.onload = () => console.log(xhr.responseText); // throws

// after
xhr.responseType = 'json';
xhr.onload = () => console.log(xhr.response);

const body = xhr.responseType === '' || xhr.responseType === 'text' ? xhr.responseText : xhr.response;

function isTextResponseType(rt: string): boolean {
  return rt === '' || rt === 'text';
}

let body: any;
try {
  body = xhr.responseText;
} catch (e) {
  if (/responseText/.test(e.message)) { body = xhr.response; } else { throw e; }
}

When it happens

Trigger: Setting `xhr.responseType = 'json'` (or 'arraybuffer'/'blob') and then reading `xhr.responseText` instead of `xhr.response`.

Common situations: Mixed code paths where one branch sets responseType for JSON and legacy code still reads responseText; copy-pasted handlers reading responseText regardless of the configured responseType.

Related errors

• Response type of '${value}' not supported.
• Http request must provide a valid url.
• Response content may not be converted to string
• Cannot save file with path: ${destinationFilePath}.
• Response content may not be converted to string

AI-assisted analysis of NativeScript/NativeScript@6800aefa65 (2026-08-30). Data as JSON: /api/errors/056e620ff6eaf1a1. Report an issue: GitHub.