XML AJAXLesson 24Free preview

AJAX Response

This lesson is part of XML · All levels

Summary

Once the server responds, the result is read through the responseText property for text or responseXML for XML documents. Callback onreadystatechange is used to ensure the status is complete (readyState 4) and HTTP successful (status 200) before data is displayed. The response is also often converted to an object with JSON.parse before use.

Key points

ResponseText contains a response as a string
ResponseXML contains a response in the form of an XML DOM tree
Read the response only when readyState 4 and status 200
JSON.parse converts the JSON string into a JavaScript object
Response data should be validated before display

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