Question
Answer and Explanation
The reason field labels are not supported directly within URLs when enclosed in quotes is due to the fundamental structure and encoding rules of URLs. Let's break down why this is the case:
1. URL Structure: URLs (Uniform Resource Locators) are structured with specific components, such as the protocol, domain, path, query parameters, and fragment identifier. The query parameter section, which often follows a ?, is typically used to pass data to the server. These parameters are formatted as key-value pairs (e.g., ?key1=value1&key2=value2).
2. Encoding Requirements: URLs need to be encoded to ensure that they can be safely transmitted across the internet. Certain characters are reserved or have special meaning within URLs. For example, spaces are replaced with %20, and the = sign is used to separate keys and values.
3. Quotes as Special Characters: In most URL schemes, double quotes (") and single quotes (') are not allowed without proper encoding. They are considered reserved characters, often used to delimit strings in programming languages and other contexts. If you were to put a field label directly with quotes in the URL, the browser and server may not interpret the URL correctly because they will not be able to treat it as a valid parameter value or key.
4. Parameter Value vs. Key: When you append a value to a key within a query string, the URL structure expects a clear separation of the key and the value, which is generally achieved using the = sign. The entire value, which can be a single or a series of words, should be properly URL-encoded. The key is not to be enclosed in quotes in the URL, but to be stated before the "=".
5. Example:
- Incorrect (with quotes in the key, the key has to be without quotes, this may not work):
https://example.com?"field label"=somevalue
- Correct (without quotes, the key/field is without quotes): https://example.com?field_label=somevalue
6. The Purpose of Encoding: In scenarios where a field label or any value contains special characters (including spaces, quotes, etc.), you must use URL encoding. For example, the quote character " becomes %22, and spaces become %20. This ensures that all characters are transmitted correctly without interfering with the URL’s structure.
7. Why it works without quotes, but encoded: So, if you want the parameter name to include a space, you can include it URL encoded https://example.com?field%20label=somevalue. As it is URL encoded, the URL can be properly interpreted.
In summary, the URL does not allow direct usage of quotes for field labels, and it requires special encoding to make the request interpretable. The URL structure requires keys and values, where keys are unquoted and values are properly URL-encoded to handle special characters. This ensures consistent processing across different systems.