Detect preferred language from browser Accept-Language header. Args: accept_language_header: HTTP Accept-Language header value Returns: Best matching supported language code
(accept_language_header: str)
| 18 | |
| 19 | |
| 20 | def detect_browser_language(accept_language_header: str) -> str: |
| 21 | """Detect preferred language from browser Accept-Language header. |
| 22 | |
| 23 | Args: |
| 24 | accept_language_header: HTTP Accept-Language header value |
| 25 | |
| 26 | Returns: |
| 27 | Best matching supported language code |
| 28 | """ |
| 29 | if not accept_language_header: |
| 30 | return DEFAULT_LANGUAGE |
| 31 | |
| 32 | # Parse Accept-Language header |
| 33 | languages = [] |
| 34 | for item in accept_language_header.split(","): |
| 35 | parts = item.strip().split(";") |
| 36 | lang = parts[0].strip() |
| 37 | |
| 38 | # Extract quality value |
| 39 | quality = 1.0 |
| 40 | if len(parts) > 1: |
| 41 | q_part = parts[1].strip() |
| 42 | if q_part.startswith("q="): |
| 43 | try: |
| 44 | quality = float(q_part[2:]) |
| 45 | except ValueError: |
| 46 | quality = 1.0 |
| 47 | |
| 48 | languages.append((lang, quality)) |
| 49 | |
| 50 | # Sort by quality (descending) |
| 51 | languages.sort(key=lambda x: x[1], reverse=True) |
| 52 | |
| 53 | # Find best match |
| 54 | for lang, _ in languages: |
| 55 | # Direct match |
| 56 | if lang in SUPPORTED_LANGUAGE_CODES: |
| 57 | return lang |
| 58 | |
| 59 | # Handle browser locales to internal locale mapping |
| 60 | # TradingView locale codes (internal) are: en, zh_CN, zh_TW, ja, etc. |
| 61 | # Browser locales typically look like: en-US, zh-CN, zh-TW, ja-JP |
| 62 | |
| 63 | # 1. Exact map for common variations |
| 64 | if lang == "zh-CN" or lang == "zh-Hans": |
| 65 | if "zh_CN" in SUPPORTED_LANGUAGE_CODES: |
| 66 | return "zh_CN" |
| 67 | if lang == "zh-TW" or lang == "zh-HK" or lang == "zh-Hant": |
| 68 | if "zh_TW" in SUPPORTED_LANGUAGE_CODES: |
| 69 | return "zh_TW" |
| 70 | if lang.startswith("ja"): |
| 71 | if "ja" in SUPPORTED_LANGUAGE_CODES: |
| 72 | return "ja" |
| 73 | if lang.startswith("en"): |
| 74 | if "en" in SUPPORTED_LANGUAGE_CODES: |
| 75 | return "en" |
| 76 | |
| 77 | return DEFAULT_LANGUAGE |
no test coverage detected