Manifest Display Validator

Validate a web application manifest display keyword without treating display_override extension values as display values.

Description

A manifest display member requests one of four standard presentation modes.

A manifest display member requests one of four standard presentation modes. Extension choices for display_override are a separate member with different accepted values.^[1]

Validate a web application manifest display keyword without treating display_override extension values as display values.

When to use Manifest Display Validator

Use this tool to validate a web application manifest display keyword without treating display_override extension values as display values.

Choose the URL, decoded source text, header value or explicit byte list requested by this tool. Paste the complete relevant input and follow its parsing and encoding conventions.

How to use Manifest Display Validator and understand its results

Choose the URL, decoded source text, header value or explicit byte list requested by this tool. Paste the complete relevant input and follow its parsing and encoding conventions.
Enter display using the field table and calculation rules, then run the tool.
Read valid. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
display	Manifest display member.	string; maximum length: 1000000	Required

Paste the display string and run the validator. It compares exact spelling with the four supported keywords; whitespace or different capitalization returns false. A correctly typed unsupported string is a successful false result.

valid=display is exactly fullscreen, standalone, minimal-ui or browser

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
valid	Whether the display value is recognized.	boolean

json

{
  "input": {
    "display": "standalone"
  },
  "output": {
    "valid": true
  }
}

Limitations and assumptions

This does not parse a manifest, assess platform support or simulate display fallback. display_override extension keywords are not accepted as ordinary display values.

Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Extremely large text inputs are rejected. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors. A successfully returned false flag is an evaluated outcome; its meaning is explained above.

Alternative or Complementary methods

Use ManifestStartUrlExtractor: Extract the raw start_url string from manifest JSON, reporting whether it is present without applying browser fallback behavior. For a complementary task, use ManifestThemeColorExtractor: Extract the raw theme_color string from manifest JSON, reporting whether it is present without applying browser fallback behavior.

References

Manifest Display Validator — tool.io

Similar or alternative tools

ManifestStartUrlExtractor
Extract the raw start_url string from manifest JSON, reporting whether it is present without applying browser fallback behavior.
ManifestThemeColorExtractor
Extract the raw theme_color string from manifest JSON, reporting whether it is present without applying browser fallback behavior.