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The Facts tab retrieves structured data from Wikidata to display quick reference information about people, places, organizations, and other entities in an organized table format.

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How It Works

1

Entity Search

The extension searches Wikidata’s entity database using the selected term to find the closest matching entity.
2

Retrieve Entity ID

Wikidata returns an entity ID (e.g., Q5373) that uniquely identifies the subject.
3

Fetch Entity Data

Using the entity ID, the extension fetches complete structured data including all properties and values.
4

Parse and Display

The extension extracts relevant properties (birth date, occupation, etc.) and displays them in a readable table.

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API Endpoints Used

The Facts tab uses two Wikidata API endpoints: 
// From background.js:141-159
`https://www.wikidata.org/w/api.php?action=wbsearchentities&search={term}&language={lang}&limit=1&format=json&origin=*`
This returns the entity ID and basic information.

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2. Entity Data Fetch

// From background.js:161-177
`https://www.wikidata.org/wiki/Special:EntityData/{entityId}.json`
This returns the complete entity data with all properties, claims, and values.
Wikidata is Wikipedia’s structured knowledge base containing millions of entities with machine-readable facts.

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Code Implementation

From content.js:743-795, the two-step fetch process: 
async function fetchFactsData(term) {
  // Step 1: Search for entity
  const searchResponse = await chrome.runtime.sendMessage({
    action: 'searchWikidata',
    term: term,
    language: currentLanguage
  });

  const entityId = searchResponse.data.id;

  // Step 2: Fetch entity details
  const entityResponse = await chrome.runtime.sendMessage({
    action: 'fetchWikidataEntity',
    entityId: entityId,
    language: currentLanguage
  });

  const factsData = entityResponse.data;
  setCache(term, 'facts', factsData);
  renderFactsContent(factsData, contentArea);
}

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Property Mapping

Wikidata uses property IDs (P31, P569, etc.) that need to be translated to human-readable labels. The extension maps 30+ common properties: 
// From background.js:190-220
const propertyMap = {
  P31: language === 'ar' ? 'النوع' : 'Instance of',
  P569: language === 'ar' ? 'تاريخ الميلاد' : 'Born',
  P570: language === 'ar' ? 'تاريخ الوفاة' : 'Died',
  P27: language === 'ar' ? 'الجنسية' : 'Country',
  P106: language === 'ar' ? 'المهنة' : 'Occupation',
  P800: language === 'ar' ? 'أعمال بارزة' : 'Notable work',
  P17: language === 'ar' ? 'البلد' : 'Country',
  P1082: language === 'ar' ? 'عدد السكان' : 'Population',
  P625: language === 'ar' ? 'الإحداثيات' : 'Coordinates',
  P36: language === 'ar' ? 'العاصمة' : 'Capital',
  P571: language === 'ar' ? 'تاريخ التأسيس' : 'Founded',
  P112: language === 'ar' ? 'المؤسس' : 'Founded by',
  P159: language === 'ar' ? 'المقر' : 'Headquarters',
  P169: language === 'ar' ? 'الرئيس التنفيذي' : 'CEO',
  P856: language === 'ar' ? 'الموقع الرسمي' : 'Website',
  P166: language === 'ar' ? 'جوائز' : 'Awards',
  // ... and 15+ more properties
};

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What Users See

The Facts tab displays:

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1. Entity Header

  • Label: The entity’s official name from Wikidata
  • Description: A brief description (e.g., “American author and entrepreneur”)

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2. Facts Table

A two-column table with property labels and values:
PropertyValue
BornJanuary 15, 1929
DiedApril 4, 1968
CountryUnited States of America
OccupationCivil rights activist, Baptist minister
// Table rendering from content.js:797-842
function renderFactsContent(data, contentArea) {
  // Title
  const title = document.createElement('h3');
  title.textContent = data.label;
  
  // Description
  if (data.description) {
    const desc = document.createElement('p');
    desc.textContent = data.description;
  }
  
  // Facts table
  const table = document.createElement('table');
  for (const fact of data.facts) {
    const tr = document.createElement('tr');
    
    const tdLabel = document.createElement('td');
    tdLabel.textContent = fact.label;
    
    const tdValue = document.createElement('td');
    tdValue.textContent = fact.value;
    
    tr.appendChild(tdLabel);
    tr.appendChild(tdValue);
    table.appendChild(tr);
  }
}
The extension displays up to 3 values per property when multiple values exist (e.g., multiple occupations or awards).

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Data Type Handling

Wikidata values come in different types that require special parsing: 
// From background.js:307-358
function extractWikidataValue(snak, langCode, entity) {
  switch (datavalue.type) {
    case 'time':
      // Parse +YYYY-MM-DDT00:00:00Z format
      const date = new Date(year, month - 1, day);
      return date.toLocaleDateString(langCode, options);
      
    case 'quantity':
      // Format numbers with locale-aware separators
      const amount = parseFloat(datavalue.value.amount);
      return amount.toLocaleString(langCode);
      
    case 'globecoordinate':
      // Format GPS coordinates
      const lat = datavalue.value.latitude.toFixed(4);
      const lon = datavalue.value.longitude.toFixed(4);
      return `${lat}, ${lon}`;
      
    case 'wikibase-entityid':
      // Return entity ID (linking not yet implemented)
      return datavalue.value.id;
      
    case 'string':
    case 'monolingualtext':
      // Return text as-is
      return datavalue.value;
  }
}

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Date Formatting

  • Full dates: “January 15, 1929” (English) or “15 يناير 1929” (Arabic)
  • Year only: “1929” when month/day are 0
  • Locale-aware: Uses toLocaleDateString() for proper formatting

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Number Formatting

  • Population: “331,893,745” (English) or “٣٣١٬٨٩٣٬٧٤٥” (Arabic)
  • Area: Uses locale-specific thousand separators

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Coordinate Formatting

Formatted as decimal degrees with 4 decimal places: “40.7128, -74.0060”

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Entity Types Supported

The Facts tab works best for:
  • People: birth/death dates, nationality, occupation, education, awards
  • Places: country, population, area, capital, coordinates, timezone
  • Organizations: founded date, founder, headquarters, CEO, industry, website
  • Creative Works: author, genre, country of origin, original language
The property mapping prioritizes the most commonly useful properties for each entity type.

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Language Support

The Facts tab fully supports bilingual display:
  • Property labels: Translated to English or Arabic
  • Entity labels: Retrieved in the requested language with fallback
  • Descriptions: Retrieved in the requested language with fallback
  • Values: Formatted according to locale (dates, numbers)
// From background.js:178-184
const langCode = language === 'ar' ? 'ar' : 'en';
const fallbackLang = langCode === 'ar' ? 'en' : 'ar';

const label = entity.labels?.[langCode]?.value 
  || entity.labels?.[fallbackLang]?.value 
  || entityId;

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Error Handling

Displays: “No quick facts available for [term].” when Wikidata has no matching entity.
Displays: “No quick facts available.” when the entity exists but has none of the mapped properties.
Displays: “Unable to fetch facts. Please try again.” for network or API errors.

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Performance

The Facts tab requires two sequential API calls (search + fetch), making it slightly slower than other tabs. Results are cached to improve subsequent lookups.

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Data Source

Wikidata: Free, no authentication required

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