@hanivanrizky/nestjs-html-parser/dist/examples/pagination-validation.js

A powerful NestJS HTML parsing service with XPath and CSS selector support, proxy configuration, random user agents, and rich response metadata including headers and status codes

"use strict";
/**
 * Example: Pagination validation and safe extraction
 *
 * This example demonstrates how to safely handle undefined selectors
 * and validate pagination patterns before extracting data using both
 * the new extractPagination method and manual extraction methods.
 */
Object.defineProperty(exports, "__esModule", { value: true });
exports.compareExtractionMethods = compareExtractionMethods;
exports.demonstrateEnhancedExtractPagination = demonstrateEnhancedExtractPagination;
exports.demonstrateNewExtractPagination = demonstrateNewExtractPagination;
exports.demonstrateOldMethodValidation = demonstrateOldMethodValidation;
exports.demonstrateUndefinedSelectorError = demonstrateUndefinedSelectorError;
const html_parser_service_1 = require("../html-parser.service");
async function demonstrateNewExtractPagination() {
    const parser = new html_parser_service_1.HtmlParserService();
    const html = `
    <div class="pageNav pageNav--skipStart pageNav--skipEnd">
  <a
    href="/forums/forums/introduction-greetings.24/page-4"
    class="pageNav-jump pageNav-jump--prev"
    >Prev</a
  >

  <ul class="pageNav-main">
    <li class="pageNav-page">
      <a href="/forums/forums/introduction-greetings.24/">1</a>
    </li>

    <li class="pageNav-page pageNav-page--earlier">
      <a href="/forums/forums/introduction-greetings.24/page-2">2</a>
    </li>

    <li class="pageNav-page pageNav-page--earlier">
      <a href="/forums/forums/introduction-greetings.24/page-3">3</a>
    </li>

    <li class="pageNav-page pageNav-page--earlier">
      <a href="/forums/forums/introduction-greetings.24/page-4">4</a>
    </li>

    <li class="pageNav-page pageNav-page--current">
      <a href="/forums/forums/introduction-greetings.24/page-5">5</a>
    </li>

    <li class="pageNav-page pageNav-page--later">
      <a href="/forums/forums/introduction-greetings.24/page-6">6</a>
    </li>

    <li class="pageNav-page pageNav-page--later">
      <a href="/forums/forums/introduction-greetings.24/page-7">7</a>
    </li>

    <li class="pageNav-page pageNav-page--skip pageNav-page--skipEnd">
      <a
        data-xf-init="tooltip"
        data-xf-click="menu"
        role="button"
        tabindex="0"
        aria-expanded="false"
        aria-haspopup="true"
        data-original-title="Go to page"
        aria-label="Go to page"
        id="js-XFUniqueId2"
        >…</a
      >

      <div class="menu menu--pageJump" data-menu="menu" aria-hidden="true">
        <div class="menu-content">
          <h4 class="menu-header">Go to page</h4>
          <div
            class="menu-row"
            data-xf-init="page-jump"
            data-page-url="/forums/forums/introduction-greetings.24/page-%page%"
          >
            <div class="inputGroup inputGroup--numbers">
              <div
                class="inputGroup inputGroup--numbers inputNumber inputGroup--joined"
                data-xf-init="number-box"
              >
                <input
                  type="number"
                  pattern="\d*"
                  class="input input--number js-numberBoxTextInput input input--numberNarrow js-pageJumpPage"
                  value="8"
                  min="1"
                  max="344"
                  step="1"
                  required="required"
                  data-menu-autofocus="true"
                /><button
                  type="button"
                  tabindex="-1"
                  class="inputGroup-text inputNumber-button inputNumber-button--up js-up"
                  data-dir="up"
                  title="Increase"
                  aria-label="Increase"
                ></button
                ><button
                  type="button"
                  tabindex="-1"
                  class="inputGroup-text inputNumber-button inputNumber-button--down js-down"
                  data-dir="down"
                  title="Decrease"
                  aria-label="Decrease"
                ></button>
              </div>
              <span class="inputGroup-text"
                ><button type="button" class="js-pageJumpGo button">
                  <span class="button-text">Go</span>
                </button></span
              >
            </div>
          </div>
        </div>
      </div>
    </li>

    <li class="pageNav-page">
      <a href="/forums/forums/introduction-greetings.24/page-344">344</a>
    </li>
  </ul>

  <a
    href="/forums/forums/introduction-greetings.24/page-6"
    class="pageNav-jump pageNav-jump--next"
    >Next</a
  >
</div>
  `;
    try {
        console.log('=== New extractPagination Method ===');
        // Using the new extractPagination method - much simpler!
        // Use the entire pageNav container to extract ALL links (including Prev/Next)
        const pages = parser.extractPagination(html, '//div[contains(@class, "pageNav")]', 'xpath', {
            verbose: true,
            baseUrl: 'https://www.bmw-sg.com',
        });
        console.log('📄 Extracted pages with new method:', pages);
        console.log(`✅ Found ${pages.length} pagination pages`);
        // Show first few pages
        pages.slice(0, 3).forEach((page, index) => {
            console.log(`  ${index + 1}. "${page.text}" -> ${page.href}`);
        });
        return pages;
    }
    catch (error) {
        console.error('❌ Extraction failed:', error);
        return [];
    }
}
async function demonstrateOldMethodValidation() {
    const parser = new html_parser_service_1.HtmlParserService();
    const html = `
    <ul class="pageNav-main">
      <li class="pageNav-page"><a href="/page-1">1</a></li>
      <li class="pageNav-page pageNav-page--current"><a href="/page-2">2</a></li>
      <li class="pageNav-page"><a href="/page-3">3</a></li>
    </ul>
  `;
    // Example of potentially undefined selector pattern
    const mappedPattern = {
        PAGE_NODE_PATTERN: {
            selector: "//li[contains(@class, 'pageNav-page')]",
        },
    };
    // Schema for page extraction
    const pageSchema = {
        href: {
            selector: './/a',
            type: 'xpath',
            attribute: 'href',
        },
        text: {
            selector: './/a/text()',
            type: 'xpath',
        },
        isCurrent: {
            selector: '.',
            type: 'xpath',
            attribute: 'class',
            transform: (className) => className?.includes('pageNav-page--current') || false,
        },
        isSkip: {
            selector: '.',
            type: 'xpath',
            attribute: 'class',
            transform: (className) => className?.includes('pageNav-page--skip') || false,
        },
    };
    try {
        console.log('\n=== Old Method with Validation (Manual Schema) ===');
        // Safe extraction with validation
        const containerSelector = mappedPattern['PAGE_NODE_PATTERN']?.selector;
        if (!containerSelector) {
            console.log('❌ No container selector found');
            return [];
        }
        console.log('✅ Container selector found:', containerSelector);
        const pages = parser.extractStructuredList(html, containerSelector, pageSchema, 'xpath', { verbose: true });
        console.log('📄 Extracted pages with old method:', pages);
        return pages;
    }
    catch (error) {
        console.error('❌ Extraction failed:', error);
        return [];
    }
}
// Example with undefined selector to show the error case
async function demonstrateUndefinedSelectorError() {
    const parser = new html_parser_service_1.HtmlParserService();
    const html = '<div>Test</div>';
    const mappedPattern = {}; // No PAGE_NODE_PATTERN
    try {
        console.log('\n=== Unsafe Extraction (will show error handling) ===');
        // This will cause undefined selector error with old method
        const containerSelector = mappedPattern['PAGE_NODE_PATTERN']?.selector;
        console.log('Container selector:', containerSelector); // undefined
        if (!containerSelector) {
            console.log('❌ No container selector found - returning empty array');
            return [];
        }
        // This code won't be reached due to validation above
        const pages = parser.extractStructuredList(html, containerSelector, {}, 'xpath');
        return pages;
    }
    catch (error) {
        console.error('❌ Error caught:', error.message);
        return [];
    }
}
// Demonstrate enhanced extractPagination with all links extraction
async function demonstrateEnhancedExtractPagination() {
    const parser = new html_parser_service_1.HtmlParserService();
    const html = `
    <div class="pageNav pageNav--skipStart pageNav--skipEnd">
        <a href="/forums/forums/introduction-greetings.24/page-4" class="pageNav-jump pageNav-jump--prev">Prev</a>
        <ul class="pageNav-main">
            <li class="pageNav-page"><a href="/forums/forums/introduction-greetings.24/">1</a></li>
            <li class="pageNav-page pageNav-page--earlier"><a href="/forums/forums/introduction-greetings.24/page-2">2</a></li>
            <li class="pageNav-page pageNav-page--earlier"><a href="/forums/forums/introduction-greetings.24/page-3">3</a></li>
            <li class="pageNav-page pageNav-page--earlier"><a href="/forums/forums/introduction-greetings.24/page-4">4</a></li>
            <li class="pageNav-page pageNav-page--current"><a href="/forums/forums/introduction-greetings.24/page-5">5</a></li>
            <li class="pageNav-page pageNav-page--later"><a href="/forums/forums/introduction-greetings.24/page-6">6</a></li>
            <li class="pageNav-page pageNav-page--later"><a href="/forums/forums/introduction-greetings.24/page-7">7</a></li>
            <li class="pageNav-page"><a href="/forums/forums/introduction-greetings.24/page-344">344</a></li>
        </ul>
        <a href="/forums/forums/introduction-greetings.24/page-6" class="pageNav-jump pageNav-jump--next">Next</a>
    </div>
  `;
    try {
        console.log('\n=== Enhanced extractPagination Method - All Links ===');
        // Extract ALL links from the entire pagination container
        const allPages = parser.extractPagination(html, '//div[contains(@class, "pageNav")]', 'xpath', {
            verbose: true,
            baseUrl: 'https://www.bmw-sg.com',
        });
        console.log('📄 All pagination links extracted:', allPages);
        console.log(`✅ Found ${allPages.length} total pagination links`);
        // Show all links
        allPages.forEach((page, index) => {
            console.log(`  ${index + 1}. "${page.text}" -> ${page.href}`);
        });
        console.log('\n=== Enhanced extractPagination Method - Custom Schema ===');
        const detailedPages = parser.extractPagination(html, '//li[@class[contains(., "pageNav-page")]] | //a[@class[contains(., "pageNav-jump")]]', 'xpath', {
            verbose: true,
            baseUrl: 'https://www.bmw-sg.com',
            schema: {
                href: {
                    selector: './/a | .',
                    type: 'xpath',
                    attribute: 'href',
                },
                text: {
                    selector: './/a/text() | ./text()',
                    type: 'xpath',
                },
                isActive: {
                    selector: '.',
                    type: 'xpath',
                    attribute: 'class',
                    transform: (className) => className?.includes('pageNav-page--current') || false,
                },
                isPrevNext: {
                    selector: '.',
                    type: 'xpath',
                    attribute: 'class',
                    transform: (className) => className?.includes('pageNav-jump') || false,
                },
                className: {
                    selector: '.',
                    type: 'xpath',
                    attribute: 'class',
                },
            },
        });
        console.log('📄 Detailed pagination info:', detailedPages);
        console.log(`✅ Found ${detailedPages.length} detailed pagination elements`);
        return allPages;
    }
    catch (error) {
        console.error('❌ Enhanced extraction failed:', error);
        return [];
    }
}
// Compare both methods
async function compareExtractionMethods() {
    console.log('\n=== Comparison: New vs Old Method ===');
    const html = `
    <ul class="pageNav-main">
      <li class="pageNav-page"><a href="/page-1">Page 1</a></li>
      <li class="pageNav-page"><a href="/page-2">Page 2</a></li>
      <li class="pageNav-page"><a href="/page-3">Page 3</a></li>
    </ul>
  `;
    const parser = new html_parser_service_1.HtmlParserService();
    const baseUrl = 'https://example.com';
    console.log('📊 New extractPagination method:');
    const newMethodPages = parser.extractPagination(html, "//li[contains(@class, 'pageNav-page')]", 'xpath', { baseUrl });
    console.log('   Result count:', newMethodPages.length);
    console.log('   Sample:', newMethodPages[0]);
    console.log('\n📊 Old extractStructuredList method:');
    const pageSchema = {
        href: {
            selector: './/a',
            type: 'xpath',
            attribute: 'href',
        },
        text: {
            selector: './/a/text()',
            type: 'xpath',
        },
    };
    const oldMethodPages = parser.extractStructuredList(html, "//li[contains(@class, 'pageNav-page')]", pageSchema, 'xpath', { baseUrl });
    console.log('   Result count:', oldMethodPages.length);
    console.log('   Sample:', oldMethodPages[0]);
    console.log('\n✅ Both methods produce equivalent results!');
    console.log('💡 New method is more convenient for common pagination use cases');
}
// Run examples
if (require.main === module) {
    (async () => {
        await demonstrateNewExtractPagination();
        await demonstrateEnhancedExtractPagination();
        await demonstrateOldMethodValidation();
        await demonstrateUndefinedSelectorError();
        await compareExtractionMethods();
    })();
}
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