自訂驗證

為您的上傳建立精密的驗證規則。

基本自訂規則

import { useDropup } from '@samithahansaka/dropup';

function CustomValidationUploader() {
  const { files, getDropProps, getInputProps } = useDropup({
    customRules: [
      // 規則 1：檢查檔案名稱
      (file) => {
        if (file.name.includes(' ')) {
          return '檔案名稱不能包含空格';
        }
        return true;
      },

      // 規則 2：檢查副檔名
      (file) => {
        const ext = file.name.split('.').pop()?.toLowerCase();
        const blocked = ['exe', 'bat', 'cmd', 'sh'];
        if (ext && blocked.includes(ext)) {
          return '不允許上傳可執行檔';
        }
        return true;
      },
    ],

    onValidationError: (errors) => {
      errors.forEach(({ file, errors }) => {
        alert(`${file.name}:\n${errors.join('\n')}`);
      });
    },
  });

  return (
    <div {...getDropProps()} style={styles.dropzone}>
      <input {...getInputProps()} />
      <p>將檔案拖放到此處（名稱不含空格，不接受可執行檔）</p>
    </div>
  );
}

非同步驗證

import { useDropup } from '@samithahansaka/dropup';

function AsyncValidationUploader() {
  const { files, getDropProps, getInputProps } = useDropup({
    customRules: [
      // 在伺服器檢查是否重複
      async (file) => {
        const hash = await calculateHash(file);
        const response = await fetch('/api/check-duplicate', {
          method: 'POST',
          headers: { 'Content-Type': 'application/json' },
          body: JSON.stringify({ hash, filename: file.name }),
        });
        const { exists } = await response.json();

        if (exists) {
          return '此檔案已經上傳過了';
        }
        return true;
      },

      // 驗證檔案內容
      async (file) => {
        if (file.type === 'application/json') {
          const text = await file.text();
          try {
            JSON.parse(text);
            return true;
          } catch {
            return '無效的 JSON 檔案';
          }
        }
        return true;
      },
    ],
  });

  return (
    <div {...getDropProps()} style={styles.dropzone}>
      <input {...getInputProps()} />
      <p>將檔案拖放到此處（會與伺服器進行驗證）</p>
    </div>
  );
}

// 計算檔案雜湊的輔助函式
async function calculateHash(file: File): Promise<string> {
  const buffer = await file.arrayBuffer();
  const hashBuffer = await crypto.subtle.digest('SHA-256', buffer);
  const hashArray = Array.from(new Uint8Array(hashBuffer));
  return hashArray.map(b => b.toString(16).padStart(2, '0')).join('');
}

圖片內容驗證

import { useDropup } from '@samithahansaka/dropup';

function ImageContentValidator() {
  const { files, getDropProps, getInputProps } = useDropup({
    accept: 'image/*',

    customRules: [
      // 檢查實際圖片尺寸
      async (file) => {
        if (!file.type.startsWith('image/')) return true;

        const dimensions = await getImageDimensions(file);

        if (dimensions.width < 200 || dimensions.height < 200) {
          return '圖片至少需要 200x200 像素';
        }

        if (dimensions.width > 4000 || dimensions.height > 4000) {
          return '圖片不能超過 4000x4000 像素';
        }

        return true;
      },

      // 檢查長寬比
      async (file) => {
        if (!file.type.startsWith('image/')) return true;

        const { width, height } = await getImageDimensions(file);
        const ratio = width / height;

        // 要求大約正方形的圖片（比例 0.8 到 1.2）
        if (ratio < 0.8 || ratio > 1.2) {
          return '圖片必須大約為正方形（長寬比 0.8-1.2）';
        }

        return true;
      },
    ],
  });

  return (
    <div {...getDropProps()} style={styles.dropzone}>
      <input {...getInputProps()} />
      <p>拖放正方形圖片（最小 200px，最大 4000px）</p>

      <div style={styles.gallery}>
        {files.map(file => (
          <img
            key={file.id}
            src={file.preview}
            alt=""
            style={styles.preview}
          />
        ))}
      </div>
    </div>
  );
}

// 取得圖片尺寸的輔助函式
function getImageDimensions(file: File): Promise<{ width: number; height: number }> {
  return new Promise((resolve, reject) => {
    const img = new Image();
    img.onload = () => {
      resolve({ width: img.width, height: img.height });
      URL.revokeObjectURL(img.src);
    };
    img.onerror = reject;
    img.src = URL.createObjectURL(file);
  });
}

const styles = {
  dropzone: {
    border: '2px dashed #ccc',
    borderRadius: 8,
    padding: 40,
    textAlign: 'center' as const,
  },
  gallery: {
    display: 'flex',
    gap: 8,
    marginTop: 16,
    justifyContent: 'center',
  },
  preview: {
    width: 80,
    height: 80,
    objectFit: 'cover' as const,
    borderRadius: 4,
  },
};

帶相依性的驗證

import { useDropup } from '@samithahansaka/dropup';
import { useState } from 'react';

function ConditionalValidation() {
  const [category, setCategory] = useState('image');

  const { files, getDropProps, getInputProps } = useDropup({
    // 根據類別動態設定 accept
    accept: category === 'image'
      ? 'image/*'
      : category === 'document'
      ? '.pdf,.doc,.docx'
      : '*/*',

    customRules: [
      (file) => {
        // 類別特定的驗證
        if (category === 'image') {
          if (!file.type.startsWith('image/')) {
            return '請上傳圖片檔案';
          }
          if (file.size > 5 * 1024 * 1024) {
            return '圖片必須小於 5MB';
          }
        }

        if (category === 'document') {
          if (file.size > 10 * 1024 * 1024) {
            return '文件必須小於 10MB';
          }
        }

        return true;
      },
    ],
  });

  return (
    <div>
      <div style={{ marginBottom: 20 }}>
        <label>
          <input
            type="radio"
            value="image"
            checked={category === 'image'}
            onChange={() => setCategory('image')}
          />
          圖片（最大 5MB）
        </label>
        <label style={{ marginLeft: 20 }}>
          <input
            type="radio"
            value="document"
            checked={category === 'document'}
            onChange={() => setCategory('document')}
          />
          文件（最大 10MB）
        </label>
      </div>

      <div {...getDropProps()} style={styles.dropzone}>
        <input {...getInputProps()} />
        <p>
          將{category === 'image' ? '圖片' : '文件'}拖放到此處
        </p>
      </div>
    </div>
  );
}

病毒/惡意軟體掃描

import { useDropup } from '@samithahansaka/dropup';

function MalwareScanUploader() {
  const { files, state, actions, getDropProps, getInputProps } = useDropup({
    customRules: [
      // 使用外部服務掃描檔案
      async (file) => {
        // 上傳到病毒掃描服務
        const formData = new FormData();
        formData.append('file', file);

        try {
          const response = await fetch('/api/scan', {
            method: 'POST',
            body: formData,
          });

          const { safe, threat } = await response.json();

          if (!safe) {
            return `偵測到惡意軟體: ${threat}`;
          }

          return true;
        } catch (error) {
          return '無法掃描檔案，請重試。';
        }
      },
    ],

    onValidationError: (errors) => {
      errors.forEach(({ file, errors }) => {
        console.error(`${file.name} 被拒絕:`, errors);
      });
    },
  });

  return (
    <div {...getDropProps()} style={styles.dropzone}>
      <input {...getInputProps()} />
      <p>檔案會在上傳前掃描惡意軟體</p>
    </div>
  );
}

預建驗證規則

import { useDropup, commonRules } from '@samithahansaka/dropup';

function PrebuiltRulesUploader() {
  const { files, getDropProps, getInputProps } = useDropup({
    customRules: [
      // 內建規則
      commonRules.noExecutables,        // 阻擋 .exe、.bat 等
      commonRules.noHiddenFiles,        // 阻擋以 . 開頭的檔案
      commonRules.maxFilenameLength(50), // 最多 50 字元
      commonRules.allowedExtensions(['.jpg', '.png', '.pdf']),

      // 結合自訂規則
      (file) => {
        if (file.name.toLowerCase().includes('temp')) {
          return '不允許暫存檔案';
        }
        return true;
      },
    ],
  });

  return (
    <div {...getDropProps()} style={styles.dropzone}>
      <input {...getInputProps()} />
      <p>已啟用嚴格檔案驗證</p>
    </div>
  );
}

驗證錯誤顯示

import { useDropup } from '@samithahansaka/dropup';
import { useState } from 'react';

type ValidationErrorType = { file: File; errors: string[] };

function ValidationErrorDisplay() {
  const [validationErrors, setValidationErrors] = useState<ValidationErrorType[]>([]);

  const { files, getDropProps, getInputProps } = useDropup({
    accept: 'image/*',
    maxSize: 5 * 1024 * 1024,
    maxFiles: 3,

    customRules: [
      (file) => {
        if (file.name.length > 50) {
          return '檔案名稱過長（最多 50 字元）';
        }
        return true;
      },
    ],

    onValidationError: (errors) => {
      setValidationErrors(errors);

      // 5 秒後清除
      setTimeout(() => setValidationErrors([]), 5000);
    },
  });

  return (
    <div>
      <div {...getDropProps()} style={styles.dropzone}>
        <input {...getInputProps()} />
        <p>最多拖放 3 張圖片（每張最大 5MB）</p>
      </div>

      {/* 驗證錯誤 */}
      {validationErrors.length > 0 && (
        <div style={styles.errorContainer}>
          <h4 style={styles.errorTitle}>部分檔案被拒絕：</h4>
          {validationErrors.map(({ file, errors }, index) => (
            <div key={index} style={styles.errorItem}>
              <strong>{file.name}</strong>
              <ul style={styles.errorList}>
                {errors.map((error, i) => (
                  <li key={i}>{error}</li>
                ))}
              </ul>
            </div>
          ))}
        </div>
      )}

      {/* 已接受的檔案 */}
      {files.length > 0 && (
        <div style={styles.acceptedFiles}>
          <h4>已接受的檔案：</h4>
          {files.map(file => (
            <div key={file.id}>{file.name}</div>
          ))}
        </div>
      )}
    </div>
  );
}

const styles = {
  dropzone: {
    border: '2px dashed #ccc',
    borderRadius: 8,
    padding: 40,
    textAlign: 'center' as const,
  },
  errorContainer: {
    marginTop: 16,
    padding: 16,
    backgroundColor: '#ffebee',
    borderRadius: 8,
    border: '1px solid #f44336',
  },
  errorTitle: {
    color: '#c62828',
    margin: '0 0 12px',
  },
  errorItem: {
    marginBottom: 8,
  },
  errorList: {
    margin: '4px 0 0',
    paddingLeft: 20,
    color: '#c62828',
  },
  acceptedFiles: {
    marginTop: 16,
    padding: 16,
    backgroundColor: '#e8f5e9',
    borderRadius: 8,
  },
};