element-自定義表單驗證-接口驗證字段是否重複

//template

		<el-col :span="8">
            <el-form-item label="合同前綴：" prop="contractPrefix">
              <el-input v-model="form.contractPrefix" placeholder="請輸入" />
            </el-form-item>
		</el-col>

//script

import {
  // 驗證合同前綴
  checkContract
} from "@/api/shipper";

//data
data () {

    // 驗證合同前綴
    const validateContract = (rule, value, callback) => {
      if (value === "" || value === null) {
        return callback(new Error("必填"));
      } else {
        this.checkContract(callback);
      }
    };
    return {
      rules: {
        contractPrefix: [
          { required: true, message: "必填", trigger: "blur" },
          {
            trigger: "blur",
            validator: validateContract
          }
        ],
}