Node-RED: 无法访问js文件中选定的下拉值。

Question

无法获得选定的下拉值，在 验证输入 功能

下面的代码用于验证用户在文本框中输入的信息，并根据在下拉菜单中选择的数据类型提供响应。

HTML.JS: HTML.JS: HTML.JS: HTML.JS: HTML.JS: HTML.JS: HTML.JS: HTML.JS: HTML.JS: HTML.JS: HTML.JS: HTML.JS: HTML.JS: HTML.JS: HTML.JS: HTML.JS: HTML.JS: HTML.JS: HTML.JS: HTML.JS: HTML.JS: HTML.JS: HTML.JS: HTML.JS: HTML.JS: HTML.JS: HTML.JS: HTML.JS: HTML.JS: HTML:

 <script type="text/javascript" src="input.js">
    RED.nodes.registerType("myNode", {
        category: "function",
        color: "#a6bbcf",
        defaults: {
            data: {
                value: ""
            }
        },
        inputs: 1,
        outputs: 1,
        icon: "file.png",
        label: function() {
            return this.data || "myNode";
        },
        oneditprepare: function() {
            $("#selectMe").on("click", function() {
                    var selectedVal = $(this).find(':selected').val();
                    console.log("selectedVal:", selectedVal)
                    if (selectedVal == "photograph") {
                        $("#select-text").hide();
                        $("#select-photograph").show();
                    } else if (selectedVal == "geolocation" || selectedVal == "text" || selectedVal == "number" || selectedVal == "decimal" || selectedVal == "sensor") {
                        // this.data = "MYDATA";
                        $("#select-photograph").hide();
                        $("#select-text").show();
                    } else {
                        $("#select-text").hide();
                        $("#select-photograph").hide();
                    }
                })
             },
    });
</script>
<script type="text/html" data-template-name="myNode">
    <div class="form-row">
        <label for="node-select-data"><i class="icon-tag"></i> Choose Input type that you want:</label>
        <select id="selectMe">            
    <option value="">Select Data Type</option>
    <option value="text">String</option>
    <option value="number">Integer</option>
    <option value="decimal">Decimal</option>
    <option value="sensor">Sensor</option>
    <option value="geolocation">Geo Location</option>
    <option value="photograph">Photograph</option>
    </select>
    </div>
    <div id="select-text" hidden>
        <label for="node-input-data"><i class="icon-tag"></i> Enter the Data to be validated:</label>
        <input type="text" id="node-input-data" placeholder="Data..">
    </div>
    <div id="select-photograph" hidden>
        <label for="node-input-data">Select a Photograph file:</label>
        <input type="file" id="node-input-data" name="myfile">
    </div>
</script>

<script type="text/html " data-help-name="myNode ">
    <p>A simple node that validates the Data respect to the data type entered</p>
</script>

JS:

module.exports = function(RED) {
    "use strict ";

    function ValidateInput(config) {
        RED.nodes.createNode(this, config);
        this.log("RED:", RED);
        this.data = config.data;
        console.log("config:", config);
        console.log("data:", data);
        var node = this;
        node.on("select", function(msg, send, done) {
            var inputEntered = node.data;
        });
        node.on("input", function(msg, send, done) {
            var inputEntered = node.data;
            var letters = /^[A-Za-z]+$/;
            var numbers = /^[0-9]+$/;
            var decimal = /^[-+]?[0-9]+\.[0-9]+$/;
            if (inputEntered.match(letters)) {
                msg = {
                    payload: "Your input have been accepted",
                };
            } else if (inputEntered.match(numbers)) {
                msg = {
                    payload: "Your input have been accepted",
                };
            } else if (inputEntered.match(decimal)) {
                msg = {
                    payload: "Your input have been accepted",
                };
            } else {
                msg = {
                    payload: "Your input is wrong for this field",
                };
            }
            node.send(msg);
        });
    }
    RED.nodes.registerType("myNode", ValidateInput);
};

Answer 1

你似乎对Node-RED节点的一般概念有误解。

HTML文件（和包含的脚本）在浏览器中运行，在配置时使用。

JS文件完全在后端运行时运行，并且不能直接访问HTML文件中任何没有被传递为 config 的节点。

如果你想验证配置输入，那么你需要在HTML文件的 oneditsave 处理程序而不是JS文件。

而不是JS文件。node.on('input',...) 函数是在之前有线节点发送新消息时调用的，它不是用来处理配置信息的。

我建议你阅读 文档 关于如何编写Node-RED节点。