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Arnau Orriols
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Diff for: ‎LICENSE

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The MIT License (MIT)
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Copyright (c) 2016 Arnau Orriols
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files (the "Software"), to deal
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in the Software without restriction, including without limitation the rights
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to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions:
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The above copyright notice and this permission notice shall be included in all
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copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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SOFTWARE.

Diff for: ‎README.md

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Python Function NodeRED Node
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=============================
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Node-RED is a wonderful tool, but Javascript can be a rather painful language to write.
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Being able to write functions with the language of your choice, and not just Javascript,
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might just be the last piece of functionality missing to make Node-RED perfect. Or not.
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In any case, this quick hacked node will let you write functions using Python instead of Javascript!
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How cool is that? Too cool to be used in production, that is for sure.
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I repeat, don't use this in production. And when you do (cause you will), please tell your manager
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I already told you so.
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Install
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-------
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Requires Python 2.7 installed in the system.
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`rpm install -g node-red-contrib-python-function`
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Usage
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-----
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Just like the plain-old function node, but writting Python instead of Javascript.
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The msg is a dictionary, (almost) all the Node-RED helper functions are avaiable, and its behaviour
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is expected to be exactly the same (at some point in the future at least).
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Caveats
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-------
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- Although it will accept virtually any msg you give it, any non-JSON data type will be silently dropped from the msg permanently.
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- Somethings is wrong with the current implementation of the IPC, that makes it blow up when there are +2 messages waiting to be processed
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- Python is by default a synchronous runtime. The function is run in a dedicated child process,
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therefore it won't block the NodeJS main process, but in any case only 1 message is processed at a time. That is, of course, unless you
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use any of the concurrency features available in Python, like multithreading, multiprocessing, Tornado, Twisted...
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- No sandboxing has been attempted whatsoever. After all, this is just to have some fun, not to be used in production, remember...?

Diff for: ‎lib/.python-function.html.swp

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Diff for: ‎lib/python-function.html

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<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/ace/1.2.3/ace.js"></script>
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<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/ace/1.2.3/ext-language_tools.js"></script>
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<script type="text/javascript">
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RED.nodes.registerType('python-function',{
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category: 'function',
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color: '#fdd0a2',
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defaults: {
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name: {value: ""},
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func: {value: "\nreturn msg"},
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outputs: {value: 1} // Ofuscated way to persist the number of outputs of the node
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},
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inputs: 1,
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outputs: 1,
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icon: "function.png",
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label: function() {
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return this.name;
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},
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oneditprepare: function() {
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$( "#node-input-outputs" ).spinner({
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min:1
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});
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var langTools = ace.require('ace/ext/language_tools');
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this.editor = ace.edit('node-input-func-editor');
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this.editor.setTheme('ace/theme/tomorrow');
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this.editor.getSession().setMode('ace/mode/python');
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this.editor.setValue($("#node-input-func").val(), -1);
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this.editor.setOptions({
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enableBasicAutocompletion: true,
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enableLiveAutocompletion: true,
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highlightSelectedWord: true,
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useSoftTabs: true,
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tabSize: 4,
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});
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var noderedKeywords = [
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'msg', 'msg.payload', 'node', 'node.send',
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'node.log', 'node.warn', 'node.error', 'node.status'
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];
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this.editor.completers.push({
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getCompletions: function (state, session, pos, prefix, callback) {
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callback(null, noderedKeywords.map(function (word) {
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return {
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name: word,
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value: word,
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score: 0,
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meta: 'Node-RED'
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};
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}));
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}
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});
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this.editor.focus();
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},
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oneditsave: function() {
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var annot = this.editor.getSession().getAnnotations();
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this.noerr = 0;
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$("#node-input-noerr").val(0);
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for (var k=0; k < annot.length; k++) {
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//console.log(annot[k].type,":",annot[k].text, "on line", annot[k].row);
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if (annot[k].type === "error") {
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$("#node-input-noerr").val(annot.length);
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this.noerr = annot.length;
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}
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}
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$("#node-input-func").val(this.editor.getValue());
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delete this.editor;
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},
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oneditresize: function(size) {
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var rows = $("#dialog-form>div:not(.node-text-editor-row)");
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var height = $("#dialog-form").height();
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for (var i=0;i<rows.size();i++) {
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height -= $(rows[i]).outerHeight(true);
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}
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var editorRow = $("#dialog-form>div.node-text-editor-row");
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height -= (parseInt(editorRow.css("marginTop"))+parseInt(editorRow.css("marginBottom")));
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$(".node-text-editor").css("height",height+"px");
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this.editor.resize();
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}
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});
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</script>
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<script type="text/x-red" data-template-name="python-function">
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<div class="form-row">
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<label for="node-input-name"><i class="fa fa-tag"></i> <span>Name</span></label>
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<input type="text" id="node-input-name" placeholder="Name">
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</div>
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<div class="form-row" style="margin-bottom: 0px;">
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<label for="node-input-func"><i class="fa fa-wrench"></i> <span>Function</span></label>
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<input type="hidden" id="node-input-func" autofocus="autofocus">
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<input type="hidden" id="node-input-noerr">
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</div>
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<div class="form-row node-text-editor-row">
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<div style="height: 250px; min-height:150px;" class="node-text-editor" id="node-input-func-editor" ></div>
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</div>
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<div class="form-row">
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<label for="node-input-outputs"><i class="fa fa-random"></i> <span>Outputs</span></label>
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<input id="node-input-outputs" style="width: 60px;" value="1">
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</div>
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<div class="form-tips"><span>See the Info tab for help writing Python functions</span></div>
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</script>
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<script type="text/x-red" data-help-name="python-function">
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<p>Just like the plain old Javascript function node, but writting Python!</p>
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<p>All functionality of the javascript function node is to be expected (now or in the near future, or in a parallel universe)</p>
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<p>Virtually all posible incoming messages are supported, available as a Python dictionary. However bear in mind that all data inside msg that is not a valid JSON data type will be dropped from it permanently</p>
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<p><pre>THIS IS NOT READY FOR PRODUCTION YET!</pre></p>
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<h2>Usage</h2>
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<p>A function block where you can write code to do more interesting things.</p>
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<p>The message is passed in as a Python dictionary called <code>msg</code>.</p>
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<p>By convention it will have a <code>msg['payload']</code> key containing
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the body of the message.</p>
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<h4>Logging and Error Handling</h4>
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<p>To log any information, or report an error, the following functions are available:</p>
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<ul>
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<li><code>node.log("Log")</code></li>
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<li><code>node.warn("Warning")</code></li>
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<li><code>node.error("Error")</code></li>
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</ul>
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</p>
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<p>The Catch node can also be used to handle errors. To invoke a Catch node,
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pass <code>msg</code> as a second argument to <code>node.error</code>:</p>
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<pre>node.error("Error msg", msg)</pre>
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<h4>Sending messages</h4>
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<p>The function can either return the messages it wants to pass on to the next nodes
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in the flow, or can call <code>node.send(messages)</code>.</p>
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<p>It can return/send:</p>
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<ul>
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<li>a single message dictionary - passed to nodes connected to the first output</li>
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<li>a list of message dictionaries - passed to nodes connected to the corresponding outputs</li>
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</ul>
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<p>If any element of the list is itself a list of messages, multiple
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messages are sent to the corresponding output.</p>
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<p>If null is returned, either by itself or as an element of the list, no
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message is passed on.</p>
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<p>See the <a target="_new" href="http://nodered.org/docs/writing-functions.html">online documentation</a> for more help.</p>
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</script>

Diff for: ‎lib/python-function.js

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module.exports = function (RED) {
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var spawn = require('child_process').spawn;
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var util = require('util');
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function indentLines(fnCode, depth) {
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return fnCode.split('\n').map((line) => Array(depth).join(' ') + line).join('\n')
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}
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function spawnFn(self) {
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self.child = spawn('python', ['-uc', self.func.code], {stdio: ['pipe', 'pipe', 'pipe', 'ipc']});
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self.child.stdout.on('data', function (data) {
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self.log(data.toString());
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});
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self.child.stderr.on('data', function (data) {
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self.error(data.toString());
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});
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self.child.on('close', function (exitCode) {
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if (exitCode) {
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self.error(`Python Function process exited with code ${exitCode}`);
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if (self.func.attempts) {
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spawnFn(self);
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self.func.attempts--;
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} else {
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self.error(`Function '${self.name}' has failed more than 10 times. Fix it and deploy again`)
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self.status({fill: 'red', shape: 'dot', text: 'Stopped, see debug panel'});
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}
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}
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});
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self.child.on('message', function (response) {
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switch (response.ctx) {
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case 'send':
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sendResults(self, response.msgid, response.value);
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break;
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case 'log':
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case 'warn':
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case 'error':
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case 'status':
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self[response.ctx].apply(self, response.value);
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break;
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default:
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throw new Error(`Don't know what to do with ${response.ctx}`);
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}
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});
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self.log(`Python function '${self.name}' running on PID ${self.child.pid}`);
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self.status({fill: 'green', shape: 'dot', text: 'Running'});
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}
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function sendResults(self, _msgid, msgs) {
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if (msgs == null) {
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return;
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} else if (!util.isArray(msgs)) {
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msgs = [msgs];
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}
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var msgCount = 0;
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for (var m=0;m<msgs.length;m++) {
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if (msgs[m]) {
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if (util.isArray(msgs[m])) {
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for (var n=0; n < msgs[m].length; n++) {
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msgs[m][n]._msgid = _msgid;
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msgCount++;
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}
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} else {
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msgs[m]._msgid = _msgid;
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msgCount++;
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}
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}
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}
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if (msgCount>0) {
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self.send(msgs);
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}
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}
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function PythonFunction(config) {
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var self = this;
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RED.nodes.createNode(self, config);
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self.name = config.name;
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self.func = {
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code: `
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import sys
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import os
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import json
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channel = os.fdopen(3, "r+")
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class Msg(object):
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SEND = 'send'
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LOG = 'log'
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WARN = 'warn'
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ERROR = 'error'
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STATUS = 'status'
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def __init__(self, ctx, value, msgid):
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self.ctx = ctx
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self.value = value
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self.msgid = msgid
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def dumps(self):
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return json.dumps(vars(self)) + "\\n"
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@classmethod
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def loads(cls, json_string):
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return cls(**json.loads(json_string))
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class Node(object):
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def __init__(self, msgid, channel):
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self.__msgid = msgid
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self.__channel = channel
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def send(self, msg):
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msg = Msg(Msg.SEND, msg, self.__msgid)
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self.send_to_node(msg)
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def log(self, *args):
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msg = Msg(Msg.LOG, args, self.__msgid)
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self.send_to_node(msg)
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def warn(self, *args):
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msg = Msg(Msg.WARN, args, self.__msgid)
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self.send_to_node(msg)
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def error(self, *args):
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msg = Msg(Msg.ERROR, args, self.__msgid)
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self.send_to_node(msg)
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def status(self, *args):
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msg = Msg(Msg.STATUS, args, self.__msgid)
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self.send_to_node(msg)
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def send_to_node(self, msg):
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self.__channel.write(msg.dumps())
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def python_function(msg):
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` + indentLines(config.func, 4) +
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`
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while True:
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raw_msg = channel.readline()
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if not raw_msg:
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raise RuntimeError('Received EOF!')
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msg = json.loads(raw_msg)
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msgid = msg["_msgid"]
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node = Node(msgid, channel)
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res_msgs = python_function(msg)
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node.send(res_msgs)
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`,
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attempts: 10
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};
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spawnFn(self);
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self.on('input', function(msg) {
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var cache = [];
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jsonMsg = JSON.stringify(msg, function(key, value) {
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if (typeof value === 'object' && value !== null) {
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if (cache.indexOf(value) !== -1) {
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// Circular reference found, discard key
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return;
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}
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// Store value in our collection
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cache.push(value);
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}
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return value;
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});
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cache = null; // Enable garbage collection
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self.child.send(JSON.parse(jsonMsg));
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});
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self.on('close', function () {
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self.child.kill();
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});
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}
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RED.nodes.registerType('python-function', PythonFunction);
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};

Diff for: ‎package.json

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{
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"name": "node-red-contrib-python-function",
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"version": "0.0.1",
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"repository": {
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"type": "git",
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"url": "https://github.com/arnauorriols/node-red-contrib-python-function"
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},
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"description": "Define a function with Python instead of Javascript",
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"keywords": [
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"node-red",
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"function",
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"Python",
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"exec",
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"polyglot",
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"hack"
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],
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"author": "Arnau Orriols",
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"license": "MIT",
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"node-red": {
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"nodes": {
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"python-function": "lib/python-function.js"
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}
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},
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"dependencies": {
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}
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}

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