Almighty converter & Useful functions

# TextArea

v=t1.value t2.value=v p1.innerHTML=v // 註解 Comment v2=t3.value t4.value=v2 p2.innerHTML=v2

My ID is p1

My ID is p2

*=already preloaded on this page

# 小工具 Utilities

• *Object keys listing: objls( object_to_list_properties )
  function objls(obj) { let objO=obj; let listK={}; while(obj!=null) { Object.getOwnPropertyNames(obj).forEach(i=>{ listK[i]=1; }); obj=obj.__proto__; } let ret=Object.keys(listK); let oname=objO.constructor.name; if(oname=="Number") ret.unshift(objO); else if(oname=="String") ret.unshift(objO.substr(0,1000)); else if(oname=="Array") ret.unshift(objO.slice(0,10).join(",")); ret.unshift(objO.constructor.name); return ret; }

• *Copy to clipboard: cbcopy( "text_to_copy" )
  function cbcopy(s){ obj=document.createElement("textarea"); obj.value=(s+""); document.body.append(obj); obj.select(); document.execCommand("copy"); obj.remove(); }
• Download current page html
  Type `javascript:` at url and paste
  (()=>{s=document.documentElement.outerHTML;a=document.createElement("a");a.href="data:text/html,"+encodeURIComponent(s);a.download="webpage.html";a.click();})()
• Eruda Console: Paste as URL
  Type `javascript:` at url and paste
  (function () { var script = document.createElement('script'); script.src="https://cdn.jsdelivr.net/npm/eruda"; document.body.appendChild(script); script.onload = function () { eruda.init() } })()
• *jQuery
  (function () { var script = document.createElement('script'); script.src="https://code.jquery.com/jquery-3.4.1.min.js"; script.integrity="sha256-CSXorXvZcTkaix6Yvo6HppcZGetbYMGWSFlBw8HfCJo="; script.crossOrigin="anonymous"; document.body.appendChild(script); })()
• *Advanced alert and showlist:
  function alert2(pgText,cvtBR,asText){ if(pgText && typeof(pgText)=="object") {pgText=JSON.stringify(pgText,null,1); cvtBR=true;} pgText+=""; if(cvtBR && !asText) pgText=pgText.split("\n").join("<br>"); var dlg=$(`<div>`) .css("position","fixed") .css("width","80vw") .css("height","80vh") .css("left","10vw") .css("top","5vh") .css("background-color","#38383c") .css("color","white") .css("overflow-wrap","break-word") .css("border-radius","20px") .css("font-size","20px") .css("padding","10px") .css("overflow","auto") .attr("onclick","$(this).remove()"); if(asText) dlg[0].innerText=(pgText); else dlg.html(pgText); $("body").append(dlg); } async function showlist(title,list,multi){ if(typeof(list)=="string") { list=list.split(","); } if(!list) return ""; return (await new Promise(resolve=>{ showlist_resolve=resolve; alert2(`<h3 class="alert alert-success text-center"> ${title}</h3> \n`+ `<ul class="list-group">\n`+ ` <li class="list-group-item list-group-item-danger text-center">取消Cancel</li> `+ list.map(i=>(` <li class="list-group-item list-group-item-info" onclick="showlist_resolve(this.innerHTML);">${i}</li> `)).join("\n")+ `</ul> `); })); //new Promise }

# 數學 Mathematics

• 排列Permutations: patt( array_of_items )
  function patt(arr){ if(arr.constructor.name!="Array") return []; arr=arr.slice(); if(arr.length==1) return [arr]; else if(arr.length==2) return [arr,arr.slice().reverse()]; else { let sum=[]; let el=arr.shift(); let darr=patt(arr); for(var i in new Array(arr.length+1).fill(0)) sum.push(...darr.map(item=> { let cp=item.slice(); cp.splice(i,0,el); return cp; })); return sum; } }
• 組合Combinations: comb( array_of_items , number_of_selection )
  function comb(a,n){ var ids=new Array(n).fill(0).map((i,ind)=>ind); var res=[]; //console.log(indexes); var evs=""; for(i in ids) evs+=`for(ids[${i}]=((ids[${i}-1]==null)?(-1):ids[${i}-1])+1;ids[${i}]<=a.length-n+${i};ids[${i}]++){\n`; evs+=`res.push(a.filter( (ii,ind)=>(ids.indexOf(ind)!=-1) ));\n`; evs+="}\n".repeat(n); console.log(evs); eval(evs); return (res); }

Javascript object keys listing (no matter enumerable or not)

function objls(obj)
      {
          let objO=obj;
          let listK={};
          while(obj!=null)
            {
                Object.getOwnPropertyNames(obj).forEach(i=>{
                    listK[i]=1;
                });
                obj=obj.__proto__;
            }
          let ret=Object.keys(listK);
          let oname=objO.constructor.name;
          if(oname=="Number")
            ret.unshift(objO);
          else if(oname=="String")
            ret.unshift(objO.substr(0,1000));
          else if(oname=="Array")
            ret.unshift(objO.slice(0,10).join(","));

          ret.unshift(objO.constructor.name);
          return ret;
      }





alert(objls(performance));

Zip/Unzip folder in Node.js

First, install jszip by npm install jszip, then paste the following code

Then you can use genZip("folder/to/zip","abc.zip") and extractZip("abc.zip","folder/to/extract/to") as promises to zip/unzip your folder

You can also pass an Array to genZip's first argument to zip multiple files and folders

Copy to Clipboard

 function cbcopy(s){

  obj=document.createElement("textarea");

  obj.value=(s+"");

  document.body.append(obj);

  obj.select();

  document.execCommand("copy");

  obj.remove();

}

hello world

Web crawling By Puppeteer @ Node.js - Part 2/2, How to make it work on Android?

Outlines

1. Install ubuntu on Android by AndroNix
2. Install node.js and puppeteer
3. start web crawling
4. advanced adjustments to display chinese characters