topic Re: Synchronous Custom Printing - output names are not unique? in ArcGIS JavaScript Maps SDK Questions

Synchronous Custom Printing - output names are not unique?

TracySchloss — Thu, 20 Jun 2013 18:38:26 GMT

I have a custom print service set up, defined as synchronous. I'm using the print widget and at first I thought I had everything working. As I'm testing, I started to notice that some of my printouts weren't what I currently had on the screen, they were ones that I had created a little earlier.

I started looking closer at the output created in my arcgisoutput\printTemplate\ExportWebMap_GPServer, studying how long those files were around before they were automatically cleared out. I haven't got it down to the minute, but around 15 minutes seems to be their life cycle. Next I realized the once these were cleared, new files getting generated have the exact same names as the ones that I created several minutes ago! Because the names are the re-used, the browser is displaying the cached PDF from the earlier print request, not the one I just created.

How can I work around this? Why aren't these names unique? Is this the behavior of the out of the box printTools or specific to my custom service? Do I Just tell the users they have to clear their browser histories if they start seeing this?

I originally had this set up as asynchronous, but that came with its own set of problems, probably because the code sample I'm using was based on synchronous print requests. I am 3 weeks into trying to get this print to work and I'm running out of time!

Re: Synchronous Custom Printing - output names are not unique?

KenBurcham — Thu, 20 Jun 2013 19:08:44 GMT

We have this same problem with printing from our (customized) Tax Parcel Viewer web app (haven't tried with others). I have a note to look into it but haven't yet.

The urls that come back from the server linking to the generated pdf will have a guid-like string of characters, with the last digit incrementing sequentially. It seems like there is a session timeout mis-match or something, where the user who prints a couple of maps and then waits a bit and then goes to print another, will find themselves getting the first map they printed. The next time they try the process, they get the second print. And it increments along until they get back to the actual map they were trying to get! If you manually guess and change the last digit, sometimes you can find the one you're after faster by the ol' trial and error method.

Hope that gives a tiny bit more info as to what is happening. I would love to know a better workaround or better yet, a fix!

Thanks,

ken.

Re: Synchronous Custom Printing - output names are not unique?

TracySchloss — Thu, 20 Jun 2013 19:15:36 GMT

It isn't a solution, but it does make me feel a little better that I'm not just seeing things. I have observed the same 'stepping through the set' of PDFs that you are describing. When I noticed the older printouts, at first I thought it was random. Now that I've deliberately created several and monitored the output, it is definitely systematically walking through the list.

My expectation was that the guid was forever unique, maybe based on a date/time somehow. I've made a note of what that number is today, I'll see if it is different tomorrow.

It did help to set the browsers to clear that history on exit. I don't think that's a very user friendly solution.

Re: Synchronous Custom Printing - output names are not unique?

BenFousek — Sun, 12 Dec 2021 01:49:45 GMT

var time = new Date();
dojo.place('<div style="padding-bottom:2px;border-bottom:1px solid #B5BCC7;margin-bottom:4px;"><a href="' + result.url + '?time=' + time.getTime() + '" target="_blank">' + title + '</a><br /><span style="font-size:10px;color:#444;">' + time.toLocaleString() + '</span></div>', 'tasks-print-result', 'last');

Add a timestamp to the url.

Tracy - You should throw a party once you get all the kinks out of printing. I did. 🙂

Re: Synchronous Custom Printing - output names are not unique?

TracySchloss — Sun, 12 Dec 2021 01:49:48 GMT

I have no clue where I would put that code - too cryptic for me! Nowhere in my version of a print set up, based on the printer widget, do I see a place for me to specify a different output URL name. You must be going about it the other way. I thought about switching to purely printTask and printParameters, but I could find no examples of this and I'm SO CLOSE to getting this other to work. Or so I thought.

//functions for printing
function openPrint () {
  clearTextInput('txtTitle');
  var fp = dijit.byId('floater_print');
   if ((fp.style =="visibility: hidden;") || (fp.style="VISIBILITY:hidden;")) {
      fp.style.visibility="visible";
      fp.show();
   }      
}
function setupPrinting(){     //called from my init function        
var layouts = [{
            "layoutName": "FMDC_Landscape",
            "label": "Landscape - PDF",
            "format": "PDF",
            "options": {
                "legendLayers": [], // empty array means no legend
                "scalebarUnit": "Miles",
                "titleText": "",
                "customTextElements": [{
                    "legalDescriptionText": ""
                }, {
                    "subTitleText": ""
                }]
            }
        }, {
            "layoutName": "FMDC_Portrait",
            "label": "Portrait - PDF",
            "format": "PDF",
            "options": {
                "legendLayers": [], // empty array means no legend
                "scalebarUnit": "Miles",
                "titleText": "",
                "customTextElements": [{
                    "legalDescriptionText": ""
                }, {
                    "subTitleText": ""
                }]
            }
        }];
        
        // create the print templates, could also use dojo.map
        dojo.forEach(layouts, function(lo){
            var t = new esri.tasks.PrintTemplate();
            t.layout = lo.layoutName;
            t.label = lo.label;
            t.format = lo.format;
            t.layoutOptions = lo.options;
            templates.push(t);
        });
        
        var printer = new esri.dijit.Print({
            "map": map,
            "templates": templates,
            url: printUrl
        }, dojo.byId("PrintDiv2"));
        
        printer.startup();
        
        dojo.connect(printer, "onPrintStart", function(){
            var printTitle = dojo.byId("txtTitle").value;
            if (printTitle.length < 1) {
                printTitle = currentCountyName + " County";
            }
            var customElementString;
            var checkName = "";
            if (printName.length > 5) {
                checkName = 'Owner: ' + printName;
            }
            if (printDeed.length < 16) {   //feature has deed book and page information         
            customElementString = [
                {"legalDescriptionText": checkName+'\r\n Description :' + fullLegalString},
             { "subTitleText": print_subTitle}
            ];
            }else{
               customElementString = [
                {"legalDescriptionText": checkName+'\r\n Description :' + fullLegalString + '\r\n' + printDeed},
             { "subTitleText": print_subTitle}
            ];
            }
           // console.log("fullLegalString = "+fullLegalString + "<br> subTitleText = " + print_subTitle);
            for (var i = 0; i < templates.length; i++) {
                this.templates.layoutOptions.titleText = printTitle;
                this.templates.layoutOptions.customTextElements = customElementString;
            }
            
            dojo.connect(printer, "onError", function(err){
                console.log("Printer Error: " + err);
            });
            dojo.connect(printer, 'onPrintComplete', function(value){
                console.log('The url to the print image is : ' + value.url);
            });
        });
    }

The print tool is in a floating pane opened by a button.

     <div id="floater_print" dojoType="dojox.layout.FloatingPane" title='Create Print Page' dockTo="dock_print" style="visibility:hidden; height:260px" closable="false" resizable="true" dockable="true">
          <div id="info">
            <div id="note">
              <ol>   
              <li> Enter a Title    
              <input id="txtTitle" style="width:250px" type="text"  value="Enter a map title" class="textBox"
              onclick="clearTextInput('txtTitle');"  />     
              </li>   
                <li> Click the dropdown arrow on the Print button to choose Landscape or Portrait. </li>
                <li> The 'Printing' prompt indicates your page is being generated. </li>
                <li> When the printout is ready, the print button will change to a link Printout.</li> 
                <li>Click Printout to view your PDF.</li>
             </ol>
            </div>
        <div id="PrintDiv2" > </div>
    </div> 
   </div>

Re: Synchronous Custom Printing - output names are not unique?

BenFousek — Sun, 12 Dec 2021 01:49:50 GMT

Adding the querystring "?time=SOME_TIME" to the end of the url prevents cache.

In your code:

dojo.connect(printer, 'onPrintComplete', function(value){
    var time = new Date();
    var url = value.url + '?time=' + time;
    console.log('The url to the print image is : ' + url);
});

Re: Synchronous Custom Printing - output names are not unique?

TracySchloss — Thu, 20 Jun 2013 20:10:15 GMT

In any code related to the onPrintComplete event, wouldn't the value already be determined by the outcome of the print request? Could you maybe do something in onPrintStart instead?

If I append the date to the url within the function, it doesn't seem like I'm changing the name of the URL or the output file name. When I tried it, my console log looked different, but both the name of the PDF in the browser and the name generated on the server were the same names as always.

Re: Synchronous Custom Printing - output names are not unique?

BenFousek — Thu, 20 Jun 2013 20:29:14 GMT

I don't know how you could do something onPrintStart because you don't have the image url back from the server yet.

Wait a second...I just noticed you are using the print widget. There isn't a way to alter the returned url before the widget turns the button into a link without hacking the widget on a local install. I use esri.tasks.PrintTask, which returns the output url, which I'm able to add the timestamp to before creating a link or button.

Re: Synchronous Custom Printing - output names are not unique?

JohnGravois — Thu, 20 Jun 2013 20:46:43 GMT

i just wanted to chime in and let you all know that this is a REST bug that I logged a little while back which has been tested and confirmed fixed in 10.2.

[NIM090204:When using a custom print service, sometimes old print requests are returned due to the way output files are named]

sorry for the inconvenience.

Re: Synchronous Custom Printing - output names are not unique?

TracySchloss — Fri, 21 Jun 2013 12:32:33 GMT

Is there a suggested workaround to this bug? Is it specific to synchronous requests? It seems odd that the report is "sometimes old print requests are returned" and not all the time.

I'd be interested in finding a print example that does not work with the dijit, but instead works directly with the printTask. From other threads, it sounds like there used to be some examples posted in earlier versions of the API. I assume once the dijit was offered as the main print solution, these were removed. If I can specify the name of the output file, that should be a solution to the repeated use of the output names.

If I use printTask and printParameters instead, then should I execute it as deferred? If I submit my request that way, I assume this works as a submitted job and I need to listen for the results it? Does that mean my print service needs to be defined as asynchronous? It's synchronous right now.

Re: Synchronous Custom Printing - output names are not unique?

JohnGravois — Fri, 21 Jun 2013 14:30:05 GMT

printTask includes the method execute(), so you'll definitely be fine working with your synchronous print service

heres a little more information from my bug report that should help clarify why the problem only occurs "sometimes".

Custom Print Services generates the same 32-character string for all its output files, which causes old print requests to be displayed again.

Steps to reproduce:
1. Submit several print requests to the OOTB 10.1 print service and notice that each output filename includes a random 32-character sequence.
2. Publish a Custom Print Service (using existing templates) and notice that the same 32-character string is repeated in all output files. Only incremented numbers appended to the end guarantee the filename is unique (see attached screenshots).

This causes a problem in web applications when an additional print request is submitted after previous jobs have already been deleted from the server. Because the response URL can easily be identical, stale content from the cache might be displayed instead of the correct printout.

Sample application attached (can also be found at http://[internalserver]/printTask.html).
1. Open the application and click print
2. Pan the map to a different location
3. Wait 15 minutes and send another print request
Notice that if the URL is identical, the first printout will be displayed again. It is necessary to force a refresh of the page to display the appropriate output.

Re: Synchronous Custom Printing - output names are not unique?

MattLane — Fri, 21 Jun 2013 14:37:18 GMT

i just wanted to chime in and let you all know that this is a REST bug that I logged a little while back which has been tested and confirmed fixed in 10.2.

[NIM090204:When using a custom print service, sometimes old print requests are returned due to the way output files are named]

sorry for the inconvenience.

Tested and fixed in 10.2, but can we get a patch or at least roll it into the next service pack, for 10.1?

The cache-busting they mention above isn't always the best idea either. If the user runs the print, then waits 15 minutes (coffee break?) before hitting the link, they will be getting someone else's print.

Re: Synchronous Custom Printing - output names are not unique?

TracySchloss — Sun, 12 Dec 2021 01:49:53 GMT

I didn't find a basic printTask example, so I put this together for whoever might be reading the forums about printing issues. This looks a lot like the print dijit, but is based on printTask and printParameters. It still doesn't the address the issue of 'duplicate' PDF output. But it does seem less buggy than the print dijit and it's working for me in IE.

I don't see where I can control the output name. I wonder if there are maybe additional options if I had authored my service with Python instead of the Export Web Map server tool?

This is based on my custom print service, but it's generic enough I'd think it would work with the OOTB printTool with minimal changes.

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> 
<html> 
  <head> 
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> 
    <meta http-equiv="X-UA-Compatible" content="IE=7, IE=9, IE=10" /> 
    <!--The viewport meta tag is used to improve the presentation and behavior of the samples  
      on iOS devices--> 
    <meta name="viewport" content="initial-scale=1, maximum-scale=1,user-scalable=no"/> 
    <title>Print Task Example</title> 
    <link rel="stylesheet" type="text/css" href="https://serverapi.arcgisonline.com/jsapi/arcgis/3.4/js/dojo/dijit/themes/claro/claro.css"> 
    <link rel="stylesheet" type="text/css" href="https://serverapi.arcgisonline.com/jsapi/arcgis/3.4/js/esri/dijit/css/Popup.css"> 
    <link rel="stylesheet" type="text/css" href="https://serverapi.arcgisonline.com/jsapi/arcgis/3.4/js/dojo/dojox/layout/resources/FloatingPane.css">
    <link rel="stylesheet" type="text/css" href="https://serverapi.arcgisonline.com/jsapi/arcgis/3.4/js/dojo/dojox/layout/resources/ResizeHandle.css">
    <link rel="stylesheet" type="text/css" href="https://serverapi.arcgisonline.com/jsapi/arcgis/3.4/js/esri/css/esri.css" >    
    <link type="text/css" rel="stylesheet" href="css/style.css">
    
    <script type="text/javascript">var dojoConfig = {parseOnLoad: true};</script> 
    <script type="text/javascript" src="https://serverapi.arcgisonline.com/jsapi/arcgis/?v=3.4"></script> 
    
    <script type="text/javascript"> 
      dojo.require("dijit.layout.BorderContainer"); 
      dojo.require("dijit.layout.ContentPane"); 
      dojo.require("dojox.layout.FloatingPane");
     dojo.require("dijit.form.Button");
    dojo.require("dijit.form.Select");
      dojo.require("esri.map"); 
      dojo.require("esri.dijit.Popup"); 
      dojo.require("esri.layers.FeatureLayer");
      dojo.require("dijit.form.Button");
      dojo.require("esri.tasks.PrintTask");
       
      var loading;
      var map; 
      var spatialReference;    
      var idFromClick = true;
      var districtLayer;
      var geometryPt;
      var currentExtent;
      var layouts = [];
      var templates = [];
      var template;
      var printServiceUrl = "https://myPrintServerName/arcgis/rest/services/printTemplate/ExportWebMap/GPServer/Export%20Web%20Map";
       
    function init() {     
      spatialReference = new esri.SpatialReference({wkid: 102100 });
        startExtent = new esri.geometry.Extent(-10583000, 4287025, -9979000, 4980462, spatialReference);
        map = new esri.Map("map",{   extent:startExtent  });
        var basemap = new esri.layers.ArcGISTiledMapServiceLayer("https://server.arcgisonline.com/ArcGIS/rest/services/Canvas/World_Light_Gray_Base/MapServer"); 
        map.addLayer(basemap); 
   
        roadLayer = new esri.layers.ArcGISDynamicMapServiceLayer("https://services.arcgisonline.com/ArcGIS/rest/services/Reference/World_Transportation/MapServer",{id:'countyLayer'});
        map.addLayer(roadLayer);   
        
        dojo.connect(dijit.byId('map'), 'resize', map, map.resize);//resize the map when the browser resizes      
 
 setUpPrinting();
    }//end init function

 
function clearTextInput (id) {
    dojo.byId(id).value="";
}
//functions for printing
function openPrint () {
  clearTextInput('txtTitle');
  var fp = dijit.byId('floater_print');
   if ((fp.style = "visibility: hidden;") || (fp.style = "VISIBILITY:hidden;")) {
      fp.style.visibility="visible";
      fp.show();
   }      
}
function setUpPrinting() {
    var templateList = dijit.byId("templateSelect");
     layouts = [{
            "layoutName": "Custom_Landscape",
            "label": "Landscape",
            "format": "PDF",
            "options": {
                "legendLayers": [], // empty array means no legend
                "scalebarUnit": "Miles",
                "titleText": ""
            }
        }, {
            "layoutName": "Custom_Portrait",
            "label": "Portrait",
            "format": "PDF",
            "options": {
                "legendLayers": [], // empty array means no legend
                "scalebarUnit": "Miles",
                "titleText": ""
            }
        }];
       dojo.forEach(layouts, function(layout){
            var pTemplate = new esri.tasks.PrintTemplate();
            pTemplate.layout = layout.layoutName;
            pTemplate.label = layout.label;
            pTemplate.format = layout.format;
            pTemplate.layoutOptions = layout.options;
            pTemplate.showAttribution = false;
            templates.push(pTemplate);
                       
            templateList.addOption({
             label: layout.label,
             value: layout.label
           });
            
        });
        
}


function submitPrint() {
    var deferred;
    var printTitle = dojo.byId("txtTitle").value;
    var printParams = new esri.tasks.PrintParameters();
    printParams.map = map;
    var status = dojo.byId("printStatus");
    status.innerHTML = "Printing ...";
    var e = dijit.byId("templateSelect");
    var choice = e.value;
    if (choice == "Portrait") {
        template = templates[1];
    }else{
        template = templates[0];
    }
    if (!template) {
        template = templates[0];
    }
    printParams.template = template;
    template.layoutOptions.titleText = printTitle;
    
    var printTask = new esri.tasks.PrintTask(printServiceUrl,printParams);
    //printTask.execute(printParams,printComplete,printError);
    deferred = printTask.execute(printParams);
        deferred.addCallback(function (response){
         //   console.log("response = " + response.url);       
        status.innerHTML = "";

   var select = dijit.byId("templateSelect");
   var selectOptions = select.getOptions();
  select.set("value", "Choose Print Format");
   
            var link = dojo.byId("printLink");
            link.innerHTML = "<a  href="+response.url+ " target=_blank ;'>Printout</a> ";
            link.onclick = function(){link.innerHTML = '';};
        });
    
    deferred.addErrback(function (error) {
        console.log("Print Task Error = " + error);
        status.innerHTML = "Print Error" + error;
    });
    
}

function printError(err) {
    console.log("Printer Error: " + err);
    
}
      dojo.addOnLoad(init); 
    </script> 

 </head> 
  <body class="claro">
      <div dojotype="dijit.layout.BorderContainer" data-dojo-props="design:'headline'"  style="width: 100%; height: 100%; margin: 0; border:0px;"> 
      <div id="header" dojotype="dijit.layout.ContentPane" region="top">  Print Task Example </div>
       <div dojotype="dijit.layout.ContentPane" id="centerPane" region="center"> 
                    <button id="btnPrint" dojotype="dijit.form.Button" onClick="openPrint();">Print</button> 
            <div id="map" dojotype="dijit.layout.ContentPane" title="Map" >
             <div dojoType="dojox.layout.Dock" id="dock_print"></div>
            </div>
        <div id="floater_print" dojoType="dojox.layout.FloatingPane"  title="Print Tools" dockTo="dock_print" style="visibility:hidden" closable="false" resizable="true"  dockable="true" >     
          
            <div id="note">
              <ol>   
              <li> Enter a Title    
              <input id="txtTitle" style="width:250px" type="text"  value="Enter a map title" class="textBox"
              onclick="clearTextInput('txtTitle');"  />     
              </li>   
                <li> Click the dropdown arrow on the Print format to choose Landscape or Portrait. </li>
                <li> The 'Printing' prompt indicates your page is being generated. </li>
                <li> When the printout is ready, click Printout to view your PDF.</li> 
             </ol>
        
    <select  id="templateSelect" data-dojo-type="dijit.form.Select"  >
         <option>Choose Print Format</option>
     </select>
<button id="btnPrintSubmit" dojotype="dijit.form.Button" onClick="submitPrint();">Print</button> 
        </div>
<div id="printStatus"></div>
<div id="printLink"></div>
    </div>
   </div>  
  </body>
</html>

Re: Synchronous Custom Printing - output names are not unique?

JianHuang — Sun, 12 Dec 2021 01:49:56 GMT

This is a service side bug. Luckily we have a workaround on client.
If you are using printTask, just simply attach a time stamp at the end of the result url. If you are using printDijit, please try the code

dojo.connect(printer, "onPrintComplete", function(result){
  var currentTime = new Date();
  result.url += "?ts="+currentTime.getTime();
});

Re: Synchronous Custom Printing - output names are not unique?

TracySchloss — Sun, 12 Dec 2021 01:49:59 GMT

Could you clarify where this goes since I'm using printTask and not the dijit? I'm appending the timestamp to the end of the response.url before I provide that as a link to the user and that's enough to never see old PDFs?

    deferred = printTask.execute(printParams);
        deferred.addCallback(function (response){ 
             var time = new Date();
    var outputUrl = response.url + '?time=' + time;  
            var link = dojo.byId("printLink");
             link.innerHTML = "<a  href="+outputUrl+ " target=_blank ;'>Printout</a> ";
         //   link.innerHTML = "<a  href="+response.url+ " target=_blank ;'>Printout</a> ";
        });

Re: Synchronous Custom Printing - output names are not unique?

TracySchloss — Fri, 21 Jun 2013 20:46:36 GMT

Either I'm not using the right syntax or this isn't a solution. After several minutes of creating and monitoring my PDF output, I'm still see previously cached PDFs. Bummer.

Re: Synchronous Custom Printing - output names are not unique?

JianHuang — Fri, 21 Jun 2013 22:13:59 GMT

try time.getTime(), which returns the unix time.

Re: Synchronous Custom Printing - output names are not unique?

TracySchloss — Sun, 12 Dec 2021 01:50:01 GMT

Time worked instead of date. When I looked at the ?time parameter when it was Date, it was truncating on the day ?time=Mon. That's no good. Switching it to the time instead took care of it. I could watch the original big long guid name get removed and replaced and see the browser properly show the newer version by the same name.

Here's the updated submitPrint function:

function submitPrint() {
    var deferred;
    var printTitle = dojo.byId("txtTitle").value;
    var printParams = new esri.tasks.PrintParameters();
    printParams.map = map;
    var status = dojo.byId("printStatus");
    status.innerHTML = "Printing ...";
    var e = dijit.byId("templateSelect");
    var choice = e.value;
    if (choice == "Portrait") {
        template = templates[1];
    }else{
        template = templates[0];
    }
    if (!template) {
        template = templates[0];
    }
    printParams.template = template;
    template.layoutOptions.titleText = printTitle;
    
    var printTask = new esri.tasks.PrintTask(printServiceUrl,printParams);
    deferred = printTask.execute(printParams);
        deferred.addCallback(function (response){  
             var d = new Date();
            var dateTime =  d.getTime(); 
            var outputUrl = response.url + '?time=' + dateTime;  
        status.innerHTML = "";

   var select = dijit.byId("templateSelect");
   var selectOptions = select.getOptions();
  select.set("value", "Choose Print Format");
   
            var link = dojo.byId("printLink");
             link.innerHTML = "<a  href="+outputUrl+ " target=_blank ;'>Printout</a> ";
         //   link.innerHTML = "<a  href="+response.url+ " target=_blank ;'>Printout</a> ";
            link.onclick = function(){link.innerHTML = '';};
        });
    
    deferred.addErrback(function (error) {
        console.log("Print Task Error = " + error);
        status.innerHTML = "Print Error" + error;
    });
    
}