topic Re: Hopeless at timing and still using Legacy code in ArcGIS JavaScript Maps SDK Questions

Hopeless at timing and still using Legacy code

AdrianMarsden — Sat, 11 Dec 2021 20:57:35 GMT

OK - I've a site I wrote years back which did work, but now due to a data centre move I realise it onl;y worked becasue the requests were resolved quickly, on the "new" network my code needs attention for timing.

I have this

        dojo.connect(dynamicMapServiceLayer, "onLoad", function () {
            var content = "";
            var i = 0
            //return the layer descriptions and © text into arrays - we use this later for the info dialog to generate hyperlinks and © text
            dojo.forEach(dynamicMapServiceLayer.layerInfos, function (layer) {
                //console.debug(dynamicMapServiceLayer.layerInfos[layer.id])
                var requestHandle = esri.request({
                    url: mapserviceCustom + "/" + layer.id + "?f=json",
                    handleAs: "json",
                    load: function (data) {
                        LayerAttach[layer.id] = data.hasAttachments;                        
                        LayerDescriptions[layer.id] = data.description;
                        //LayerCopyright[layer.id] = data.copyrightText;
                        console.debug(dynamicMapServiceLayer)
                        dynamicMapServiceLayer.layerInfos[layer.id].copyrightText = data.copyrightText;
                        
                    },
                }, { useProxy: true });               
            });                
        });  ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

That runs during the init of my site and gets more info from the REST of the service regarding each layer, I use this to dynamically control the copyright notice on the map, as this varies per layer. I store this info in the layer description.

I've not looked at this for a long time, but I know I need to do something to stop the rest of the code working until all this has run, as a later part of my init code will use the results - but my hack skills are exhausted. Most of the site is in legacy and most examples I have found are in AMD. So any help gratefully received.

Cheers

ACM

Re: Hopeless at timing and still using Legacy code

RobertScheitlin__GISP — Sat, 11 Dec 2021 20:57:38 GMT

Adrian,

I am not real sure about legacy code but in AMD I would use a Promise/All (which you likely can use in your legacy code). The way it would work is:

        dojo.connect(dynamicMapServiceLayer, "onLoad", function () {
            var content = "";
            var i = 0;
            //return the layer descriptions and © text into arrays - we use this later for the info dialog to generate hyperlinks and © text
            var defs = dojo.map(dynamicMapServiceLayer.layerInfos, dojo._base.lang.hitch(this, function (layer) {
              return esri.request({
                url: mapserviceCustom + "/" + layer.id + "?f=json",
                content: {
                  f: 'json'
                },
                handleAs: 'json',
                callbackParamName: 'callback'
              });
            }));
            dojo.promise.all(defs).then(function (results) {
              //now you are ready to proceed
              dojo.forEach(results, function(data){
                LayerAttach[data.id] = data.hasAttachments;
                LayerDescriptions[data.id] = data.description;
                console.debug(dynamicMapServiceLayer)
                dynamicMapServiceLayer.layerInfos[data.id].copyrightText = data.copyrightText;
              });
            });                
        });‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Re: Hopeless at timing and still using Legacy code

AdrianMarsden — Mon, 27 Nov 2017 15:57:59 GMT

Many thanks - Embarrassingly, when I was searching for an answer, I found I'd already asked the same question in March!

Anyway, I'll give that a go when I have time and get back. For now I put a awful hack in the part that calls this info not to fire off until the array length of LayerDescriptions equals the number of layers

Re: Hopeless at timing and still using Legacy code

AdrianMarsden — Mon, 27 Nov 2017 16:05:23 GMT

I gave it a very quick go - a slight modification, not "dojo._base.lang.hitch" but "dojo.hitch" - that gets it "working" - it is giving me loads of proxy errors now - but I'll have to look at them a different day

Many thanks

Re: Hopeless at timing and still using Legacy code

AdrianMarsden — Mon, 27 Nov 2017 16:39:09 GMT

Mark as the answer - many thank - I think I need a bit more tweaking in my next bit of code, but I hink the wait is there now.

Cheers