Changes for page Configure your SOAP web service
Last modified by Erik Bakker on 2024/08/26 12:38
From version 30.1
edited by Erik Bakker
on 2022/06/10 13:22
on 2022/06/10 13:22
Change comment:
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To version 28.1
edited by Erik Bakker
on 2022/06/10 13:12
on 2022/06/10 13:12
Change comment:
There is no comment for this version
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... ... @@ -1,10 +1,10 @@ 1 1 {{container}}{{container layoutStyle="columns"}}((( 2 -In s omecases, you wantto treateach uniquepartofyourinputfile asits message insteadofprocessingthecompletefile asits message.In thismicrolearning, we will learnhowyoucanprocessa(large)fileona per-linebasis.2 +In this microlearning, we will learn how you can define a header line in which you specify the naming of the various columns. Some external systems require a header line when you supply them with data via a flat file that is placed somewhere. 3 3 4 4 Should you have any questions, please contact [[academy@emagiz.com>>mailto:academy@emagiz.com]]. 5 5 6 -* Last update: May 31th, 20217 -* Required reading time: 7minutes6 +* Last update: May 28th, 2021 7 +* Required reading time: 5 minutes 8 8 9 9 == 1. Prerequisites == 10 10 ... ... @@ -12,84 +12,50 @@ 12 12 13 13 == 2. Key concepts == 14 14 15 -This microlearning centers around learning how to p rocessanincomingfile per line.15 +This microlearning centers around learning how to place a header line on a flat-file output. 16 16 17 -By processing per line,we mean:Splittinguptheinputintodiscernablepieces thateachwillbecome auniquemessage17 +By header line we mean: A line in the output that defines the naming of the various columns 18 18 19 -* Easy way of reading a file line by line and sending it to eMagiz (Low on memory) 20 -* Ability to process each line based on distinctive logic that is relevant on line level 21 -* Can be used for flat file as well as XML input files 19 +Some external parties require that the first line in the flat file output (i.e. CSV) is filled with column names (i.e. headers). In eMagiz, we call this line a header line. 22 22 23 -== 3. ProcessingaFileperLine ==21 +== 3. Header line == 24 24 25 -In s omecases,youwanttotreateachuniquepartofyourinputfile asits message insteadof processingthecomplete file asitsmessage.Inthismicrolearning,wewilllearn howyou canprocessa(large)file onaper-line basis.23 +In this microlearning, we will learn how you can define a header line in which you specify the naming of the various columns. Some external systems require a header line when you supply them with data via a flat file that is placed somewhere. The header line is the first line in the flat file output. Within this line, the various column names are specified for clarity. 26 26 27 -To makethisworkin eMagiz you need to navigate to the Create phase of eMagiz and open the entryflow in which you want to retrievethe file to a certain location. Within the context of this flow, we need to add functionality that will ensure thateach line is read andprocessedseparatelyand willbecomeitsuniquemessage. To do so first enter "Start Editing" mode on flow level. After you have done so please add a fileitemreadermessagesourceto the flow. We will use this component to readandprocess our input file ona per-linebasis.25 +To add such a header line in eMagiz you need to navigate to the Create phase of eMagiz and open the exit flow in which you want to drop the file to a certain location. Within the context of this flow, we need to add functionality that will ensure that a header line is written to the output before any functional lines are added. To do so first enter "Start Editing" mode on flow level. After you have done so please add a file outbound channel adapter to the flow including an input channel. We will use this component to write our header line to the flat file output. 28 28 29 - The first step would be todefinethe directoryfromwhichwe readourmessages. As alwaysreferencetothedirectorywiththehelpofaroperty.27 +Ensure that the directory to which you reference is the same as in your functional file outbound channel adapter. 30 30 31 -[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity- processing-a-file-per-line--file-item-reader-directory.png]]29 +[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity-header-line--file-outbound-channel-header-line.png]] 32 32 33 - Secondly,justaswhen readingthefile asawhole ensure thatyou use afiltertoretrieve onlythecorrectfilesfrom thedirectory.31 +Now it is time to turn our attention to the Advanced tab. For the Mode select Ignore. Select this option to ensure that the header line is only written down once when there is no output created yet and not somewhere in the middle, in the end, or every time. Furthermore, select the option Append New Line to ensure that the remainder of the information is not appended to the same line. 34 34 35 - === 3.1ItemType===33 +[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity-header-line--file-outbound-channel-header-line-advanced.png]] 36 36 37 - Now itistimetoselectourItemreaderType.As the helptextof theeMagizcomponentsuggestthereare twochoiceswiththiscomponent. Thefirst(andmostfrequently used)optionistheFlatfileitemreader.Withthisoption,youcan readeachlinewithin theflatfileinputfile andoutputis at aseparatemessage.Thesecondoptionis calledthe Stax eventitemreader. With thisoption,youcan read your inputXML and outputmessagesonaper-record basis.35 +After you have done so we need to add a standard transformer that defines the various column names to be written to the flat file output. To do so add the standard transformer component to the canvas including an input channel. After you have done so define the relevant SpEL expression. In this case, we advise using a property value that represents a string of column names. The value of the property should be something as follows: 38 38 39 - [[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity-processing-a-file-per-line--item-reader-type-options.png]]37 +'Header1;Header2;Header3;Header4' 40 40 41 - Basedonyourchoice the exact configurationwill differ.39 +Do note that the separator, in this case, needs to match the requirements of the external system. At the flow configuration level, the standard transformer should look as follows. 42 42 43 - ==== 3.1.1 Stax EventItem Reader====41 +[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity-header-line--define-columns-names.png]] 44 44 45 - For theStaxeventitemreader,youneed to definethe name oftheelementon whichyouwant tosplit theXMLanddefine whetheryouwantto throwanrincaseno suchelementexistsin theinputfile(By(de)selectingthe optionStrict).ThedefaultsettingofMagizisadvisableforthis option.43 +Our last step is to ensure that this piece of logic is tied to the main flow and is executed before writing the functional line(s) to the output file. To make that happen we need to add a wiretap to the flow. With the help of this functionality, you can define which part of the logic takes precedence over another part of the logic. To do so double click on the channel on which you want to place a wiretap, select the option wiretap and select the correct wiretap channel. After you have done this the result should be something as follows: 46 46 47 -[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity- processing-a-file-per-line--stax-event-item-reader-config.png]]45 +[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity-header-line--wiretap-result.png]] 48 48 49 - ====3.1.2FlatFileItemReader====47 +With these couple of steps, you have now successfully added logic to your flow that will ensure that a header line is added before any functional line(s) are written to the output file. 50 50 51 -For the Flat File item reader, there are some more choices and configurations to be made. There are three options you can choose from: 52 -- Pass through line mapper 53 -- Default line mapper 54 -- Pattern matching composite line mapper 55 - 56 -Each of these options has some advantages and disadvantages. Adhering to the best practices of eMagiz (i.e. no transformation in the entry) the best option would be to use the pass-through line mapper. As the name suggests this option does nothing except give a string back to the flow on a per line basis. However, choosing this option means that the actual transformation from that string to XML needs to happen later in the process (most likely in the onramp) with the help of a flat-file to XML transformer (more on that component in a later course). 57 - 58 -The other two options transform the input line into an XML output. So you win one step in the process. However, no standard eMagiz error handling is advisable when you start transforming data within the entry. So in case, something goes wrong to analyze the error will become more difficult. Furthermore, another potential disadvantage is that when one line fails the processing of the rest of the file also halts. 59 - 60 -For the remainder of this microlearning, we will assume that the option pass through line mapper is chosen. 61 - 62 -[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity-processing-a-file-per-line--flat-file-item-reader-passthrough.png]] 63 - 64 -As you can see on the Basic level we are done. However, it is always good to check out the settings on the Advanced tab, especially in this case, to see if there are additional configuration options that could benefit us. The setting of most interest, in this case, is the Lines to Skip setting (default setting is 0). With this setting, you can define whether or not you want to process the header line(s) that exists within your input file. The remainder of the settings is (in most cases) good the way eMagiz has set them up. 65 - 66 -[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity-processing-a-file-per-line--flat-file-item-reader-passthrough-advanced.png]] 67 - 68 -=== 3.2 Poller === 69 - 70 -Now that we have selected and configured the item reader type it becomes time to fill in the last part of the configuration, the poller. For polling eMagiz offers three options: 71 - 72 -- Fixed Delay Trigger 73 -- Fixed Rate Trigger 74 -- Cron Trigger 75 - 76 -Of these options, the cron trigger is used most frequently in eMagiz. The reason being is that you can define this option via a property that you can alter without having to alter the flow version in Create. 77 - 78 -[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity-processing-a-file-per-line--poller-config.png]] 79 - 80 -After finishing all these configuration steps we can press Save to save our work and ensure that we can process the input file on a per-line basis. 81 - 82 82 == 4. Assignment == 83 83 84 -Configure an e ntryin which you define thecomponent andconfiguration neededtorocessa fileonper-linebasis.51 +Configure an exit in which you define and write a header line to a flat-file output before adding functional lines. 85 85 This assignment can be completed with the help of the (Academy) project that you have created/used in the previous assignment. 86 86 87 87 == 5. Key takeaways == 88 88 89 -* Easy way of reading a file line by line and sending it to eMagiz (Low on memory) 90 -* Ability to process each line based on distinctive logic that is relevant on line level 91 -* Can be used for flat file as well as XML input files 92 -* Try to avoid complex transformations within the entry 56 +* The header line contains the names of the columns of the flat file output 57 +* Use the Ignore mode to ensure the header line is created once 58 +* Use the wiretap to ensure the header line is created first 93 93 94 94 == 6. Suggested Additional Readings == 95 95 ... ... @@ -99,6 +99,6 @@ 99 99 100 100 This video demonstrates how you could have handled the assignment and gives you some context on what you have just learned. 101 101 102 -{{video attachment="novice-file-based-connectivity- processing-a-file-per-line.mp4" reference="Main.Videos.Microlearning.WebHome"/}}68 +{{video attachment="novice-file-based-connectivity-header-line.mp4" reference="Main.Videos.Microlearning.WebHome"/}} 103 103 104 104 )))((({{toc/}}))){{/container}}{{/container}}