Last modified by Erik Bakker on 2024/08/26 12:38
From version 32.1
edited by Erik Bakker
on 2022/06/10 13:30
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edited by Erik Bakker
on 2022/06/10 13:22
Change comment: There is no comment for this version

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Title
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1 -Character set
1 +Processing a File per Line
Content
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1 1  {{container}}{{container layoutStyle="columns"}}(((
2 -n some cases, the input you receive or the output that you need to send to an external party cannot handle all characters or the input or output is written with the help of a character set. In this microlearning, we will learn how you can define the character set for file-based connectivity to ensure that you can process and deliver files according to the specifications.
2 +In some cases, you want to treat each unique part of your input file as its message instead of processing the complete file as its message. In this microlearning, we will learn how you can process a (large) file on a per-line basis.
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, 2021
7 -* Required reading time: 7 minutes
6 +* Last update: May 28th, 2021
7 +* Required reading time: 5 minutes
8 8  
9 9  == 1. Prerequisites ==
10 10  
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12 12  
13 13  == 2. Key concepts ==
14 14  
15 -This microlearning centers around learning how to define the character set to ensure that eMagiz processes the information correctly.
15 +This microlearning centers around learning how to process an incoming file per line.
16 16  
17 -By character set, we mean: The composite number of different characters that are being used and supported by computer software and hardware. It consists of codes, bit patterns, or natural numbers used in defining some particular character.
17 +By processing per line, we mean: Splitting up the input into discernable pieces that each will become a unique message
18 18  
19 -* Some external system talk in a different character set
20 -* eMagiz talks in default UTF-8 as a character set and assumes everyone else also does this
21 -* In cases of mismatch correct is at the point where you talk with the other system (i.e. entry or exit)
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
22 22  
23 -== 3. Character set ==
23 +== 3. Processing a File per Line ==
24 24  
25 -In some cases, the input you receive or the output that you need to send to an external party cannot handle all characters or the input or output is written with the help of a character set. In this microlearning, we will learn how you can define the character set for file-based connectivity to ensure that you can process and deliver files according to the specifications.
25 +In some cases, you want to treat each unique part of your input file as its message instead of processing the complete file as its message. In this microlearning, we will learn how you can process a (large) file on a per-line basis.
26 26  
27 -Sometimes external systems only talk in a specific character set. To ensure that all the data is properly communicated between eMagiz and the other system we need to make sure that we define which character set that is so we can tell it to eMagiz via a component. That way eMagiz will deviate from its default (i.e. UTF-8) and will process the file according to that different character set. In practice, we mainly see windows-1252 as an alternative that pops up once in a while. In various components that deal with file handling, you can define the character set on which eMagiz should act. Examples of such components are:
27 +To make this work in eMagiz you need to navigate to the Create phase of eMagiz and open the entry flow in which you want to retrieve the file to a certain location. Within the context of this flow, we need to add functionality that will ensure that each line is read and processed separately and will become its unique message. To do so first enter "Start Editing" mode on flow level. After you have done so please add a file item reader message source to the flow. We will use this component to read and process our input file on a per-line basis.
28 28  
29 -- File to string transformer
30 -- Flat file to XML transformer
31 -- File outbound channel adapter
29 +The first step would be to define the directory from which we read our messages. As always reference to the directory with the help of a property.
32 32  
33 -In all these components you have the option to define the character set within the Advanced tab of the component. In this microlearning, we will use the File to string transformer to illustrate how that will look.
31 +[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity-processing-a-file-per-line--file-item-reader-directory.png]]
34 34  
35 -[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity-characterset--characterset-configuration.png]]
33 +Secondly, just as when reading the file as a whole ensure that you use a filter to retrieve only the correct files from the directory.
36 36  
37 -In this field, you can define the character set of your choice. To make this work in eMagiz you need to navigate to the Create phase of eMagiz and open the entry flow in which you want to retrieve the file to a certain location. Within the context of this flow, we need to add functionality that will ensure that the correct character set is used. To do so first enter "Start Editing" mode on flow level. After that open, the File to string transformer, navigate to the Advanced tab, and fill in the correct character set. After you have defined the correct character set the only thing left to do is to Save the component. See the suggested additional readings section on the complete list of character sets that are supported by Java 8.
35 +=== 3.1 Item reader Type ===
38 38  
39 -Congratulations you have successfully learned how to specify the character set.
37 +Now it is time to select our Item reader Type. As the help text of the eMagiz component suggest there are two choices with this component. The first (and most frequently used) option is the Flat file item reader. With this option, you can read each line within the flat file input file and output is at a separate message. The second option is called the Stax event item reader. With this option, you can read your input XML and output messages on a per-record basis.
40 40  
39 +[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity-processing-a-file-per-line--item-reader-type-options.png]]
40 +
41 +Based on your choice the exact configuration will differ.
42 +
43 +==== 3.1.1 Stax Event Item Reader ====
44 +
45 +For the Stax event item reader, you need to define the name of the element on which you want to split the XML and define whether you want to throw an error in case no such element exists in the input file (By (de)selecting the option Strict). The default setting of eMagiz is advisable for this option.
46 +
47 +[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity-processing-a-file-per-line--stax-event-item-reader-config.png]]
48 +
49 +==== 3.1.2 Flat File Item Reader ====
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 +
41 41  == 4. Assignment ==
42 42  
43 43  Configure an entry in which you define the component and configuration needed to process a file on a per-line basis.
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45 45  
46 46  == 5. Key takeaways ==
47 47  
48 -* Some external system talk in a different character set
49 -* eMagiz talks in default UTF-8 as a character set and assumes everyone else also does this
50 -* In cases of mismatch correct is at the point where you talk with the other system (i.e. entry or exit)
51 -* eMagiz provides several components within which you can define the character set
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
52 52  
53 53  == 6. Suggested Additional Readings ==
54 54  
55 -If you are interested in this topic and want more information on it please read the help text provided by eMagiz and read the following links:
96 +There are no suggested additional readings on this topic
56 56  
57 -* https://docs.oracle.com/javase/8/docs/technotes/guides/intl/encoding.doc.html
58 -* https://www.techopedia.com/definition/941/character-set
59 -* https://www.smashingmagazine.com/2012/06/all-about-unicode-utf8-character-sets/
60 -
61 61  == 7. Silent demonstration video ==
62 62  
63 63  This video demonstrates how you could have handled the assignment and gives you some context on what you have just learned.
64 64  
65 -{{video attachment="novice-file-based-connectivity-characterset.mp4" reference="Main.Videos.Microlearning.WebHome"/}}
102 +{{video attachment="novice-file-based-connectivity-processing-a-file-per-line.mp4" reference="Main.Videos.Microlearning.WebHome"/}}
66 66  
67 67  )))((({{toc/}}))){{/container}}{{/container}}