# Fixed Length Parser

*Fixed Length Parser* processes a stream of fixed length data as an input and give elements as parsed output. This is useful when the source data is in text format (information is contained in a single field) and it needs to be put into multiple fields for further integration.

In this document, we will learn how you can use *Fixed Length Parser* in Astera.

### Sample Use-Case

The sample data that we are using is a fixed length text file containing customers’ information.

![](/files/6AqfxyRFwCgLm214mnsX)

Observe that all the information such as name, street number, street type, city, state, and zip code are concatenated in a single field. We want to parse the *Contact\_Details* field into *Name*, *Street Number*, *Street Type*, and other respective fields.

To parse the data into separate fields, we will use the *Fixed Length Parser* object in Astera.

#### Extracting Data

To parse the data, we first have to extract it. Since the data is stored in a continuous stream, can not extract it directly using a *Fixed Length File Source* object. Therefore, we will use a combination of transformations to get the desired outcome. The diagram below explains the process that we’ll be following, right from extraction to to parsing the data.

![](/files/a4srAGkJ46ENV8jCH2SO)

Let’s begin with extracting the data.

1. Go to *Toolbox > Transformations > Constant Value* and drag-and-drop the *Constant Value* object onto the designer.

![](/files/LF84AM5cplC4GgB89TBe)

2. Right-click on the object’s header and select *Properties* from the context-menu.

![](/files/acMfnnEKdN027DqbBLMK)

3. In the *Constant Value* field, provide the file path of the source file (file containing customers data in a stream). Click *OK*.

![](/files/rtRxyFmWlnfR9AYRgQ8s)

4. Next, go to *Toolbox > Function Transformations > Files > ReadFileText(String filePath) - String*, and drag-and-drop the object onto the designer.

![](/files/sGyHNd3p2hVZps2uhECP)

You an see that the dragged transformation object has two sub-nodes - *Input* and *Output.*

5. Expand the *Input* node and map the *Value* field from the *Constant Value Transformation* object to the *filePath* field inside the *Read File Text* object.

![](/files/E2Eoe6N29voYantipI3F)

This will redirect Astera to read the data from the given file path. Now we can use the *Fixed Length Parser* object to parse the text data into separate fields.

#### Using Fixed Length Parser

1. To get the *Fixed Length Parser* object, go to *Toolbox > Text Processors > Fixed Length Parser* and drag-and-drop the object onto the designer. Map the *Value* field, under the *Read File Text* object, onto the *Text* field inside the *Fixed Length Parser* object.

![](/files/EPUJWF7caqVO8qQmzuJj)

You can see that the dragged-object also contains an *Output* sub-node which is currently empty.

2. Configure the *Fixed Length Parser* object by right-clicking on its header and selecting *Properties*.

![](/files/pl2JdAY1upGEhN9xjIRL)

3. A properties window will open. Here you will see three options, make sure the first two options are checked.

![](/files/2xzfgDvijM8SbP3XqxU9)

4. Click *Next*, and you will be directed to a *Source Fields* window.

![](/files/y2i6PDMovarlUOYJsQts)

Here, you have to provide the name of each field that you want to parse the source date into, as shown below.

![](/files/WW2B9pGMvbsYBrAM8rfP)

5. Click *OK*. Now, expand the *Output* node inside the *Fixed Length Parser* object. You will see all the fields that you have created in the previous step.

![](/files/YB0sgqGWfKRVwbIzDClX)

6. Right-click on the object’s header and select *Preview Output* from the context menu.

![](/files/gg4C4DP3AiinITiakG27)

A *Data Preview* window will open. Expand the nodes, and you will see a parsed output of each record.

![](/files/SZpvRRsdSv0yopJTN520)

To store this parsed output, write it to a destination file.

#### Writing to a Destination

1. Right-click on the *Output* sub-node inside the *Fixed Length Parser* object, and go to *Write to > Excel Workbook Destination*. An *Excel Workbook Destination* object will be added to the dataflow designer with auto-mapped fields.

![](/files/C5leC3igAbFfcLIloGEq)

2. Configure settings for the *Excel Workbook Destination* object.

Learn how to configure settings for *Excel Workbook Destination* from [here](/dataflows/destinations/excel-workbook-destination.md).

3. Click on the *Start Dataflow* icon, located in the toolbar at the top, to create this destination file.

![](/files/Lvorb8Q4sLCWP6k4rVtx)


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