Choose a data extraction method

Introduction

Dynamic parameters are link or form parameters generated by the server. Normally invisible to the end-user, these parameters are inserted into submitted links and forms.

Unless the test designer decides otherwise, during the test run the recorded values are submitted "as is". Therefore, these values need to be re-worked using a process of data extraction and re-insertion. The Search for dynamic parameters function, included in the Post-recording Wizard, allows you to identify the dynamic parameters and automatically configures the User Path to allow the extraction and insertion of the appropriate data.

The Search for dynamic parameters function automatically handles dynamic parameters in the vast majority of cases. For more complex cases, the parameter must be managed manually using one of the extraction methods described hereinafter.

Extraction methods

NeoLoad provides various data extraction methods to extract and insert link or form parameters. The methods are used automatically by the Search for dynamic parameters function and can be used explicitly for manual extraction.

The following section briefly outlines each method and provides guidance on choosing the appropriate method for each particular case.

• Link extractors.To use a link extractor, select the Follow a link from the previous request request type.

  In this mode, NeoLoad searches for a link in the previous response according to the criteria entered in the request definition pane and submits the link it finds.

  The advantages of using a link extractor are:

  • it can search for a link using its "id" or "name" attribute, its label or its path. For example, you can search for a link whose id attribute is "search-tab" or whose (text) is "Next";
  • because it extracts the link as a whole, there is no risk of extracting in error a parameter from one link and another parameter from another link or from another part of the HTML page.

  This type of extractor only works with standard links declared in HTML code and cannot be used where the link is created dynamically using JavaScript calls.

  See Follow a link from the previous request and Follow a link from the previous request.

• Form extractors. To use a form extractor, select the Submit a form in the previous request request type.

  In this mode, NeoLoad searches for a form in the previous response according to the criteria entered in the request definition pane and submits the form it finds. Custom values can be inserted in the extracted form.

  The advantages of using a form extractor are:

  • it can search for a form using its "id" or "name" attribute, its label or its path. For example, you can search for a form whose id attribute is "search-form";
  • it can search for a form according to its occurrence within a page. For example, you can search for the first form in a page without being more specific;
  • because it extracts the form as a whole, there is no risk of extracting in error a parameter from one form and another parameter from another form or from another part of the HTML page.

  See Submit a form from the previous request and Submit a form from the previous request.

• Variable extractors on parameters. To use a variable extractor defined on a parameter, select the Manually define the request request type. Edit the parameter and select the Use an extracted value option.

  In this mode, NeoLoad extracts the data using a regular expression. You may fine-tune the extraction for extracting multiple values.

  The advantages of a using variable extractor on a parameter are:

  • it can extract data from the entire response body, it is not limited to links and forms;
  • the extraction is automatically configured.

  See Use a manual definition and Handle an application dynamic parameters.

• Variable extractors on requests. To define a variable extractor on a request, first select the request whose response contains the data to be extracted. Next, click on the Advanced button, select the Variable Extractors tab and click on the + (plus) button.

  In this mode, NeoLoad extracts the data using a regular expression. You may fine-tune the extraction for extracting multiple values.

  The advantages of using a variable extractor on a request are:

  • it can extract data from the entire response body, it is not limited to links and forms;
  • the value may be changed prior to its use. As the extractor is placed on a request that precedes the request that inserts the value, we may use JavaScript to format the value, do a calculation and re-insert the modified value.

  See Variable extractors.

Framework parameters

Thanks to its Search for generic dynamic parameters function, NeoLoad can detect and automatically configure dynamic parameters.

The Search for generic dynamic parameters section allows you to automatically detect an application custom dynamic parameters without having to declare them in advance. When this detection fails, the parameter needs to be handled using a variable extractor. NeoLoad allows you to add this Variable Extractor to a list of pre-defined rules so that the search for Framework dynamic parameters automatically handles this custom parameter at each new recording.

See Framework dynamic parameter handling.

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