> For the complete documentation index, see [llms.txt](https://doc.orbeon.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://doc.orbeon.com/form-builder/advanced/services-and-actions/synchronize-repeated-content.md). # Synchronizing repeated content ## Availability This is available since Orbeon Forms 2018.2. This is an Orbeon Forms PE feature. ## Rationale Often, forms require some kind of [master-detail interface](https://en.wikipedia.org/wiki/Master%E2%80%93detail_interface), where you first enter a list of initial information, and then complete the information for each item of the list in more details on a separate screen. A way of doing this with Orbeon Forms consists in: * using a [repeated grid](/form-builder/form-editor/repeated-grids.md) for the basic information * using a [repeated section](/form-builder/form-editor/section-settings.md#repeated-content), later in the form, for the details The difficulty is how to synchronize the two. This is doable with custom XForms code, but it is difficult and error-prone. So Orbeon Forms 2018.2 and newer includes a component which does this synchronization automatically for you. ## Configuration With Orbeon Forms 2018.2, there is no user interface for this yet. You insert the component by editing the source of the form definition with the ["Edit Source"](/form-builder/advanced/edit-source.md) toolbox button, and insert a piece of XML in the source. The synchronization component looks like this: ```xml ``` It takes the following required XML attributes: * `left`: the name of the source (or "left") repeated grid or repeated section * `right`: the name of the destination (or "right") repeated grid or repeated section * `sync-on-form-load` (optional): [\[SINCE Orbeon Forms 2023.1\]](/release-notes/orbeon-forms-2023.1.md) can be set to `none` to disable right grid synchronization based on left grid on form load; disabling synchronization on load is a way to support having multiple lefts defined to synchronize with a single right, but only one left doing so at any given time, e.g. because the other lefts are irrelevant * `version`: must be `2018.2` Names are as you see them in the Form Builder user interface with the ["Grid Settings"](/form-builder/form-editor/repeated-grids.md#grid-settings) or ["Section Settings"](/form-builder/form-editor/section-settings.md#basic-settings) dialogs. In addition, it can automatically copy the value of controls from the source to the destination. You specify this with nested `` elements. They take the following required XML attributes: * `left`: the name of the source (or "left") control * `right`: the name of the destination (or "right") control Names are as you see them in the Form Builder user interface with the ["Control Settings"](/form-builder/form-editor/control-settings.md#basic-options) dialog. ## How synchronization works The synchronization takes place from "left" to "right": * Upon form initialization, unless you specified `sync-on-form-load="none"` (see above), the iterations and values are enforced, which means: * Extra iterations in the destination are removed from the end if needed, to match the number of iterations in the source. * New iterations in the destination are added at the end if needed, to match the number of iterations in the source. * For each iteration, the values of controls specified with `` are copied over. * When iterations are added in the source: * Corresponding iterations are added in the destination, at the same position. * When iterations are moved in the source: * Corresponding iterations are moved in the destination. * When iterations are removed in the source: * Corresponding iterations are removed in the destination. * When values of controls specified by `` change in the source: * The values of the matching controls in the destination are updated. ## Full example The following example does the following: * Synchronize repeated iterations between repeated grid `master-grid` and repeated section `detail-section`. * For each iteration, copy over the value of the `traveler-name` and `traveler-birth-date` form controls. ```xml ``` The following screenshots show how the form looks like when using the wizard view: ![Master view](/files/-LTYnfaNjlPhVGc1REtm) ![Detail view](/files/-LTYoaUnrRohhrx9eueJ) ## Paging large repeated sections \[SINCE Orbeon Forms 2019.1] When paging of large repeated sections is enabled, optionally with a repetition label, each master repetition appears as its own wizard page. This reduces the size of wizard pages and makes it easier to fill out a form. ![Detail view](/files/-Lp5J3_-6nxxGQc-77Ph) ![Detail view](/files/-Lp5J3_1gCqwAEhuRZlK) See [Paging large repeated sections](/form-runner/features/wizard-view.md#paging-large-repeated-sections) for detail of the configuration. ## Limitations With Orbeon Forms 2018.2, the `` has the following limitations: * The *source* grid or section must be visible for the synchronization to work. The destination, on the other hand, can be hidden. * Both repeated content must be at the top-level: they cannot be nested within other repeated sections. * Synchronization within section templates is not supported. ## See also * [Simple Actions](broken://pages/-LEkBr90Nq9hbV8krZWy) * [HTTP services](/form-builder/advanced/services-and-actions/http-services.md) * [Database services](/form-builder/advanced/services-and-actions/database-services.md) * [Repeated grids](/form-builder/form-editor/repeated-grids.md) * [Repeated sections](/form-builder/form-editor/section-settings.md#repeated-content) * [Paging large repeated sections](/form-runner/features/wizard-view.md#paging-large-repeated-sections) * Blog posts * [Synchronized master-detail views](https://blog.orbeon.com/2019/01/synchronized-master-detail-views.html) * [Paging large repeated sections](https://blog.orbeon.com/2019/09/paging-large-repeated-sections.html) * [Repeated sections](https://blog.orbeon.com/2014/01/repeated-sections.html)