gristlabs_grist-core/app/client/components/LinkingState.js

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const _ = require('underscore');
const ko = require('knockout');
const dispose = require('../lib/dispose');
const gutil = require('app/common/gutil');
/**
* Returns if the first table is a summary of the second. If both are summary tables, returns true
* if the second table is a more detailed summary, i.e. has additional group-by columns.
* @param {MetaRowModel} summary: RowModel for the table to check for being the summary table.
* @param {MetaRowModel} detail: RowModel for the table to check for being the detailed version.
* @returns {Boolean} Whether the first argument is a summarized version of the second.
*/
function isSummaryOf(summary, detail) {
let summarySource = summary.summarySourceTable();
if (summarySource === detail.getRowId()) { return true; }
let detailSource = detail.summarySourceTable();
return (summarySource &&
detailSource === summarySource &&
summary.getRowId() !== detail.getRowId() &&
gutil.isSubset(summary.summarySourceColRefs(), detail.summarySourceColRefs()));
}
/**
* Maintains state useful for linking sections, i.e. auto-filtering and auto-scrolling.
* Exposes .filterColValues, which is either null or a computed evaluating to a filtering object;
* and .cursorPos, which is either null or a computed that evaluates to a cursor position.
* LinkingState must be created with a valid srcSection and tgtSection.
*
* There are several modes of linking:
* (1) If tgtColId is set, tgtSection will be filtered to show rows whose values of target column
* are equal to the value of source column in srcSection at the cursor. With byAllShown set, all
* values in srcSection are used (rather than only the value in the cursor).
* (2) If srcSection is a summary of tgtSection, then tgtSection is filtered to show only those
* rows that match the row at the cursor of srcSection.
* (3) If tgtColId is null, tgtSection is scrolled to the rowId determined by the value of the
* source column at the cursor in srcSection.
*
* @param gristDoc: GristDoc instance, for getting the relevant TableData objects.
* @param srcSection: RowModel for the section that drives the target section.
* @param srcColId: Name of the column that drives the target section, or null to use rowId.
* @param tgtSection: RowModel for the section that's being driven.
* @param tgtColId: Name of the reference column to auto-filter by, or null to auto-scroll.
* @param byAllShown: For auto-filter, filter by all values in srcSection rather than only the
* value at the cursor. The user can use column filters on srcSection to control what's shown
* in the linked tgtSection.
*/
function LinkingState(gristDoc, srcSection, srcColId, tgtSection, tgtColId, byAllShown) {
this._srcSection = srcSection;
let srcTableData = gristDoc.getTableModel(srcSection.table().tableId()).tableData;
// Function from srcRowId (i.e. srcSection.activeRowId()) to the source value. It is used for
// filtering or for cursor positioning, depending on the setting of tgtCol.
let srcValueFunc = srcColId ? srcTableData.getRowPropFunc(srcColId) : _.identity;
// If linking affects target section's cursor, this will be a computed for the cursor rowId.
this.cursorPos = null;
// If linking affects filtering, this is a computed for the current filtering state, as a
// {[colId]: colValues} mapping, with a dependency on srcSection.activeRowId(). Otherwise, null.
this.filterColValues = null;
// A computed that evaluates to a filter function to use, or null if not filtering. If
// filtering, depends on srcSection.activeRowId().
if (tgtColId) {
if (byAllShown) {
// Include all values present in srcSection.
this.filterColValues = this.autoDispose(ko.computed(() => {
const srcValues = new Set();
const viewInstance = srcSection.viewInstance();
if (viewInstance) {
for (const srcRowId of viewInstance.sortedRows.getKoArray().all()) {
if (srcRowId !== 'new') {
srcValues.add(srcValueFunc(srcRowId));
}
}
}
return {[tgtColId]: Array.from(srcValues)};
}));
} else {
this.filterColValues = this.autoDispose(ko.computed(() => {
const srcRowId = srcSection.activeRowId();
const srcValue = srcValueFunc(srcRowId);
return {[tgtColId]: [srcValue]};
}));
}
} else if (isSummaryOf(srcSection.table(), tgtSection.table())) {
// We filter summary tables when a summary section is linked to a more detailed one without
// specifying src or target column. The filtering is on the shared group-by column (i.e. all
// those in the srcSection).
// TODO: This approach doesn't help cursor-linking (the other direction). If we have the
// inverse of summary-table's 'group' column, we could implement both, and more efficiently.
this.filterColValues = this.autoDispose(ko.computed(() => {
const srcRowId = srcSection.activeRowId();
const filter = {};
for (const c of srcSection.table().columns().all()) {
if (c.summarySourceCol()) {
const colId = c.summarySource().colId();
const srcValue = srcTableData.getValue(srcRowId, colId);
filter[colId] = [srcValue];
}
}
return filter;
}));
} else if (isSummaryOf(tgtSection.table(), srcSection.table())) {
// TODO: We should move the cursor, but don't currently it for summaries. For that, we need a
// column or map representing the inverse of summary table's "group" column.
} else {
this.cursorPos = this.autoDispose(ko.computed(() => srcValueFunc(srcSection.activeRowId())));
}
}
dispose.makeDisposable(LinkingState);
/**
* Returns a boolean indicating whether editing should be disabled in the destination section.
*/
LinkingState.prototype.disableEditing = function() {
return this.filterColValues && this._srcSection.activeRowId() === 'new';
};
module.exports = LinkingState;